WO2024208591A1

WO2024208591A1 - Method and system for determining the position of objects in an area with variable terrain

Info

Publication number: WO2024208591A1
Application number: PCT/EP2024/057444
Authority: WO
Inventors: Markus Oberholzer; Ezio Alfieri
Original assignee: Rheinmetall Air Defence Ag
Priority date: 2023-04-05
Filing date: 2024-03-20
Publication date: 2024-10-10
Also published as: DE102023108771A1

Abstract

The invention relates to a method and a system (7) for determining the position of objects (1) in an area (2) with variable terrain, in particular in a war zone. A comparison is made between current topography information (Takt) and known topography information (Tbek), with the current topography information (Takt) being determined by means of at least one flying object (F1, F2, F3), preferably a drone, particularly preferably a quadrocopter, arranged at a certain flight altitude (Hakt), in a step a), and with the current topography information (Takt) being correlated with the known topography information (Tbek) for determining the position of the objects (1), in particular military targets (Z) and/or the flying objects (F1, F2, F3) themselves, in a step b). The determining of the flying objects' own positions is improved and the determining of the position of foreign objects (Z) in an area without GNSS reception is made possible by increasing the flight altitude (H) of the flying object (F1, F2, F3) until the current topography information (Takt) matches the known topography information (Tbek) with sufficient accuracy.

Description

Method and system for determining the position of objects in an area with variable terrain

The invention relates to a method for determining the position of objects in an area with variable terrain with the features of the preamble of patent claim 1 or 2, as well as a system for determining the position of objects in an area with variable terrain with the features of the preamble of patent claim 14.

Such a method for determining the position of objects in an area with changing terrain, in particular in a war zone, is carried out by comparing current topography information and known topography information. The current topography information is determined using at least one flying object, preferably a drone, arranged at a certain altitude in a step a). The current topography information is then correlated with the known topography information to determine the position of the objects, namely in particular the flying objects themselves, in a step b).

In particular for carrying out such a method, there is a system for determining the position of objects in an area with variable terrain, in particular in a war zone, with at least one flying object having at least one recording device and with an evaluation unit. The flying object is designed to determine current topographic information in a step a) by means of the recording device at a certain altitude of the flying object. The evaluation unit is designed to determine the position of the objects, namely in particular the flying objects themselves, in a step b) by means of a correlation of the current topographic information with known topographic information.

The determination of the positions of vehicles and aircraft in civil and military applications is usually carried out using global navigation satellite systems (GNSS). However, the availability of these GNSS systems is not always guaranteed, particularly in war zones. For example, the signal transmission can be disrupted by the parties to the conflict or the general accessibility of the systems can be limited by third parties. It is therefore necessary to provide alternative means of determining positions in areas without GNSS availability. US20220057213 discloses a method for determining the position of a flying object, in which the position of the flying object is determined by comparing images taken using the flying object with known, historical satellite images. To this end, in a first step, various classes of characteristic landscape objects ("landmarks") and landscape areas ("landcover") are defined in satellite images. In a second step, the images taken using the flying object are then correlated with the satellite images using a convolutional neural network ("Convolutional Neural Network" / "Siamese CNN"). The method can be used for various types of flying objects such as drones, airplanes, helicopters or rockets. To improve accuracy, it is proposed here that images from different heights are compared with the satellite images. For alternative or additional use, other methods of positioning such as visual inertial odometry (VIO), radar topographic mapping or database comparisons with digital terrain models obtained by laser imaging, detection and ranging (LIDAR) are also proposed.

The method known from the state of the art only allows the recording flying object to determine its own position and does not allow for the position of foreign objects to be determined. It is also recommended that the VlO method be used in war zones as an alternative to static satellite image comparison due to the changing topography of terrain. The VlO method uses an originally known position of the flying object and extrapolates the current position based on sequentially recorded images. At least the initial position of the flying object must therefore be known and several images must be taken while the flying object is moving in order to determine the final position. This approach is therefore not suitable for determining the position of a quasi-static flying object with an unknown initial position. This approach also does not allow the position of foreign objects to be determined without the use of additional devices such as laser rangefinders or radars.

