Method for triggering the diffusion of an active substance for seeding a cloud cell, and associated mission controller of an aerostatic seeding device

Abstract

The invention relates to a method (100) for triggering the delivery of an active substance for seeding a cloud cell implemented by a mission controller of an aerostatic seeding device. Such a method includes a step (111) of producing a first indicator (SC) that determined seeding criteria (SP) are met, and a step (113) of producing a second indicator of admissibility (GRC) of the geographical ground return zone estimated with regard to determined geographical data designating authorised and / or prohibited ground return zones (AGRA) for the aerostatic seeding device. The seeding and the ground return are initiated (121, 131) on the basis of the first and second indicators (SC, GRC).

Description

[0001] Method for triggering the diffusion of an active substance to seed a cloud cell, mission controller of an associated aerostatic seeding device

[0002] The invention relates to the field of devices used for the prevention and / or disruption of meteorological and microphysical balances. Such devices are used for all types of use and preferably, but not limited to, to provide cloud cell seeding functions (also known as "cloud seeding").

[0003] Climate change affects all of us. The agricultural sector is particularly affected by unexpected weather events such as hailstorms. The resulting damage can be significant for future harvests.

[0004] Most meteorological phenomena, such as rain, hail, or snow, are caused by supercooling of water within cloud cells or, more generally, the atmosphere. A cloud cell is essentially made up of liquid water droplets suspended in the atmosphere. Solar irradiation vaporizes these. Warm air thus formed and present in the atmosphere consequently contains low-density water vapor, which rises to altitude. As it does so, the pressure decreases and the previously formed warm air cools, condensing into droplets around fine particles present in the atmosphere, which agglomerate to form a cloud cell, the precursor to rain, snow, or hail.When a cloud cell reaches an area or region with a temperature between zero and minus thirty-five degrees Celsius, ice crystals form from ice nuclei (also known as "freeze nuclei"). Supercooled water droplets within the cloud cell move towards the ice crystals. The water droplets then migrate towards the ice crystals and allow the crystals to grow until they become snowflakes. Depending on the outside temperature on the ground, such snowflakes, when precipitated, turn into rain, for example in summer, or remain as snow in winter. Hail formation results from a process of ice crystal growth in the presence of updrafts or currents of warm air strong enough to keep the crystals suspended in a cloud cell, called a "cumulonimbus".Thus, in the presence of ascending currents, supercooled water droplets are pushed towards the highest and coldest region of the cloud cell where ice crystals concentrate to mix with said crystals and thus form hailstones. Said hailstones are in turn carried by ascending currents and other ice crystals then come to agglomerate with the hailstones, some of which are too large to remain within the cloud cell. The hailstones are then precipitated towards the ground.

[0005] In view of the damage likely to be caused by episodes of rain, snow or even hail, methods or processes for seeding cloud cells have been devised to disrupt microphysical balances in order to alter precipitation formation processes. Such methods make it possible to increase the condensation of water vapor into liquid water available in a cloud cell and thus increase or decrease the size and number of droplets present within said cloud cell. Ultimately, such methods can cause precipitation or, alternatively, hailfall in predetermined areas.To do this, particles, possibly artificial, or active substances, also known as "artificial freezing nuclei", are introduced into a cloud cell in order to modify the exchanges between the different states of water, for example, by accelerating the growth of certain droplets or the solidification of said droplets into ice crystals. Throughout the document, the expressions "agent", "particles" or "active substance" will be used interchangeably to describe seeding elements. Said particles or active substances preferably have a strong affinity with water. In addition, depending on the type of action or the desired altitude, different types of active substances may be used.Generally, for cold areas, such as those located at an altitude of over three thousand meters, such particles can advantageously be made up of ice-forming nuclei, such as silver iodide or copper iodide. The use of silver iodide is particularly interesting and therefore preferred, since it is the most effective particle in small quantities at a temperature below minus five degrees Celsius. Alternatively or in addition, hygroscopic salts, in the form of, for example, sodium, calcium or magnesium salts, alginates are used, advantageously in warmer areas. Finally, one can also use cooling materials, such as dry ice, which acts at around minus thirty-five degrees Celsius, thus allowing crystallization of supercooled water and thus providing a similar or identical effect to silver iodide.Alternatively, such refrigerants may consist of propane or liquid nitrogen.

[0006] Such particles are usually distributed by aerosols. The presence of updrafts within a cloud cell increases the effectiveness of the particles or agents for seeding. Indeed, the updrafts entrain and suck up said particles, which disperse within the cloud cell, reaching the supercooled water and encountering ice crystals or hailstones.

[0007] In order to ensure the diffusion of such particles, whatever their composition, different techniques and systems can be used.

[0008] Seeding a cloud cell can be carried out by air, for example using aircraft adapted for cloud cell seeding. Seeding particle diffusers can thus be advantageously positioned at the level of the wings of said aircraft. The pilots of such aircraft cause the diffusion of seeding particles at the base of a cloud cell or on the flank of the latter. Such a seeding technique requires experienced and seasoned pilots, given the significant turbulence they must face. In addition, to treat several cloud cells simultaneously, it is generally necessary to use aircraft and pilots, multiplying the cost of such a seeding technique tenfold. Furthermore, such aerial aircraft cannot circulate freely and must comply with the air traffic rules in force depending on the territories overflown.

[0009] An alternative technique to aircraft consists of seeding a cloud cell by using rockets, such as "parahail" rockets, generally launched from the ground or from certain aerial devices such as airplanes, instead of or in addition to the diffusers mentioned above. The effectiveness of this technique depends on updrafts. These can alter the propagation of seeding particles within the cloud cell. This alternative rocket technique also has many disadvantages. The use of explosive devices requires compliance with strict pyrotechnic standards. When these rockets are launched from an airplane or if they are launched from areas with high air traffic, it is necessary to comply with the air traffic regulations in force.Finally, a rocket launch is not necessarily synonymous with an efficient propagation of the seed particles, their trajectories being difficult to control.

[0010] To improve seeding accuracy and reduce cost, aerostatic seeding devices, commonly referred to as "balloons," have been created. Such seeding devices are simple, modular, and adaptable to a multitude of applications. They allow for freedom from the safety standards and constraints previously mentioned.

[0011] Figure 1 illustrates an example of design of such a seeding balloon 10 comprising a container 12 of an active substance AS associated with means of delivery or diffusion 13 of said active substance AS. Such an aerostatic seeding device 10 taken, for example from document EP3454643B1, comprises one or more aerostatic means 11 connected, by any physical connection L, to said container 12 and means of delivery or diffusion 13. The term "aerostatic means" means any element whose lift in the atmosphere, more precisely air, is due to the use of a gas lighter than air. For example, such a gas may advantageously but not exclusively be helium. Alternatively, hydrogen or hot air may optionally be used.Such a seeding device 10 of a cloud cell 1 is generally arranged so that a rupture or destruction of said aerostatic means 11 can be caused when said seeding device 10 reaches a predetermined position and / or altitude.

[0012] The container 12 is advantageously sealed, or even hermetic, in order to preserve the integrity of the active substance AS. It thus prevents any unexpected chemical reaction between said active substance AS and the environment of said seeding device 10. As shown in FIG. 1, such a container 12 may consist of a nacelle, i.e. a basket or a streamlined shell. The means 13 for delivering or diffusing the active substance are arranged to generate a progressive and possibly controlled diffusion or, alternatively, a sudden and instantaneous diffusion. They may comprise a regulating device, such as a valve, a relief valve, or more generally any equipment making it possible to stop or regulate the flow of the active substance AS into the atmosphere, in particular within the cloud cell. Said means of delivery or diffusion 13 may then act like a spray or an aerosol.Such delivery or diffusion means 13 may also consist of one or more pyrotechnic torches, ensuring the diffusion of the active substance AS that they contain (for example, condensation nuclei such as silver iodide). The use of double-focus torches is particularly advantageous. Indeed, when the upper focus is oriented towards the aerostatic means 11 and it becomes incandescent at the end of combustion, this can cause the rupture of the aerostatic means 11 and therefore a return of the seeding device 10 to the ground.

[0013] The arrangement of such aerostatic seeding devices 10 makes it possible, where appropriate, to provide a container 12 of an active substance AS and means for delivering or diffusing the latter 13 consisting of a single physical entity. Said containers 12 and / or means for delivering or diffusing 13 of a seeding device 10 may also be included within the casing of one of the aerostatic means 11. Said casing thus directly acts as a container 12 of the active substance AS. The delivery of the latter can then be caused when said casing ruptures. Such alternative arrangements of an aerostatic seeding device 10 make it possible to reduce the number of elements composing it and thus simplify its manufacture, its installation and therefore reduce its costs.

[0014] The envelope of such aerostatic means 11 (also commonly called “balloons”) may be mainly made of elastic compounds, preferably but not limited to polymers, such as rubber, latex, neoprene, chlorophene, polyethylene. The aerostatic means 11 may, moreover, be advantageously sealed after introduction of the gas into said aerostatic means by any suitable closing means. Said aerostatic means 11, in particular by their dimensions, nature and physicochemical properties, are arranged to convey the active substance AS to the vicinity of the cloud cell 1 and effectively seed the latter.

