FR3040804A1 - METHOD FOR AIDING THE INTERPRETATION OF THE DETECTION INFORMATION DISPLAYED ON A DISPLAY DEVICE OF A TREATMENT SYSTEM ASSOCIATED WITH AN AIRBORNE RADAR; TREATMENT SYSTEM ASSOCIATED - Google Patents

Abstract

This method of assisting the interpretation of the detection information displayed on a display device of a processing system associated with an airborne radar, characterized in that it comprises the steps of: choosing (110) a category targets of interest; calculating in real time (130) a radar detection capability according to the chosen target category; and displaying (140) the calculated detection capability on the display device.

Description

METHOD FOR AIDING THE INTERPRETATION OF THE DETECTION INFORMATION DISPLAYED ON A DISPLAY DEVICE OF A TREATMENT SYSTEM ASSOCIATED WITH AN AIRBORNE RADAR; TREATMENT SYSTEM ASSOCIATED

The present invention relates to the field of airborne radars and processing systems associated with such radars.

Currently, when a radar is working in an area where the environment greatly disrupts the detection, its processing system traces a large amount of detection information to the radar operator. This information is displayed on a system display device, such as a screen.

However, in the case where no detection information is raised by the processing system, the operator can not know if there is really no target to detect in the area observable by the radar, or if the radar can not detect the target due to poor radar programming or because of acquisition conditions that prevent the radar from detecting the target (the target is not discriminating from "clutter" caused by the environment) .

Thus, the operator is not able to decide between one or the other of these two hypotheses and must therefore select one with a non-zero probability of being wrong: - either he trusts the programmed mode of operation of the radar, considering that there is no target in the search area, but it then takes the risk of not fulfilling its mission; - Or it changes the settings of the radar and observes again the search area, but then loses valuable time in case there is indeed no target in this area. The invention aims to overcome this problem.

For this purpose, the subject of the invention is a method of assisting the interpretation of the detection information displayed on a display device of a processing system associated with an airborne radar, characterized in that it comprises the steps consisting in: - choosing a category of targets of interest; - calculate in real time a detection capability of the radar according to the chosen category of targets; and, - display the calculated detection capacity on the display device.

According to particular embodiments, the method comprises one or more of the following characteristics, taken in isolation or in any technically possible combination: the method comprises a step of defining an operating mode for the radar according to the category targets of interest, the detection capability of the radar being calculated according to the operating mode defined for the radar and the target category chosen; the step of calculating a radar detection capability comprises calculating a detection probability of a target belonging to the chosen target category, taking into account the detection environment conditions; the area observable by the radar being subdivided into a plurality of blocks, the step of calculating a detection capability of the radar then consists in determining a detection probability for each of said blocks; the step of displaying the detection capability implements a calculated detection capacity evaluation function, able to generate a graph representative of said calculated detection capacity; the graph is a two-dimensional graph adapted to be superimposed on a geographical representation of an area observable by the radar; and a category of targets of interest being defined by a plurality of attributes, the step of choosing a category of targets of interest is to enter a value for each of said attributes, the plurality of attributes including at least one attribute among the type of the target, the class of the target, the speed of the target and the size of the target. The invention also relates to a processing system associated with an airborne radar, characterized in that it comprises, for the implementation of a previous method: - an input interface allowing an operator to choose a target category of interest; a calculation unit programmed to calculate a radar detection capacity according to the chosen category of targets; and a display device for displaying the calculated detection capacity and the radar detection information. The invention and its advantages will be better understood on reading the description which follows, given solely for illustrative purposes and non-limiting example of an embodiment, with reference to the accompanying drawings in which: - Figure 1 is a block representation of the method of aid according to the invention; FIG. 2 is a representation of a graphical interface allowing the operator to choose a category of targets of interest; FIG. 3 is a representation of the operator's screen comprising a graph representative of the detection capability of the radar for a first category of targets, and FIG. 4 is a representation of the operator's screen comprising a graph. representative of the detection capability of the radar for a second category of targets more difficult to detect, different from the first.

The implementation of the method for assisting the interpretation of the detection information displayed on a display device of a processing system associated with the radar is intended to indicate to the operator, in real time, whether a category of targets is detectable by the radar in its current configuration and for the current acquisition conditions taking into account the environment as observed by the radar.

One embodiment of this aid method will be described in relation to FIG.

The help method 100 starts with a step 110 during which the operator chooses a category of targets of interest for which he wishes to know the current detection capacity of the radar.

A category of targets is defined by several characteristic attributes, such as the size of the target "TARGET SIZE" (small, medium, large, ...), the type of the target "TARGET TYPE" (fast, slow, ... ) and / or the target class "TARGET CLASS" (aircraft carrier, frigate, ...).

Figure 2 shows a graphical interface displayed on the screen of the operator and allows him to simply make this choice. In this example, a menu with as many drop-down sub-menus as attributes facilitates the selection by the operator of the values of the various attributes so as to define a category of targets of interest, "TARGET CATEGORY".

For example, the sub-menu associated with the class attribute of the target, "TARGET CLASS", contains the jetski values, "JETSKI"; lifeboat, "LIFE BOAT; fast boat, "FAST BOAT"; submarine, "SUBMARINE"; as well as other values, not shown in FIG. 2, such as frigate, "FRIGATE"; aircraft carrier "AIRCRAFT CARRIER"; generic boat of medium size, "GENERIC MEDIUM SIZED"; large generic boat, "GENERIC LARGE SIZED".

When no particular choice as to the value of an attribute is made by the operator, the undetermined value, "ALL", is displayed. At the end of the selection of the values of the attributes, the operator validates his choice by clicking on the validation button "APPLY".

