Method and device for water column profile measurement

Abstract

A method and device for water column profile measurement have the following features: • the method uses a measuring arrangement with a flying drone (10), a submersible cable (20) and a measuring probe (30) for measuring physical quantities, such that one end of the submersible cable (20) is connected to the flying drone (10) and another end of the submersible cable (20) is connected to the measuring probe (30), with the steps: • Flight of the drone (10) with the immersion cable (20) and the measuring probe (30) from a base station to at least one marine measuring position, • At each of the at least one marine measurement position, the following steps are carried out: ▪ Lowering the drone (10) and the associated lowering of the measuring probe (30) into the sea while recording measurement data with the measuring probe (30), ▪ Ascent of the drone (10) and the concomitant submersion of the measuring probe (30) in the sea with optional recording of measurement data with the measuring probe (30), • Return flight of the drone (10) with the immersion cable (20) and the measuring probe (30) to the base station and placing the measuring probe (30) on the base station. The measuring probe, submersible cable, and drone are reusable. The ocean is not polluted with debris. Measurements can be taken in shallow waters.

Description

[0001] The invention relates to a method and a device for water column profile measurement of physical quantities.

[0002] DE 696 04 575 T2 describes a method and device for water column profile measurement. The method uses a measuring arrangement with a probe holder that accommodates a plurality of measuring probes for measuring physical quantities. The measuring arrangement is dropped into the sea, for example from an aircraft, at a predetermined ocean measuring position. Since the measuring arrangement is heavier than water, it sinks to the seabed. A single measuring probe, on the other hand, is lighter than water. A release device for an individual measuring probe releases it from the probe holder. The released measuring probe rises through the water column, recording the measurement data. After reaching the water surface, the measurement data is transmitted to a satellite for subsequent analysis. After this time, this measuring probe is used up and, like the probe holder and the other measuring probes later, becomes marine litter.

[0003] US Patent No. 3,561,268 A1 also shows a disposable measuring probe that remains in the water as waste after use. These disposable measuring probes are inexpensive and their measurement accuracy is correspondingly low. Furthermore, the ballast weights are made of lead and poison the oceans.

[0004] A measuring probe in the shape of an elongated cylinder is known from a brochure (CTD60Mc - ultra deep Sea, Online and Memory Probe up to 11 000 m from Sea & Sun Technology).

[0005] WO 2022 / 038005 A1 shows an air-water drone for detecting mines in shallow waters.

[0006] Further state of the art is shown in the following documents: - RANGAN, Srinivasan [et al.]: A study on drone stability on lifting and hovering with the CTD sensor and instrumentation payload for ocean observation applications. July 2021. - RANGAN, Srinivasan [et al.]: A customized drone for ocean and atmospheric measurements and its performances. In: Maritime technology „and research, Vol. 6, Juli-September 2024, No. 3, Art.-Nr. 267638, 13 S. - ISSN 2651-205X. - RANGAN, Srinivasan [et al.]: Adapting the drone technology for marine applications - a high resolution water quality measurement system using drone (part 3). In: Marine engineers review India, Vol. 16, 2022, No. 12, S. 23-26. ISSN 2250-1967. - RANGAN, Srinivasan [et al.]: Adapting the drone technology for marine applications - a high resolution water quality measurement system using drone (part 2). In: Marine engineers review India, Vol. 16, 2022, No. 10, S. 14-21. - ISSN 2250-1967. - KOPARAN, Cengiz (et al.]: Temperature profiling of waterbodies with a UAVintegrated sensor subsystem. In: Drones, Vol. 4, 2020, No. 3, Art.-Nr. 35, 10 S. - I_SSN 2504- 446X. - KOPARAN, Cengiz [et al.]: Autonomous in situ measurements of noncontaminant water quality indicators and sample collection with a UAV. In: Water, Vol. 11, 2019, No. 3, Art.-Nr. 604, 15 S. - ISSN 2073-4441. - CHUNG, Michaella (et al.]: Obtaining the thermal structure of lakes from the air. In: Water, Vol. 7, 2015, No.11, S. 6467-6482. -ISSN 2073-4441. - POULSEN, Ebbe [et al.]: Uncrewed aerial vehicle with onboard winch system for rapid, cost-effective, and safe oceanographic profiling in hazardous and inaccessible areas. In: HardwareX, Vol. 18, 2024, Art.-Nr. e00518, 21 S. - ISSN 2468-0672. - US 2017 / 0 328 814 A1 - SEA & SUN Technology GmbH: CTD60Mc - ultra deep sea. Online and memory probe up to 11000 m. Trappenkamp, 2018. 2 S. - Firmenschrift. - WO 2024 / 132 529 A1