[0015] Furthermore, as shown in Figure 1, whatever the configuration of an aerostatic seeding device 10, the active substance AS can be associated with propagation marker particles M detectable by any suitable analysis means. The presence of such marker particles M is particularly clever since it allows a user of the seeding device 10, such as a farmer, to observe the propagation of the active substance AS and thus to ensure the effectiveness of the seeding device of a cloud cell. Such particles M can advantageously be analyzable by any suitable analysis means, such as, by way of non-limiting examples, an ultraviolet spectrophotometer or an infrared spectrometer, by absorption or by fluorescence.Alternatively, some M particles are colored so that they can be detected and / or observed in the visible range with the naked eye, or possibly even with the aid of a magnifying optical vision system. According to a particularly preferred application example, such marker particles M may comprise particles, flakes or filaments of aluminum, plastics or micro-glasses that are highly reflective by radar, commonly used in “CHAFF” type countermeasure systems, in particular to jam a radar.

[0016] To control the delivery of an active substance AS at a selected altitude and according to the position of a cloud cell to be seeded, the delivery or diffusion means 13 of a seeding device 10 cooperate with or comprise a seeding mission controller 15. Such a mission controller 15 may also be arranged to cause the seeding device 10, or at least the elements 12, 13 and 15, to fall or return to the ground.

[0017] Figure 2 illustrates such an arrangement of mission controller 15. The latter generally consists of an electronic entity comprising a processing unit 15-1, for example in the form of a microcontroller or a microprocessor. In addition, the mission controller 15 may cooperate with, or comprise, one or more measurement sensors 15-4 cooperating with said processing unit 15-1 and delivering to the latter a measurement of a first physical quantity GP1 representative of the pressure within the aerostatic means 11. Such a sensor 15-4 may measure said absolute or relative pressure within the aerostatic means 11 or a pressure differential between the environment adjacent to said aerostatic means 11 and the interior of the envelope of the latter. By way of non-limiting examples, such a sensor 15-4 may consist of one or more manometers, piezometers or even barometers.Alternatively or additionally, such a sensor 15-4 can deliver a measurement of a first quantity GP1 relating to the temperature and / or the humidity level within the aerostatic means and / or in an environment close to said aerostatic means. Said processing unit 15-1 is arranged to compare the measurement of the first physical quantity GP1 with a predetermined threshold. The latter can be recorded in a data memory 15-2 cooperating with said processing unit 15-1. When said measurement GP1 reaches said threshold, the processing unit 15-1 is arranged to generate a first electrical command SCc, (called “seeding command” or “seeding command” according to English terminology) of a first actuator 15-7 causing actuation of the delivery or diffusion means 13 of the active substance AS. Alternatively, said delivery or diffusion means 13 are directly actuable by electrical command.In this case, said first actuator 15-7 is limited to any means arranged to route said first electrical command SCc produced by the processing unit 15-1 to said delivery or broadcasting means 13, such as a wired communication bus or a wireless communication interface.

[0018] Unlike balloons described as "high attitude" carrying important measuring or telecommunication instruments and therefore requiring very expensive aerostatic means, of very large dimensions like the balloons described in connection with the document US2022 / 0289357A1, the seeding devices generally use aerostatic means of more modest dimensions and costs in the form of consumables. Thus, to cause a return to the ground of a seeding device 10, the processing unit 15-1 of such a seeding device 10 can be arranged to generate a second electrical command GRCc called "ground return command" or "ground return command" according to English terminology) of a second actuator 15-8 causing a rupture of the integrity of the envelope of the aerostatic means 11.Deprived of the aerostatic means 11 capable of maintaining it in the atmosphere, the latter having been destroyed, such a seeding device (i.e. mainly its nacelle 12) suddenly becomes heavier than air and falls. According to the state of the art, the strategy for returning a seeding device to the ground is basic. It generally consists of causing such a return after the triggering of the delivery or diffusion means 13 have fulfilled their mission. Conversely, as described in document US2022 / 0289357A1, the aerostatic means or balloons of a meteorological or telecommunications aerostatic device may be left free to burst due to wear or by reaching an excessive altitude, without controlling the time or place of such a burst, and consequently, the drift of such a meteorological or telecommunications aerostatic device.Alternatively, such aerostatic means (or balloons) are preserved and not destroyed, the latter being deflated on command during the flight of the meteorological or telecommunications aerostatic devices. A command to deflate the envelope or to turn over a balloon which until then provided the lifting action of an aerostatic device can be generated from the ground or directly by said aerostatic device in view of certain predefined emergency conditions. Preserving the integrity of the envelope of an aerostatic means or balloon during a return to the ground of an aerostatic device requires complex implementation. The assembly consisting of the aerostatic means or balloons (deflated) and the transported load remains integral and integrated until a fall to the ground possibly slowed by the optional deployment of a parachute.

[0019] The arrangement of an aerostatic seeding device 10 is completely different. Depending on the embodiments of such a device, the actuators 15-7 and 15-8 previously mentioned for, on the one hand, causing actuation of the means for delivering or diffusing 13 of the active substance AS and, on the other hand, destroying the integrity of the aerostatic means (or lift balloons), may consist of a single physical entity. The same applies to the first and second electrical controls. This is the case, for example, when the means for delivering or diffusing 13 of the active substance AS consist of one or more double-focus pyrotechnic torches whose respective upper foci are oriented towards the aerostatic means 11 so that the generated spray licks the envelope of said aerostatic means 11.

[0020] An aerostatic seeding device 10 may however comprise a deflation device 15-11, for example of the pyrotechnic plug type or in the form of a solenoid valve, controlled by the mission controller 15 and activated to cause a partial and progressive deflation of the aerostatic means 11 in order to regulate the altitude of the free flight of said aerostatic seeding device 10 and prevent the reaching of an excessive altitude likely to cause the bursting of the aerostatic means 11.

[0021] In order for a mission controller 15 of a seeding device 10 to be able to operate in complete autonomy, the latter may comprise an electrical energy source 15-5, in the form of one or more batteries for example. When such a mission controller is on board the seeding device 10, an electrical energy source 15-5 may consist of photovoltaic cells positioned on said seeding device 10, a wind turbine or even capacitors previously charged and capable of delivering sufficient electrical energy to enable the operation of the mission controller 15.

[0022] Furthermore, as a variant or in addition, to allow better traceability of the seeding of such a cloud cell, a device 10 for seeding such a cloud cell according to the invention may further comprise a sensor 15-9 for measuring and collecting a second physical quantity GP2 relating to the trajectory and / or the position of the seeding device 10. Such a sensor 15-9 cooperates with the processing unit 15-1 which can record in the data memory 15-2, said second quantity GP2 measured and collected according to a given periodicity for traceability purposes. Such a sensor 15-9 may be arranged to measure and collect the acceleration, the position or the angular velocity of a seeding device 10 during its movement in the atmosphere. In this case, said sensor 15-9 may consist of an accelerometer and / or a gyroscope.Alternatively or in addition, such a sensor 15-9 may comprise an inertial unit generally comprising three gyrometers and three accelerometers, or a GPS type geolocation system (“Global Positioning System” according to Anglo-Saxon terminology).

[0023] The mission controller 15 also comprises a program memory 15-6 arranged to comprise instructions of a program P whose execution by the processing unit 15-1 causes an implementation of a method for triggering the delivery or diffusion of an active substance AS to seed a cloud cell 1. The data memories 15-2 and programs 15-6 can be dissociated or form a single physical entity.

[0024] "Memory" means any computer memory, whether volatile or not. Non-volatile memory is a computer memory whose technology retains its data in the absence of an electrical power supply. It can contain data resulting from inputs, calculations, measurements and / or program instructions. The main non-volatile memories currently available are electrically writable, such as EPROM technology (Erasable Programmable Read-Only Memory), or electrically writable and erasable, such as EEPROM technology (Electrically-Erasable Programmable Read-Only Memory), flash, SSD (Solid-State Drive), etc. Non-volatile memories are distinguished from so-called "volatile" memories, whose data is lost in the absence of an electrical power supply.The main volatile memories currently available use RAM (Random Access Memory), DRAM (dynamic random access memory, requiring regular updating), SRAM (static random access memory requiring such updating when there is a power shortage), etc.

[0025] The mission controller 15 may also be arranged to communicate with a remote electronic object 20, to communicate and / or transfer a representation of the physical quantity(ies) GP1, GP2 measured and collected in real time or to communicate with a station 30 for preparing and / or launching a seeding device 10. To do this, the mission controller 15 comprises communication means 15-3 cooperating with the processing unit 15-1. Said communication means 15-3 provide communication N, possibly wired or wireless, to the remote electronic object 20 within communication range. Such a remote electronic object 20 may advantageously consist of a computer, a smartphone, a tablet or any other equipment or electronic object arranged to communicate with the mission controller 15.Such communication means 15-3 may also be of the “long distance” type and allow transmission to the remote electronic object 20 (or to the station 30) of all or part of the content of the data memory 15-2 through messages distributed by a network using, for example, LoRaWAN, GSM, GPRS or satellite technologies and protocols, in the case where said communication is wireless. The invention cannot be limited by these examples of communication technologies alone.

[0026] A station 30 for preparing and / or launching a cloud cell seeding device 10 generally comprises equivalent equipment or means for:

[0027] - determine and / or inject a quantity and / or a pressure of gas into the aerostatic means 11;

[0028] - launching or releasing a seeding device 10 of a cloud cell;

[0029] - initialize and / or configure the data memory 15-2 and / or programs 15-6 of the mission controller 15 when the latter is on board the seeding device 10.

[0030] Such a station 30 may further comprise equipment for integrating and / or loading an active substance AS into the container 12.

[0031] Such initialization and / or such configuration can advantageously be carried out by wire or wireless means, advantageously by coupling using RFID (“Radio-frequency identification” according to Anglo-Saxon terminology) or BT (“Bluetooth” according to Anglo-Saxon terminology) type communication protocols.

