Laser spot detection system and associated detection method

Abstract

Laser Spot Detection System and Associated Detection Method. The present invention relates to a laser spot detection system (12) on, or near, a protected installation (10). The detection system (12) comprises one or more entities (14), each entity (14) comprising at least one laser warning detector (16). Each entity (14) is suitable for being positioned near the protected installation (10) such that the protected installation (10) and its surroundings are within the field of view of the laser warning detector (16) or within the overall field of view of all the laser warning detectors (16). Figure for the abstract: 1

Description

Title of the invention: Laser spot detection system and associated detection method

[0001] The present invention relates to a system for detecting laser spots on, or near, an installation to be protected. The present invention also relates to an associated detection method.

[0002] The present invention relates to the field of self-protection, more specifically to the detection of laser tasks on an installation to be protected, such as a vehicle, a platform or a building.

[0003] Laser spot detection, also called LAD (Laser Alert Detector), consists of detecting laser beams directed towards an installation to be protected. These lasers can have several origins, including: designation for munitions guidance, rangefinding for a fire control system, for example, or beam-rider (or beam guidance). These lasers are generally at wavelengths around 1.0 pm or 1.5 pm.

[0004] The known DAL solutions are DALs distributed over a vehicle to be protected.

[0005] However, one of the limitations is the large number of sensors required to form a DAL. Indeed, the sensors are confined to the laser spot (direct DAL), which necessitates sensors distributed every few meters to detect a laser spot at every point of the installation to be protected. This is particularly the case for detecting small laser spots with very low illumination near the spot (the "top hat" shape) or on large targets such as ships. Current DALs are therefore unsuitable for protecting installations that are large relative to the laser spot (they would require too many sensors).

[0006] Another limitation is that often, in the case of ammunition designation, the laser spot is not directly on the target, but nearby, and is brought to bear on the target at the very end of the guidance sequence. Thus, current laser designators cannot detect such spots.

[0007] There is therefore a need for a system capable of detecting laser spots on or near an installation to be protected, regardless of the size of the installation to be protected in relation to the laser spots.

[0008] To this end, the invention relates to a laser spot detection system on, or near, an installation to be protected, the detection system comprising one or more entities, each entity comprising at least one laser alert detector, each entity being suitable for being positioned near the installation to be protected so that the installation to be protected and its surroundings are within the field of vision of the laser warning detector or within the overall field of vision of all laser warning detectors.

[0009] According to other advantageous aspects of the invention, the system comprises one or more of the following features, taken individually or in all technically possible combinations:

[0010] - where each entity is mobile so as to follow any possible movements of the installation to be protected;

[0011] - the installation to be protected is a vehicle and the one or each entity is a vehicle escort;

[0012] - where each entity is a drone, such as a land, air or naval drone;

[0013] - the number of entities is greater than or equal to two;

[0014] - the laser warning detector(s) have a field of vision greater than 80°, preferably greater than or equal to 90°, or the set of laser warning detectors has an overall field of view greater than 80°, preferably greater than or equal to 90°;

[0015] - the laser warning detector or each laser warning detector is suitable for detecting laser spots whose wavelength is at least one of the following wavelengths: 0.8 pm, 1.06 pm and 1.5 pm.

[0016] The invention also includes a method for detecting laser spots on, or near, an installation to be protected, by a detection system as described above, the method comprising the steps of: - positioning of the detection system component(s) near the installation to be protected so that the installation to be protected and its surroundings are either within the field of vision of the laser warning detector or within the overall field of vision of all the laser warning detectors, and - detection, by the laser warning detector(s), of a laser spot on or near the installation to be protected.

[0017] According to other advantageous aspects of the invention, the method comprises one or more of the following features, taken individually or in all technically possible combinations:

[0018] - the detection step includes: - the determination of a position for the laser spot, a spectral characteristic relating to the laser spot, and a temporal code relating to the laser spot, as a function of the backscattering of the laser beam that caused the laser spot on said laser warning detector, and - Identifying the type of laser responsible for the laser spot based on its spectral characteristics, temporal code, and a database associating predefined spectral characteristics and time codes with types of lasers;

[0019] - the method includes a step of moving the entity or entities of the system detection following a movement of the installation to be protected, so as to keep the installation to be protected and its surroundings in the field of vision of the laser warning detector or in the overall field of vision of all the laser warning detectors.

[0020] The invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the drawings in which:

[0021] [Fig-1] [Fig.1] is a schematic view of an example of an installation to be protected and a laser task detection system on, or near, the installation to be protected, the detection system comprising an entity including a laser warning detector, and

[0022] [Fig.2] [Fig.2] is a schematic view of another example of an installation to protect and a laser task detection system on, or near, the installation to be protected, the detection system comprising two entities each comprising a laser alert detector.