The invention is based on the object of providing a method and a device by means of which the determination of one's own positions is improved and the position determination of foreign objects in an area without GNSS reception is made possible. In particular, the invention is based on the object of enabling position determination in an area with changing topography, such as a war zone. This object underlying the invention is now initially solved by a method for determining the position of objects in an area with changing terrain with the features of patent claim 1.

One aspect of the invention is essentially that at least one match value between the current topography information and the known topography information is determined in a step c), wherein the match value is compared with a predetermined threshold value in a step d), wherein the flight altitude of the flying object is increased in a step e) if the match value is smaller than the threshold value, wherein in a step f) the steps a) to e) are repeated until in step d) the match value is greater than or equal to the threshold value.

Surprisingly, simulations have shown that, at sufficient altitude, reliable positioning can be carried out even in significantly changed terrain/territories, such as in a war zone, using landscape objects ("landmarks") and/or landscape areas ("landcover") in images and/or videos. Alternatively or additionally, digital terrain models recorded at different altitudes can be compared with the known, historical data in the same way. Furthermore, it has been shown that not only the flying object's own position can be determined in this way, but that foreign objects such as military targets and/or vehicles can also be reliably located. In this case, the position of the foreign object is calculated using known parameters of the known, historical topography information.

In the method, a flying object, preferably the unmanned drone, particularly preferably the remote-controlled quadrocopter, takes a topographical image from a first height. From this topographical image, associated topographical information, in particular a corresponding data set, is obtained. By comparing this current topographical information with known topographical information, a neural network or an algorithm determines match values in the 0% to 100% range. The match values can be carried out for the entirety of the topographical information or only for a part of the topographical information, such as certain landscape objects ("landmarks") and/or landscape areas ("landcover") contained in the topographical information. If the selected, determined match value is not above an associated, previously defined threshold value, the flying object is moved upwards to a greater height and another topographical image is taken with subsequent comparison. This process is repeated until the threshold for the determined match is reached or exceeded.

The increase in flight altitude and thus the expansion of the recording area/area is based on the assumption that although the terrain may be significantly changed locally by war, more similarities with the original, known topography can be identified in a larger section. For example, a local artillery strike may have rendered buildings and streets unrecognizable in a limited area, but will not have the same effect over a larger area.

Topographic information can be obtained, for example, using image recordings, video streams and/or digital terrain models recorded via LIDAR or radar. Other photogrammetric recording methods for obtaining topographic information are known to those skilled in the art. In comparison to "passive" image recordings, e.g. using cameras, "active" recording methods such as radars have the significant disadvantage in war zones that the detectability of the flying object by the other party to the conflict is increased. Position determination by pure (passive) image comparison is therefore preferable.

In the case of recordings of continuous video streams, position determination can be carried out using known methods of object detection in such video image material.

Known/historical topographic information includes, for example, maps of any kind, satellite images, digital terrain models, videos/films, static images of the terrain and/or semantic descriptions. Maps can include, for example, private and official topographic maps such as traditional maps, nautical charts and/or schematic drawings, thematic maps and physical maps.

The topographical information can be extracted from the semantic descriptions (text descriptions) using appropriately trained neural networks. For example, if it is known from such a description that a building with an unusual height of over 200m exists at a certain location, this topographical information can be used on its own for comparison with current topographical information and/or combined with other known, historical topographical information. In principle, all available known, historical topographical information can be are combined to form a comparison source, which is then compared with corresponding current topographic information.

The design of the flying object, e.g. as a drone, in particular as a quadrocopter, is only relevant insofar as topographic information must be able to be determined from different heights using the flying object.

The object underlying the invention is also achieved by a method for determining the position of objects in an area with changing terrain with the features of patent claim 2.

One aspect of the invention then essentially lies in the fact that the current topography information and the known topography information are presented by means of a display device to at least one human operator in a step c), wherein the operator compares the current topography information and the known topography information with one another in a step d), wherein the flight altitude of the flying object is increased in a step e), wherein in a step f) the steps a) to e) are repeated until in step d) the operator enters the information by means of an input device that the current topography information corresponds sufficiently precisely to the known topography information.

