FR3127297A1 - HEMISPHERIC OPTRONIC SYSTEM FOR DETECTION AND LOCATION OF THREATS WITH REAL-TIME PROCESSING - Google Patents

Abstract

HEMISPHERIC OPTRONIC SYSTEM FOR DETECTION AND LOCATION OF THREATS WITH REAL-TIME PROCESSING The hemispherical optronic system for detection and location of threats comprises an optronic module and processing means, the optronic module having a plurality of cameras arranged so as to cover a solid angle of 2.pi steradians. According to the invention, the cameras are of identical type and are arranged in a regular and symmetrical manner and the processing means are of the real-time type and are arranged in such a way as to ensure a first level of wide-bandwidth processing and a second level processing at reduced bandwidth, the first level comprising parallel processing of the video streams from the cameras ensuring geometric and photometric corrections and production of detected threat information, and the second level comprising processing of fusion and filtering of the information of detected threat from the first level and a production of confirmed threat information comprising the angular coordinates in a local geographical reference of each confirmed threat.

Description

HEMISPHERIC OPTRONIC SYSTEM FOR DETECTION AND LOCATION OF THREATS WITH REAL-TIME PROCESSING

The invention generally falls within the field of defense and security technologies, and relates to the detection and location of targets or threats. More particularly, the invention relates to a hemispherical optronic system for detecting and locating threats, in particular for the fight against drones, namely, piloted or autonomous drones, alone or in clouds.

In the state of the art, several technologies have been proposed to detect and locate drone type threats. In general, these technologies are of the radioelectric or optronic type. They include passive or active type radars and mobile or fixed type optronic systems.

Existing radar technologies offer the advantages of an interesting operating range of several kilometers and real-time processing, but provide low location precision (of the order of 100 mrd – milliradian) and are not suitable for the coverage of half a space, that is, for the coverage of a solid angle of 2.pi steradians. To improve the location accuracy of a radar system, it is known to associate it with an optronic system which provides the required accuracy. In addition, radar technologies are not very suitable for urban use due to the high rates of false alarms generated by the environment and the acceptability of the active technology.

A mobile-type optronic system generally comprises one or more image sensors mounted on a mobile turret. Such an optronic system is compatible with a real-time processing requirement and is capable of providing high location accuracy, of the order of 0.3 mrd. However, this type of optronic system is only functional in a restricted solid angle, which disqualifies it when the real-time coverage of half a space is required.

Fixed-type optronic systems have been proposed for half-space coverage. Known fixed optronic systems fall into three categories, namely, single-sensor systems, civil or industrial multi-sensor systems and military multi-sensor systems.

The aforementioned mono-sensor systems include a single sensor coupled to anamorphic optics. The available sensor technologies (“CCD” or “CMOS”) do not allow this architecture to achieve high performance in terms of location accuracy and range of use. These systems, essentially intended for the industrial or private surveillance market, have the main function of delivering a video representation of half a space, their performance in terms of location accuracy and range of use being limited respectively to approximately 50 mrd and at a maximum of 150 meters.

Concerning the civil or industrial multi-sensor systems mentioned above, these also have the main function of delivering a video representation of a half-space and essentially group together cameras intended for leisure and surveillance. This technology provides a video representation of a half-space by merging image data from several sub-spaces and is incompatible with real-time processing. A detect and locate feature is available in some systems. The operating range obtained with this technology is a maximum of 200 to 300 meters.

Thus, the Chinese company INSTA360 INNOVATION TECH CO LTD, holder of patent application CN112837207A, markets a camera intended for leisure under the INSTA360® PRO 2® brand. This camera has four or six image sensors associated with “fisheye” type lenses. The sensors are all arranged in the same slice of sphere, being arranged in a circle in a regular manner, with the same angular difference between two neighboring sensors.