[0023] The installation to be protected 10 is a static or mobile installation.

[0024] A protected installation 10 and a laser task detection system 12 T are illustrated in the examples in Figures 1 and 2.

[0025] The installation to be protected 10 is, for example, a vehicle (naval, land or air), a platform, a building, or even a tactical deployment. The term "installation" therefore refers broadly to any element to be protected. In the examples in Figures 1 and 2, the installation to be protected 10 is a vehicle (battle tank).

[0026] The detection system 12 is suitable for detecting laser spots T on, or near, an installation to be protected 10. By the term "near" it is understood to be in the environment of the installation to be protected 10. The laser spot is for example 1 meter from the installation to be protected.

[0027] The detection system 12 comprises one or more entities 14.

[0028] Preferably, the entity or each entity 14 is mobile so as to follow any movements of the installation to be protected 10. Alternatively, in the case where the installation to be protected 10 is fixed, the entity or each entity 14 may be static.

[0029] Preferably, each entity 14 is a drone. This allows the entities 14 to move easily within the environment.

[0030] The drone or each drone is, for example, an aerial drone, a ground drone (solves the energy problems of aerial drones) or a naval drone.

[0031] Alternatively, the installation to be protected 10 is a vehicle and each entity 14 is an escort vehicle. For example, the installation to be protected 10 is a naval vessel, and the entities 14 are a fleet of ships escorting the naval vessel.

[0032] In the example illustrated by [Fig.1], the detection system 12 comprises a single entity 14.

[0033] In one embodiment, the detection system 12 comprises two or more entities 14. This facilitates monitoring of the entire installation to be protected 10. In particular, in the example illustrated in [Fig. 2], the detection system 12 comprises two entities 14, each monitoring different portions of the installation to be protected 10. The entities 14 are then, for example, positioned on either side of the installation to be protected 10 so as to cover different parts of the installation to be protected 10.

[0034] The or each entity 14 comprises at least one laser warning detector 16 (LWD).

[0035] The or of each entity 14 is suitable for being positioned near the installation to be protected 10 such that the installation to be protected 10 and its surroundings are within the field of vision of the laser warning detector 16 or within the overall field of vision of all the laser warning detectors 16. The surroundings of the installation to be protected are the immediate environment of the installation to be protected 10, i.e., a few meters around the installation to be protected 10, typically 5 meters, or even 10 meters. More generally, the surroundings of the installation to be protected are an area where the impact of a munition would be likely to cause damage to the installation to be protected 10.

[0036] The overall field of vision is the sum of the fields of vision of all the laser warning detectors 16.

[0037] By way of example, the laser warning detector or each laser warning detector 16 includes a sensor suitable for receiving a laser flux arriving at the detector, and a processing unit suitable for detecting a laser task T as a function of the laser flux collected by the sensor.

[0038] Preferably, the laser warning detector(s) 16 have a field of view greater than 80°, preferably greater than or equal to 90°. This allows the laser warning detectors 16 to monitor a wide area.

[0039] Alternatively, at least one laser warning detector 16 has a field of view of less than 80°, but the set of laser warning detectors has an overall field of view greater than 80°, preferably greater than or equal to 90°.

[0040] Preferably, the laser warning detector(s) 16 is suitable for detecting laser spots T whose wavelength is at least one of the following wavelengths: 0.8 pm, 1.06 pm and 1.5 pm. The spectral range of the sensor of each laser warning detector 16 is therefore compatible with the aforementioned wavelengths.

[0041] Advantageously, the laser warning detector or each of the 16 is capable of detecting at least the wavelength 1.06 pm (typical wavelength of a designating laser).

[0042] An example of a method for detecting laser spots T on, or near, an installation to be protected 10, by the detection system 12 described above, will now be described.

[0043] The detection method includes a step 100 of positioning the or each entity 14 of the detection system 12 in the vicinity of the installation to be protected 10 so that the installation to be protected 10 and its surroundings are either in the field of vision of the laser warning detector 16 or in the overall field of vision of all the laser warning detectors 16.

[0044] When the entity or each entity 14 is mobile, the positioning step 100 is carried out directly by the entities 14.

[0045] Otherwise, the detection system 12 has for example been previously positioned according to the installation to be protected 10.

[0046] The detection method includes a step 200 of detection, by the laser warning detector(s) 16, of a laser spot T on, or near, the installation to be protected 10.