The advantage here is that the automated threshold value analysis can be completely replaced by a human operator. It is assumed that the spatial imagination of the human operator can achieve better results than a fully automated machine interpretation depending on the situation. It is also conceivable to combine the evaluation by a human operator with the automated threshold value analysis, e.g. with the help of a neural network. In other words, this means nothing other than the possibility for the operator to either take over the automatically determined position determination or to carry out their own position determination during the ongoing process.

In a preferred embodiment of the method, the flight altitude of the flying object in step e) is increased stepwise, preferably in 9 m to 11 m steps. Depending on the available computing power, it may be advantageous to reduce the amount of topography correlations / topography comparisons accordingly by a step-by-step approach.

In an alternative embodiment of the method, the flight altitude of the flying object is continuously increased.

If a very high, in particular theoretically infinite, computing power is available, the topography comparison can also be carried out continuously or quasi-continuously, i.e. with very small time intervals between the individual topography comparisons. In this case, it would be advantageous if the match value also approaches the predefined threshold value in an equally continuous manner. The step-by-step procedure, on the other hand, usually leads to time delays in determining the position, so that the threshold value can easily be exceeded to a greater extent before a positive comparison result is available.

Advantageously, the flight altitude of the flying object is increased in a final step e) such that in the subsequent final step d) the match value exceeds the threshold value by a maximum of 5%.

If the flying object is in a higher flight position, which may be unnecessarily high if the step-by-step approach is used, the flying object can be more easily detected by another party. The flying object could then be neutralized just as easily by the other party. However, it is also conceivable that the match value exceeds the threshold value by a maximum of 5% if the step-by-step approach is used. For example, the upcoming increase in flight altitude could be calculated based on the comparisons already made between the match values and the threshold values from the current and past flight altitudes. If the gap between the match value and the threshold value is large, the flight altitude is then increased significantly; if the gap between the match value and the threshold value is small, the flight altitude is only increased slightly.

In a further advantageous embodiment of the method, a horizontal position of the flying object is changed in step e).

This allows the aircraft to fly to an optimal position for positioning. The horizontal movement can be carried out separately or simultaneously with the vertical movement. The horizontal position of the flying object is preferably changed linearly.

The flying object can change its position linearly/laterally in one of the cardinal directions (north, east, west, south) and take another picture from the new position. This increases the probability of achieving a positive comparison result at a certain, low altitude, so that the risk of the flying object being detected and neutralized by third parties is reduced.

In an alternative, advantageous embodiment of the method, the horizontal position of the flying object is changed in a spiral shape.

The flying object performs circular movements. The spiral circling preferably takes place at a distance from the starting point. Advantageously compared to simply increasing the flight altitude, linear lateral and spiral movement profiles allow a higher chance of a positive result at a lower flight altitude. Successful topography comparison at the shortest distance from the starting point or at the lowest flight altitude can be achieved with the spiral movement. The disadvantage of this approach, however, is the potentially longer time required to achieve a positive result compared to a linear lateral movement or simply increasing the altitude.

Advantageously, the position of one of the objects is determined using a triangulation method.

In an extension of the described method, lateral and vertical movements of the flying object can be carried out with corresponding topographic information for the triangulation of foreign objects such as military targets. In this way, the distance to a foreign object can be easily determined by the relation of the foreign object to corresponding landscape objects ("landmarks") and/or landscape areas ("landcover") in different topographic information. This different topographic information is determined using the flying object located at different positions.

According to a further embodiment of the method, the position of one of the military targets is determined by arranging the flying object above the target and in the region of a normal to the earth's surface passing through the target and by subsequently determining the position of the flying object itself. The determination of the position of the flying object itself is also referred to as self-positioning. The military target then has the same horizontal position as the flying object and the vertical position of the military target corresponds to the known vertical position of the earth's surface.

Particularly preferably, two or more flying objects communicating with each other are provided for carrying out the method.

The process can therefore be extended to a group of two or more flying objects. For example, three drones communicating with each other can exchange a positive topography comparison with the other drones.

The security of the flying objects against being shot down by the enemy can be increased by repeating steps a) to e) in step f) for all of the two or more flying objects until in step d) the match value of only one of the two or more flying objects is greater than or equal to the threshold value.

More accurate and faster position determinations of the objects are possible if the triangulation procedure is carried out with the current topography information of the two or more flying objects.