[0007] The invention is based on the object of creating an alternative method and an alternative device for water column profile measurement.

[0008] This object is achieved according to the invention by the features of claim 1 directed to a method and by the features of claim 7 directed to a device.

[0009] The advantages of the invention lie in the sustainability and environmental compatibility of the measuring setup. Furthermore, this invention should also enable measurements in very shallow coastal areas where ships cannot enter.

[0010] The inventive idea of ​​the method or device for water column profile measurement lies in the use of an aerial drone, a submersible cable, and a measuring probe. The unit consisting of the aerial drone, submersible cable, and measuring probe flies from a base station to at least one ocean measuring point. At each ocean measuring point, the aerial drone descends. Because one end of the submersible cable is connected to the aerial drone and the other end of the submersible cable is connected to the measuring probe, the measuring probe follows the descent of the aerial drone and records ocean measurement data. As the aerial drone ascends, the measuring probe also submerges and emerges from the ocean. Once the measurement data has been collected from all ocean measuring points, the aerial drone returns to the base station and deploys the measuring probe. The measuring probe, submersible cable, and aerial drone are reused. The ocean is not polluted with waste.In particular, no cables are left in the ocean where marine mammals or fish could become entangled. The water column profile measurement is carried out in a sustainable and environmentally friendly manner. As the measuring probe descends through a central inflow channel, fresh seawater flows from below into an adjoining, also central measuring chamber, where the measurement data is recorded. The seawater flows out again via radial, upwardly inclined discharge channels. The measurement data are recorded in the measuring chamber. The dynamic pressure at the inflow channel as the measuring probe descends ensures that the measuring chamber is always perfused with seawater at the current water depth. The measuring probe 30 has a cylindrical probe core 32, which has individual sensors 31a, 31b, and 31c at its base.

[0011] The structural design is surprisingly simple, since the extension of the inflow channel 35 is the measuring chamber 36 and the receptacle of the cylindrical probe core 32 forms the extension of the measuring chamber 36.

[0012] According to an advantageous embodiment of the invention, the immersion cable is released from the drone when the measuring probe is placed on the base station. This release prevents the immersion cable from becoming entangled, for example, in the drone's rotors.

[0013] As an alternative to unhooking the immersion cable, a drone with a driven reel is used. Before the measuring probe is placed on the base station, the immersion cable is wound up from the driven reel to prevent it from becoming entangled with moving parts of the drone.

[0014] According to a further advantageous embodiment of the invention, the measuring probe sinks into the sea and collects measurement data at a sinking speed of 7 m / s ± 2 m / s. This range represents a compromise between the parameters of the required time and the accuracy of the measurement.

[0015] According to a further advantageous embodiment of the invention, the acquired measurement data is transmitted wired to the drone and wirelessly from the drone to the base station. The measurement data can thus be evaluated immediately after acquisition.

[0016] According to a further advantageous embodiment of the invention, the measuring probe records measurement data of conductivity, temperature, and water depth. A water column profile measurement using this physical measurement data ensures that the accuracy of sonar methods is increased, as it allows the speed of sound in the water column to be determined very precisely.

[0017] Subclaims 8 to 12 relate to advantageous embodiments of the device according to the invention. The advantages of the method subclaims apply accordingly to the respective device subclaims.