[0032] To accompany or orient the trajectory of a seeding device 10 of a cloud cell 1 during its return to the ground, that is to say after the latter no longer benefits from the lift provided by destroyed or undocked aerostatic means 11, such a seeding device 10 may comprise return-to-ground trajectory correction means 15-10 cooperating with the nacelle 12. Such optional correction means 15-10 make it possible in particular to correct the trajectory of the seeding device 10 during the return to the ground and / or to attenuate the fall speed of the latter. By way of non-limiting examples, such corrective means 15-10 may consist of one or more electrically controlled thrusters cooperating with the first processing unit 15-1 of the mission controller 15, or even one or more wings or flaps that can be deployed or retracted passively or in response to such electrical commands.Examples of embodiments of such trajectory correction means 15-10 will be described in connection with figures 7 to 10.

[0033] Seeding devices using known aerostatic means address many of the drawbacks raised by solutions using aircraft or rockets. Such aerostatic seeding devices naturally follow the upward flows that feed the clouds. They can enter areas of strong turbulence or regions of supercooled water unlike other diffusion vectors. In multicellular situations, for which the choice of the cell to be treated is delicate or complex, such aerostatic seeding devices will move naturally within the cells, including within the most virulent cells.

[0034] Seeding devices comprising aerostatic means, however, have certain disadvantages. The main disadvantage is inherent in the intrinsic nature of the free flight described by these aerostatic seeding devices, with the optional implementation of trajectory correction means for returning to the ground. Indeed, the fallout or return to the ground of such known aerostatic seeding devices is quite random or poorly controlled. When seeking to reduce hailfall, the fallout of an aerostatic seeding device generally occurs in plains, in agricultural and rural areas. The fallout or recovery of such a seeding device is less critical than during a treatment seeking to optimize snowfall. In this second case, the fallout of an aerostatic seeding device can occur in mountainous, or even very steep and / or inhabited areas.

[0035] Therefore, aerostatic seeding devices must meet constraints of density, weight and geographical areas of operation in order to prevent an untimely fall of all or part of such an aerostatic seeding device on inhabitants and / or not cause material damage.

[0036] Added to this disadvantage of uncontrolled fallout are increasingly strict regulations on environmental protection and the obligation to recycle waste. In addition, the components carried by such devices are becoming increasingly sophisticated and therefore expensive. It is therefore essential to find the remains of such aerostatic seeding devices upon their fall.

[0037] Finally, there are constraints according to which it is not permitted for such a seeding device to evolve along cross-border trajectories.

[0038] This set of constraints or drawbacks hinders the development or operation of this type of aerostatic seeding device, which is nevertheless particularly economical and effective.

[0039] The invention addresses the drawbacks previously discussed by proposing an aerostatic seeding device preventing any risk of fallout on prohibited or regulated areas while optimizing the chances of success of the seeding mission.

[0040] Among the many advantages provided by the invention, we can mention:

[0041] - a significant gain in terms of seeding mission success thanks to a detailed analysis of the atmosphere and an adaptation of the seeding strategy;

[0042] - the possibility of decorrelating, depending on the arrangement of the aerostatic seeding device, the phase of delivery of an active substance to seed a cloud cell and the phase of return to the ground of the latter; thus, the two phases can be simultaneous, successive or asynchronous, whatever the sequence of triggering of said phases;

[0043] - a particularly effective and inexpensive implementation likely to promote the operation of aerostatic seeding devices with due regard for the safety of all and the environment.

[0044] To this end, the invention provides a method for triggering the delivery or diffusion of an active substance for seeding a cloud cell, implemented iteratively by a processing unit of a mission controller of an aerostatic seeding device, the latter comprising:

[0045] - aerostatic means arranged to raise said aerostatic seeding device into the air;

[0046] - means of diffusion or delivery of the active substance;

[0047] - a sensor for measuring a first physical quantity representative of an atmosphere prevailing around or in said aerostatic means;

[0048] - a first actuator arranged to cause actuation of the means for delivering or diffusing the active substance;

[0049] - a second actuator arranged to cause a sudden and irremediable suppression of any lift in the air of said seeding device provided by the aerostatic means.

[0050] Such a process involves:

[0051] - a step of collecting the first physical quantity;

[0052] - a step of estimating the seeding conditions of the cloud cell from the first physical quantity collected and producing a first indicator of satisfaction of seeding criteria determined by said estimated seeding conditions. To prevent any risk of falling into prohibited or regulated areas, or even to avoid operating within unauthorized flight volumes, while optimizing the chances of success of a seeding mission, the aerostatic seeding device further comprises a sensor for measuring a second physical quantity representative of the trajectory and / or the position of the seeding device with respect to the ground or stars. Thus, a method for triggering the delivery or diffusion of an active substance for seeding a cloud cell is arranged so that it comprises:

[0053] - a step of collecting the second physical quantity;

[0054] - a step of estimating a geographical return zone to the ground of the aerostatic seeding device from the second physical quantity and producing a second indicator of admissibility of the geographical return zone to the ground estimated with regard to determined geographical data designating authorised and / or prohibited return zones to the ground for said aerostatic seeding device;

[0055] - a step of producing a first command to activate the first actuator from a first determined combination of values ​​of the first and second indicators produced;

[0056] - a step of producing a second command to activate the second actuator from a second determined combination of values ​​of said first and second indicators produced.

[0057] The operation of an aerostatic seeding device can be carried out in different geographical regions. The categorization of return-to-ground zones into authorized or prohibited zones can be scalable. The seeding methods or preferences can also be dictated by an operator or local regulations. To take these constraints into account, the invention provides that the processing unit of the mission controller can cooperate with a data memory arranged to record and / or update the geographical data designating authorized and / or prohibited return-to-ground zones for the aerostatic seeding device and one or more seeding parameters including the determined seeding criteria.In this case, a method according to the invention may comprise a step of reading said data memory, prior to the implementation of the step of estimating the seeding conditions of the cloud cell and / or the step of estimating a geographical area of ​​return to the ground.

[0058] Certain regions or countries impose aviation safety constraints for any object capable of moving in the air. To meet this need, a method according to the invention may comprise a step of producing a third indicator of satisfaction of aviation safety constraints to seed a cloud cell from the first physical quantity and / or the second physical quantity collected. In this case, the steps of producing a first and second command are configured to integrate said third indicator to produce said commands.

[0059] To adapt to such air safety constraints, depending on the locations of operation of an aerostatic seeding device, or even to such constraints when these are likely to be dynamic, the invention provides that the processing unit of the mission controller can cooperate with a data memory arranged to record and / or update the data designating said air safety constraints. The method therefore comprises a step of reading said data memory prior to the implementation of the step of estimating the seeding conditions of the cloud cell and / or the step of estimating a geographical area of ​​return to the ground.

[0060] According to an advantageous embodiment, the steps of producing a first command to activate the first actuator and producing a second command to activate the second actuator may each result from a Boolean operation relating to the first, second, or even third indicators produced, the latter being expressed in a Boolean form. According to a particular embodiment, it may be provided that the first and second actuators of an aerostatic seeding device consist of the same actuator arranged to jointly or successively cause actuation of the means for delivering or diffusing the active substance and a sudden and irremediable suppression of any lift in the air of said seeding device provided by the aerostatic means.In this case, the steps of producing a first and a second command can produce a single and same trigger command for said same actuator.

[0061] To prioritize seeding when a passive return to the ground would risk affecting prohibited return zones, the aerostatic seeding device may include trajectory correction means. In this case, a method according to the invention may advantageously include a step of controlling said return-to-ground trajectory correction means so that the device reaches the estimated geographical return-to-ground zone of the aerostatic seeding device.

[0062] According to a second subject, the invention relates to a computer program product comprising one or more program instructions interpretable by a processing unit of a mission controller for seeding a cloud cell by an aerostatic seeding device, said program instructions being loadable into a non-volatile memory of said mission controller and designed so that the execution of said instructions by said processing unit causes the implementation of a method for triggering the delivery or diffusion of an active substance for seeding a cloud cell as expressed previously.

[0063] According to a third subject, the invention further relates to a computer-readable storage medium comprising the instructions of such a computer program product. According to a fourth subject, the invention also relates to a mission controller for seeding a cloud cell by an aerostatic seeding device, said mission controller comprising a processing unit and a program memory recording the instructions of the computer program product according to the invention.

[0064] According to a fifth object, the invention relates to an aerostatic seeding device comprising:

[0065] - aerostatic means arranged to raise said aerostatic seeding device into the air;

[0066] - means of diffusion or delivery of an active substance (AS) to seed a cloud cell;

[0067] - a sensor for measuring a first physical quantity representative of an atmosphere prevailing around or in said aerostatic means;

[0068] - a sensor for measuring a second physical quantity representative of the trajectory and / or position of the seeding device with respect to the ground or stars;

[0069] - a first actuator arranged to cause actuation of the means for delivering or diffusing the active substance;

[0070] - a second actuator arranged to cause a sudden and irremediable suppression of any lift in the air of said seeding device provided by the aerostatic means;

[0071] - a cloud cell seeding mission controller according to said fourth object.

[0072] The invention further provides such an aerostatic seeding device similar to the previous one except that the mission controller is not embedded in said aerostatic seeding device but communicates with the latter from a remote computer and / or electronic entity. In this case, such an aerostatic seeding device comprises a processing unit arranged to communicate with a remote cloud cell seeding mission controller.

[0073] According to two embodiments, the second actuator arranged to cause a sudden and irremediable suppression of any lift in the air of such a seeding device provided by the aerostatic means can be designed to cause the destruction of the aerostatic means or the separation of the latter from the rest of the seeding device.

[0074] When the mission controller is not embedded in said aerostatic seeding device, the invention further relates to an electronic object cooperating via a communication link with such a seeding device, said electronic object comprising said mission controller.

