阅读说明：本技术 用于跟踪目标和补偿大气湍流的系统和方法 (System and method for tracking targets and compensating for atmospheric turbulence ) 是由 瑞吉斯·格拉塞尔 玛丽·娜米-哈比 于 2019-06-21 设计创作，主要内容包括：本发明公开了用于跟踪目标和补偿大气湍流的系统和方法。该系统包括：至少两个光源(2),其中每个光源向目标(4)发射光束(3)；至少两个准直器(6),用于对相关联的光源(2)的光束(3)进行准直；参比装置(7),用于反射从所有准直器(6)出射的光束(3)的部分光束(8)；至少两个瞄准模块(9),用于引导来自光源(2)的光束(3)以到达目标(4)的预定区域(10)；至少两个检测模块(11),用于接收和检测由参比装置(7)反射的部分光束(8)；用于确定偏差角度的模块(13)；用于确定相位偏差的模块(28)；以及调节模块(14),用于调节每个光源(2),以便补偿大气湍流。(The invention discloses a system and a method for tracking a target and compensating for atmospheric turbulence. The system comprises: at least two light sources (2), wherein each light source emits a light beam (3) towards a target (4); at least two collimators (6) for collimating the light beams (3) of the associated light sources (2); a reference device (7) for reflecting part (8) of the beams (3) emerging from all the collimators (6); at least two aiming modules (9) for directing a light beam (3) from a light source (2) to reach a predetermined area (10) of a target (4); at least two detection modules (11) for receiving and detecting the partial light beams (8) reflected by the reference device (7); a module (13) for determining a deviation angle; a module (28) for determining a phase deviation; and an adjustment module (14) for adjusting each light source (2) so as to compensate for atmospheric turbulence.)

1. A system for tracking targets and compensating for atmospheric turbulence,

characterized in that the system comprises:

-at least two light sources (2), each configured to emit a light beam (3) along a propagation axis (5) in an emission direction (E) towards a target (4),

-at least two collimators (6), wherein each collimator (6) is associated with a respective one of the light sources (2), wherein each collimator (6) is configured to collimate a light beam (3) of the associated light source (2),

-a reference device (7) arranged downstream of all the collimators (6) along the emission direction (E), the reference device (7) comprising a reflection plane (29) configured to reflect part beams (8) of the light beams (3) exiting from all the collimators (6),

-at least two aiming modules (9), wherein each of said aiming modules (9) is associated individually and in its entirety with one of said light sources (2), wherein each of said aiming modules (9) is configured to direct a light beam (3) from said light source (2) to reach a predetermined area (10) of said target (4),

-at least two detection modules (11), wherein each detection module (11) is associated individually and in its entirety with one of the light sources (2), wherein each detection module (11) comprises a first detection surface (12) configured to receive the partial light beam (8) reflected by the reflection plane (29) of the reference arrangement (7), the partial light beam (8) reflected by the reflection plane (29) of the reference arrangement (7) being received and detected at a current position on the first detection surface (12),

-at least two means (13) for determining deviation angles configured to determine deviation angles (β 1, β 2, β 3) respectively from spatial displacements on the first detection surface (12) between a reference position on the first detection surface (12) and the current position, the deviation angles (β 1, β 2, β 3) being determined after each aiming means (9) directs each of the light beams (3) to reach a predetermined area (10) of the target (4), wherein the deviation angles correspond to angles between the partial light beams (8) reflected by the reflection plane (29) of the reference device (7) and the propagation axis (5),

-a module (28) for determining a phase deviation configured to determine a phase deviation from deviation angles (β 1, β 2, β 3) determined by the at least two modules (13) for determining deviation angles, wherein the module (28) for determining a phase deviation is configured to determine a recombined wavefront from deviation angles (β 1, β 2, β 3), the phase deviation being determined by the module (28) for determining a phase deviation by comparing the recombined wavefront with a planar wavefront parallel to the reflection plane (29) of the reference device (7);

-at least two adjustment modules (14) configured to adjust each of said light sources (2) according to said phase deviation determined by said module for determining phase deviation (28) so as to compensate for atmospheric turbulence.

2. The system of claim 1, wherein the first and second sensors are disposed in a common housing,

characterized in that each collimator (6) comprises at least one exit pupil, wherein each collimator has an optical axis (17), wherein the optical axis (17) forms a non-zero angle (a) with the propagation axis (5) such that the propagation axis (5) and the optical axis (17) intersect on the exit pupil of each collimator (6).

3. The system of claim 2, wherein the first and second sensors are arranged in a single package,

characterized in that said non-zero angle (a) has a value greater than 0 ° and less than or equal to 5 °.