The method 100 is preferably continued by the step 120 of choosing the operating mode of the radar. Preferably, it is an automatic choice given the category of target of interest just chosen by the operator. It may alternatively be a choice left to the operator. This is shown in the menu of Figure 2, where the first drop-down submenu allows the operator to define the operating mode of the radar.

Then, in step 130, the processing system calculates the detection capacity of the radar, according to the chosen category of targets and, possibly, according to the mode of operation chosen for the radar.

This calculation step takes into account the instantaneous position of the aircraft carrying the radar and the current detection environment. By detection environment, we mean here the different sources of noise that can interfere with the detection of the target, such as sea clutter.

Advantageously, the geographical area observable by the radar at the current time is divided into distance / azimuth blocks and a detection capacity is calculated for each of these blocks.

In a preferred embodiment, this step consists in calculating a probability of detection of the category of targets sought.

The detection probability in an elementary block depends on the detection environment in this block, as detected by the radar in an acquisition substep 132.

The probability of detection can then be calculated in a step 134 theoretically, assuming that the sea clutter is distributed according to a statistical law, for example a "K law", and then estimating the parameters of this distribution from the acquisitions made by the radar in step 132. It can then be deduced a detection threshold for a given false alarm probability and a minimum detectable radar equivalent area (SER), which depends on the category of targets chosen by the operator . A probability of detection is finally calculated, as for example described in the document FR 2 971 057 A1. Step 134 therefore leads to a probability value per block of the observable area taking into account the category of targets of interest and the current operating conditions of the radar.

In a final step 140, the probability of detection is displayed on the operator's screen.

Several ways to display the detection capability information of the radar on the screen is conceivable. Preferably, the detection capability is rendered in the form of a graph that can be superimposed on the 2D representation of the observable area on which the detection information delivered by the processing system is displayed. Advantageously, a map of the observable area is also displayed in the background.

For the generation of this graph, a valuation function is used to retranscribe the values of the probability of detection into graphic information easily interpretable by the operator.

Different valuation functions, which differ from each other by valuation criteria, can be used.

For example, a valuation function is used which retranscribes the detection probability values according to a color scale: green for an optimal probability of detecting a target belonging to the chosen category of targets, for example greater than 0.95; orange for a poor detection probability, for example between 0.05 and 0.95; and blue for a zero probability of detection, for example less than 0.05.

A virtual image is then generated by assigning a color to each tile of the observable area.

This virtual image is displayed on the screen.

FIGS. 3 and 4 show, superimposed on a map, the probability of detection of two different categories of targets, in a circular observation zone around the instantaneous position of the aircraft carrying the radar, and taking into account the conditions of environment (identical for the two figures) encountered at the current time in this zone. In these figures, the color scale is represented by different hatching: the value "1" corresponding to the green color; "0,5", in the color orange; and "0", in the color blue.

Thus, the present method makes it possible to enhance the display of the detection information acquired by the radar, by associating therein, in a clear and readable manner, a probability of detection in the observable zone. The operator thus knows exactly the capacity of the radar, at the present time, to detect a particular category of targets, taking into account the mode of operation of the radar and the observed environmental conditions. The enrichment of the display is a decision aid.

This solves the problem of whether, in the search area, a radar is able to detect a specific maritime target. The operator therefore has a precise and reliable knowledge of the tactical situation (presence or not of target) likely to enable him to effectively fulfill the mission assigned to him, in particular to detect more quickly a particular target. For example, if during an overflight of an area, the radar is found to be unable to detect a particular target, for example because of too much sea or a wrong orientation of the radar antenna compared In the wind, the flight plan of the aircraft is changed to move to an area in which the detection capability of the radar will be higher. This optimizes the use of resources and the probability of success of the operational mission.

For the operator, the implementation of this aid method allows a reduction of its workload and nervous tension during the performance of the mission.

The method just described is intended to be implemented by the processing or operating systems associated with airborne surveillance and / or maritime patrol radars.

Claims (8)

CLAIMS 1Procedure for interpreting the detection information displayed on a display device of a processing system associated with an airborne radar, characterized in that it comprises the steps of: - choosing (110) a category of interest targets; - calculate in real time (130) a detection capability of the radar according to the chosen category of targets; and, - displaying (140) the calculated detection capacity on the display device. The method according to claim 1, further comprising a step of defining (120) an operating mode for the radar according to the category of targets of interest, the detection capability of the radar being calculated according to the operating mode defined for the radar and the chosen target category. The method of claim 1 or claim 2, wherein the step of calculating (130) a radar detection capability includes calculating a detection probability of a target belonging to the selected target category. , taking into account the environmental conditions of detection. The method of claim 3, wherein, wherein a radar observable area is subdivided into a plurality of tiles, the step of calculating (130) a radar detection capability then determines a detection probability for each of said blocks. 5. - Method according to any one of the preceding claims, wherein the step of displaying (140) the detection capability implements a function of valuation of the calculated detection capacity, able to generate a graph representative of said calculated detection capacity. 6. - Method according to claim 5, wherein the graph is a two-dimensional graph adapted to be superimposed on a geographical representation of a zone observable by the radar. The method of any one of the preceding claims, wherein, a category of targets of interest being defined by a plurality of attributes, the step of selecting (120) a category of targets of interest is enter a value for each of said attributes, the attribute plurality having at least one attribute of the target type, the target class, the target speed and the target size. 8, - processing system associated with an airborne radar, characterized in that it comprises, for the implementation of a method of assistance according to any one of the preceding claims: - an input interface allowing a operator to choose a category of interest targets; a calculation unit programmed to calculate a radar detection capacity according to the chosen category of targets; and a display device for displaying the calculated detection capacity and the radar detection information.