Furthermore, the Korean company HANWHA TECHWIN CO LTD, holder of Korean patent application KR20210022973A, markets a "dome" type surveillance camera under the WISENET® PNM-9080VQ® brand. The camera has a central image sensor and three manually adjustable peripheral image sensors. The peripheral sensors are regularly distributed in a circle, with an angular difference of 120° between two neighboring sensors, and are all arranged in the same slice of sphere. This slice of sphere is perpendicular to a central axis of the camera along which the central sensor is aligned. Besides the general disadvantages mentioned above for this category of multi-sensor systems, the angular mobility of the peripheral sensors in this camera introduces a factor of positioning uncertainty which can only affect the localization accuracy.

Regarding the aforementioned military multi-sensor systems, these are designed to operate in the infrared spectrum and are not suitable for detecting threats without thermal signatures. The ability of these systems to accurately detect small threats with a low heat signature, such as electrically powered aerial drones, is therefore limited. The ARTEMIS® and SUMIT360® systems marketed respectively by the industrial groups THALES® and FLIR® belong to this category of multi-sensor systems.

There is therefore a need for a hemispherical optronic system for detecting and locating threats, in particular for the fight against drones, which does not have the aforementioned drawbacks of the state of the art and which is capable of providing a detection and localization of threats over 2.pi steradians, in real time with high precision.

The invention relates to a hemispherical optronic system for detecting and locating threats comprising an optronic module and processing means, the optronic module having a plurality of cameras arranged so as to cover a solid angle of 2.pi steradians. According to the invention, the cameras are of identical type and are arranged in a regular and symmetrical manner and the processing means provide real-time processing and are arranged so as to provide a first level of wide-bandwidth processing and a second low-bandwidth processing level, the first level comprising parallel processing of the video streams from the cameras ensuring geometric and photometric corrections and production of detected threat information, and the second level comprising processing of fusion and filtering of the detected threat information from the first level and a production of confirmed threat information comprising the angular coordinates in a local geographical reference of each confirmed threat.

According to a particular characteristic, the real-time processing means comprise proximity signal processing modules integrated in the cameras and a central digital processing unit, the proximity signal processing modules at least partially providing the first level of processing and the digital central processing unit at least partially providing the second level of processing.

According to another particular characteristic, the second level of reduced-bandwidth processing carried out by the real-time processing means also comprises at least one video playback for at least one camera.

The invention thus provides for a two-level processing architecture which makes it possible to guarantee real time. The first level processes all the detection channels in parallel with the very wide bandwidth required to process the video streams from the image sensors. The processing includes geometric and photometric corrections and the production of information related to threats detected but not confirmed at this stage (thumbnail, index), which require much lower bandwidth. The second level merges and processes the information from the first level in order to filter the detected threats and to restore only the confirmed threats, through their angular coordinates in a local geographical reference. This second level also allows the video restitution of one or more detection channels.

According to yet another particular characteristic, the regular and symmetrical arrangement of the cameras satisfies the mathematical theory known as the “tiling of the sphere” with tiles of identical shape.

According to yet another particular characteristic, the cameras are arranged on first and second parallel sphere slices, a first group of cameras being arranged in the first sphere slice and a second camera group being arranged in the second sphere slice, with the diameter of the first slice being greater than that of the second slice.

According to yet another particular characteristic, the first group comprises eight cameras and the second group comprises four cameras.

According to yet another particular characteristic, the optronic module comprises a one-piece mechanical support structure on which the cameras are mounted in a fixed manner.

According to yet another particular characteristic, in addition to the proximity signal processing module, each camera comprises a large-aperture, high-resolution and temperature-compensated fixed focal length optical pickup device which is associated with an image sensor of the camera.

According to yet another particular characteristic, the cameras comprise a so-called “CMOS” type image sensor.

The invention also relates to a set of two systems as described briefly above which are connected by a communication link of the wired, radio or optical type.