[0075] Such an electronic object may advantageously consist of a station for preparing and / or launching the seeding device, said station comprising equipment arranged for:

[0076] - determine and / or inject a quantity and / or pressure of gas into the aerostatic means of the seeding device;

[0077] - launch or release the seeding device towards a cloud cell to be seeded.

[0078] Other features and advantages will become more apparent upon reading the following description and examining the accompanying figures, including:

[0079] - figure 1 illustrates an example of an aerostatic seeding device according to the prior art;

[0080] - Figure 2 illustrates a functional architecture of a mission controller of an aerostatic seeding device;

[0081] - figure 3 illustrates a first example of a method according to the invention, for triggering the delivery or diffusion of an active substance to seed a cloud cell implemented iteratively by a processing unit of a mission controller of an aerostatic seeding device;

[0082] - figure 4 illustrates an example of production of commands for triggering the delivery of active substance and / or return to the ground of an aerostatic seeding device implemented within the framework of such a first example of a method in accordance with the invention;

[0083] - figure 5 illustrates a second example of a method according to the invention, for triggering the delivery or diffusion of an active substance to seed a cloud cell implemented iteratively by a processing unit of a mission controller of an aerostatic seeding device;

[0084] - figure 6 illustrates an example of production of commands for triggering the delivery of active substance and / or return to the ground of an aerostatic seeding device implemented within the framework of such a second example of method in accordance with the invention;

[0085] - Figure 7 is an enlarged perspective view of the nacelle of an aerostatic seeding device comprising a first arrangement of ground return trajectory correction means;

[0086] - Figure 8 is an enlarged perspective view of the nacelle of an aerostatic seeding device comprising a second arrangement of ground return trajectory correcting means whose blades occupy an unfolded configuration;

[0087] - Figure 9 is an enlarged perspective view of the nacelle of an aerostatic seeding device comprising a second arrangement of ground return trajectory correcting means, the blades of which occupy a folded configuration; - Figure 10 is an enlarged perspective view of the nacelle of an aerostatic seeding device comprising a third arrangement of ground return trajectory correcting means.

[0088] Let us preferentially but not limitatively describe the invention through a first example of arrangement of an aerostatic seeding device such as the device 10 previously described in connection with figures 1 and 2.According to this example, the processing unit 15-1 on board said device 10 (for example, in its nacelle 12) is capable of implementing a method designed to integrate different GP1 measurements emanating from measurement sensors 15-4, in order, on the one hand, to cause a dispersion of the active substance AS by activating (via a first so-called seeding command SCc) a first actuator 15-7 causing an actuation of the delivery or diffusion means 13 of the active substance AS and thus seeding a storm cell and, on the other hand, to cause a return to the ground of the seeding device 10, by activating (via a second so-called seeding command GRCc) a second actuator 15-8 causing a rupture of the integrity of the envelope of the aerostatic means 11.Such an actuator 15-8 may be of a pyrotechnic nature, consisting for example of an electrically controlled torch oriented so that the generated spray is directed towards the casing of the aerostatic means 11 and causes the latter to burst. Alternatively, such an actuator 15-8 may consist of an electrically controlled striker arranged to perforate the casing of said aerostatic means 11.

[0089] Other variants of said invention will be studied, among which:

[0090] - a second example of seeding device 10 for which the first and second actuators 15-7 and 15-8 of said device 10 consist of a single physical entity, for example when the dispersion of the active substance is done by torch; in this case, the first and second electrical controls are combined to form a single triggering command TC or “triggering command” according to English terminology);

[0091] - a third example of a seeding device 10 comprising delivery or diffusion means 13 which can be configured in order to adjust the size and / or the flow of the particles of an active substance;

[0092] - a fourth example of a seeding device 10 comprising a plurality of active substances and means of delivery or diffusion 13 of the latter;

[0093] - a fifth example of seeding device 10 using ground return trajectory correction means 15-10, not only to optimize its pre-diffusion trajectory but to optimize its ground return trajectory, including to ensure diffusion of active substance during said return to the ground;

[0094] - a sixth example of a seeding device 10 designed so that the on-board processing unit relays commands for actuating said first and second actuators 15-7, 15-8 emanating from a remote mission controller installed in an aerostatic seeding device preparation and / or launch station or, more generally, installed in a communicating object remote from the aerostatic seeding device whose mission is piloted, said commands being conveyed by wired or wireless N communication.

[0095] According to a seventh variant, the second actuator 15-8 may be arranged, not to cause destruction or a rupture of the integrity of the envelope of the aerostatic means 11, but to cause a separation of said aerostatic means 11 from the rest of the seeding device 10. Said aerostatic means 11 becoming free to continue their journeys alone in the atmosphere, are lost. The rest of the seeding device begins its fall. Such an actuator 15-8 may consist of an electrically controlled blade for cutting a link L securing the aerostatic means 11 to the rest of the seeding device 10 (in particular its nacelle 12).Alternatively, such an actuator 15-8 may consist of an electromagnet associating said aerostatic means 11 with the rest of the elements of said seeding device 10 including the nacelle 12, arranged so that its electrical power supply can be cut off under the control of the processing unit 15-1 of the mission controller 15 causing a sudden and irremediable release of the aerostatic means 11. Such an actuator 15-8 could further consist of a pneumatic connector or any other suitable means controllable by the processing unit 15-1.

[0096] More generally, within the meaning of the invention, such a second actuator 15-8 will therefore be arranged to cause a sudden and irremediable suppression of any lift in the air of said seeding device provided by the aerostatic means so that the latter become free and lost or destroyed.

[0097] According to the first example of arrangement of an aerostatic seeding device such as the device 10 previously described in connection with figures 1 and 2, a processing unit 15-1 of a mission controller embedded in said device 10 is capable of collecting GP1 measurements (temperature, pressure, hygrometry) via sensors 15-4 and of controlling with respect to determined threshold values ​​the first and second actuators 15-7 and 15-8 to respectively trigger the delivery or diffusion of an active substance AS by delivery or diffusion means 13 and cause a return to the ground like the prior art by a rupture of the envelope of the aerostatic means 11.

[0098] According to the invention, such a processing unit 15-1 is adapted with regard to the prior art, so that it can exploit the second physical quantity GP2 measured by the sensor(s) 15-9 (inertial unit, gyrometers, accelerometers, or GPS-type geolocation system) relating to the trajectory and / or the position of the seeding device 10, not only for the purposes of traceability or mission reporting in accordance with the state of the art but to produce the commands SCc and GRCc of the actuators 15-7 and 15-8, i.e. the delivery of the active substance and the return to the ground of the seeding device 10.

[0099] According to the state of the art, such a processing unit 15-1 considers that the seeding conditions SC are required (SC equal to the Boolean value “TRUE” or “VRAI” according to English terminology) as soon as the first measurement GP1 (possibly plural) has reached one or more predetermined threshold values, such as an altitude, target pressure and / or hygrometry levels. The command GRCc is produced immediately, that is to say immediately or after a predetermined duration (to allow the time necessary for the delivery or diffusion of the active substance) in order to cause a return to the ground of the seeding device 10. Thus, such a return to the ground is caused independently of the geographical impacts or consequences generated by such a return to a regulated geographical area, inhabited or not, suitable for recovery of said aerostatic seeding device 10.

[0100] The invention provides for remedying this drawback by modifying the production of said electrical commands SCc and GRCc to take into account an estimation of an end-of-flight zone for the aerostatic seeding device 10 so as to seek good seeding conditions while preventing a return to the ground in an inappropriate geographical zone. The invention further provides for taking into account constraints linked to the air safety of the areas flown over. Generally, air safety requires that any seeding cannot be caused below or above certain altitudes. For this, the processing unit 15-1 can implement a method 100 in accordance with the invention as illustrated in FIG. 3.

[0101] Let us now examine, in connection with said figure 3, the implementation of a first method 100 for triggering the delivery or diffusion of an active substance to seed a cloud cell.

[0102] Such a first method 100 for triggering the delivery or diffusion of an active substance for seeding a cloud cell in accordance with the invention is arranged to be implemented iteratively according to a predetermined periodicity T, for example between half a second and a few seconds to a few tens of seconds by a processing unit 15-1 of a mission controller 15 of an aerostatic seeding device 10. Let us take as a preferred example of implementation, a mission controller 15 embedded in the aerostatic seeding device 10 illustrated by FIG. 1, for example within the nacelle 12 of the latter.

[0103] Such a method 100 consists of a plurality of steps 101 to 103 aimed at collecting static or dynamic parameters necessary for the ultimate production of commands S Ce and GRCc (in respective steps 121 and 131) to activate a first actuator 15-7 and cause the delivery or diffusion of an active substance AS by delivery or diffusion means 13, and a second actuator 15-8 to cause a return to the ground of the aerostatic seeding device 10 by a separation of the aerostatic means 11 from the rest of the seeding device 10 or by a rupture of the integrity of the envelope of said aerostatic means 11.

[0104] Like certain methods according to the prior art, the method 100 comprises a first step 101 of collecting one or more first physical quantities GP1 delivered by one or more measurement sensors 15-4, said physical quantity or quantities GP1 being representative of an atmosphere prevailing around and / or in said aerostatic means (pressure, temperature, hygrometry, dust, etc.).

[0105] Such a first physical quantity GP1 (possibly plural) is used by the method 100 in a step 111 of estimating the seeding conditions of the cloud cell 1. According to the state of the art, such a step may consist of a comparison of said first quantity GP1 with a predetermined threshold. When said first quantity GP1 is plural, said predetermined threshold is also plural. Such a threshold may be one of the fixed parameters of the method 100.