[0047] In particular, detection is carried out following the reception of the backscatter of the laser beam at the origin of the laser spot T on said laser warning detector 16.

[0048] In an example implementation, detection step 200 includes: - the determination of a position for the laser spot T, a spectral characteristic relating to the laser spot T and a temporal code relating to the laser spot T, as a function of the backscattering of the laser beam at the origin of the laser spot T on said laser warning detector 16. The spectral characteristic includes information relating to the wavelength of the laser beam at the origin of the laser spot T. The temporal code includes information relating to the temporal sequence of the pulses of the laser beam at the origin of the laser spot T. - Identification of the type of laser responsible for the laser spot T based on the spectral characteristic, the time code, and a database associating predefined spectral characteristics and time codes with types of lasers (e.g., designation, rangefinding, or beam-rider). This allows, for example, determining whether the detected laser spot T originates from a designation laser or from a rangefinding laser (in which case the laser warning detector(s) 16 are likely to detect, for example, several spectral bands, typically at least 1.06 pm, and for example also 0.8 pm or 1.5 pm).

[0049] The detection method includes a step 300 of generating an alert, by said laser alert detector 16, when a laser spot T has been detected. The alert is intended in particular to inform an operator to initiate protective actions or an automatic response or countermeasure system.

[0050] In this case, various actions can then be implemented. These actions include, for example, maneuvers to evade a possible shot, the deployment of smoke grenades, interceptor fire, or decoys.

[0051] Where appropriate, the method includes a step 400 of moving the entity or entities 14 of the detection system 12 following a movement of the installation to be protected 10, so as to maintain the installation to be protected 10 and its surroundings in the field of vision of the laser warning detector 16 or in the overall field of vision of all the laser warning detectors 16.

[0052] Thus, the system 12 and the detection method make it possible to detect laser spots T on or near the installation to be protected 10, providing a complete view of the installation to be protected 10 and its surroundings, with a reduced number of sensors. In particular, this allows for an indirect view of the laser spots T and the detection of small spots with low divergence, spots near the installation to be protected 10, or coverage of a large platform or building. The detection system 12 is therefore equivalent to an indirect laser warning detector 16.

[0053] In addition, implementation is facilitated since the laser warning detector(s) 16 are not integrated into the installation to be protected 10.

[0054] A person skilled in the art will understand that the embodiments described can be combined with each other provided that they are technically compatible.

Claims

Demands

1. A method for detecting laser spots (T) on, or near, an installation to be protected (10), by a laser spot detection system (12) on, or near, an installation to be protected (10), the detection system (12) comprising two or more entities (14), each entity (14) comprising at least one laser warning detector (16), each entity (14) being suitable for being positioned near the installation to be protected (10) such that the installation to be protected (10) and its surroundings are within the overall field of vision of all the laser warning detectors (16), the method comprising the steps of: - positioning each entity (14) of the detection system (12) near the installation to be protected (10) such that the installation to be protected (10) and its surroundings are within the overall field of vision of all the laser warning detectors (16), and detection,by one of the laser warning detectors (16), of a laser spot (T) on or near the installation to be protected (10), the detection step comprising: • the determination of a position for the laser spot (T), a spectral characteristic relating to the laser spot (T) and a temporal code relating to the laser spot (T), as a function of the backscattering of the laser beam at the origin of the laser spot (T) on said laser warning detector (16), and • the identification of the nature of the laser at the origin of the laser spot (T) as a function of the spectral characteristic, the temporal code, and a database associating predefined spectral characteristics and temporal codes with types of lasers.

2. A method according to claim 1, wherein each entity (14) is mobile so as to follow any movements of the installation to be protected (10).

3. Method according to claim 2, wherein the installation to be protected (10) is a vehicle and each entity (14) is an escort vehicle.

4. A method according to claim 2, wherein each entity (14) is a drone, such as a land, air or naval drone.

5. A method according to any one of claims 1 to 4, wherein each laser warning detector (16) has a field of view greater than 80°, preferably greater than or equal to 90°, or the set of laser warning detectors (16) has an overall field of view greater than 80°, preferably greater than or equal to 90°.

6. A method according to any one of claims 1 to 5, wherein each laser warning detector (16) is suitable for detecting laser spots (T) whose wavelength is at least one of the following wavelengths: 0.8 pm, 1.06 pm and 1.5 pm.

7. A method according to any one of claims 1 to 6, wherein the method comprises a step of moving the entity or entities (14) of the detection system (12) following a movement of the installation to be protected (10), so as to maintain the installation to be protected (10) and its surroundings in the field of vision of the laser warning detector (16) or in the overall field of vision of all the laser warning detectors (16).

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