The invention thus proposes a new architecture having a plurality of very high performance detection channels organized in a parallel structure. The optronic system provides location data for detected threats with minimal latency. The exploitation of the video data produced by the cameras requires a very high bandwidth. This is the reason why the invention provides parallel exploitation of video data, in particular for enhancement, calibration (geometric, photometric and colorimetric) and detection processing. Preferably, no merging of solid angle sectors (corresponding to the detection channels) is carried out for the restitution. The invention provides for individual restitution of the sectors, which provides increased decision support.

Other characteristics and advantages of the present invention will appear more clearly on reading the detailed description below of several particular embodiments of the invention, with reference to the appended drawings, in which:

There is a perspective view of the outer casing of a particular embodiment with twelve detection channels of the optronic system according to the invention.

There is a transparent side view of the optronic system of the .

There is a top view of the optronic system of the , showing a first angular positioning of the integrated cameras of this one.

There is a side view of the optronic system of the , showing another angular positioning of this one's built-in cameras.

There is a side view of the optronic system of the , showing first relative positions of the cameras of the optronic system, which are arranged in first and second parallel sphere slices.

There is a top view of the optronic system of the , showing other relative positions of the cameras of the optronic system, which are aligned symmetrically according to planes parallel to perpendicular central planes.

There is a schematic block diagram showing twelve detection channels of the optronic system of the , as well as a central digital processing unit thereof.

There is a first functional block diagram relating to high-bandwidth digital processing executed on the image data of a detection channel of the optronic system of the , for the detection of threat tracks on the detection path and the video restitution thereof.

There is a second functional block diagram relating to reduced-bandwidth digital processing executed on the data emanating from the various detection channels of the optronic system of the , for multi-lane 2D tracking of threat trails and video playback of selected lanes.

is a third functional block diagram relating to a reduced-bandwidth digital processing executed on the data emanating from the different detection channels of two coupled optronic systems of the , for multi-lane 3D tracking of threat tracks, geolocation and alarm generation.

With reference to Figs. 1 to 10, a particular embodiment SO of the hemispherical optronic threat detection and localization system according to the invention is now described below.

As it appears more clearly in Figs.1 and 2, the SO optronic system appears externally in the general form of a half-sphere inside which are housed the various functional organs of the system. The optronic system SO comprises a housing forming a base BO and a cover CO in the form of a half-sphere.

The housing BO houses a central digital processing unit UC, shown in , which provides in particular control functions of the optronic system SO and real-time data processing functions described in more detail below. Furthermore, with more particular reference to Figs.1 and 7, connectors CN1 to CN4 are mounted on the box BO and correspond respectively to communication interfaces C2 and IHM, a video reproduction bus VID and a power supply link in PW energy. The C2 communication interface is dedicated to an operational command and control system, called “C2” responsible for decision-making relative to detected threats. The IHM communication interface is a proprietary man-machine interface dedicated in particular to software update and system maintenance operations.

The BO box supports the fixed mounting of twelve cameras V1 to V12, clearly visible to the , forming an optronic module which comprises twelve threat detection channels V1d to V12d corresponding respectively to the twelve cameras V1 to V12. The cameras V1 to V12 are all of the same type so as to obtain twelve detection channels V1d to V12d having substantially identical characteristics. It will be noted that the references V1(d) to V12(d) used in the figures designate the cameras V1 to V12 and the detection channels V1d to V12d corresponding to them, respectively.

The cameras V1 to V12 are mounted fixed on a mechanical structure supporting (not shown) the optronic module. Typically, this supporting mechanical structure is made in the form of a single piece, with standard mechanical details, which is economically advantageous. As shown schematically in , each camera V1 to V12 essentially comprises an image sensor CI1 to CI12, a shooting lens OP1 to OP12 and a proximity signal processing module M1 to M12. The assemblies formed by the image sensors CI1 to CI12 and their respective shooting optics OP1 to OP12 are designed to require no adjustment.