Therefore, no new position needs to be taken by a single flying object in order to perform the triangulation.

The object underlying the invention is also achieved by a system for determining the position of objects in an area with changing terrain with the features of patent claim 14.

One aspect of the invention then essentially lies in the fact that the evaluation unit is designed to determine at least one match value between the current topography information and the known topography information in a step c), wherein the evaluation unit is designed to compare the match value with a predetermined threshold value in a step d), wherein the flying object is designed to increase its flight altitude in a step e) if the match value is smaller than the threshold value, wherein the evaluation unit and the flying object are designed are to repeat steps a) to e) in a step f) until the match value in step d) is greater than or equal to the threshold value.

The system further preferably has a display device for one or more human operators. The display device is coupled to the evaluation unit so that the current topography information and/or the known topography information can be displayed using the display device. Furthermore, an input device is preferably coupled to the evaluation unit so that the information that the current topography information matches the known topography information sufficiently accurately can be entered using the input device.

Preferably, a measuring range of the recording device is directed downwards from the flying object or the measuring range is directed sideways from the flying object.

The recording device can be designed to take exclusively "top-down" recordings against the direction of flight. Alternatively or additionally, the recording device can be designed to take 360° sideways recordings of topography and/or objects. The recording angle and/or perspective can be freely selected, for example to reduce the amount of data or to achieve a larger coverage area. In this case, it is particularly advantageous that foreign objects such as military targets can also be located over long distances. Depending on the flight altitude and the weather conditions, position determinations/localizations over several kilometers, e.g. 2km, 5km, 10km, 20km or any intermediate values to these distances, are possible.

According to an advantageous embodiment of the system, the recording device is designed as an (image/video) camera, as a laser range finder, as a LIDAR system and/or as a radar system.

The methods and the system for determining the position of objects in an area with changing terrain are used in particular in the area of military vehicles, convoys and/or positions. In particular, the evaluation unit, the display device and/or the input device are then arranged within such a vehicle, convoy and/or within such a position. The evaluation unit, the display device and/or the input device can also be arranged in a control center which is far away, for example several 100km or several 1000km, from the actual event, namely the flying objects. There are now a number of possibilities for designing and developing the method and system according to the invention in an advantageous manner. Reference is firstly made to the claims subordinate to claims 1, 2 and 14. A preferred embodiment of the method and system according to the invention is now explained and described in more detail below using the drawing and the associated description. The drawing shows:

Fig.1 is a flow chart of a first embodiment of the method for

Determining the position of objects in an area with changing terrain,

Fig.2 is a flow chart of a second embodiment of the method for

Determining the position of objects in the area with changing terrain,

Fig.3 shows a schematic representation of a system for determining the position of objects in the area with changing terrain,

Fig.4a shows a schematic representation of a first movement pattern of a flying object of the system for determining the position of objects in the area with variable terrain, and

Fig.4b shows a schematic representation of a second movement pattern of the flying object of the system for determining the position of objects in the area with changing terrain.

The two methods for determining the position of objects 1 in an area 2 with changing terrain, in particular in a war zone, according to Fig. 1 and 2 include a comparison of current topography information Takt and known topography information T _be k. The current topography information Takt is determined in a step a) by means of at least one flying object Fi, F ₂ , F ₃ arranged at a certain flight altitude H _a kt, preferably a drone, particularly preferably a quadrocopter. The current topography information Takt is correlated with the known topography information T _be k to determine the position of the objects 1, namely in particular military targets Z and/or the flying objects Fi, F ₂ , F ₃ themselves, in a step b). Fig.3 shows such an area 2 with changing terrain, in particular a war zone. On the right-hand side, an image of the known topographic information Tbek is shown and on the left-hand side an image of the current topographic information Takt is shown, whereby the current topographic information Takt differs from the known topographic information T _be k by the partial destruction of a tower and by a crater created, for example, by a bomb, whereby the houses adjacent to the crater are also partially destroyed. The correlation of the current topographic information Takt with the known topographic information T _be k means a comparison in which the differences are determined. Such a comparison is preferably carried out on a digital level with the aid of data sets of the topographic information Takt, T _b ek. The comparison is carried out, for example, with the aid of landscape objects ("landmarks") such as the tower shown in Fig.3, the houses and/or the mountain peak. The comparison is also carried out, for example, with the aid of landscape areas ("landcover") such as the road shown in Fig.3, the contour of the mountain and/or the horizon.