[0106] Alternatively, said threshold may be variable or adjustable. In this case, the value of said threshold may be recorded in a data memory 15-2 cooperating with said processing unit 15-1. According to the example illustrated by FIG. 3, the method 100 then comprises a step 102 of collecting seeding parameters consisting of reading configuration data SP recorded in such a data memory 15-2 cooperating with the processing unit of the mission controller 15. Such seeding parameters SP may correspond to thresholds of temperature, atmospheric pressure, humidity, altitude, dust, beyond which or from which, seeding of a cloud cell is relevant. Such seeding parameters SP may be determined and fixed or alternatively be updated, including during the flight of such an aerostatic seeding device 10.Indeed, all or part of such update values ​​of said SP parameters can be communicated from a remote station 30 or more generally from any electronic object 20 possibly remote from the mission controller 15, for example via communication means 15-3.

[0107] Knowing the first physical quantity GP1 and the seeding parameters SP, the method 100 may comprise a step 111 of estimating the seeding conditions of the cloud cell 1 like known techniques. More precisely, such a step 111 produces a first indicator SC which may be Boolean to signify that from the first physical quantity GP1 collected, said estimated seeding conditions satisfy or do not satisfy one or more determined seeding criteria translated by said threshold SP. Alternatively, such an indicator SC may consist of a probability value of such satisfaction of seeding conditions in the more or less short term, ultimately, used in a step 121 of producing a command SCc to cause or defer the delivery of the active substance.

[0108] The invention provides for not being limited for such SCc control production to the sole estimation of the seeding conditions based on the first quantity GP1. Indeed, as mentioned previously, it is essential to control the return to the ground of a seeding device, whether the seeding phase has been effective or not, so that said return to the ground takes place in a legal or relevant geographical area. We will see that the invention provides for being able to trigger a seeding procedure while the seeding conditions are not required to facilitate a return to the ground in an authorized ground area.

[0109] For this, a method 100 according to the invention and in accordance with the example illustrated by FIG. 3, comprises a step 103 of collecting a second physical quantity GP2 (possibly plural) delivered by one or more measurement sensors 15-9 (inertial unit, gyrometers, accelerometers, GPS type geolocation system, etc.), said second physical quantity GP2 being representative of the trajectory and / or the position of the seeding device 10 with respect to the ground or stars.

[0110] Like the SP parameters, the data memory 15-2 may include other parameters such as AGRA geographic data designating authorized or reciprocally prohibited return-to-ground zones, for example according to the topography of the ground, the territoriality or habitability of the latter, etc. These AGRA data may also designate authorized or prohibited flight volumes for the aerostatic seeding device 10. Such AGRA parameters may also be updated during the mission of the aerostatic seeding device 10 if the return-to-ground conditions change, under the action of a remote station 30 or more generally from any electronic object 20 remote from the mission controller 15, for example via communication means 15-3 of the latter.

[0111] A method 100 according to the invention therefore comprises a step 113 of estimating a geographical area of ​​return to the ground of the aerostatic seeding device 10 from the second physical quantity GP2, or even from the first physical quantity GP1 (air current vectors for example). Such an estimation can be implemented according to different methods.

[0112] A first method may consist of projecting vertically onto the ground the current position of the aerostatic seeding device 10 during its evolution in the atmosphere and thus obtaining an estimated point zone of return to the ground, said aerostatic seeding device 10 being considered as a simple body falling vertically. Such a projection may be corrected by taking into account possible horizontal winds likely to cause drift. Optionally, an estimated zone of return to the ground may not consist of a geographical point on the ground but consist of an enlarged zone or area around said point, the perimeter of which may describe a predetermined geometric shape (circle, oval, ellipse, quadrilateral, trapezoid, etc.) centered or eccentric around said point projected vertically onto the ground to take into account an uncertainty or a tolerance as to the trajectory modeled as being substantially vertical of said aerostatic seeding device 10.

[0113] A second method for estimating in step 113 an estimated return to ground area may be more sophisticated and rely on one or more mathematical models (whose parameters are possibly dynamic or distinct from a first cloud cell to a second) of ascending, descending, and shear currents or winds within the cloud cell to be seeded. Such models may be chosen from those available in the literature or may be designed on purpose. The ground position may not result from a simple vertical projection separating said ground from the aerostatic seeding device 10 but along a curve adjusted via said mathematical model(s) of said currents within the cloud cell 1 and / or below it.Similarly, the estimated ground return area may not consist of a geographical point on the ground but of an extended area around said projected point, the perimeter of which may describe a predetermined geometric shape (circle, oval, ellipse, quadrilateral, trapezium, etc.) centered or eccentric around said projected point according to said curve.

[0114] A third method for estimating in step 113 a return-to-ground zone may further rely on a modeling of said aerostatic seeding device 10 in the return-to-ground configuration. Indeed, if such a device 10 describes a swirling and divergent trajectory with respect to a simple vertical, independently of the atmospheric conditions, such a third method may combine one of the first two variants with said mathematical or parametric model of said aerostatic seeding device 10.

[0115] The invention cannot be limited by the choice of the technique used to estimate (in step 113) a ground return zone, whether it is point-like or describes an enlarged surface. Said step 113 therefore consists of comparing such an estimated return zone with the AGRA data and thus producing a second GRC indicator reflecting the fact that said estimated ground return zone is included or not in an authorized zone determined by the AGRA data. Such a second GRC indicator can be Boolean, like the first indicator SC, and signify that, from the second physical quantity GP2 collected, or even from the first physical quantity GP1 collected, the estimated return zone is authorized or prohibited.Alternatively, such a GRC indicator may consist of a probability value that a return to the ground will take place in an authorized or prohibited zone in the more or less short term or even a coverage rate of the estimated return zone with authorized (or reciprocally prohibited) zones, ultimately, used in a step 121 of producing a command SCc to cause the delivery of the active substance but also in a step 131 of producing a second command GRCc for activating an actuator (such as the second actuator 15-8 described in connection with FIGS. 1 and 2) causing a return to the ground of the aerostatic seeding device 10 by a rupture of the casing of its aerostatic means 11 or a separation of the latter from the rest of said seeding device. The invention provides that said steps 121 and 131 jointly exploit the first and second indicators SC and GRC to produce said commands SCc and GRCc.Indeed, depending on the implementation of step 131, a return to the ground may be deferred or anticipated, despite a risk of a less than optimal return to the ground, in favor of seeking the success of the seeding mission. Conversely, seeding may be anticipated or canceled in favor of a return to the ground within a favorable zone.

[0116] The invention further provides for integrating a third optional constraint to produce a SCc command aimed at triggering the seeding of a cell and / or a second GRCc command to cause a return to the ground of the aerostatic seeding device 10.

[0117] This third constraint may concern conditions to be met in terms of aviation safety. Indeed, depending on the spaces to be covered in the atmosphere, it may be that corridors or volumes are defined in three dimensions, within which the delivery of active substances and uncontrolled flight phases are permitted or refused.

[0118] Like the AGRA data, the data memory 15-2 may also include FS data describing such air safety constraints (minimum or maximum altitudes, volumes or air corridors), static or dynamic like the SP seeding parameters and the AGRA data.

[0119] According to this embodiment, step 102 may consist of collecting or reading such FS data. A method 100 may comprise a step 112 of producing a third FSC indicator of satisfaction of air safety constraints for seeding a cloud cell 1 from the first physical quantity GP1 and / or the second physical quantity GP2 collected (in steps 101 and 103) as well as from such FS data. In this case, steps 121 and 131 of producing a first and second commands SCc, GRCc integrate said third FSC indicator to produce said commands SCc, GRCc. Such a third FSC indicator may consist, like the first or second SC, GRC indicator, of a Boolean indicator to signify that from the second physical quantity GP2 collected, or even from the first physical quantity GP1, the aerostatic seeding device 10 is evolving in a space allowing seeding or not.Alternatively, such an FSC indicator may consist of a probability value of such satisfaction of air safety constraints in the more or less short term or of a rate of satisfaction of such air safety constraints.

[0120] In connection with Figures 3 and 4, let us examine an example of joint exploitation of the three indicators SC, GRC and FSC as expressed previously, the latter being Boolean, for the purpose of simplifying the example. Thus, according to this example of carrying out steps 121 and 131, we will consider that:

[0121] SC = "TRUE" (or "TRUE" in Anglo-Saxon terminology - value illustrated by the number 'T in base two, in figure 4) when the seeding conditions are satisfied to effectively seed the cloud cell;

[0122] SC = "FALSE" (or "FALSE" in Anglo-Saxon terminology - value illustrated by the number '0' in base two, in figure 4) when the seeding conditions are insufficient to effectively seed the cloud cell;

[0123] GRC = "TRUE" (or "TRUE" in Anglo-Saxon terminology - Boolean value illustrated by the number 'T in base two, in figure 4) when the estimated return to ground area would be authorized (or mostly authorized), if such a return to ground were caused;

[0124] GRC = "FALSE" (or "FALSE" in Anglo-Saxon terminology - Boolean value illustrated by the number '0' in base two, in figure 4) when the estimated return to the ground zone would be prohibited (or mostly prohibited), if such a return to the ground were caused;

[0125] FSC = "TRUE" (or "TRUE" in Anglo-Saxon terminology - Boolean value illustrated by the number 'T in base two, in figure 4) when the air safety constraints are satisfied to trigger seeding of a cloud cell;

[0126] FSC = "FALSE" (or "FALSE" in Anglo-Saxon terminology - Boolean value illustrated by the number '0' in base two, in figure 4) when the said air safety constraints are not satisfied to trigger seeding of a cloud cell.

