System for detecting laser spots and associated detection method

Abstract

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Description

[0001] DESCRIPTION

[0002] TITLE: Laser task detection system and associated detection method

[0003] The present invention relates to a system for detecting laser tasks on, or in the vicinity of, an installation to be protected. The present invention also relates to an associated detection method.

[0004] The present invention relates to the field of self-protection, more precisely to the detection of laser tasks on an installation to be protected, such as a vehicle, a platform or a building.

[0005] Laser task detection, also called DAL (Laser Warning Detector), consists of detecting laser beams in the direction of a facility to be protected. These lasers can have several origins, including: designation for ammunition guidance, telemetry of a fire control system for example, or beam-rider (or beam control). These lasers are generally at wavelengths around 1.0 pm or 1.5 pm.

[0006] Known DAL solutions are DALs distributed over a vehicle to be protected.

[0007] However, one of the limitations is the large number of sensors required to form a DAL. Indeed, the sensors are limited to the laser task (direct DAL), which requires sensors distributed every few meters to locate a laser task at any point of the installation to be protected. This is particularly the case for the detection of small laser tasks with very little illumination near the task ("top hat" shape) or on large targets such as ships. Current DALs are therefore incompatible for the protection of large installations relative to the laser task (would require too many sensors).

[0008] Another limitation is that often, in the case of designation for munitions, the laser task is not directly on the target, but nearby, and is rallied on the target at the very end of guidance. Thus, current DALs do not allow the detection of such tasks.

[0009] There is therefore a need for a system capable of detecting laser tasks on or near an installation to be protected, regardless of the size of the installation to be protected in relation to the laser tasks.

[0010] To this end, the invention relates to a system for detecting laser tasks on, or in the vicinity of, an installation to be protected, the detection system comprising one or more entities, the or each entity comprising at least one laser alert detector, the or each entity being capable of being positioned in the vicinity of the installation to be protected so that the installation to be protected and its surroundings are in the field of vision of the laser alert detector or are in the overall field of vision of all the laser alert detectors.

[0011] According to other advantageous aspects of the invention, the system comprises one or more of the following characteristics, taken individually or in all technically possible combinations:

[0012] - the or each entity is mobile so as to follow any movements of the installation to be protected;

[0013] - the installation to be protected is a vehicle and the or each entity is an accompanying vehicle;

[0014] - the or each entity is a drone, such as a land, air or naval drone;

[0015] - the number of entities is greater than or equal to two;

[0016] - the or each laser warning detector has a field of vision greater than 80°, preferably greater than or equal to 90°, or all of the laser warning detectors have an overall field of vision greater than 80°, preferably greater than or equal to 90°;

[0017] - the or each laser warning detector is capable of detecting laser tasks whose wavelength is at least one of the following wavelengths: 0.8 pm, 1.06 pm and 1.5 pm.

[0018] The invention also comprises a method for detecting laser tasks on, or in the vicinity of, an installation to be protected, by a detection system as described previously, the method comprising the steps of: positioning the or each entity of the detection system in the vicinity of the installation to be protected so that the installation to be protected and its surroundings are in the field of vision of the laser alert detector or are in the overall field of vision of all the laser alert detectors, and detection, by the or one of the laser alert detectors, of a laser task on or in the vicinity of the installation to be protected.

[0019] According to other advantageous aspects of the invention, the method comprises one or more of the following characteristics, taken individually or in all technically possible combinations:

[0020] - the detection step comprises: determining a position for the laser task, a spectral characteristic relating to the laser task and a time code relating to the laser task, as a function of the backscattering of the laser beam at the origin of the laser task on said laser warning detector, and identifying the nature of the laser at the origin of the laser task as a function of the spectral characteristic, the time code, and a database associating predefined spectral characteristics and time codes with laser natures;

[0021] - the method comprises a step of moving the entity(ies) of the detection system following a movement of the installation to be protected, so as to maintain the installation to be protected and its surroundings in the field of vision of the laser alert detector or in the overall field of vision of all the laser alert detectors.

[0022] The invention will appear more clearly on reading the description which follows, given solely by way of non-limiting example, and made with reference to the drawings in which:

[0023] - Figure 1 is a schematic view of an example of an installation to be protected and of a system for detecting laser tasks on, or in the vicinity of, the installation to be protected, the detection system comprising an entity comprising a laser warning detector, and

[0024] - Figure 2 is a schematic view of another example of an installation to be protected and a system for detecting laser tasks on, or in the vicinity of, the installation to be protected, the detection system comprising two entities each comprising a laser alert detector.

[0025] The installation to be protected 10 is a static or mobile installation.

[0026] An installation to be protected 10 and a system 12 for detecting laser tasks T are illustrated in the examples of figures 1 and 2.

[0027] 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 designates in the broad sense an element to be protected. In the examples of figures 1 and 2, the installation to be protected 10 is a vehicle (battle tank).

[0028] The detection system 12 is capable of detecting laser tasks T on, or in the vicinity of, an installation to be protected 10. The term “proximity” is understood to mean in the environment of the installation to be protected 10. The laser task is, for example, 1 meter from the installation to be protected.

[0029] The detection system 12 comprises one or more entities 14.

[0030] Preferably, the 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 or each entity 14 may be static.

[0031] Preferably, the or each entity 14 is a drone. Thus, this allows the entities 14 to easily move in the environment.

[0032] The or each drone is, for example, an aerial, terrestrial (solves the energy problems of aerial drones) or naval drone. Alternatively, the installation to be protected 10 is a vehicle and the or each entity 14 is an accompanying vehicle. For example, the installation to be protected 10 is a naval vessel, and the entities 14 are a fleet of ships surrounding the naval vessel.