As visible in Figs.1 and 2, the cover CO comprises twelve portholes (not marked) for the fields of vision of the twelve cameras V1 to V12, respectively, arranged in correspondence with the shooting optics thereof.

In general, in an optronic system according to the invention, high resolution cameras are necessary to obtain a large number of pixels per steradian and guarantee the accuracy of threat detection.

In the SO optronic system, the image sensors CI1 to CI12 have been chosen of the "CMOS" type, with a large size (image resolution), preferably available on catalog for a lower cost. Thus, for example, an "8K" technology "CMOS" image sensor available in the catalog and providing an image of 8192x4320 pixels may be chosen for the CI1 to CI12 image sensors. In addition, it should be noted that the analog/digital conversion integrated in the “CMOS” type image sensors CI1 to CI12 provides excellent immunity against electromagnetic radiation, despite the high number (12) of windows required for the V1 cameras. at V12. Of course, image sensors other than “CMOS” type sensors could be chosen in certain particular embodiments of the invention, for example to satisfy specific constraints.

The OP1 to OP12 optics must be suitable for the CI1 to CI12 image sensors which are large format, typically greater than 40 mm. They are therefore bulky. Furthermore, the exploitation of the pixel resolution over the entire field of vision of the image sensors CI1 to CI12 requires that the optics OP1 to OP12 be of high quality. Fixed focal length and iris type optics, with a large aperture and high resolution and resistant to mechanical shocks have been chosen for the OP1 to OP12 optics. The focus of OP1 to OP12 optics is optimized for threats within a specified distance range, for example, 20m to 1000m, and must be kept fixed over a wide temperature range to ensure performance is achieved. wanted. For this, the optics OP1 to OP12 are each equipped with a static focusing compensation device. The temperature behavior of optics OP1 to OP12 having been characterized beforehand, the static focusing compensation devices are calibrated accordingly.

The M1 to M12 digital proximity processing modules of the V1 to V12 cameras include on-board software that essentially performs real-time image detection and enhancement processing, and in particular geometric corrections and harmonization processing. Typically, the modules M1 to M12 are each made with a programmable gate circuit called “FPGA” (for example of the Kintex® Ultrascale® type) associated with a “DDR4” dynamic random access memory of very high bandwidth, for example, greater than 10Gb /s. Indeed, the bandwidth of the "DDR4" memory must be high for the performance of the required real-time processing and the real-time restitution of the video streams.

With reference to Figs.1 to 6, the cameras V1 to V12 are arranged geometrically in a regular and symmetrical manner, in order to optimally cover a total solid angle of 2.pi steradians. Each of the cameras V1 to V12 provides coverage of a solid corner sector of the hemisphere. The geometric layout of the V1 to V12 cameras allows identical distinct threat detection paths that can be cloned, guarantees the achievement of high precision performance (spatial resolution), with parallel and real-time processing of image data , and makes it possible to optimize the volume and the cost of the SO optronic system.

As better visible in Figs.4 to 6, the cameras V1 to V12, shown without their optics OP1 to OP12 in Figs.5 and 6, are arranged on two superimposed levels, namely, on first and second slices of parallel sphere TS1 and TS2, with the diameter of the first slice TS1 being greater than that of the second slice TS2.

In the first slice of sphere TS1, the eight cameras V1 to V8 are distributed in a regular and symmetrical way with an angular difference EA1 projected on a horizontal plane of 45° between two directly neighboring cameras (cf. ) and with a first elevation angle AE1 (cf. ).

In the second slice of sphere TS2, the four cameras V9 to V12 are distributed in a regular and symmetrical way with an angular difference EA2 projected on a horizontal plane of 90° between two directly neighboring cameras (cf. ) and with a second elevation angle AE2 (cf. ) greater than the aforementioned first elevation angle AE1.

In top view, as shown in , the cameras V1 to V12 appear as being aligned symmetrically according to planes parallel with respect to two central planes of perpendicular symmetry.