[0127] Steps 121 and 131 are arranged to combine the three indicators SC, GRC and FSC to produce the appropriate command SCc, GRCc. Figure 4 illustrates an embodiment according to which said steps 121 and 131 consist of the implementation of a Boolean operation relating to said indicators SC, GRC, FSC produced respectively in steps 111, 113 and 112. Thus, step 121 can consist of the production of a command SCc aimed at triggering the delivery or diffusion of the active substance AS if the result SO of the expression SO=FSC-(GRC+SC) is “TRUE”, either when the indicator GRC=0 or when the indicator SC=1, on the condition that the indicator FSC=1.Thus, the delivery or diffusion of the active substance AS is triggered when the seeding conditions SC are satisfactory for effectively seeding the cloud cell (whether this is triggered before or after triggering a return-to-ground phase of the device 10, or even concomitantly) or when a return to the ground of the “post-seeding” seeding device of the cloud cell would risk taking place in a prohibited or inappropriate area. However, it is required that the air safety constraints be satisfied. In all other situations, the SCc command is not produced and the active substance remains conveyed by the seeding device.

[0128] For its part, step 131 may consist of producing a GRCc command aimed at triggering a return to the ground of the aerostatic seeding device if the result GRO of the expression GRO=GRC+FSC-SC is “TRUE” (or “TRUE” according to English terminology), or when the indicator GRC=0 or the Boolean combination of the indicators FSC and SC is equal to “TRUE” (or “TRUE” according to English terminology). A return to the ground is systematically triggered when such a delayed return to the ground of the seeding device (whether there has been seeding of the cloud cell or not) would risk taking place in a prohibited or inappropriate zone. It may also be systematically triggered post-seeding. In all other situations, the GRCc command is not produced and the aerostatic seeding device continues its evolution in the atmosphere.We can see that in this example, it was chosen to carry out a return to the ground even though the load of active substance AS had not been released. Such a situation can be used to advantage, for testing purposes for example, when it is not necessary and unnecessarily desired to release said active substance before returning to the ground when the seeding conditions were not satisfactory and when an uncontrolled return to the ground of the seeding device is not desired, if said seeding device moves too far from the launch point. The fact of being able to cause a return to the ground, without having previously released the active substance, makes it possible to potentially seed a cloud cell from above during the return to the ground of the seeding device if the seeding conditions become favorable.

[0129] Figure 4 describes in the form of a truth table TT1 whose lines ttO to tt7 describe the respective SO, GRO results of combinations of the three indicators SC, FSC and GRC for steps 121 and 131. Said figure 4 further illustrates the Karnaugh tables KMSO and KMGRO making it possible to obtain the Boolean expressions previously mentioned, thanks to the groupings a1 and a2 for SO and b1 and b2 for GRO. This approach makes it easy to design the processes implemented by said steps 121 and 131. Any other method could alternatively be used. For example, when said indicators SC, GRC and FSC are not Boolean but express percentages or probabilities, said steps 121 and 131 can implement the Monte Carlo Method or any suitable alternative probabilistic or statistical method (for example based on Machine Learning or any other technique) to produce the SCc and GRCc commands appropriately.

[0130] The method 100 has been described through a first example of arrangement of an aerostatic seeding device such as that described in connection with figures 1 and 2. According to this first example, the mission controller 15 is embedded on said device 10 and is arranged to produce two distinct commands SCc and GRCc respectively addressed to a first actuator 15-7 causing the delivery or diffusion of the active substance AS and to a second actuator 15-8 causing a rupture of the envelope of the aerostatic means 11 or a separation of the latter from the rest of said seeding device 10, said first and second actuators 15-7 and 15-8 being distinct from each other.In connection with Figures 5 and 6, let us briefly study a variant of such a method 100 in accordance with the invention, applied to a second example of an arrangement of an aerostatic seeding device 10 for which the first and second actuators 15-7 and 15-8 of said device 10 consist of a single physical entity 15-7 / 8, for example when the dispersion of the active substance AS is carried out by means of a torch, the end of combustion of which causes a rupture of the casing of the aerostatic means 11.

[0131] According to this second example, the first and second commands SCc and GRCc are combined to form a single triggering command TC (or “triggering command” according to English terminology) for the diffusion of the active substance followed by a return to the ground of the aerostatic seeding device.

[0132] Steps 101, 102, 103, 111, 112, 113 of the method 100 according to FIG. 5 are respectively similar to steps 101, 102, 103, 111, 112, 113 of the method 100 illustrated by FIG. 3. On the other hand, instead of steps 121 and 131 previously described, a step 141 consists of producing an activation command TCc of the single actuator 15-7 / 8.

[0133] In the same way as for the previous example illustrated by figure 4, figure 6 illustrates an example of a truth table TT2 whose lines tt0 to tt7 describe the result SGR0 of combinations of the three indicators SC, FSC and GRC for step 141. Said figure 6 further illustrates a Karnaugh table KMSGRO whose groupings b1 and b2 make it possible to easily obtain a Boolean expression combining the three indicators SC, GRC and FSC, to produce the command TCc aimed at triggering the delivery or diffusion of the active substance AS followed by a return to the ground of the aerostatic seeding device.

[0134] Such a step 141 may consist of producing the command TCc if the result SGRO of the expression SGRO=GRC+FSC-SC is TRUE (or “TRUE” according to English terminology). When such an expression is calculated, the actuator 15-7 / 8 is activated when the indicator GRC=0 (or “FALSE”) or when the indicators SC and FSC are equal to “1” (or “TRUE”). The delivery or diffusion of the active substance AS is triggered when the seeding conditions SC and the aerial constraints FSC are satisfied to effectively seed the cloud cell or when a return to the ground of the seeding device would risk taking place in a prohibited or inappropriate zone. In all other situations, the command TCc is not produced, the active substance remains transported by the seeding device in the atmosphere.We can see that in this example, the load of active substance AS is systematically released when the seeding device returns to the ground, even when the seeding conditions were not required, unlike the previous example illustrated by Figure 4. The priority here is to prevent any return to the ground in an inappropriate geographical area and to reduce the weight of the device during its return to the ground (reduction achieved by the delivery of the active substance). Any other combination of the indicators SC, FSC and GRC could be chosen instead to design step 141.

[0135] Whether the configuration of an aerostatic seeding device 10 corresponds to the first or second example previously mentioned (i.e. when a device comprises two separate actuators 15-7 and 15-8 or a single actuator 15-7 / 8), the invention provides that the means for delivering or diffusing 13 the active substance AS can be parameterized in order to adjust the size and / or the flow of the particles forming said active substance AS. For this, the seeding parameters SP, advantageously recorded in the data memory 15-2 of the mission controller 15 embedded in said device 10, can characterize degrees of opening of the nozzle(s) for dispersing said active substance AS with regard to the quantity or concentration of dust present in the atmosphere at the time of seeding, or even the size and / or distribution of the water droplets.The measurement of such a dust concentration may be or be part of the first physical quantity GP1 measured and collected in a step 101 of the method 100. The step 111 of estimating the seeding conditions further determines a nozzle opening parameter whose value is conveyed or translated by the command SCc or TCc for activating the diffusion of said substance produced in step 121 or 141. In general, a large nozzle opening will be preferred to produce large particles of active substance AS if the atmosphere is clean and a small opening to produce fine particles of active substance AS if the atmosphere is rich in dust. Such differentiated treatment with regard to the dust present in the atmosphere could also be envisaged by the invention, not only according to the density of said dust during the seeding of the cell but also according to the type of dust detected.

[0136] The invention provides that, thanks to a fine analysis of the atmosphere (via the measured and collected physical quantity GP1) combined with knowledge of the position GP2 of the aerostatic seeding device, the seeding of a cloud cell can be accomplished by the diffusion of a first active substance AS1 or the diffusion of a second active substance AS2 distinct from the previous one, or even a combination of said active substances AS1 and AS2. For this, the invention provides that the seeding device 10 carries a plurality of active substances AS1, AS2 and / or means for delivering or diffusing 13 such substances.Like the previous example for which the opening of nozzles can be automatically controlled to adapt the size of the particles of active substance to the quality of the atmosphere, it is possible to choose the active substance, either a "cocktail" of active substances chosen from a plurality, or even a sequence of diffusions of distinct particles, which will offer the most promising seeding. Instead of measuring the quantity or type of dust present in the atmosphere, the invention thus proposes to take into account the first quantity GP1, when this characterizes the ambient temperature and / or hygrometry to choose the active substance(s) to be diffused (jointly or successively) during seeding.Thus, in the data memory 15-2, data or parameters SP may designate silver iodide if the ambient temperature is below minus five degrees Celsius or, alternatively, favor hygroscopic salts in warmer areas. Steps 111 and 121 and 141 are then adapted to respectively produce and convey in a command SCc, TCc a parameter for determining the active substance to be delivered. Alternatively, there are as many commands SCc, TCc as there are actuators 15-7 respectively associated with the means 13 for diffusing or delivering active substance.

[0137] We have mentioned, in the context of the first example of arrangement of an aerostatic seeding device according to the invention, the fact that a mission controller 15 of the latter is configured to estimate a return zone to the ground. This estimation is accomplished in a step 113 of the method 100 according to figures 3 and 5. We have also mentioned the possibility of using different methods or processes to accomplish such an estimation, from the simplest method (vertical projection) to the most sophisticated (modeling of the seeding device and / or ambient currents and winds).