[0033] In the example illustrated by FIG. 1, the detection system 12 comprises a single entity 14.

[0034] In a variant, the detection system 12 comprises a number of entities 14 greater than or equal to two. This makes it easier to monitor the entire installation to be protected 10. In particular, in the example illustrated by 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.

[0035] The or each entity 14 comprises at least one laser warning detector 16 (LWD).

[0036] The or each entity 14 is suitable for being positioned close to the installation to be protected 10 so that the installation to be protected 10 and its surroundings are in the field of vision of the laser warning detector 16 or are in 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.

[0037] The overall field of view is the sum of the fields of view of all 16 laser warning detectors.

[0038] By way of example, the or each laser alert detector 16 comprises a sensor capable of receiving a laser flux arriving at the detector, and a processing unit capable of detecting a laser task T as a function of the laser flux collected by the sensor.

[0039] Preferably, the or each laser warning detector 16 has 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.

[0040] Alternatively, at least one laser warning detector 16 has a field of vision of less than 80°, but all of the laser warning detectors have an overall field of vision of greater than 80°, preferably greater than or equal to 90°.

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

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

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

[0044] When the 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 comprises a step 200 of detection, by the or one of the laser alert detectors 16, of a laser task T on, or in the vicinity of, the installation to be protected 10.

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

[0048] In an exemplary implementation, the detection step 200 comprises: determining a position for the laser task T, a spectral characteristic relating to the laser task T and a time code relating to the laser task T, as a function of the backscattering of the laser beam at the origin of the laser task T on said laser warning detector 16. The spectral characteristic comprises information relating to the wavelength of the laser beam at the origin of the laser task T. The time code comprises information relating to the time sequence of the pulses of the laser beam at the origin of the laser task T. identifying the nature of the laser at the origin of the laser task T as a function of the spectral characteristic, the time code, and a database associating predefined spectral characteristics and time codes with types of lasers (for example, designation, telemetry or beam-rider).This makes it possible, for example, to determine that the detected laser task T comes from a designation laser or comes from a laser performing telemetry (in this case the laser alert detector(s) 16 are capable of detecting, for example, several spectral bands, typically at least 1.06 pm, and for example also 0.8 pm or 1.5 pm). The detection method comprises a step 300 of generating an alert, by said laser alert detector 16, when a laser task T has been detected. The alert is in particular intended to inform an operator to initiate protective actions or an automatic response or countermeasure system.

[0049] In this case, various actions can then be implemented. These actions include, for example, maneuvers to dodge a possible shot, sending smoke bombs, interceptor shots or decoys.

[0050] Where appropriate, the method comprises a step 400 of moving the entity(ies) 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 alert detector 16 or in the overall field of vision of all the laser alert detectors 16.

[0051] Thus, the system 12 and the detection method make it possible to detect the laser tasks T on or near the installation to be protected 10, by having a complete vision of the installation to be protected 10 and its surroundings, with a reduced number of sensors. In particular, this makes it possible to have an indirect vision of the laser tasks T and to detect small tasks with low divergence, tasks near the installation to be protected 10 or to cover a platform or a large building. The detection system 12 is thus the equivalent of an indirect laser warning detector 16.

[0052] Furthermore, implementation is facilitated since the laser alert detector(s) 16 are not integrated into the installation to be protected 10.

[0053] Those skilled in the art will understand that the described embodiments can be combined with each other provided that they are technically compatible.

Claims

CLAIMS 1. System (12) for detecting laser tasks (T) on, or in the vicinity of, an installation to be protected (10), the detection system (12) comprising one or more entities (14), the or each entity (14) comprising at least one laser warning detector (16), the or each entity (14) being capable of being positioned in the vicinity of the installation to be protected (10) so that the installation to be protected (10) and its surroundings are in the field of vision of the laser warning detector (16) or are in the overall field of vision of all the laser warning detectors (16).

2. System (12) according to claim 1, in which the or each entity (14) is mobile so as to follow any movements of the installation to be protected (10).

3. System (12) according to claim 2, in which the installation to be protected (10) is a vehicle and the or each entity (14) is an accompanying vehicle.

4. System (12) according to claim 2, wherein the or each entity (14) is a drone, such as a land, air or naval drone.

5. System (12) according to any one of claims 1 to 4, wherein the number of entities (14) is greater than or equal to two.

6. System (12) according to any one of claims 1 to 5, in which the or each laser warning detector (16) has a field of vision greater than 80°, preferably greater than or equal to 90°, or all of the laser warning detectors (16) have an overall field of vision greater than 80°, preferably greater than or equal to 90°.

7. System (12) according to any one of claims 1 to 6, in which the or each laser alert detector (16) is capable of detecting laser tasks (T) whose wavelength is at least one of the following wavelengths: 0.8 pm, 1.06 pm and 1.5 pm.

8. Method for detecting laser tasks (T) on, or in the vicinity of, an installation to be protected (10), by a detection system (12) according to any one of claims 1 to 7, the method comprising the steps 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 in the field of vision of the alert detector laser (16) or either in the overall field of vision of all the laser warning detectors (16), and detection, by the or one of the laser warning detectors (16), of a laser task (T) on or near the installation to be protected (10).

9. The method of claim 8, wherein the detection step comprises: determining a position for the laser task (T), a spectral characteristic relating to the laser task (T) and a time code relating to the laser task (T), as a function of the backscattering of the laser beam at the origin of the laser task (T) on said laser warning detector (16), and identifying the nature of the laser at the origin of the laser task (T) as a function of the spectral characteristic, the time code, and a database associating predefined spectral characteristics and time codes with laser natures.

10. Method according to any one of claims 8 or 9, in which the method comprises a step of moving the entity(ies) (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).