According to the first embodiment from Fig.1, at least one match value W between the current topography information Takt and the known topography information T _b ek is determined in a step c). The match value W is then compared with a predetermined threshold value S in a step d). The flight altitude H of the flying object Fi, F2, F3 is increased in a step e) if the match value W is smaller than the threshold value S. In a step f), steps a) to e) are repeated until in step d) the match value W is greater than or equal to the threshold value S.

When determining the match value W, for example, the current topographic information Takt and the known topographic information T _be k are considered in their entirety. However, it is also conceivable that one or more landscape objects and/or landscape areas are used to determine the match value W, since these are then sufficient to carry out a sufficiently accurate position determination of relevant objects 1.

Step d) involves the query as to whether W < S. If this query is answered with yes (Y), step e), namely increasing the flight altitude H of the flying object Fi, F2, F3, is carried out, in order to then carry out step a) again. If this query W < S is answered with no (N), the method is terminated, since a sufficiently accurate position determination of relevant objects 1 can then be carried out using the then current topography information Takt and is also carried out. Step f) is made possible in particular with the aid of the above-mentioned query. According to the second embodiment from Fig.2, the current topography information Takt and the known topography information T _be k are shown by means of a display device 3 to at least one human operator 4 in a step c). The operator 4 then compares the current topography information Takt and the known topography information T _be k with each other in a step d). The flight altitude H of the flying object Fi, F2, F3 is increased in a step e). In a step f), steps a) to e) are repeated until in step d) the operator 4 enters the information by means of an input device 5 that the current topography information Takt matches the known topography information T _be k sufficiently accurately.

The images of the current topography information Takt and the known topography information T _be k from Fig. 3 are preferably shown next to each other and simultaneously on the display device. The display device 3 is designed, for example, as an electronic screen or as a projector. Step d) according to the second embodiment from Fig. 2 also includes the query as to whether or not the operator 4 has entered the information that the current topography information Takt matches the known topography information T _be k sufficiently precisely. If this query is answered with No (N), step e), namely increasing the flight altitude H of the flying object Fi, F2, F3, is carried out in order to then carry out step a) again. If this query is answered with Yes (J), the method is terminated, since a sufficiently precise position determination of relevant objects 1 can then be carried out with the then current topography information Takt and is also carried out. Step f) is made possible in particular with the aid of the aforementioned query.

The flight altitude H of the flying object Fi, F2, F3 is increased in step e), e.g. step by step, preferably in 9 m to 11 m steps.

Fig.4a and 4b show a schematic representation of two different movement patterns of the flying object Fi, F ₂ , F ₃ . A dotted line symbolizes a flight path of the flying object Fi , F ₂ , F ₃ . The flying object Fi , F ₂ , F ₃ is shown at four different altitudes H, namely at a current flight altitude Hakt, at a flight altitude H _akt -i preceding the current flight altitude H _a kt, and at two flight altitudes H _a kt+i , Hakt+2 following the current flight altitude H _a kt. These flight altitudes H _akt -i, Hakt, H _a kt+i and H _a kt+2 could correspond to the steps mentioned, whereby at each flight altitude H _akt -i, Hakt, H _a kt+i and Hakt+2 the then current topography information Takt is determined using the flying object Fi, F ₂ , F ₃ . On At each of the flight altitudes H _a kt-i , Hakt, H _a kt+i and H _a kt+2 the flying object Fi, F ₂ , F ₃ preferably stops briefly for the duration of the determination of the current topography information T _akt and the subsequent query.

According to Fig.4a and 4b, the flight altitude H of the flying object Fi, F ₂ , F ₃ could also be increased continuously, in particular along the flight paths symbolized by the dot-dash lines. The then current topography information T _akt is then determined continuously, i.e. also between the shown flight altitudes H _a kt-i, Hakt, H _a kt _+i and H _a kt ₊ 2, using the flying object Fi, F ₂ , F ₃ and the associated queries are carried out. If the query according to Fig.1 can be answered with No and according to Fig.2 with Yes, the process is terminated and the flying object Fi, F ₂ , F ₃ reduces its flight altitude H again and flies back to a base station, for example.