4. The system of any one of claims 1 to 3,

characterized in that each of said sighting modules (9) comprises:

a second detection surface (18) configured to receive an image (19) representative of the object (4),

-a unit (20) for positioning configured to position, on an image (19) of the target (4) received by the second detection surface (18), a position of the predetermined area (10) to be reached by the light beam (3) on the target (4) and a current position of an area that has been reached by the light beam (3),

-a unit (21) for calculating configured to calculate a movement to be made between a current position of an area that the light beam (3) has reached and a position of the predetermined area (10) to be reached on the target (4),

-a moving unit (22) configured to move the light source (2) according to the movement to be made calculated by the unit for calculating (21) such that the current position of the area that the light beam (3) has reached overlaps with the position of the predetermined area to be reached (10).

5. The system of claim 4, wherein the first and second sensors are arranged in a single package,

characterized in that the system further comprises a plate (23) arranged in the propagation axis (5), wherein the plate (23) has the following surface: the surface being configured to receive a light beam (3) from the light source (2) and to receive the image (19) representing the object (4),

and wherein said surface is capable of transmitting a light beam (3) from said light source (2) and reflecting said image (19) representing said object (4) towards said second detection surface (18).

6. The system of claim 4, wherein the first and second sensors are arranged in a single package,

characterized in that the system further comprises a plate (23) arranged in the propagation axis (5), wherein the plate (23) has the following surface: the surface being configured to receive a light beam (3) from the light source (2) and to receive the image (19) representing the object (4),

and said surface being capable of reflecting a light beam (3) from said light source (2) and transmitting said image (19) representing said object (4) towards said second detection surface (18).

7. The system of any one of claims 1 to 3,

characterized in that the system further comprises an aiming laser device (24) configured to emit an aiming laser beam (25) onto the predetermined area (10) to be reached on the target (4),

and each of said sighting modules (9) comprising:

-a second detection surface (18) configured to receive an image (26) representing a position of the aiming laser beam (25) on the target and a position of the light beam (3) on the target (4),

-a unit (20) for positioning configured to position the position of the aiming laser beam (25) on the target (4) and the current position of the light beam (3) on the target (4) on the image (26) received by the second detection surface (18),

-a unit (21) for calculating configured to calculate a movement to be made between the current position of the light beam (3) on the target (4) and the position of the aiming laser beam (25) on the target (4),

-a moving unit (22) configured to move the light source (2) according to the movement to be made calculated by the unit for calculating (21) such that the current position of the light beam (3) on the target overlaps with the position of the aiming laser beam (25) on the target.

8. The system of claim 7, wherein the first and second sensors are arranged in a single package,

characterized in that the system further comprises a plate (23) arranged in the propagation axis (5), wherein the plate (23) has the following surface: the surface being configured to receive a light beam (3) from the light source (2) and to receive the image (26) representing the position of the aiming laser beam (25) on the target and the position of the light beam (3) on the target,

and said surface being capable of transmitting a light beam (3) from said light source (2) and reflecting said image (26) representing the position of said aiming laser beam (25) on said target and the position of said light beam (3) on said target towards said second detection surface (18).

9. The system of claim 7, wherein the first and second sensors are arranged in a single package,

characterized in that the system further comprises a plate (23) arranged in the propagation axis (5), wherein the plate (23) has the following surface: the surface being configured to receive a light beam (3) from the light source (2) and to receive the image (26) representing the position of the aiming laser beam (25) on the target and the position of the light beam (3) on the target,

and said surface being capable of reflecting a light beam (3) from said light source (2) and transmitting said image (26) representing the position of said aiming laser beam (25) on said target and the position of said light beam (3) on said target towards said second detection surface (18).

10. Method of using a system (1) for tracking targets (4) and compensating for atmospheric turbulence according to any one of claims 1 to 9,

characterized in that the method comprises the following cyclically repeated steps:

-an emission step (E1) carried out by each of said light sources (2), comprising emitting a light beam (3) along a propagation axis (5) along an emission direction (E) towards said target (4),

-a step (E2) of collimating a light beam (3) carried out by each of said collimators (6), said step of collimating a light beam comprising collimating each of said light beams (3) emitted by each of said light sources (2),

-a targeting step (E3) carried out by each of said targeting modules (9), said targeting step comprising directing said light beam (3) from said light source (2) to reach a predetermined area (10) of said target (4),

-a detection step (E4) carried out by each of said detection modules (11), said detection step comprising receiving and detecting on said first detection surface (12) said partial light beam (8) reflected by said reflection plane (29) of said reference device (7) in the current position,

-a step (E5) of determining a deviation angle carried out by each of said modules (13) for determining a deviation angle, said step of determining a deviation angle comprising determining a deviation angle (β 1, β 2, β 3) from a spatial displacement on said first detection surface (12) between a reference position on said first detection surface (12) and said current position, said deviation angle (β 1, β 2, β 3) being determined after each of said aiming modules (9) directs each of said light beams (3) to reach said predetermined area (10) of said target (4), said deviation angle (β 1, β 2, β 3) corresponding to an angle between said partial light beam (8) reflected by said reflection plane (29) of said reference device (7) and said propagation axis (5),

-a step (E6) of determining a phase deviation, carried out by the module (28) for determining a phase deviation, comprising determining a phase deviation from the deviation angle (β 1, β 2, β 3) determined in the step (E5) of determining a deviation angle, the step (E6) of determining a phase deviation comprising determining a recombined wavefront from the deviation angle (β 1, β 2, β 3), wherein the phase deviation is determined in the step (E6) of determining a phase deviation by comparing the recombined wavefront with a planar wavefront parallel to the reflection plane (29) of the reference device (7);

-an adjustment step (E7) carried out by each of said adjustment modules (14), said adjustment step comprising adjusting each of said light sources (2) according to the phase deviation determined in said step (E6) of determining a phase deviation (28) to compensate for atmospheric turbulence.

