Communications – electrical: acoustic wave systems and devices – Distance or direction finding – By combining or comparing signals
Patent
1991-01-03
1992-11-03
Pihulic, Daniel T.
Communications, electrical: acoustic wave systems and devices
Distance or direction finding
By combining or comparing signals
367136, G01S 380, G01S 1100, G01V 100
Patent
active
051611279
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention relates to a method of determining the target direction and target range of sound generating targets, such wheeled or track-laying vehicles, with the aid of a sensing arrangement composed of a plurality of sensors including acoustic sensors to determine the target direction, i.e. the target bearing angle.
For the full realization of area defense mines, sensors are required which reconnoiter potential targets (wheeled and track-laying vehicles) with sufficient accuracy so that the ammunition can be used effectively. As a function of the deployment system (throwing system, etc.) and the ammunition (e.g., conventional ammunition, target sensing ammunition) target range and direction must be determined. Typical distance ranges are--depending on the design of the ammunition--40 to 300 m.
German Patent No. 3,140,728 discloses, for example, a method of determining the target direction and target range in which the target is detected by means of an airborne sound sensor composed of four microphones. The range is determined with the aid of an active target sensor composed of a sound source and the mentioned airborne sound sensor. The primary drawback of this arrangement is that the target detection device itself must include a sound source. Moreover, such active sensors are easy to detect.
German Patent No. 3,601,053 discloses an actuator arrangement for a rigid directional mine including a laser range finder. In this case as well, an active sensor is involved which is easy to detect.
DE-OS German Offenlegungsschrift (printed unexamined application) 3,705,981 discloses a device for detecting a target and initiating ignition that includes a seismic sensor and an acoustic sensor composed of two directional microphones and in this case, the seismic sensor serves to activate the directional microphones, and thus constitutes a so-called prompting sensor. The bearing angle is then determined with the aid of the directional microphones. The target range is not measured by this prior art device.
Finally, DE-OS German Offenlegungsschrift (printed unexamined application) 3,804,495 discloses an electronic ignition device for antitank mines which includes a seismic sensor and three magnetic field sensors. In this case again, the seismic sensor serves as a prompting sensor.
SUMMARY OF THE INVENTION
It is the object of the present invention to further develop the method described above so that a determination of the target direction and target range can be made solely by means of passive sensors.
This is accomplished according to the invention by a method of determining the target direction and target range of sound generating targets, such as wheeled or track-laying vehicles, with the aid of a sensor arrangement composed of a plurality of sensors with acoustic sensors for airborne sound being employed to determine the target direction (bearing angle determination), and wherein, to find the target range, in addition to the acoustic sensors, a seismic sensor is employed, a characteristic line in the airborne sound spectrum and a characteristic line in the solid-borne sound spectrum is measured for each signal source characteristic of the target, the radial target velocity (V.sub.z,r) is calculated from the Doppler shift of these spectral lines and from the propagation velocity (C) of the corresponding waves, and the target range (r) is calculated from the radial target velocity and the bearing angle (.alpha.).
Particularly advantageous features of the method are disclosed in the dependent claims.
The method according to the invention thus utilizes the effect that drive assemblies and track-laying noises of wheeled and track-laying vehicles actuate the airborne sound and solid-borne earth or sound borne sound channels in the same manner. The bearing angle .alpha. relative to the target is preferably obtained from the airborne sound channel by way of a correlation method. For this purpose, at least three microphones should be arranged preferably in the form of an equilateral triangle.
F
REFERENCES:
patent: 3995223 (1976-11-01), Gimber et al.
patent: 4811308 (1989-05-01), Michel
Pihulic Daniel T.
Rheinmetall GmbH
LandOfFree
Method of determining the target direction and target range of s does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of determining the target direction and target range of s, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of determining the target direction and target range of s will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2055460