Thus, by considering a first central plane of symmetry PC1, the cameras V7, V12, V9 and V2 and the cameras V6, V11, V10 and V3 appear as being aligned respectively in the first parallel planes P1 and P2 which are symmetrical with respect to the central foreground PC1. The cameras V8 and V1 and the cameras V5 and V4 appear as being aligned respectively in other first parallel planes P3 and P4 which are symmetrical with respect to the first central plane PC1 and more distant from the latter than the first parallel planes P1 and P2 . Moreover, by considering a second central plane of symmetry PC2 perpendicular to the first central plane PC1, the cameras V8, V12, V11 and V5 and the cameras V1, V9, V10 and V4 appear as being aligned respectively in second parallel planes P5 and P6 which are symmetrical with respect to the second central plane PC2. The cameras V7 and V6 and the cameras V2 and V3 appear as being aligned respectively in other second parallel planes P7 and P8 which are symmetrical with respect to the second central plane PC2 and further from the latter than the second parallel planes P5 and P6 .

In accordance with the invention, the optimal geometric configuration of the optronic system SO, with the cameras V1 to V12, was determined using the mathematical theory of the tiling of the sphere with tiles of identical shape, and with the data from following entry:

- Identical detection channels;

- Symmetry in the distribution of detection channels;

- Cameras with "CMOS" type image sensors with an image resolution available in the catalogue;

- Defined volume of the optronic system;

- Absence of adjustments to the sets of image sensors and associated shooting optics in the cameras;

- Mechanical structure carrying monobloc type cameras and produced with standard precision.

The volume of the SO optronic system is defined by a diameter of 500 mm and a height of 500 mm. The "CMOS" type image sensors that were chosen have an effective size of 60 Mpx (megapixels), which gives a useful size greater than 40 Mpx. The detection channels each have a useful field of 50°x50°. The mass of the SO optronic system is less than 20 kg.

In the general architecture described above of the optronic module of the SO system of the invention, the optical and electronic functional organs thereof are static. As a result, the optronic module of the SO system of the invention benefits from excellent robustness to mechanical stress, which in particular facilitates the holding of the reference frames. Furthermore, the cost of the optronic module is optimized thanks in particular to the use of the above-mentioned “CMOS” type image sensors available in the catalogue, and therefore without specific development, of the one-piece supporting mechanical structure with standard accuracies and the chosen design without adjusting the sets of image sensors and shooting optics.

Furthermore, it should be noted that the optronic system of the invention can be declined in several configurations for reduced fields of observation, due to the symmetry in the distribution of the detection channels. Thus, for example, the monitoring of pi/2 steradians, 2pi/3 steradians or pi steradians could be ensured respectively with a three-channel configuration, a four-channel configuration and a six-channel configuration.

With particular reference now to the , the central digital processing unit UC is chosen to be suitable for real-time processing and in particular performs the following functions F1_UC to F8_UC:

- F1_UC: Control of cameras V1 to V12, each consisting of an image sensor CI1 to CI12, optics OP1 to OP12 and a proximity signal processing module M1 to M12;

- F2_UC: Management of synchronization of detection channels V1d to V12d;

- F3_UC: Spatial and temporal setting of detection channels V1d to V12d;

- F4_UC: 2D tracking of detected threats;

- F5_UC: 3D tracking of detected threats (on data emanating from the association of two optronic systems according to the invention, and possibly from another system providing the distance at which the threats are located);

- F6_UC: Video playback on demand, simultaneously, of the twelve angular sectors corresponding to the detection channels V1d to V12d;

- F7_UC: Management of communication interfaces (C2, HMI), dialogues and data exchanges;

- F8_UC: Management of energy conversion, energy distribution and management of the charge of the electric batteries of the optronic system.