11. The method of claim 10, wherein the first and second light sources are selected from the group consisting of,

characterized in that said aiming step (E3) comprises the following sub-steps:

-a receiving sub-step (E31) carried out by a second detection surface (18), said receiving sub-step comprising receiving an image (19) representative of the object (4) on the second detection surface (18),

-a positioning sub-step (E32) carried out by a unit for positioning (20) comprising positioning, on an image (19) of the target (4) received by the second detection surface (18), the position of the predetermined region (10) to be reached by the light beam (3) on the target (4) and the current position of the region reached by the light beam (3),

-a calculation sub-step (E33) carried out by a unit (21) for calculating, said calculation sub-step comprising calculating a movement to be made between a current position of a region that the light beam (3) has reached and a position of the predetermined region (10) to be reached on the target (4),

-a movement sub-step (E34) carried out by a movement unit (22), comprising moving the light source (2) according to the movement to be made calculated by the unit for calculating (21) so that the current position of the area reached by the light beam (3) overlaps with the position of the predetermined area to be reached (10).

12. The method of claim 10, wherein the first and second light sources are selected from the group consisting of,

characterized in that said aiming step (E3) comprises the following sub-steps:

-an emission sub-step (E35) carried out by an aiming laser device (24), said emission sub-step comprising the emission of an aiming laser beam (25) onto said predetermined area (10) to be reached on said target (4),

-a receiving sub-step (E36) carried out by a second detection surface (18), said receiving sub-step comprising receiving an image (26) representative of the position of the aiming laser beam (25) on the target (4) and of the position of the light beam (3) on the target (4),

-a positioning sub-step (E37) carried out by a unit for positioning (20) comprising positioning on the image (26) received by the second detection surface (18) the position of the aiming laser beam (25) on the target (4) and the current position of the light beam (3) on the target (4),

-a calculation sub-step (E38) carried out by a unit for calculating (21) comprising calculating a movement to be made between a current position of the light beam (3) on the target (4) and a position of the aiming laser beam (25) on the target (4),

-a movement sub-step (E39) carried out by a movement unit (22), comprising moving the light source (2) according to the movement to be made calculated by the unit for calculating (21) so that the current position of the light beam (3) on the target (4) overlaps with the position of the aiming laser beam (25) on the target (4).

Technical Field

The present invention relates to the field of laser sighting devices, and more particularly to a system for tracking a target and compensating for atmospheric turbulence.

Background

Controlling the parameters of the laser beam or any other directed beam is an important issue. In the following, in the description, the terms "beam" or "light beam" will be used to denote a laser beam or any other directed light beam.

The distance between the light source emitting the light beam to specify the target and the target can be very large. Generally, the use of a single beam is not sufficient to contact the target, since the power of the single beam is greatly reduced by the path between the source of the beam and the target. Therefore, in general, several basic beams are used in combination; this makes it possible to obtain a beam of very high power formed by all the elementary beams.

When a large number of elementary beams are used, the configuration of each beam must be known separately in order to adjust the parameters of each beam to maintain the maximum power of the beam formed by all the elementary beams. However, it is difficult to determine which elementary beams have an operating configuration that reduces the power of the beam formed by all the elementary beams in order to adjust the configuration of said beams.

There are devices that can solve this problem. However, these devices implement complex adaptive optics loops or implement devices that require large amounts of computation. Therefore, these devices are not suitable for systems comprising a large number of elementary beams.

Disclosure of Invention

The present invention aims to overcome these drawbacks by proposing a system that makes it possible to track targets and compensate for turbulence generated by the atmosphere.

To this effect, the invention relates to a system for tracking targets and compensating for atmospheric turbulence.

According to the invention, the system comprises:

at least two light sources, each light source being configured to emit a light beam along a propagation axis in an emission direction towards a target,

at least two collimators, wherein each collimator is associated with a respective one of the light sources, wherein each collimator is configured to collimate a light beam of the associated light source,

a reference arrangement arranged downstream of all collimators in the emission direction, the reference arrangement comprising a reflection plane configured to reflect part of the beams exiting from all collimators,

-at least two aiming modules, wherein each aiming module is associated individually and in its entirety with one of the light sources, wherein each aiming module is configured to direct a light beam from the light source to reach a predetermined area of the target.

