System for detecting laser spots and associated detection method
The system addresses the challenge of detecting laser spots on large installations by using mobile entities with wide-field detectors, ensuring comprehensive coverage and identification of laser types, enhancing protection efficacy.
Patent Information
- Authority / Receiving Office
- AE · AE
- Patent Type
- Applications
- Current Assignee / Owner
- THALES SA
- Filing Date
- 2024-12-18
AI Technical Summary
Existing laser spot detection systems require a large number of sensors to cover large installations, and they fail to detect laser spots that are not directly on the target but in proximity, especially for small spots with low irradiance or on large targets.
A detection system comprising mobile entities with wide-field laser warning detectors positioned around the installation to provide comprehensive coverage, capable of detecting laser spots within a large area, including those in proximity to the target, using drones or accompanying vehicles, and identifying laser types based on spectral features and time codes.
Enables efficient detection of laser spots on or near large installations with reduced sensor numbers, allowing for indirect detection of small spots and varied laser types, facilitating protection measures.
Smart Images
Figure ABST_ABST
Abstract
Description
TITLE: System for detecting laser spots and associated detection method The present invention relates to a system for detecting laser spots on, or in proximity to, an installation to be protected. The present invention also relates to an associated detection method.The present invention relates to the field of self-protection, more precisely to the detection of laser spots on an installation to be protected, such as a vehicle, a platform or a building.The detection of laser spots, also called DAL (Laser Warning Detector), consists in detecting laser beams directed toward an installation to be protected. These lasers can have several origins, notably: designation for munition guidance, rangefinding of a fire control system for example, or also beam-rider (or beam riding). These lasers are generally at wavelengths around 1.0 µm or 1.5 µm.The known DAL solutions are DALs distributed over a vehicle to be protected.Nevertheless, one of the limitations is the large number of sensors necessary to form a DAL. Indeed, the sensors are circumscribed to the laser spot (direct DAL), which requires sensors distributed every few meters to locate a laser spot at any point of the installation to be protected. This is notably the case for the detection of small laser spots with very little irradiance in proximity to the spot (“top hat” shape) or on targets of large dimensions such as ships. Current DALs are therefore incompatible for the protection of installations of large size relative to the laser spot (would require too many sensors).Another limitation is that often, in the case of designation for munitions, the laser spot is not directly on the target, but in proximity, and is rallied onto the target at the very end of guidance. Thus, current DALs do not make it possible to detect such spots.There is therefore a need for a system making it possible to detect laser spots on or in proximity to an installation to be protected, whatever the size of the installation to be protected with respect to the laser spots.To this end, the invention relates to a system for detecting laser spots on, or in proximity to, an installation to be protected, the detection system comprising one or more entities, the or each entity comprising at least one laser warning detector, the or of each entity being suitable for being positioned in proximity to the installation to be protected such that the installation to be protected and its surroundings is in the field of view of the laser warning detector or is in the overall field of view of the set of laser warning detectors.According to other advantageous aspects of the invention, the system comprises one or more of the following features, taken in isolation or according to all technically possible combinations:- the or each entity is mobile so as to follow any movements of the installation to be protected;- the installation to be protected is a vehicle and the or each entity is an accompanying vehicle;- the or each entity is a drone, such as a land, aerial or naval drone;- the number of entities is greater than or equal to two;- the or each laser warning detector has a field of view 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°;- the or each laser warning detector is suitable for detecting laser spots whose wavelength is at least one of the following wavelengths: 0.8 µm, 1.06 µm and 1.5 µm.The invention also comprises a method for detecting laser spots on, or in proximity to, 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 proximity to the installation to be protected such that the installation to be protected and its surroundings is in the field of view of the laser warning detector or is in the overall field of view of the set of laser warning detectors, anddetecting, by the or one of the laser warning detectors, a laser spot on or in proximity to the installation to be protected.According to other advantageous aspects of the invention, the method comprises one or more of the following features, taken in isolation or according to all technically possible combinations:- the detection step comprises:the determination of a position for the laser spot, of a spectral feature relating to the laser spot and of a time code relating to the laser spot, as a function of the backscatter of the laser beam at the origin of the laser spot on said laser warning detector, andthe identification of the nature of the laser at the origin of the laser spot as a function of the spectral feature, of the time code, and of a database associating predefined spectral features and time codes with natures of lasers;- the method comprises a step of moving the entity or entities 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 view of the laser warning detector or in the overall field of view of the set of laser warning detectors.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:- figure 1 is a schematic view of an example of an installation to be protected and of a system for detecting laser spots on, or in proximity to, the installation to be protected, the detection system comprising an entity comprising a laser warning detector, and- figure 2 is a schematic view of another example of an installation to be protected and of a system for detecting laser spots on, or in proximity to, the installation to be protected, the detection system comprising two entities each comprising a laser warning detector.The installation to be protected 10 is a static or mobile installation.An installation to be protected 10 and a system 12 for detecting laser spots T are illustrated in the examples of figures 1 and 2.The installation to be protected 10 is, for example, a vehicle (naval, land or aerial), a platform, a building, or also 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).The detection system 12 is suitable for detecting laser spots T on, or in proximity to, an installation to be protected 10. By the term “proximity”, it is understood in the environment of the installation to be protected 10. The laser spot is for example 1 meter from the installation to be protected.The detection system 12 comprises one or more entities 14.Preferably, the or each entity 14 is mobile so as to follow any movements of the installation to be protected 10. As a variant, in the case where the installation to be protected 10 is fixed, the or each entity 14 can be static.Preferably, the or each entity 14 is a drone. Thus, this allows the entities 14 to move easily in the environment.The or each drone is, for example, an aerial, land (solves the energy problems of aerial drones) or naval