[0138] The invention provides an advantageous and alternative embodiment making it possible to optimize the chances of success of the seeding mission by requesting, when the aerostatic seeding device has them, ground return trajectory correction means 15-10 (for example, one or more electrically controlled thrusters, one or more wings that can be deployed or retracted passively or in response to an electrical command), to optimize its ground return trajectory and / or a diffusion (seeding) during said ground return. Thus, while a free, provoked ground return would risk taking place in an unauthorized region, the use of such trajectory correction means makes it possible to cause an accompanied ground return, that is to say one that can prevent a fall in a prohibited region, by altering the ground return trajectory.It is thus possible to defer the seeding phase somewhat, so that the seeding conditions are more favorable, even if it means flying over prohibited return-to-ground zones and targeting an “accompanied or controlled” return-to-ground within an authorized zone under the action of the return-to-ground trajectory correction means 15-10. According to this advantageous embodiment, step 113 is adapted to take into account the capabilities of the return-to-ground trajectory correction means 15-10 and thus estimate the trajectory of an active return-to-ground in an authorized zone. A method 100 according to the invention further comprises a step 132 or 142 of producing TRc commands to control said means 15-10 and guide the return-to-ground of the aerostatic seeding device in accordance with the estimate made in step 113.

[0139] In connection with Figures 1 and 2, Figure 7 illustrates a first embodiment of ground return trajectory correction means 15-10. The nacelle 12 comprises in this case:

[0140] - a 12-1, 12-2, 12-3 support;

[0141] - means of delivery or diffusion 13 of the active substance AS in the form of a torch;

[0142] - an inflation connector end piece 230 designed to be connected in a sealed manner to a complementary end piece of an external inflation device not shown so as to ensure the inflation of the aerostatic means 11;

[0143] - a hollow sleeve 240 onto which the neck 11-1 of the casing of the aerostatic means 11 is fitted securely and tightly (for example via a plastic clamping collar), this sleeve 240 being in fluid communication with the inflation connector end piece 230 and being provided with an internal non-return valve preventing the deflation of said aerostatic means 11 during the separation between the complementary end piece of the inflation device and the connector end piece 240; and

[0144] - a mission controller 15 on board said aerostatic seeding device 10.

[0145] Advantageously made from a cut and folded sheet of metal, the support 12-1 comprises a first flat attachment portion having for example a rectangular shape and against which the mission controller 15 is fixed. This support 12-1 also comprises a second curved attachment portion 12-2 fixedly supporting the torch 13 via embedding clips 12-3 and which is connected to the first flat portion 12-1 by a connecting portion 12-4.

[0146] The means of delivery or diffusion 13 of the active substance AS are in this case constituted by a pyrotechnic torch comprising a sealed cylindrical envelope 13-1 containing active particles having a strong affinity for water and advantageously constituted by ice-forming nuclei such as silver iodide or copper iodide and preferably in the form of powders or crystals. This cylindrical envelope 13-1 also contains a pyrotechnic mixture, also referred to as an explosive charge, and making it possible to ensure the combustion of the torch 13 and the dispersion of the active particles.

[0147] This pyrotechnic torch 13 also comprises the actuator 15-7, not visible in FIG. 7, advantageously housed in the sealed cylindrical casing 13-1 and designed to cause the activation of the pyrotechnic mixture. This actuator 15-7 is for example constituted by an igniter capable of generating sufficient heat to trigger the combustion of a priming composition making it possible to cause the activation of the pyrotechnic mixture of the torch 13. It is advantageously actuable by means of an electrical signal emitted by the mission controller 15 and transmitted by an electrical cable electrically connected by one of its ends to this trigger and the other end of which is provided with a connector which is connected to a complementary connector provided on this mission controller 15.

[0148] The ground return trajectory correction means 15-10 are of the active rotating rigid wing type and comprise one or a plurality of motorized rotors 261 (advantageously four arranged in a square of which they constitute the corners) preferably extending along the same mean plane and connected to an element of the nacelle 12 (in this case, to the flat attachment portion of the support 12-1) by connecting arms 262. Each of these motorized rotors 261, arranged at the distal end of a respective connecting arm 262, comprises a rotary propeller 261 A driven by a corresponding motor (not visible) housed in a hollow body 261 B formed at this distal end of the connecting arm 262.

[0149] Each rotary propeller 261 A comprises a central hub and several blades extending radially from this central hub and the number of which is advantageously between two and five.

[0150] The central hub and blades of each 261 A rotary propeller are preferably molded as a single piece from a thermoplastic polymer.

[0151] According to embodiment variants not shown, these motorized rotors 261 can be extended in the lower part by support legs intended to come to rest on the ground at the time of landing of the aerostatic seeding device 10, so as to prevent the mission controller 15 from coming into direct contact with the ground.

[0152] Said mission controller 15 is advantageously configured to control the operation of each of the motorized rotors 261 as a function of data transmitted by on-board sensors (gyroscope, accelerometer and / or magnetometer) not shown in FIG. 7, so as to maintain the stability and control of the aerostatic seeding device 10 during its descent.

[0153] Said mission controller 15 is advantageously configured to activate the motorized rotors 261 at the time of bursting or release of the aerostatic means 11 so as to manage the descent of the aerostatic device 1. Alternatively and in order to limit energy consumption, said mission controller 15 may be configured to activate the motorized rotors 261 only below a predetermined threshold altitude. In such a case, the aerostatic seeding device 10 may advantageously be equipped with a self-righting system in flight.

[0154] According to other variant embodiments and in order to limit the electrical consumption so as to optimize the mass of the energy source 15-5 carried by the nacelle 12, the mission controller 15 can be configured to activate the motorized rotors 261 only during part of the descent phase of the device 10, for example when its altitude or its speed reaches a predetermined threshold.

[0155] Figures 8 and 9 illustrate a second embodiment of ground return trajectory correction means 15-10 of the passive rotating rigid wing type. These means comprise a self-rotating propeller 271 secured to an element of the nacelle 12 and comprising several blades 271 A (in this case two aligned blades) the number of which is advantageously between two and five. For reasons of simplicity and manufacturing cost, the proximal ends of the blades 271 A of this self-rotating propeller 271 are advantageously rigidly fixed to an element of the nacelle 12 (in this case, to the flat attachment portion of the support 12-1), so that the entire nacelle 12 is driven in rotation on itself during the descent of the aerostatic seeding device 10.

[0156] It will be understood that the descent of this aerostatic seeding device 10 maintains the rotation of this self-rotating propeller 271 generating lift resulting in a reduction in the descent speed. In order to limit the additional mass generated by the self-rotating propeller 271 so that the lift it generates is sufficient to significantly reduce the descent speed of the aerostatic seeding device 10, this propeller 271 will preferably be made of a low-density, high-stiffness material such as, for example, beech, balsa, expanded polystyrene or even impact-resistant polystyrene. In order to ensure sufficient braking of the aerostatic seeding device 10 after the dispersion of the active particles contained in the diffuser 13, the diameter of this propeller 271 will advantageously be greater than or equal to twenty centimeters and preferably between thirty and forty centimeters.As illustrated by Figure 9 and in order to facilitate the ascent phase of the aerostatic seeding device 10 by limiting the drag generated by the self-rotating propeller 271, the blades 271 A of the latter are advantageously foldable around an axis (for example parallel to their axis of rotation as shown in this Figure 9); these blades 271 A being configured to unfold automatically at the time of deflation, bursting or release of the aerostatic means 11 so as to manage the descent of the aerostatic device 10.

[0157] According to alternative embodiments not shown, the self-rotating propeller 271 can also be mounted to rotate freely on a mast fixed to an element of the nacelle 12 (for example to the support 12-1) so as to limit the rotation of this nacelle 12 during the descent of the aerostatic seeding device 10. According to other alternative embodiments not shown and with the aim of limiting the vibrations generated while increasing the lift generated, the ground return trajectory correction means 15-10 may comprise two superimposed counter-rotating propellers such as 271 mounted to rotate freely on the same mast fixed to an element of the nacelle 12.

[0158] According to other embodiment variants not shown, the self-rotating propeller 271 can also be mounted integral with another element of the nacelle 12 such as for example the casing 13-1 of the means 13 for delivery or diffusion of the active substance AS.

[0159] Figure 10 illustrates a third embodiment of ground return trajectory correction means 15-10 of the fixed rigid wing type comprising two coplanar wings 281 fixed to an element of the nacelle 12 (in this case to the envelope 13-1 of the means 13 for delivery or diffusion of the active substance AS) and arranged symmetrically.

[0160] It will be understood that the lift generated by these wings 281 during the descent of the aerostatic seeding device 10 will cause this device 10 to glide, substantially limiting the vertical component of its fall speed. These return-to-ground trajectory correction means 15-10 also advantageously comprise a tail 282 provided with at least one pitch stabilizing surface 282A extending parallel to the plane of the wings 281. In order to limit the additional mass generated by this fixed wing so that the lift it generates is sufficient to significantly reduce the descent speed of the seeding device 10, the wings 281 and the tail 282 will preferably be made of a low-density, high-stiffness material such as, for example, beech, balsa, expanded polystyrene or even impact-resistant polystyrene.According to other embodiments not shown, the wings 281 can each be provided with a torsion device or an aileron controlled by the mission controller 15 and making it possible to modulate their lift so as to allow control of the descent of the aerostatic seeding device 10.

[0161] Different embodiments of a method 100 for triggering the delivery or diffusion of an active substance AS to seed a cloud cell have been described, said method 100 being implemented iteratively by a processing unit 15-1 of a mission controller 15 on board said aerostatic seeding device 10, for example in the nacelle 12 of the latter.