[0018] Embodiments of the invention are explained in more detail below with reference to the drawings. These are highly simplified schematic diagrams: Fig. 1 a measuring arrangement with a flying drone, an immersion cable and a measuring probe, in a perspective view; Fig. 1a an alternative drone to the one in Fig. 1 shown flying drone; Fig. 2 which in Fig. 1 shows the measuring probe of the measuring arrangement, in an enlarged sectional view; Fig. 3a to 3e each in Fig. 1 shows the measuring arrangement shown at successive points in time, illustrating individual process steps, each in a front view.

[0019] Fig. Figure 1 shows a device for water column profile measurement. The device comprises a measuring arrangement with a drone 10, a submersible cable 20, and a measuring probe 30 for measuring physical quantities. Fig. 2 supplements the Fig. 1, in which the measuring probe 30 is shown enlarged. One end of the immersion cable 20 is connected to the drone 10, and the other end of the immersion cable 20 is connected to the measuring probe 30.

[0020] The facility is trained to carry out the following steps: • Outward flight of the drone 10 with the immersion cable 20 and the measuring probe 30 from a base station to at least one marine measuring position, • At each of the at least one marine measurement position, the following steps are carried out: ◯ Lowering the drone 10 and the concomitant lowering of the measuring probe 30 into the sea 40 while recording measurement data with the measuring probe 30, ◯ Ascent of the drone 10 and the concomitant submersion of the measuring probe 30 in the sea 40 with optional recording of measurement data with the measuring probe 30, • Return flight of the drone 10 with the immersion cable 20 and the measuring probe 30 to the base station and setting down the measuring probe 30 on the base station.

[0021] The device has a release device 15 for releasing the immersion cable 20 from the drone 10 when the measuring probe 30 is placed on the base station.

[0022] Fig. 1a shows an alternative to the release device 15, in which the flying drone 10 has a drivable reel 14 with which the immersion cable 20 can be wound up before the measuring probe 30 is placed on the base station.

[0023] The immersion cable 20, for example, is 120 m long. With this length, the measuring probe 30 can reach a depth of 100 m when sinking into the sea 40. The drone 10 is still at a safe distance of 20 m above sea level. Since parts of the North Sea and the Baltic Sea are less than 100 m deep, the aforementioned length of the immersion cable is often sufficient for water column profile measurements. Furthermore, it does not violate applicable regulations regarding drone flight operations. Longer cables can also be used on the open sea to reach greater depths.

[0024] The measuring probe 30 has a streamlined fairing 31 in order to collect measurement data as the measuring probe 30 sinks in the sea 40 at a sinking speed of 7 m / s.

[0025] When viewed in the lowering position, the measuring probe 30 has a lower, longitudinally axial inflow channel 35. As the measuring probe 30 descends, fresh seawater flows through the opening of the longitudinally axial inflow channel 35 into an adjacent measuring chamber 36, where the measurement data is recorded. The seawater is drained from the measuring chamber 36 via radial, upwardly inclined outflow channels 34.

[0026] The measuring probe 30 has a cylindrical probe core 32, which has individual sensors 31a, 31b, and 31c at its base. The design is surprisingly simple, since the extension of the inflow channel 35 forms the measuring chamber 36, and the receptacle of the cylindrical probe core 32 forms the extension of the measuring chamber 36.

[0027] The measuring probe 30 is a CTD (Conductivity-Temperature-Depth) measuring probe. Its individual sensors 31a, 31b, and 31c record measurement data for conductivity, temperature, and water depth. The water depth can be derived from the pressure.

[0028] For ease of assembly, the panel 31 is divided into two parts in the longitudinal direction and has a head part 31a and a foot part 31b.

[0029] A data cable is integrated into the immersion cable 20 for transmitting the acquired measurement data to the drone 10 via a wired connection. The drone 10 has a radio device with an antenna 39 for transmitting the measurement data via radio from the drone 10 to the base station.