At least two detection modules, wherein each detection module is associated individually and in its entirety with one of the light sources, wherein each detection module comprises a first detection surface configured to receive the partial light beam reflected by the reference arrangement, the partial light beam reflected by the reflection plane of the reference arrangement being received and detected at a current position on the first detection surface,

at least two modules for determining deviation angles, configured to determine deviation angles respectively depending on a spatial displacement on the first detection surface between a reference position on the first detection surface and a current position, the deviation angles being determined after each sighting module has directed each light beam to reach a predetermined area of the target, wherein the deviation angles correspond to the angles between the partial light beams reflected by the reflection plane of the reference arrangement and the propagation axis.

-means for determining a phase deviation configured to determine the phase deviation from the deviation angle determined by the at least two means for determining deviation angles, wherein the means for determining a phase deviation is configured to determine a recombined wavefront from the deviation angles, the phase deviation being determined by the means for determining a phase deviation by combining the recombined wavefront with a plane wavefront parallel to a reflection plane of the reference device;

-at least two adjusting modules configured to adjust each light source according to the wave front determined by the module for determining a wave front, to compensate for atmospheric turbulence.

Thus, according to the present invention, it is possible to both track the target to be reached and compensate for the effects of turbulence generated by the atmosphere without using a complex optical loop or extensive calculations.

Advantageously, each collimator comprises at least one exit pupil, wherein each collimator has an optical axis, wherein the optical axis forms a non-zero angle with the propagation axis such that the propagation axis and the optical axis intersect at the exit pupil of each collimator.

In a non-limiting manner, the non-zero angle has a value greater than 0 ° and less than or equal to 5 °.

According to a first embodiment, each sighting module comprises:

a second detection surface configured to receive an image representing an object,

a unit for positioning configured to position, on the target image received by the second detection surface, a position of a predetermined area on the target to be reached by the light beam and a current position of an area that the light beam has reached,

a unit for calculating configured to calculate a movement made between a current position of the area that the light beam has reached and a position of a predetermined area to be reached on the target,

a moving unit configured to move the light source such that a current position of the area that the light beam has reached overlaps with a position of the predetermined area to be reached, in accordance with the movement to be made calculated by the unit for calculating.

According to a first alternative of the first embodiment, the system further comprises a plate arranged in the propagation axis, wherein the plate has a lower surface configured to receive the light beam from the light source and to receive an image representing the object.

The surface is capable of transmitting a light beam from the light source and reflecting an image representing the target towards the second detection surface.

According to a second alternative of the first embodiment, the system further comprises a plate arranged in the propagation axis, wherein the plate has a lower surface configured to receive the light beam from the light source and to receive an image representing the object.

The surface is capable of reflecting a light beam from the light source and transmitting an image representing the target towards the second detection surface.

According to a second embodiment, the system further comprises an aiming laser device configured to emit an aiming laser beam onto a predetermined area on the target to be reached.

Each aiming module comprises:

a second detection surface configured to receive an image representing a position of the aiming laser beam on the target and a position of the light beam on the target,

a unit for positioning configured to position the position of the aiming laser beam on the target and the current position of the beam on the target on the image received by the second detection surface,

a unit for calculating configured to calculate a movement to be made between a current position of the light beam on the target and a position of the aiming laser beam on the target,

a moving unit configured to move the light source such that the current position of the light beam on the target overlaps with the position of the aiming laser beam on the target, according to the movement to be performed calculated by the unit for calculating.

According to a first alternative of the second embodiment, the system further comprises a plate arranged on the propagation axis, wherein the plate has a lower surface configured to receive the light beam from the light source and to receive an image representing the position of the aiming laser beam on the target and the position of the light beam on the target.

The surface is capable of transmitting a light beam from the light source and reflecting an image representing the location of the aiming laser beam on the target and the location of the light beam on the target toward the second detection surface.

According to a second alternative of the second embodiment, the system further comprises a plate arranged on the propagation axis, the plate having a lower surface configured to receive the light beam from the light source and to receive an image representing the position of the aiming laser beam on the target and the position of the light beam on the target.

The surface is capable of reflecting the light beam from the light source and transmitting an image representing the location of the aiming laser beam on the target and the location of the light beam on the target toward the second detection surface.

The invention also relates to a method for using the system for tracking targets and compensating for atmospheric turbulence.