In the optronic system SO, concerning the functions F2_UC and F3_UC, the temporal coherence between the detection channels V1d to V12d must be guaranteed to ensure precise tracking. This implies a synchronization of the image captures (start and duration of exposure). Depending on the observed relative speeds of the threats, the cameras V1 to V12 may or may not be authorized to perform different poses. A loss of exposure duration consistency may be accepted if the motion blurs do not call into question the determination of the coordinates for tracking.

In addition to the aforementioned interfaces C2 and IHM, the video reproduction bus VID and the power supply link PW corresponding respectively to the aforementioned connectors CN1 to CN4, the central digital processing unit UC will also be able to manage other communication interfaces, bus and others, according to the embodiments of the optronic system of the invention. Thus, for example, when the optronic system SO is designed to be associated with another analog optronic system of the invention, designated SO' hereafter, for 3D tracking of detected threats (function F5_UC), additional connectivity means are provided for data communication between these two systems SO, SO′, typically via a specific wired link, or via a radio or optical link.

When two optronic systems SO and SO' cooperate, the central digital processing unit UC of the master system manages the real-time data communications between the two systems. The data exchanged in real time between the optronic systems SO and SO', in particular make it possible to guarantee temporal consistency between the two systems and the exchanges of geolocation necessary for coupling and triangulation. The central digital processing unit UC uses the detection data of the two times twelve (2 x 12) detection channels, i.e. the data of the twenty-four (24) angular sectors covered in total by the two systems SO, SO', so as to carry out a filtering of potential threats retained. A final filtering is carried out using algorithms executed directly by the “CPU” processor (for “Central Processing Unit”) of the UC unit.

Figs.8 and 9 show a digital processing architecture of the SO optronic system.

There shows in detail a high-bandwidth digital processing, designated TLB below, applied to the twelve detection channels V1d to V12d. The processing is executed in parallel in each detection channel V1d to V12d of the optronic system SO, respectively by the signal processing modules M1 to M12 cooperating with the central digital processing unit UC. The high-bandwidth TLB processing ensures the detection of threat tracks on the track with the generation of two angular coordinates, the generation of thumbnails (label, index) representative of the threats and the video restitution of the track. In the optronic system SO, the TLB processing delivers its output data, detailed below, with a maximum latency which does not typically exceed 50 ms. The output data, for each of the detection channels, is transmitted to the central digital processing unit UC as input data for a reduced-bandwidth digital processing described below with reference to the .

As shown at , considering the detection channel Vnd (n being an integer from 1 to 12) with which the camera Vn (OPn, CIn, Mn) is associated, the processing TLB essentially comprises eight processing blocks B1a to B8a. These eight processing blocks B1a to B8a are installed in the signal processing module Mn included in the camera Vn.

Block B1a carries out geometric correction processing on the input video data E0 delivered by the image sensor CIn. Intrinsic geometric corrections are performed on the input video data E0 according to predefined calibration data E1 called “factory calibration data”.

Block B2a carries out a conversion processing in a local geographical reference of the video data coming from block B1a, from altitude data E2 provided by internal altitude sensors of the optronic system SO.

Block B3a performs dynamic photometric harmonization processing on the video data from block B2a, using luminance and chrominance data E3 from the other detection channels. These E3 luminance and chrominance data are typically provided by a numerical estimation model.

Blocks B4a to B6a process the video data to deliver detected threat track output data PMn(CA, IX) including angular coordinates CA and vignettes IX. Block B4a performs image enhancement processing on the video data from block B3a, with a view to subsequent processing for automatic threat track detection. Block B5a performs the automatic threat track detection processing from the enhanced video data provided by block B4a. Block B6a performs 2D filtering on the threat tracks detected automatically by block B5a and delivers the aforementioned output data PMn(CA, IX).

Blocks B7a and B8a perform a video restitution processing for the detection channel Vnd and outputs the corresponding video restitution VIDn. Block B7a performs image enhancement processing on the video data from block B3a, with a view to displaying them on screen. Block B8a provides functions for adapting and converting video data to the desired format for video restitution VIDn.

