EP2372297B1

EP2372297B1 - Method of terrain reconnaissance by means of a mortar bomb

Info

Publication number: EP2372297B1
Application number: EP20100185325
Authority: EP
Inventors: Adam Bartosiewicz; Wojciech Komorniczak; Dariusz Tyminski; Piotr Wojciechowski; Krzysztof Wysocki
Original assignee: Wb Electronics Spolka Z Oo
Current assignee: Wb Electronics Spolka Z Oo
Priority date: 2010-03-31
Filing date: 2010-10-01
Publication date: 2013-11-06
Anticipated expiration: 2030-10-01
Also published as: EP2372297A1

Description

The subject of the invention is a method of terrain reconnaissance by means of a mortar bomb.
Methods of terrain reconnaissance are known for example from patent specification US 3,962,537 . These methods consist in that a mortar bomb, equipped with an observation unit with a camera, a parachute, and a transmitter, is fired toward a terrain subject to a reconnaissance. When the mortar bomb is positioned above such terrain, the observation unit is disconnected from the shell of the mortar bomb in order to monitor the terrain by means of the camera falling down slowly with the parachute, simultaneously transmitting images of the terrain by means of radio, infrared or other radiation, to a receiver installed at a command post, where the received signals are suitably processed, registered or displayed directly on a display unit of a computer. However, the observation unit does not fall down steadily. The vertical fall trajectory is deviated by the wind, which creates crosswise image oscillations. However, the fact that the falling unit rotates is very disadvantageous as the picture seen on the display unit rotates as well. Any attempts to eliminate the rotation of the observation unit would result in an excessive enlargement of the observation unit and the mortar bomb itself. According to patent specification W02004 057263 , the observation unit is not separated from the mortar bomb, but the mortar bomb trajectory is mechanically stabilized in such a way that the photographed terrain is always in a view of the camera.
The method of terrain reconnaissance is known, as well, from US 7,283,156 patent specification where in one embodiment, the airborne imaging system of the present invention includes a blister housing attached to a host vehicle. At the appropriate time in flight, a sensor suite is deployed from the blister housing. The sensor suite is eccentrically weighted to induce a pendular motion as it is suspended from a paradevice. To increase the imaging footprint of the system, the paradevice is designed for angular motion and the look down angle of the imaging system can be adjusted from the vertical. The data is broadcast to a receiving station that processes individual frames to create a continuously updated mosaic of the area of interest.
The object of the invention is to create a method eliminating the rotation of the image displayed on the display unit.
The essence of the method consisting in firing a mortar bomb, equipped with an observation unit comprised of a camera, a parachute, and a transmitter, toward a terrain subject to a reconnaissance, where after a specified time the observation unit is separated from the shell of the mortar bomb and monitors the terrain, simultaneously sending a signal from the camera by means of radio, infrared or other radiation to a receiver situated at a command post where signals received from the camera are displayed on a computer display unit after being converted into the digital format, lies in that a deviation value of a determined axis of the observation unit from the north-south direction N-S is detected in the observation unit for a single image by means of a magnetometer or a satellite navigation system GPS, said consecutive deviation values being converted into a N-S deviation signal sent synchronically with the signal from the camera to the receiver, in which the position of each consecutive image on the display unit is corrected by its corresponding value of the deviation from the N-S direction by means of a known image rotation algorithm. As a result, an image on the display unit of a computer does not rotate in spite of the rotation of the observatory unit.
An embodiment of this invention is shown in the drawing which depicts a block diagram of an electronic circuit by means of which the method according to the invention is realized.
A shell of a mortar bomb comprises an observation unit provided with a TV camera K, a parachute, a radio transmitter N, a magnetometer M, a disrupting charge L together with its fuse, a supply unit Zn for an observation unit with an inertial power-on switch Wb, with a time-lag cut-out switch Wc for switching off a supply unit Zn, as well as with a controller Sn. The mortar bomb is fired by means of a mortar. Before dropping the mortar bomb into a tube, a delay time is set for the disrupting charge L in the observation unit. The observation unit in the fired mortar bomb is fed with a supply voltage by means of the inertial power-on switch Wb, and after the determined delay time the disrupting charge L is initiated, the parachute is opened, and the observation unit slowly falls down. During the falling stage, the camera K generates a video signal corresponding to the observed terrain being in its view. At the same time, the values of a momentary deviation of the observation unit from the north direction are detected, and information concerning these deviation values is encoded in a sound channel of a TV signal, said signal being transmitted by the radio transmitter N to a command post. After receiving this signal by means of a receiver 0 at the command post, single images are separated from film frames, and a position of each of the consecutive images on a screen is corrected, by means of a known picture rotation algorithm, by its value of the deviation from the N-S direction. Thus obtained images are simultaneously registered in a memory P for future analysis, if required. Separate frames are converted in a functor F2 of the algorithm into separate appropriately positioned images. When watching an image on the screen, one may also use a functor F1 in order to magnify the image and to change its central point's position in relation to the centre of the screen of a display unit E.

Reference signs

K: - camera
E: - display unit
F1: - functor in the algorithm enlarging an image and moving its central point
F2: - functor in the algorithm converting frames into images
L: - disrupting charge with its fuse
M: - magnetometer
N: - transmitter
O: - receiver
P: - memory
Sn: - controller of a receiver
So: - controller of a transmitter
Wb: - inertial power-on switch
Wc: - time-lag cut-out switch
Zn: - transmitter supply unit
Zo: - receiver supply unit

Claims

A method for terrain reconnaissance by means of a mortar bomb, consisting in that the mortar bomb with an observation unit being comprised of a camera (K), a parachute and a transmitter (N) is fired toward a terrain subject to a reconnaissance, where the observation unit, after a specified time, is separated from the shell of the mortar bomb and monitors the terrain simultaneously sending a signal from the camera (K) by radio, infrared or other radiation to a receiver (O) situated at a command post, where signals received from the camera (K) are displayed on a computer display unit (E) after being converted into the digital format, characterized in that a deviation value of a specified axis of the observation unit from the north-south direction N-S is detected in the observation unit for a single image by means of a magnetometer (M) or a satellite navigation system GPS, said consecutive deviation values being converted into a N-S deviation signal, sent synchronically with the signal from the camera (K) to the receiver (O), in which the position of each consecutive image on the display unit (E) is corrected by its corresponding value of the deviation from the N-S direction by means of a known image rotation algorithm.