[0162] The invention also provides an embodiment according to which said mission controller 15 is not directly embedded in an aerostatic seeding device 10, but implemented by a remote electronic object such as the object 20 described in connection with FIG. 1 or a station 30 for preparing and / or launching aerostatic seeding devices. In this case, such an aerostatic seeding device comprises an on-board processing unit arranged to cooperate directly with the sensors 15-4, 15-9 and / or actuators 15-7, 15-8, 15-7 / 8, 15-10 of said aerostatic seeding device and to relay the physical quantities GP1, GP2 measured by the sensors 15-4, 15-9 and the commands SCc, GRCc, TCc, TRc produced by the remote mission controller 15 to control the actuators 15-7, 15-8, 15-7 / 8, 15-10 according to the arrangement of the aerostatic seeding device 10.Communication between the seeding device 10 and said mission controller 15 is carried out via suitable communication means, including means 15-3, via a wireless or wired link N. According to this embodiment, said electronic object 20 and / or the station 30 are arranged to integrate the mission controller 15, that is to say, arranged to implement a method 100 for triggering the delivery or diffusion of an active substance AS in accordance with the invention.

[0163] The invention has been described in its use in connection with cloud cell seeding applications, in particular for hail prevention. It can also be implemented to act on any type of meteorological phenomenon, such as, by way of non-limiting examples, the suppression of fog, the increase of precipitation in the form of rain, the mitigation of tropical cyclones, the preservation of lightning or even the fight against frost. Alternatively, the invention can also be used to increase snow precipitation, for example in ski resorts or to store water in winter in the form of snow.

Claims

CLAIMS 1. Method (100) for triggering the delivery or diffusion of an active substance (AS) for seeding a cloud cell (1) implemented iteratively (T) by a processing unit (15-1) of a mission controller (15) of an aerostatic seeding device (10), the latter comprising: - aerostatic means (11) arranged to raise said aerostatic seeding device (10) into the air; - means of diffusion or delivery (13) of the active substance (AS); - a measuring sensor (15-4) of a first physical quantity (GP1) representative of an atmosphere prevailing around or in said aerostatic means (11); - a first actuator (15-7) arranged to cause actuation of the means for delivering or diffusing (13) the active substance (AS); - a second actuator (15-8) arranged to cause a sudden and irremediable suppression of any lift in the air of said seeding device provided by the aerostatic means (11); said method (100) comprising: - a step (101) of collecting the first physical quantity (GP1); - a step (111) of estimating the seeding conditions of the cloud cell (1) from the first physical quantity (GP1) collected and of producing a first indicator (SC) of satisfaction of seeding criteria determined (SP) by said estimated seeding conditions; said method (100) being characterized in that: - the aerostatic seeding device (10) further comprises a sensor (15-9) for measuring a second physical quantity (GP2) representative of the trajectory and / or the position of the seeding device (10) with respect to the ground or stars; - the method (100) comprises: o a step (103) of collecting the second physical quantity (GP2); o a step (113) of estimating a geographical return zone to the ground of the aerostatic seeding device (10) from the second physical quantity (GP2) and of producing a second admissibility indicator (GRC) of the geographical return zone to the ground estimated with regard to determined geographical data designating authorized and / or prohibited return zones (AGRA) to the ground for said aerostatic seeding device (10); o a step (121) of producing a first command (SCc) for activating the first actuator (15-7) from a first determined combination of values ​​of the first and second indicators (SC, GRC) produced;o a step (131) of producing a second command (GRCc) for activating the second actuator (15-8) from a second determined combination of values ​​of said first and second indicators (SC, GRC) produced.; 2. Method (100) according to the preceding claim, for which: said processing unit (15-1) cooperates with a data memory (15-2) of the mission controller (15), arranged to record and / or update the geographic data designating authorized and / or prohibited return-to-ground zones (AGRA) for the aerostatic seeding device (10) and one or more seeding parameters (SP) including the determined seeding criteria; - the method comprises a step (102) of reading said data memory (15-2), prior to the implementation of the step (111) of estimating the seeding conditions of the cloud cell (1) and / or the step (113) of estimating a geographical return zone to the ground.

3. Method according to any one of the preceding claims, for which: - said method (100) comprises a step (112) of producing a third indicator (FSC) of satisfaction of air safety constraints (FS) to seed a cloud cell (1) from the first physical quantity (GP1) and / or the second physical quantity (GP2) collected (101, 103) and; - the steps (121, 131) of producing a first and second command (SCc, GRCc) each combine said third indicator (FSC) with the values ​​of said first and second indicators (SC, GRC) to respectively produce said first and second commands (SCc, GRCc).

4. Method (100) according to the preceding claim, for which: - said processing unit (15-1) cooperates with a data memory (15-2) of the mission controller (15), arranged to record and / or update the data (FS) designating the air safety constraints; - the method comprises a step (102) of reading said data memory (15-2), prior to the implementation of the step (112) of estimating the seeding conditions of the cloud cell (1) and / or the step (113) of estimating a geographical return zone to the ground.

5. Method (100) according to claim 5 or 6, for which the steps (121) of producing a first command (SCc) for activating the first actuator (15-7) and of producing a second command (GRCc) for activating the second actuator (15-8) each result from a Boolean operation relating to the first, second and third estimated indicators (SC, FSC, GRC) (111, 112, 113), the latter being expressed in a Boolean form.

6. Method according to any one of the preceding claims for which: - the first and second actuators (15-7, 15-8) consist of the same actuator (15-7 / 8) arranged to jointly or successively cause actuation of the means for delivering or diffusing (13) the active substance (AS) and a sudden and irremediable suppression of any lift in the air of said seeding device provided by the aerostatic means (11); - the steps (121, 131) of producing a first and a second command (SCc, GRCc) consist of the production (141) of a single trigger command (TC) of said same actuator (15-7 / 8).

7. Method according to any one of the preceding claims, for which: - the device includes ground return trajectory correction means (15-10); - the method (100) comprises a step (132, 142) of piloting said ground return trajectory correcting means (15-10) so that the device (10) reaches the estimated (113) geographical ground return zone (GRC) of the aerostatic seeding device (10).

8. Computer program product (P) comprising one or more program instructions interpretable by a processing unit (15-1) of a mission controller (15) for seeding a cloud cell (1) by an aerostatic seeding device (10), said program instructions being loadable into a non-volatile memory (15-6) of said mission controller (15) and designed so that the execution of said instructions by said processing unit (15-1) causes the implementation of a method (100) for triggering the delivery or diffusion of an active substance (AS) for seeding a cloud cell (1) according to any one of the preceding claims.

9. Computer-readable storage medium comprising the instructions of a computer program product (P) according to the preceding claim.

10. Mission controller (15) for seeding a cloud cell (1) by an aerostatic seeding device (10), said mission controller comprising a processing unit (15-1) and a program memory (15-6) recording the instructions of the computer program product (P) according to claim 8.

11. Aerostatic seeding device (10) comprising: - aerostatic means (11) arranged to raise said aerostatic seeding device (10) into the atmosphere; - means for diffusing or delivering (13) an active substance (AS) for seeding a cloud cell (1); - a measuring sensor (15-4) of a first physical quantity (GP1) representative of an atmosphere prevailing around or in said aerostatic means (11); - a sensor (15-9) for measuring a second physical quantity (GP2) representative of the trajectory and / or the position of the seeding device (10) with respect to the ground or stars; - a first actuator (15-7) arranged to cause actuation of the means for delivering or diffusing (13) the active substance (AS); - a second actuator (15-8) arranged to cause a sudden and irremediable suppression of any lift in the air of said seeding device provided by the aerostatic means (11); - a mission controller (15) for seeding a cloud cell (1) according to the preceding claim.

12. Aerostatic seeding device (10) comprising: - aerostatic means (11) arranged to raise said aerostatic seeding device (10) into the atmosphere; - means for diffusing or delivering (13) an active substance (AS) for seeding a cloud cell (1); - a measuring sensor (15-4) of a first physical quantity (GP1) representative of an atmosphere prevailing around or in said aerostatic means (11); - a sensor (15-9) for measuring a second physical quantity (GP2) representative of the trajectory and / or the position of the seeding device (10) with respect to the ground or stars; - a first actuator (15-7) arranged to cause actuation of the means for delivering or diffusing (13) the active substance (AS); - a second actuator (15-8) arranged to cause a sudden and irremediable suppression of any lift in the air of said seeding device provided by the aerostatic means (11); - a processing unit arranged to communicate (N) with a mission controller (15) for seeding a cloud cell (1) according to claim 10, said mission controller being remote from said aerostatic seeding device (10).

13. Aerostatic seeding device (10) according to claim 11 or 12, wherein the second actuator (15-8) arranged to cause a sudden and irremediable suppression of any lift in the air of said seeding device provided by the aerostatic means (11) is designed to cause the destruction of the aerostatic means (11) or the separation of the latter (11) from the rest of the seeding device (10).

14. Electronic object (20) cooperating according to a communication link (N) with a seeding device (10) according to claim 12, said electronic object (20) comprising a mission controller (15) according to claim 10.

15. Electronic object according to the preceding claim consisting of a station (30) for preparing and / or launching the seeding device (10), said station comprising equipment arranged for: - determining and / or injecting a quantity and / or a pressure of gas into the aerostatic means (11) of the seeding device (10); - launching or releasing the seeding device (10) towards a cloud cell (1) to be seeded.

16. Station (30) for preparing and / or launching a seeding device (10) when the latter complies with claim 11, said station comprising equipment arranged for: - determining and / or injecting a quantity and / or a pressure of gas into the aerostatic means (11) of the seeding device (10); - launching or releasing the seeding device (10) towards a cloud cell (1) to be seeded; - initialize the data memory (15-2) and / or programs (15-6) of the mission controller (15) of said seeding device (10).

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