There shows in detail a digital processing at reduced bandwidth, designated TBR below, supervised by the central digital processing unit UC and executed on the data PM1 to PM12 and VID1 to VID12. The data PM1 to PM12 and VID1 to VID12 are those outputted by the high-bandwidth processings TLB executed in parallel by the signal processing modules M1 to M12, respectively. TBR processing provides 2D multi-channel tracking of threat tracks and functions for generating alarms, angular localization, generation of thumbnails (label, index) and video playback of selected channels. In the optronic system SO, the processing TBR delivers its output data, detailed below, with a maximum latency which does not typically exceed 100 ms, at the interfaces of the central digital processing unit UC.

As shown at , the TBR processing essentially comprises four processing blocks B1b to B4b. These four processing blocks B1b to B4b are executed by the processor CPU of the central digital processing unit UC.

Block B1b first carries out a processing of fusion and filtering of the threat track data PM1 to PM12 supplied as input by the processings TLB of the twelve detection channels V1d to V12d. On the filtered data of threat tracks, the block B1b carries out a multi-path tracking processing of filtered threat tracks and outputs data of retained threat tracks PMF(CA, IX) including angular coordinates CA and vignettes IX. The retained threat track data PMF(CA, IX) are provided at blocks B2b and B3b.

Block B2b performs alarm generation processing. Generated alarms AL are associated with the retained threat track data PMF(CA, IX) and output with this data PMF(CA, IX).

The block B3b receives as input the video restitution data VID1 to VID12 provided by the TLB processings of the twelve detection channels V1d to V12d, as well as the retained threat track data PMF(CA, IX) provided by the block B1b. In block B3b, an overlay processing is carried out on the video data VID1 to VID12 so as to integrate therein by overlay the selected threat track data PMF. The block B4b authorizes a selection of the detection channels for which the broadcasting of the video data with the threat track data retained superimposed is requested by a selection command CS. The video data VID_VS of the selected detection channels are output by block B4b.

The processing configuration described above of the optronic system SO, with more particular reference to Figs.8 and 9, is capable of providing processing with in particular the following characteristics:

- Digital flow rate: 140 Gb/s of real-time flow to be processed;

- Processing up to 120 threat tracks in parallel;

- Threat track refresh rate: 10 Hz;

- Restitution of the videos of the 12 channels V1d to V12d with the superimposition of the threats;

- Range of use of 1 km for threats of the order of 30 x 30 cm.

There shows in detail a digital processing at reduced bandwidth, designated TBR2 hereafter, supervised by the central digital processing unit UC and executed on threat track data PM1 to PM12, PM1' to PM12', emanating from the channels of detection V1d to V12d, V1d' to V12d', of two optronic systems SO, SO', respectively, which are coupled as indicated above. TBR2 processing provides 3D multi-path tracking of threat trails and functions for alarm generation, geolocation and thumbnail generation. Threat location data E4 emanating from one or more other systems and indicating the distances of the threats can also be used by the processing TBR2 for carrying out its aforementioned functions.

As shown at , the TBR2 processing essentially comprises four processing blocks B1c to B4c. These four processing blocks B1c to B4c are executed by the processor CPU of the central digital processing unit UC.

Blocks B1c, B1c' each perform first a filter processing of the threat track data PM1 to PM12, PM1' to PM12', respectively. On the filtered threat track data, the blocks B1c, B1c′ each carry out a multi-channel tracking processing of filtered threat tracks and deliver as output selected threat track data PMF(CA, IX), PMF′ (CA, IX), respectively, similarly to block B1b of the TBR treatment (cf. ). The retained threat track data PMF(CA, IX), PMF'(CA, IX), are supplied to the blocks B2c.