drone.As a variant, 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 framing the naval vessel.In the example illustrated by figure 1, the detection system 12 comprises a single entity 14.In a variant, the detection system 12 comprises a number of entities 14 greater than or equal to two. This makes it possible to facilitate the surveillance of the whole of the installation to be protected 10. In particular, in the example illustrated by figure 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.The or each entity 14 comprises at least one laser warning detector 16 (DAL).The or of each entity 14 is suitable for being positioned in proximity to the installation to be protected 10 such that the installation to be protected 10 and its surroundings is in the field of view of the laser warning detector 16 or is in the overall field of view of the set of 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.The overall field of view is the sum of the fields of view of the set of laser warning detectors 16.By way of example, the or each laser warning detector 16 comprises a sensor suitable for receiving a laser flux arriving on the detector, and a processing unit suitable for detecting a laser spot T as a function of the laser flux collected by the sensor.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 an extended area.As a variant, at least one laser warning detector 16 has a field of view 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°.Preferably, the or each laser warning detector 16 is suitable for detecting laser spots T whose wavelength is at least one of the following wavelengths: 0.8 µm, 1.06 µm and 1.5 µm. 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 suitable for detecting at least the wavelength 1.06 µm (typical wavelength of a designation laser).An example of a method for detecting laser spots T on, or in proximity to, an installation to be protected 10, by the detection system 12 described previously, will now be described.The detection method comprises a step 100 of positioning the or each entity 14 of the detection system 12 in proximity to the installation to be protected 10 such that the installation to be protected 10 and its surroundings is in the field of view of the laser warning detector 16 or is in the overall field of view of the set of laser warning detectors 16.When the or each entity 14 is mobile, the positioning step 100 is carried out directly by the entities 14.Otherwise, the detection system 12 has for example been previously positioned as a function of the installation to be protected 10.The detection method comprises a step 200 of detecting, by the or one of the laser warning detectors 16, a laser spot T on, or in proximity to, the installation to be protected 10.In particular, the 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.In one implementation example, the detection step 200 comprises:the determination of a position for the laser spot T, of a spectral feature relating to the laser spot T and of a time code relating to the laser spot T, as a function of the backscatter of the laser beam at the origin of the laser spot T on said laser warning detector 16. The spectral feature comprises information relating to the wavelength of the laser beam at the origin of the laser spot T. The time code comprises information relating to the time sequence of the pulses of the laser beam at the origin of the laser spot T.the identification of the nature of the laser at the origin of the laser spot T as a function of the spectral feature, of the time code, and of a database associating predefined spectral features and time codes with natures of lasers (for example, designation, rangefinding or also beam-rider). This makes it possible for example to determine that the detected laser spot T comes from a designation laser or comes from a laser performing rangefinding (in this case the laser warning detector(s) 16 are likely to detect for example several spectral bands, typically at least 1.06 µm, and for example also 0.8 µm or 1.5 µm).The detection method comprises a step 300 of generating an alert, by said laser warning detector 16, when a laser spot T has been detected. The alert is notably intended to inform an operator to engage protection actions or an automatic response or countermeasure system.In this case, different actions can then be put in place. These actions are for example maneuvers for evading possible firing, the sending of smoke grenades, interceptor shots or decoys.Where applicable, the method comprises 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 view of the laser warning detector 16 or in the overall field of view of the set of laser warning detectors 16.Thus, the system 12 and the detection method make it possible to detect the laser spots T on or in proximity to the installation to be protected 10, by having a complete view of the installation to be protected 10 and of its surroundings, with a reduced number of sensors. In particular, this makes it possible to have an indirect view of the laser spots T and to detect small spots with low divergence, spots in proximity to the installation to be protected 10 or to cover a platform or a building of large dimension. The detection system 12 is thus the equivalent of an indirect laser warning detector 16.In addition, the implementation is facilitated since the laser warning detector or detectors 16 are not integrated into the installation to be protected 10.The person skilled in the art will understand that the described embodiments can be combined with one another provided that they are technically compatible.
Claims
1. System (12) for detecting laser spots (T) on, or in proximity to, 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 of each entity (14) being suitable for being positioned in proximity to the installation to be protected (10) such that the installation to be protected (10) and its surroundings is in the field of view of the laser warning detector (16) or is in the overall field of view of the set of laser warning detectors (16).
2. System (12) according to claim 1, wherein 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, wherein 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, aerial 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, wherein the or 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°.
7. System (12) according to any one of claims 1 to 6, wherein the or each laser warning detector (16) is suitable for detecting laser spots (T) whose wavelength is at least one of the following wavelengths: 0.8 µm, 1.06 µm and 1.5 µm.
8. Method for detecting laser spots (T) on, or in proximity to, 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 proximity to the installation to be protected (10) such that the installation to be protected (10) and its surroundings is in the field of view of the laser warning detector (16) or is in the overall field of view of the set of laser warning detectors (16), anddetecting, by the or one of the laser warning detectors (16), a laser spot (T) on or in proximity to the installation to be protected (10).
9. Method according to claim 8, wherein the detection step comprises:the determination of a position for the laser spot (T), of a spectral feature relating to the laser spot (T) and of a time code relating to the laser spot (T), as a function of the backscatter of the laser beam at the origin of the laser spot (T) on said laser warning detector (16), andthe identification of the nature of the laser at the origin of the laser spot (T) as a function of the spectral feature, of the time code, and of a database associating predefined spectral features and time codes with natures of lasers.
10. Method according to any one of claims 8 or 9, 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 view of the laser warning detector (16) or in the overall field of view of the set of laser warning detectors (16).