Abstract
A feasible technique, using carrier-phase data from GPS and CCD camera, is presented to identify ground target location as well as azimuth angle of a low altitude aircraft/helicopter without using any gyroscope measurements; the baseline vector can also be identified using GPS compass. The ground target¡¦s image is extracted from background and recorded by image processing technique. By integrating ground target¡¦s location and the recorded GPS data, the designated states can be estimated by using extended Kalman filter technique.
Basically, the extended Kalman filter does the state estimation job, and it¡¦s a nonlinear measurement process. By processing these time update and measurement update, the integer ambiguity as well as azimuth angle can be determined.
The proposed GPS compass system consists of three componets : pointer, sensor, and controller. By using carrier-phase data from two GPS receivers, we can compute the baseline vector, whose length is equal to one meter, and achieve the direction accuracy within one degree. The integer ambiguity number is resolved by rotating the baseline vector; the conventional antenna swapping technique is a special case of the proposed method. Therefore, the GPS compass may replace these magnetic compass or gyroscope used in navigation system.
By continuously snapping ground target image using CCD camera and utilizing the GPS receivers, the coordinate of the ground target can be identified. Simulation justifies the feasibility of the proposed scenario. Simulation has shown that the estimation errors for stationary and traveling with constant velocity ground targets are within 1.8 m and 6 m, respectively.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0716104-153901 |
| Date | 16 July 2004 |
| Creators | Huang, Kou-jen |
| Contributors | Chin-Der Wann, Shiunn-Jang Chern, Hsin-Hsyong Yang, Chao-Ji Chou |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0716104-153901 |
| Rights | withheld, Copyright information available at source archive |
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