The flight altitude H of the flying object Fi, F ₂ , F ₃ is increased in a last step e) according to the first embodiment of the method from Fig.1 such that in the subsequent last step d) the match value W exceeds the threshold value S by a maximum of 5%.

The agreement value W could exceed the threshold value S, for example with the then current topography information T _akt determined at the flight altitude H _ak t+2.

According to Fig.4a and 4b, in step e) a horizontal position of the flying object Fi, F ₂ , F ₃ is also changed.

The flying object Fi, F ₂ , F ₃ also moves sideways.

The change in the horizontal position occurs simultaneously with the change in the vertical position. However, the change in the horizontal position could also occur at the same height H, so that at the same height H two or more topographic information items T _akt are determined one after the other by means of the flying object Fi, F ₂ , F ₃ .

According to Fig.4a, the horizontal position of the flying object Fi, F ₂ , F ₃ is changed linearly.

According to Fig.4b, the horizontal position of the flying object Fi, F ₂ , F ₃ is changed in a spiral shape. It would also be conceivable to develop other flight paths, which are adapted to area 2, for example, and in which landscape objects and/or landscape areas are preferably used as cover for military objectives Z.

The position of one of the objects 1, Fi, F2, F3, Z is determined using a triangulation method.

Triangulation is a geometric method of measuring distances by measuring angles within triangles. The calculation is then carried out using trigonometric functions. The position of one of the objects 1, Fi, F2, F3, Z is thus determined relative to a known position in the known topography information T _be k.

The position of one of the military targets Z could alternatively or additionally be determined by arranging the flying object Fi, F2, F3 above the target Z and in the area of a normal to the earth's surface 6 passing through the target Z and by subsequently determining the position of the flying object Fi, F ₂ , F ₃ itself.

If the flying object Fi, F2, F3 is located above the target Z, which is arranged between a house and a mountain according to Fig.3, a current topography information Takt is preferably determined in order to identify the target.

It is conceivable that two or more communicating flying objects Fi, F2, F3 are intended to carry out the procedure.

Fig.3 shows three flying objects Fi, F ₂ , F ₃ , namely a first flying object Fi, a second flying object F ₂ and a third flying object F ₃ . Fig.3 shows an image of the current topography information determined by means of the first flying object Fi. In this image, the other two flying objects F2, F3 are shown with dashed lines due to their optional use in the method.

When using two or more flying objects Fi, F2, F3, in step f) steps a) to e) according to Fig.1 are repeated for all of the two or more flying objects Fi, F ₂ , F ₃ until in step d) the match value W of only one of the two or more flying objects Fi, F2, F3 is greater than or equal to the threshold value S. When using two or more flying objects Fi, F ₂ , F3 and the method according to Fig.2, the current topography information Takt of these two or more flying objects Fi, F ₂ , F ₃ is available to the operator 4 in order to make the decision as to whether the current topography information Takt corresponds sufficiently accurately to the known topography information T _be k .

When using two or more flying objects Fi, F ₂ , F 3 , the triangulation procedure is carried out using the current topography information of the two or more flying objects Fi , F ₂ , F ₃ .

A system 7 for determining the position of objects 1 in an area 2 with changing terrain, in particular in a war zone, is shown in Fig. 3. The system 7 is used in particular to carry out the method described above. The system 7 has at least one flying object Fi, F ₂ , F3 having at least one recording device 8 and an evaluation unit 9. The flying object Fi, F ₂ , F ₃ is designed to use the recording device 8 to determine current topography information Takt in a step a) at a specific flight altitude H _a kt of the flying object Fi, F ₂ , F _3. The evaluation unit 9 is designed to _determine the position of the objects 1, namely in particular of military targets Z and/or the flying objects Fi, F ₂ , F3 themselves, in a step b) by means of a correlation of the current topography information Takt with known topography information T be k.

