Data processing: vehicles – navigation – and relative location – Navigation – Employing position determining equipment
Reexamination Certificate
1999-04-28
2001-04-03
Chin, Gary (Department: 3661)
Data processing: vehicles, navigation, and relative location
Navigation
Employing position determining equipment
C342S158000
Reexamination Certificate
active
06212471
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to object locating systems and more particularly to efficient use of a sensor in searching for objects from a moving platform, and to the complete coverage of an area to be searched.
BACKGROUND OF THE INVENTION
In searching an area to find an object of interest using a vehicle and a sensor, the search may be conducted from any type of human-operated or computer-operated vehicle: aircraft, land-based, sea-based, underwater, or spaced-based. The type of sensor includes radar, acoustic, visual, infrared, and any other type of sensor suitable to finding an object. An object of the search may be a vehicle, a person or any other type of object that one may find using a sensor. Possible obstructions to finding the object of the search include terrain, buildings, trees, and undersea topography. Given the above parameters, it is difficult to search an area completely and efficiently. The problems in searching efficiently and effectively given the above parameters are: 1. determining what areas the sensor “saw” during a particular “look”; 2. keeping track of areas that have already been searched; 3. determining how to optimally employ the sensor to continue the search to completion in a given search sector; i.e. when to use the sensor, what direction to point the sensor, what mode (e.g. field of view) of operation, and location and altitude of sensor activation.
An example of a search illustrating the problems detailed above involves using one or more aircraft and onboard radar to search for and locate vehicles on the ground. The aircraft fly at low altitudes and scan the ground using radar sensors. In order to search efficiently, it is best to search only those sectors of the search area traversable by the type of vehicle which is the search object. That is, those parts of the search area which are too steep or watery should not be included in an efficient search because it is already known that those areas could not hold a vehicle. Further, it is most efficient to keep track of those sectors of the search area that have already been searched. Due to terrain blockage, a given scan may miss areas on the ground that may hold a vehicle. It is therefore important to keep track of the details of how the sensor was used in each scan so that the area may be searched completely in subsequent scans.
It remains desirable to have an efficient and accurate search method and apparatus using a moving vehicle and a sensor.
It is an object of the present invention to provide a method and apparatus to efficiently search for an object from a moving platform using a sensor.
It is another object of the present invention to provide a method and apparatus to eliminate sections of a search scheme of an area due to unlikelihood of the search object's presence in that area.
It is another object of the present invention to provide a method and apparatus that keeps tracks of areas that have been already searched and eliminates them from the search scheme automatically.
SUMMARY OF THE INVENTION
The problems of accurately and efficiently searching an area from a moving vehicle using a sensor are solved by the present invention of a dynamic optimal sensor employment system for searching an area.
A sensor on some kind of a moving platform or search vehicle, e.g. a helicopter, either manned or unmanned, is used to search an area for some kind of object, e.g. a car. Each time the sensor in the search vehicle is activated, the dynamic optimal sensor employment system (“the system”) determines which areas were searched at that moment. It does this by using a terrain database, information about the sensor state when it scanned (azimuth, elevation, mode, etc.) and a line-of-sight algorithm. The system determines this instantaneous coverage not only for the moving platform or search vehicle, such as the primary aircraft, designated “ownship”, but also for other team members (“teammates”) who report scan information to ownship via digital messages.
This system maintains a dynamic history of all areas that have been searched. This history is maintained in the form of an array where each cell in the array represents a section of the search area (e.g. 30 meter by 30 meter square “cells” of ground). Each cell in the array has a counter that indicates how many times the associated sector of the search area has been scanned, and each time the sectors are scanned with ownship or team sensors, the counter is incremented. Cells that are too steep or otherwise non-trafficable by a land vehicle, such as a lake or a river, are marked ahead of time to indicate there is no need to search them.
The system then dynamically determines what sensor activations are required to search the areas that are known to be trafficable but have not yet been scanned by ownship or teammates. Specifically, the system determines the time, location, direction, field-of-view, and altitude that best satisfy an optimization criteria, and then automatically activates the sensor to generate this coverage. In a military situation, it is preferable to perform the radar scans from a lower altitude to minimize exposure of the aircraft to threats. If the system determines that good coverage can only be obtained from a higher altitude, then it issues the appropriate commands to the autopilot and/or flight director to initiate a climb. The automatic scan activation is inhibited until the higher altitude is reached or a time-out occurs. At the higher altitude, the scan is reenabled. In this manner, the aircraft proceeds along a preplanned route, or anywhere else the pilot chooses, and the system automatically scans whenever and wherever appropriate.
The present invention does not deal with detection with the sensor. That functionality is available in current systems and is not covered in the description of the present invention. One key feature is that the system operates in an opportunistic fashion. That is, it does not rely on a preplanned route or preplanned sensor scans for its ownship or team members. Instead, it adapts to the current situation and employs the sensor only as needed. The system is also opportunistic in that it does not rely on selecting an observation point at some time in the future and then monitoring for an x,y,z capture criteria. Instead, the system is always watching for a good chance to activate the sensor, and does so immediately when it makes sense to do so.
The present invention together with the above and other advantages may best be understood from the following detailed description of the embodiments of the invention illustrated in the drawings, wherein:
REFERENCES:
patent: 4495500 (1985-01-01), Vickers
patent: 4531125 (1985-07-01), Beyer et al.
patent: 4780719 (1988-10-01), Frei et al.
patent: 5087916 (1992-02-01), Metzdorff et al.
patent: 5161125 (1992-11-01), Maccabee
patent: 5327149 (1994-07-01), Kuffer
patent: 5359334 (1994-10-01), Gutman
patent: 5367615 (1994-11-01), Economy et al.
patent: 5517419 (1996-05-01), Lanckton et al.
patent: 5557397 (1996-09-01), Hyde et al.
patent: 5596494 (1997-01-01), Kuo
patent: 5646907 (1997-07-01), Maccabee
Bodenhorn Chris A.
Stiles Peter N.
Szczerba Robert J.
Chin Gary
Cohen Jerry
Erlich Jacob N.
Lockheed Martin Corporation
Perkins Smith & Cohen LLP
LandOfFree
Dynamic optimal sensor employment for searching an area does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Dynamic optimal sensor employment for searching an area, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dynamic optimal sensor employment for searching an area will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2525212