[0030] The following describes the process of a measuring company for a water column profile measurement. - A ship represents the base station. - The ship transports a measuring arrangement comprising an aerial drone 10, a submersible cable 20 and a measuring probe 30. - The drone 10 is launched and moved upwards. The immersion cable 20 is pulled upwards. - When the drone 10 reaches a height corresponding to the cable length, the measuring probe 30 lifts. - The drone 10 has a navigation system and flies to the first marine measurement point. - The individual steps are: - Lowering the drone 10 and the concomitant lowering of the measuring probe 30 into the sea 40 while recording measurement data with the measuring probe 30. Fig. 3a illustrates the beginning of the descent, with the measuring probe 30 just submerged. Fig. Figure 3b illustrates the end of the descent, with the probe just touching the seabed. An impact sensor detects contact with the seabed and transmits this information to the drone 10, also via the aforementioned data cable. - Ascent of the aerial drone 10 and concomitant submersion of the measuring probe 30 in the sea 40 with optional recording of measurement data with the measuring probe 30. Fig. Figure 3c illustrates the time at which the measuring probe 30 leaves the sea 40. - Additional marine measurement points are flown to. The aforementioned individual steps are carried out at each marine measurement point. - Then the drone 10 returns to the base station with the immersion cable 20 and the measuring probe 30, illustrated in Fig. 3d, and the placement of the measuring probe 30 on the base station, illustrated in Fig. 3e. - Due to the long cable length, the measuring probe 30 swings in rough seas. The lowering process of the measuring probe 30 is simplified by using a release device 15. If, as Fig. 3e shows that the measuring probe 30 is placed on the base station, the immersion cable 20 is detached from the drone 10 so that the rotors of the drone 10 do not get caught in the immersion cable 20. - As an alternative to the release device 15, a drivable reel 14 can be used on the drone 10. The drivable reel 14 not only facilitates the landing process, but also the takeoff process. The drivable reel also allows the immersion cable 20 to be unwound to a length corresponding to the specified water column at the offshore measurement position.

[0031] Deviations or additions to the previous embodiments are possible, for example, as follows: ▪ The descent rate in the example is 7 m / s. The descent rate could also have a different value, ranging from 7 m / s ± 2 m / s. ▪ The measuring probe 30 could have further individual sensors in addition to the individual sensors 33a, 33b, 33c of the CTD measuring probe. ▪ The measurement data from the measuring probe 30 could also be read out at the base station. • Drone 10 is a multicopter. Unlike the illustration, the drone could also have more than four rotors. ▪ A power cable for supplying power to the measuring probe could also be integrated into the immersion cable 20. List of reference symbols: 10 flying drones 14 reels 15 Notching device 20 immersion cables 30 measuring probe 31 cladding 31a Head part of the panel 31b Foot part of the cladding 32 probe core 33a, 33b, 33c each a single sensor 34 Outflow channel 35 Inflow channel 36 Measuring room 39 Antenna 40 Sea