According to the invention, the method comprises the following cyclically repeated steps:

an emission step carried out by each light source, the emission step comprising emitting a light beam along a propagation axis in an emission direction towards a target,

-a step of collimating the light beams, performed by each collimator, comprising collimating each light beam emitted by each light source,

-a targeting step carried out by each targeting module, the targeting step comprising directing a light beam from a light source to reach a predetermined area of a target,

a detection step carried out by each detection module, the detection step comprising receiving and detecting on the first detection surface the partial beam reflected by the reflection plane of the reference device at the current position,

a step of determining a deviation angle carried out by each module for determining a deviation angle, the step of determining a deviation angle comprising determining a deviation angle from a spatial displacement on the first detection surface between a reference position on the first detection surface and a current position, the deviation angle being determined after each aiming module has directed each light beam to reach a predetermined area of the target, wherein the deviation angle corresponds to an angle between a portion of the light beam reflected by the reflection plane of the reference arrangement and the propagation axis,

a step of determining a phase deviation, performed by the module for determining a phase deviation, the step of determining a phase deviation comprising determining a phase deviation from the deviation angle determined in the step of determining a deviation angle, the step of determining a phase deviation comprising determining a recombined wavefront from the deviation angle, wherein the phase deviation is determined in the step of determining a phase deviation by comparing the recombined wavefront with a planar wavefront parallel to the reflection plane of the reference device,

-an adjustment step, performed by each adjustment module, comprising adjusting each light source according to the phase deviation determined in the step of determining the phase deviation, to compensate for atmospheric turbulence.

According to a first embodiment, the aiming step comprises the following sub-steps:

a receiving sub-step carried out by the second detection surface, the receiving sub-step comprising receiving an image representative of the object on the second detection surface,

a positioning sub-step, carried out by the unit for positioning, comprising positioning, on the image of the target received by the second detection surface, the position of a predetermined area on the target to be reached by the light beam and the current position of the area reached by the light beam,

a calculation sub-step carried out by the unit for calculating, the calculation sub-step comprising calculating the movement to be made between the current position of the region reached by the beam and the position of a predetermined region to be reached on the target,

a movement sub-step implemented by the moving unit, the movement sub-step comprising moving the light source according to the movement to be made calculated by the unit for calculating, such that the current position of the area that the light beam has reached overlaps with the position of the predetermined area to be reached.

According to a second embodiment, the aiming step comprises the following sub-steps:

a firing sub-step carried out by the aiming laser device, the firing sub-step comprising the firing of an aiming laser beam onto a predetermined area to be reached on the target,

a receiving sub-step carried out by the second detection surface, the receiving sub-step comprising receiving an image representative of the position of the aiming laser beam on the target and of the beam on the target,

a positioning sub-step, carried out by the unit for positioning, comprising positioning on the image received by the second detection surface the position of the aiming laser beam on the target and the current position of the beam on the target,

a calculation sub-step carried out by the unit for calculating, the calculation sub-step comprising calculating the movement to be made between the current position of the beam on the target and the position of the aiming laser beam on the target,

a movement sub-step carried out by the moving unit, the movement sub-step comprising moving the light source according to the movement to be performed calculated by the unit for calculating, such that the current position of the light beam on the target overlaps with the position of the aiming laser beam on the target.

Drawings

The invention and its features and advantages will appear more clearly on reading the description made with reference to the accompanying drawings, in which:

figure 1 shows an overall perspective view of the tracking system,

figure 2 shows a schematic cross-section of a tracking system,

figure 3 shows a part of a tracking system according to a first embodiment,

figure 4 shows the same part of a tracking system according to a second embodiment,

figure 5 schematically shows the steps of a method using the tracking system according to the first embodiment,

fig. 6 schematically shows the steps of a method using a tracking system according to a second embodiment.

Detailed Description

The remainder of the description will refer to the figures mentioned above.

The invention relates to a system 1 for tracking an object 4 and for compensating for atmospheric turbulence. In the following description, the "system for tracking an object and compensating for atmospheric turbulence" shall be referred to as a "tracking system".

The target 4 may be a moving target or a stationary target. For example, the target may be a fighter plane or a building. In fig. 1 and 3, the target 4 corresponds to a tree.

As shown in fig. 1 and 2, the tracking system 1 comprises at least two light sources 2, preferably a plurality of light sources 2. For example, the tracking system 1 comprises several tens of light sources 2. The light sources 2 are each configured to emit a light beam 3 in a direction along a propagation axis 5 towards a target 4 in an emission direction indicated by the arrow labelled E.

In a non-limiting manner, each light source 2 may be a laser, or a transmitter of directed light, or an end of an optical fiber transmitting the light of the laser or directed light.

The tracking system 1 further comprises at least two collimators 6. Each collimator 6 is associated with a respective one of the light sources 2. Each collimator 6 is configured to collimate the light beam 3 of the associated light source 2.

Preferably, each light source 2 is arranged in the focal plane of the collimator 6 associated with that light source 2.

Advantageously, each collimator 6 comprises at least one exit pupil and has an optical axis 17. The optical axis 17 forms a non-zero angle α with the propagation axis 5 such that the propagation axis 5 intersects the optical axis 17 at the exit pupil of each collimator 6.

In a non-limiting manner, the angle α between the propagation axis 5 and the optical axis 17 has a value greater than 0 ° and less than or equal to 5 °. Preferably, the angle α is between 2 ° and 3 °.