Block B2c carries out harmonization processing on the data of the two optronic systems SO and SO', namely, essentially on the data of the selected threat tracks PMF(CA, IX), PMF'(CA, IX). On the data output by the block B2c, the block B3c determines potential threats MC and performs distance estimation processing by triangulation which provides distances at which the threats MC are located with respect to a reference point. Block B3c transmits to block B4c the threat data MC with their estimated distances D. Block B4c performs a comparison and consistency processing between the data received from block B3c and the aforementioned data E4 received from one or more other systems in a to detect and reject false alarms. Block B4c outputs alarms AL and confirmed threat data MC (GL, IX) with geolocations CL and corresponding thumbnails IX.

The invention is not limited to the particular embodiments which have been described here by way of example. The person skilled in the art, depending on the applications of the invention, may make various modifications and variants falling within the scope of protection of the invention.

Claims (10)

Hemispherical optronic system for detecting and locating threats comprising an optronic module and processing means (M1 to M12, UC), said optronic module having a plurality of cameras (V1 to V12) arranged so as to cover a solid angle of 2. pi steradians, characterized in that said cameras (V1 to V12) are of identical type and are arranged in a regular and symmetrical manner and said processing means (M1 to M12, UC) are of real-time type and are arranged in such a way as to ensure a first high-bandwidth (TLB) processing level and a second reduced-bandwidth (TBR) processing level, said first high-bandwidth (TLB) processing level comprising parallel processing of the video streams of said cameras (V1 to V12) ensuring geometric and photometric corrections (B2a, B3a) and production of detected threat information (B4a to B6a, PM1 to PM12), and said second level of processing at reduced bandwidth (TBR) comprising a processing of merging and filtering (B1b) detected threat information (PM1 to PM12) from said first high bandwidth processing level (TBR) and a production of confirmed threat information (B2b, PMF(CA, IX)) comprising angular coordinates (AC) in a local geographic reference of each confirmed threat. System according to Claim 1, characterized in that the said processing means comprise proximity signal processing modules (M1 to M12) integrated in the said cameras (V1 to V12) and a central digital processing unit (UC), the said modules proximity signal processor (M1 to M12) at least partially providing said first level of high bandwidth (TLB) processing and said digital central processing unit (CPU) at least partially providing said second level of reduced bandwidth processing (TBR). System according to Claim 1 or 2, characterized in that the said second level of reduced-bandwidth processing (TBR) carried out by the said processing means also comprises at least one video restitution (VID_VS) for at least one camera (V1 to V12, CS). System according to any one of Claims 1 to 3, characterized in that the said regular and symmetrical arrangement of the said cameras (V1 to V2) satisfies the mathematical theory known as the “tiling of the sphere” with tiles of identical shape. System according to any one of Claims 1 to 4, characterized in that the said cameras (V1 to V12) are arranged on first and second parallel sphere slices (TS1, TS2), a first group of cameras (V1 to V8) being arranged in said first sphere slice (TS1) and a second group of cameras (V9 to V12) being arranged in said second sphere slice (TS2), with the diameter of said first sphere slice (TS1) being greater than that of the second sphere slice (TS2). System according to claim 5, characterized in that said first group of cameras comprises eight cameras (V1 to V8) and said second group of cameras comprises four cameras (V9 to V12). System according to any one of Claims 1 to 6, characterized in that the said optronic module comprises a one-piece mechanical support structure on which the said cameras (V1 to V12) are fixedly mounted. System according to any one of Claims 1 to 7, characterized in that, in addition to the said proximity signal processing module (M1 to M12), each said camera (V1 to V12) comprises an optical recording device (OP1 to OP12) with fixed focal length of large aperture, high resolution and temperature compensated which is associated with an image sensor (CI1 to CI12) of said camera (V1 to V12). System according to any one of Claims 1 to 8, characterized in that the said cameras (V1 to V12) comprise an image sensor (CI1 to CI12) of the so-called “CMOS” type. Set of two systems (SO, SO') according to any one of Claims 1 to 9 connected by a communication link of the wired, radio or optical type.