Claims

[1] Method for water column profile measurement, with the following features: • the method uses an aerial drone (10), a submersible cable (20) and a measuring probe (30) for measuring physical quantities, such that one end of the submersible cable (20) is connected to the aerial drone (10) and another end of the submersible cable (20) is connected to the measuring probe (30), wherein the measuring probe (30), considering the position of the measuring probe (30) during descent, has a lower, longitudinal axial inflow channel (35), an adjoining measuring chamber (36) and adjoining, radial and upwardly inclined discharge channels (34), wherein during descent of the measuring probe (30) fresh seawater flows into the measuring chamber (36) via the inflow channel (35) and flows out via the discharge channels (34), wherein the measurement data are recorded in the measuring chamber (36) and wherein the measuring probe (30) has a cylindrical probe core (32) which has individual sensors (31a, 31b, 31c) on the foot,wherein the extension of the inflow channel (35) is the measuring chamber (36) and the receptacle of the cylindrical probe core (32) forms the extension of the measuring chamber (36), • with the steps: • Flight of the drone (10) with the immersion cable (20) and the measuring probe (30) from a base station to at least one marine measuring position, • At each of the at least one marine measurement position, the following steps are carried out: ▪ Lowering the drone (10) and the associated lowering of the measuring probe (30) into the sea (40) while recording measurement data with the measuring probe (30), ▪ Ascent of the drone (10) and the concomitant submersion of the measuring probe (30) in the sea (40) with optional recording of measurement data with the measuring probe (30), • Return flight of the drone (10) with the immersion cable (20) and the measuring probe (30) to the base station and placing the measuring probe (30) on the base station. [2] Method according to claim 1, wherein when the measuring probe (30) is placed on the base station, the immersion cable (20) is unlatched from the flying drone (10). [3] Method according to claim 1, in which a flying drone (10) with a drivable reel (14) is used and in which the immersion cable (20) is wound up with the drivable reel (14) before the measuring probe (20) is placed on the base station. [4] Method according to one of claims 1 to 3, wherein the sinking of the measuring probe (30) in the sea (40) takes place while recording measurement data at a sinking speed of 7 m / s ± 2 m / s. [5] Method according to one of claims 1 to 4, in which the measurement data are transmitted by wire to the drone (10) and by radio from the drone (10) to the base station. [6] Method according to one of claims 1 to 5, wherein the measuring probe (30) records measurement data of conductivity, temperature and water depth. [7] Device for measuring water column profiles, with the following features: • the device comprises a flying drone (10), a submersible cable (20) and a measuring probe (30) for measuring physical quantities, such that one end of the submersible cable (20) is connected to the flying drone (10) and another end of the submersible cable (20) is connected to the measuring probe (30), wherein the measuring probe (30), considering the position of the measuring probe (30) during descent, has a lower, longitudinally axial inflow channel (35), an adjoining measuring chamber (36) and adjoining, radially and upwardly inclined discharge channels (34), designed such that when the measuring probe (30) descends, fresh seawater flows into the measuring chamber (36) via the inflow channel (35) and flows out again via the discharge channels (34), wherein the measurement data can be recorded in the measuring chamber (36), and wherein the measuring probe (30) has a cylindrical probe core (32) which has individual sensors (31a, 31b, 31c) on the base, wherein the .The measuring chamber (36) is an extension of the inflow channel (35) and the receptacle of the cylindrical probe core (32) forms the extension of the measuring chamber (36). • the facility is trained to carry out the following procedure: • Flight of the drone (10) with the immersion cable (20) and the measuring probe (30) from a base station to at least one marine measuring position, • At each of the at least one marine measurement position, the following steps are carried out: ▪ Lowering the drone (10) and the associated lowering of the measuring probe (30) into the sea (40) while recording measurement data with the measuring probe (30), ▪ Ascent of the drone (10) and the concomitant submersion of the measuring probe (30) in the sea (40) with optional recording of measurement data with the measuring probe (30), • Return flight of the drone (10) with the immersion cable (20) and the measuring probe (30) to the base station and placing the measuring probe (30) on the base station. [8] Device according to claim 7, which has a release device (15) for releasing the immersion cable (20) from the flying drone (10) when the measuring probe (30) is placed on the base station. [9] Device according to claim 7, which has a flying drone (10) with a drivable reel (14) with which the immersion cable (20) can be wound up before the measuring probe (30) is placed on the base station. [10] Device according to one of claims 7 to 9, in which the measuring probe (30) has a streamlined fairing (31) in order to record measurement data when the measuring probe (30) sinks in the sea (40) at a sinking speed of 7 m / s ± 2 m / s. [11] Device according to one of claims 7 to 10, with a data line integrated in the immersion cable (20) for the wired transmission of the recorded measurement data to the flying drone (10) and a radio device for forwarding these measurement data from the flying drone (10) to the base station. [12] Device according to one of claims 7 to 11, wherein the measuring probe (20) is a CTD (Conductivity-Temperature-Depth) measuring probe for acquiring measurement data of conductivity, temperature and water depth.

Images