The tracking system 1 further comprises a reference device 7, which reference device 7 is arranged downstream of all collimators 6 in the emission direction E. The reference arrangement 7 comprises a reflecting plane 29, which reflecting plane 29 is configured to reflect a part 8 of the light beam 3 exiting from all collimators 6. The reflecting plane 29 of the reference means 7 serves as a common reference for all collimators 6.

According to one embodiment, the reflecting plane 29 comprises a flat plate comprising at least one splitting surface able to split each light beam 3 exiting from each collimator 6 into two portions. One or more separating surfaces are able to reflect a portion 8 of the beam 3 of each collimator 6 and to transmit the remaining portion of the beam 3.

In a non-limiting manner, the one or more separating surfaces have a transmittance of between 99% and 99.9% of the light beam 3.

The tracking system 1 further comprises at least two targeting modules 9. Each aiming module 9 is associated individually and in its entirety with one of the light sources 2. Each targeting module 9 is configured to direct a light beam 3 from the light source 2 to reach a predetermined area 10 of the target 4.

The tracking system 1 further comprises at least two detection modules 11. Each detection module 11 is associated individually and in its entirety with one of the light sources 2. Each detection module 11 comprises a detection surface 12, the detection surface 12 being configured to receive the portion 8 of the light beam 3 reflected by the reflection plane 29 of the reference device 7. The beam portion 8 reflected by the reflecting plane 29 is received and detected at the current position on the detection surface 12.

The expression "associated as a whole with one of the light sources" with respect to the aiming module 9 and the detection module 11 means that these modules 9 and 11 move by following the same movements as the respective light sources 2 of these modules 9 and 11. For example, for each light source 2, the associated aiming module 9 and the associated detection module 11 are fixed on the same support to form a single optoelectronic assembly 27. The light source 2 is then configured to move by movement of the support on which the associated aiming module 9 and the associated detection module 11 are fixed. The associated sighting module 9 and the associated detection module 11 then follow the same movement as the light source 2.

The respective distance between the light source 2 and the detection surface 12 of the associated detection module 11 is stable over time, regardless of the ambient conditions. This need is preferably ensured because the distance between the light source 2 and the detection surface 12 of each detection module 11 is small. Typically, this distance is about a few millimeters. In a non-limiting manner, the distance is between 3mm and 10 mm.

According to one embodiment, in order to have a reliable and constant distance value, the detection surface 12 of each detection module 11 may be integrated directly into the glass of the laser housing through which the laser beam exits.

The tracking system 1 further comprises at least two modules 13 for determining the deviation angle as an absolute value. Each module 13 for determining the deviation angle is associated with one of the light sources 2. Each module 13 for determining deviation angles is configured to determine deviation angles β 1, β 2, β 3, respectively, from the spatial displacement between a reference position on the detection surface 12 and a current position on the detection surface 12. After each aiming module 9 directs each light beam 3 to reach a predetermined area 10 of the target 4, the deviation angles β 1, β 2, β 3 are determined by each detection module 11, respectively.

The deviation angles β 1, β 2, β 3 correspond to the angles between the beam portion 8 reflected by the reflection plane 29 of the reference device 7 and the propagation axis 5.

The tracking system 1 further comprises a module 28 for determining a phase deviation, which module 28 for determining a phase deviation is configured to determine the phase deviation from the deviation angles β 1, β 2, β 3 determined by the at least two modules 13 for determining deviation angles. Each module 13 for determining the deviation angle therefore sends a signal to the module 28 for determining the phase deviation, which signal represents the deviation angle that this module 13 has determined.

To this end, the module 28 for determining the phase deviation is configured to determine the recombined wave fronts from the deviation angles β 1, β 2, β 3. The phase deviation is determined by means of a module 28 for determining the phase deviation by comparing the recombined wave front with a plane wave front parallel to the reflection plane 29 of the reference device 7. The comparison comprises determining the distance between the recombined wavefront and the front of the plane wavefront in line with each collimator 6. All modules 13 for determining the deviation angle thus make it possible for the module 28 for determining the phase deviation to recombine the wave front 15 formed by the light beam 3.

The purpose of the tracking system 1 is therefore to ensure that the wavefront 15 from the target 4 carrying information about the atmospheric turbulence (or distortion) is always the same wavefront as the wavefront 16 emerging from the collimator 6, which reproduces the atmospheric turbulence, on the one hand. In other words, the tracking system 1 is such that the wavefront 16 emerging from the collimator 6 can always be steered on the wavefront 15 from the target 4.

The tracking system 1 thus uses the principle of a Shack Hartmann wavefront analyser, in which a displacement between a reference position of a light beam and a current position of the light beam represents a phase deviation between a reference phase corresponding to the phase of the light beam reaching the reference position and a current phase corresponding to the phase of the light beam reaching the current position.