The recording device 8 is arranged on an underside of the flying object Fi, F ₂ , F ₃ according to Fig. 3. Information such as the current topography information, timing and/or control commands for the flying objects Fi, F ₂ , F ₃ can be transmitted wirelessly between the flying objects Fi, F ₂ , F 3 and the evaluation unit 9, which is symbolized by corresponding symbols adjacent to the flying objects Fi, F ₂ , F ₃ and the evaluation unit 9. If the flying objects Fi, F ₂ , F3 are designed as unmanned drones, these drones can act autonomously or be remotely controlled by the operator 4 using the input device 5 and the evaluation unit 9.

The evaluation unit 9 is further designed to determine at least one match value W between the current topography information Takt and the known topography information T _be k in a step c) and to compare the match value W with a predetermined threshold value S in a step d). The flying object Fi, F ₂ , F ₃ is designed to increase its flight altitude H in a step e) if the match value W is smaller than the threshold value S. The evaluation unit 9 and the flying object Fi, F ₂ , F ₃ are designed to repeat steps a) to e) in a step f) until the match value W is greater than or equal to the threshold value S in step d). A measuring range of the recording device 8 is directed downwards from the flying object Fi, F ₂ , F3 or the measuring range is directed sideways from the flying object Fi, F ₂ , F ₃ .

If the position of one of the military targets Z is determined by arranging the flying object Fi, F ₂ , F ₃ above the target Z, then preferably a determination of current topographic information is carried out using a recording device 8 directed downwards from the flying object Fi, F ₂ , F ₃ .

In particular, the measuring range in azimuth direction is formed in a specific winding area.

In particular, the measuring range is directed towards characteristic landscape objects, landscape areas and/or the targets Z. It is also possible to focus successively on different characteristic landscape objects, landscape areas and/or targets Z in different topography information determinations.

The recording device 8 is designed as an image/video camera, as a laser range finder, as a LIDAR system and/or as a radar system.

list of reference symbols

1 objects

2 area

3 display device

4 operators

5 input device

6 Earth's surface

7 system

8 recording device

9 evaluation unit

Takt current topography information

Tbek known topographical information

Fi (first) flying object

F ₂ (second) flying object

F ₃ (third) flying object

Z military target

H altitude

Hakt flight altitude

Hakt_-i flight altitude

H _a kt_+i altitude

H _a kt_+2 altitude

W agreement value

S threshold

Claims

patent claims

1. Method for determining the position of objects (1) in an area (2) with variable terrain, in particular in a war zone, by means of a comparison of current topographic information (Takt) and known topographic information (T _be k), wherein the current topographic information (Takt) is determined by means of at least one flying object (Fi, F ₂ , F ₃ ) arranged at a certain flight altitude (Hakt), preferably a drone, particularly preferably a quadrocopter in a step a), wherein the current topographic information (Takt) is correlated with the known topographic information (T _be k) for determining the position of the objects (1), namely in particular military targets (Z) and/or the flying objects (Fi, F ₂ , F ₃ ) themselves, in a step b), characterized in that at least one correspondence value (W) between the current topographic information (Takt) and the known topographic information (T _be k) is determined in a step c), wherein the correspondence value (W) is compared with a predetermined threshold value (S) in a step d), wherein the flight altitude (H) of the flying object (Fi, F ₂ , F ₃ ) is increased in a step e) if the match value (W) is smaller than the threshold value (S), wherein in a step f) steps a) to e) are repeated until in step d) the match value (W) is greater than or equal to the threshold value (S).

2. Method for determining the position of objects (1) in an area (2) with variable terrain, in particular in a war zone, by means of a comparison of current topography information (Takt) and known topography information (T _be k), wherein the current topography information (Takt) is determined by means of at least one flying object (Fi, F ₂ , F ₃ ) arranged at a certain flight altitude (Hakt), preferably a drone, particularly preferably a quadrocopter in a step a), wherein the current topography information (Takt) is correlated with the known topography information (T _bek ) for determining the position of the objects (1), namely in particular military targets (Z) and/or the flying objects themselves (Fi, F ₂ , F ₃ ), in a step b), characterized in that the current topography information (Takt) and the known topography information (T _bek ) are displayed by means of a display device (3) to at least one human operator (4) in a step c), wherein the Operator (4) compares the current topography information (Takt) and the known topography information (T _be k) in a step d), whereby the flight altitude (H) of the flying object (Fi, F ₂ , F ₃ ) is increased in a step e), whereby in a step f) the steps a) to e) are repeated until in step d) the operator (4) by means of a Input device (5) enters the information that the current topography information (Takt) corresponds sufficiently accurately to the known topography information (Tbek).