At least two conditioning modules 14 form part of the tracking system 1. Each of the adjusting modules 14 is associated with one of the light sources 2. Each adjustment module 14 is configured to adjust each light source 2 according to the phase deviation determined by the module for determining phase deviation 28 in order to compensate for atmospheric turbulence. The module 28 for determining the phase deviation therefore sends a signal representing the phase deviation to each adjusting module 14, so that each adjusting module 14 adjusts the phase of the light source 2. Each adjustment module 14 therefore calculates the movement to be performed by the associated light source 2 of each adjustment module 14 on the basis of the phase deviation representative signal it receives from the module 28 determining the phase deviation. The expression "compensating for atmospheric turbulence" means eliminating the effect of atmospheric turbulence during propagation of one or more light beams.

In fig. 2, the wavefront 15 represents a wavefront whose shape is determined by the module for determining the phase deviation from the angles of variation β 1, β 2, β 3. The wavefront 16 (also shown in fig. 2) represents the wavefront after the light source 2 is adjusted.

According to a first configuration (fig. 2), each sighting module 9 comprises:

a detection surface 18, the detection surface 18 being configured to receive an image 19 representing the target 4,

a unit 20 for positioning, the unit 20 for positioning being configured to position, on an image 19 of the target 4 received by the detection surface 18, a position of a predetermined area 10 on the target 4 to be reached by the light beam 3 and a current position of an area that has been reached by the light beam 3,

a unit 21 for calculating, the unit 21 for calculating being configured to calculate a movement to be made between a current position of the area that the light beam 3 has reached and a position of the predetermined area 10 to be reached on the target 4,

a moving unit 22, the moving unit 22 being configured to move the light source 2 according to the movement to be made calculated by the unit for calculating 21 such that the current position of the area that the light beam 3 has reached overlaps with the position of the predetermined area 10 to be reached.

For the sake of clarity, fig. 2 shows the units 20, 21 and 22 for only one targeting module 9. However, it should be understood that each sighting module 9 includes these units 20, 21 and 22.

According to a first alternative of the first embodiment, the tracking system 1 further comprises a plate 23 arranged in the propagation axis 5. The plate 23 has a surface configured to receive the light beam 3 from the light source 2 and to receive an image 19 representing the target 4. Which is able to transmit the light beam 3 from the light source 2 and reflect an image 19 representing the target 4 towards the detection surface 18.

According to a second alternative of the first embodiment, the plate 23 has a surface capable of reflecting the light beam 3 from the light source 2 and transmitting (transmit) the image 19 representing the target 4 towards the detection surface 18.

According to a second embodiment (fig. 4), the tracking system 1 further comprises an aiming laser device 24, which aiming laser device 24 is configured to emit an aiming laser beam 25 onto the predetermined area 10 to be reached on the target 4. The targeting laser beam 25 may be emitted from a laser source disposed on the ground or on an aircraft.

In this second embodiment, each sighting module 9 comprises:

a detection surface 18, the detection surface 18 being configured to receive an image 26 representing the position of the aiming laser beam 25 on the target 4 and the position of the beam 3 on the target 4,

a unit 20 for positioning, the unit 20 for positioning being configured to position the position of the aiming laser beam on the target 4 and the current position of the beam 3 on the target 4 on the image 26 received by the detection surface 18,

a unit 21 for calculating, the unit 21 for calculating being configured to calculate a movement to be made between a current position of the light beam 3 on the target 4 and a position of the targeting laser beam 25 on the target 4,

a moving unit 22, the moving unit 22 being configured to move the light source 2 according to the movement to be performed calculated by the unit for calculating 21 such that the current position of the light beam 3 on the target 4 overlaps with the position of the aiming laser beam 25 on the target 4.

According to a first alternative of the second embodiment, the tracking system 1 further comprises a plate 23 arranged in the propagation axis 5. The plate 23 has a surface configured to receive the light beam 3 from the light source 2 and to receive an image 26 representing the position of the aiming laser beam 25 on the target 4 and the position of the light beam 3 on the target 4. Which is able to transmit the light beam 3 from the light source 2 and reflect an image 26 representing the position of the aiming laser beam 25 on the target 4 and the position of the light beam 3 on the target 4 towards the detection surface 18.

According to a second alternative of the second embodiment, said surface is able to reflect the light beam 3 from the light source 2 and transmit/transmit an image 26 representing the position of the aiming laser beam 25 on the target 4 and the position of the light beam 3 on the target 4 towards the detection surface 18.

Detection surface 12 and detection surface 18 may correspond to an array surface. These array surfaces include, for example, CCD sensors or CMOS arrays and processing modules. The processing module is capable of retrieving the signals generated and transmitted by the CCD sensor or CMOS to generate signals representative of the above-mentioned positions.

According to one embodiment, the array surface comprises a fiber bundle capable of transmitting the images 19, 26 and the position to the array sensor. One end of each fiber forms a portion of the array surface. The processing module of the signals is configured to retrieve the signals generated and transmitted by the array sensor. The processing module of the signal may then send a signal representative of the location. This embodiment makes it possible to overcome electromagnetic interference caused by wires, which the array sensor may be subjected to, for example.

According to one configuration, the positions correspond to coordinates determined relative to virtual markers defined in the detection surfaces 12, 18. For example, the origin of the marker is located at the center of the detection surfaces 12, 18.

The pixels of the CCD or CMOS may correspond to coordinate units.

For the first embodiment (fig. 3) and the second embodiment (fig. 4), in the same way as for the detection surface 12, the respective distance between the light source 2 and the detection surface 18 of the associated sighting module 9 is stable over time, regardless of the ambient conditions. This need is preferably ensured because the distance between the light source 2 and the detection surface 18 of each sighting module 9 is small. Typically, this distance is about a few millimeters. In a non-limiting manner, the distance is between 3mm and 10 mm.

The invention also relates to a method of using the tracking system 1 (fig. 5 and 6).

The use method comprises the following steps which are repeated circularly:

an emission step E1 carried out by each light source 2, the emission step E1 comprising the emission of a light beam 3 along a propagation axis 5 along an emission direction E towards a target 4,

a step E2 of collimating the light sources 2, performed by each collimator 6, the step E2 of collimating the light sources 2 comprising the collimation of each light beam 3 emitted by each light source 2,

a targeting step E3 carried out by each targeting module 9, the targeting step E3 comprising directing the light beam 3 from the light source 2 to reach a predetermined area 10 of the target 4,

a detection step E4 carried out by each detection module 11, the detection step E4 comprising receiving and detecting on the first detection surface 12 the beam portion 8 reflected by the reflection plane 29 of the reference device 7 at the current position,

a step E5 of determining deviation angles, carried out by each module 13 for determining deviation angles, the step E5 of determining deviation angles comprising determining deviation angles β 1, β 2, β 3 as a function of the spatial displacement between a reference position on the first detection surface 12 and a current position. The deviation angles β 1, β 2, β 3 are determined after each sighting module 9 directs each light beam 3 to reach the predetermined area 10 of the target 4, the deviation angles β 1, β 2, β 3 corresponding to the angle between the beam portion 8 reflected by the reflection plane 29 of the reference device 7 and the propagation axis 5,

a phase deviation determining step E6, carried out by the module for determining a phase deviation 28, the phase deviation determining step E6 comprising determining a phase deviation from the deviation angles β 1, β 2, β 3 determined in the deviation angle determining step E5,

an adjustment step E7 carried out by each adjustment module 14, the adjustment step E7 comprising adjusting each light source 2 according to the phase deviation determined in the phase deviation determining step E6 to compensate for atmospheric turbulence.

To this end, the step E6 of determining the phase deviation comprises determining the recombined wave fronts from the deviation angles β 1, β 2, β 3. The phase deviation is determined in a phase deviation determining step E6 by comparing the recombined wave front with a plane wave front parallel to the reflection plane 29 of the reference device 7.

According to a first embodiment (fig. 5), the aiming step E3 comprises the following sub-steps:

a receiving sub-step E31 carried out by the detection surface 18, the receiving sub-step E31 comprising receiving an image 19 representative of the object 4 on the detection surface 18,

a positioning sub-step E32, carried out by the unit for positioning 20, the positioning sub-step E32 comprising positioning, on the image 19 of the target 4 received by the detection surface 18, the position of the predetermined area 10 on the target 4 to be reached by the light beam 3 and the current position of the area that has been reached by the light beam 3,

a calculation sub-step E33, carried out by the unit for calculating 21, the calculation sub-step E33 consisting in calculating the movement to be made between the current position of the region reached by the light beam 3 and the position of the predetermined region 10 to be reached on the target 4,

a movement sub-step E34, carried out by the moving unit 22, the movement sub-step E34 comprising moving the light source 2 according to the movement to be made calculated by the unit for calculating 21, so that the current position of the area that the light beam 3 has reached overlaps with the position of the predetermined area 10 to be reached.

According to a second embodiment (fig. 6), the aiming step E3 comprises the following sub-steps:

a firing sub-step E35 carried out by the aiming laser device 24, the firing sub-step E35 comprising the firing of the aiming laser beam 25 onto the predetermined area 10 to be reached on the target 4,

a receiving sub-step E36 carried out by the detection surface 18, the receiving sub-step E36 comprising the reception of an image 26 representative of the position of the aiming laser beam 25 on the target 4 and of the position of the beam 3 on the target 4,

a positioning sub-step E37, carried out by the unit for positioning 20, the positioning sub-step E37 comprising positioning the position of the aiming laser beam 25 on the target 4 and the current position of the light beam 3 on the target 4 on the image 26 received by the detection surface 18,

a calculation sub-step E38 carried out by the unit for calculating 21, the calculation sub-step E38 comprising calculating the movement to be made between the current position of the beam 3 on the target 4 and the position of the aiming laser beam 25 on the target 4,

a movement sub-step E39, carried out by the movement unit 22, the movement sub-step E39 comprising moving the light source 2 according to the movement to be made calculated by the unit for calculating 21, so that the current position of the light beam 3 on the target 4 overlaps with the position of the aiming laser beam 25 on the target 4.