3. Method according to claim 1 or 2, characterized in that the flight altitude (H) of the flying object (Fi, F2, F ₃ ) in step e) is increased step by step, preferably in 9 m to 11 m steps.

4. Method according to claim 1 or 2, characterized in that the flight altitude (H) of the flying object (Fi, F2, F3) is continuously increased.

5. Method according to one of the preceding claims, characterized in that the flight altitude (H) of the flying object (Fi, F ₂ , F ₃ ) is increased in a last step e) such that in the subsequent last step d) the match value (W) exceeds the threshold value (S) by a maximum of 5%.

6. Method according to one of the preceding claims, characterized in that in step e) a horizontal position of the flying object (Fi, F ₂ , F ₃ ) is changed.

7. Method according to claim 6, characterized in that the horizontal position of the flying object (Fi, F ₂ , F ₃ ) is changed linearly.

8. Method according to claim 6, characterized in that the horizontal position of the flying object (Fi, F ₂ , F ₃ ) is changed in a spiral shape.

9. Method according to one of the preceding claims, characterized in that the position of one of the objects (1, Fi, F2, _F3 , Z) is determined by means of a triangulation method.

10. Method according to one of the preceding claims, characterized in that the position of one of the military targets (Z) is determined by arranging the flying object (Fi, F2, F ₃ ) above the target (Z) and in the region of a normal to the earth's surface (6) passing through the target (Z) and by subsequently determining the position of the flying object (Fi, F ₂ , F ₃ ) itself.

11. Method according to one of the preceding claims, characterized in that two or more mutually communicating flying objects (Fi, F2, F ₃ ) are provided for carrying out the method.

12. Method according to claim 11, characterized in that in step f) steps a) to e) are repeated for all of the two or more flying objects (Fi, F2, F3) until in step d) the match value (W) of only one of the two or more flying objects (Fi, F2, F3) is greater than or equal to the threshold value (S).

13. Method according to claim 11 or 12, characterized in that the triangulation method is carried out with the current topography information (clock) of the two or more flying objects (Fi, F ₂ , F ₃ ).

14. System (7) for determining the position of objects (1) in an area (2) with variable terrain, in particular in a war zone, in particular for carrying out the method according to one of the preceding claims, with at least one flying object (Fi, F2, F3) having at least one recording device (8) and with an evaluation unit (9), wherein the flying object (Fi, F ₂ , F ₃ ) is designed to determine current topographic information (Takt) in a step a) by means of the recording device (8) at a certain flight altitude (Hakt) of the flying object (Fi, F ₂ , F ₃ ), wherein the evaluation unit (9) is designed to determine the position of the objects (1), namely in particular of military targets (Z) and/or of the flying objects (Fi, F ₂ , F ₃ ) themselves, in a step b) by means of a correlation of the current topographic information (Takt) with known topographic information (Tbek), characterized in that the evaluation unit (9) is designed to determine at least one match value (W) between the current topography information (Takt) and the known topography information (Tbek) in a step c), wherein the evaluation unit (9) is designed to compare the match value (W) with a predetermined threshold value (S) in a step d), wherein the flying object (Fi, F ₂ , F ₃ ) is designed to increase its flight altitude (H) in a step e) if the match value (W) is smaller than the threshold value (S), wherein the evaluation unit (9) and the flying object (Fi, F ₂ , F ₃ ) are designed to repeat steps a) to e) in a step f) until in step d) the match value (W) is greater than or equal to the threshold value (S).

15. System (7) according to claim 14, characterized in that a measuring range of the recording device (8) is directed downwards from the flying object (Fi, F ₂ , F ₃ ) or that the measuring range of the flying object (Fi, F ₂ , F ₃ ) is directed sideways.

16. System (7) according to claim 14 or 15, characterized in that the recording device (8) is designed as an (image/video) camera, as a laser range finder, as a LIDAR system and/or as a radar system.