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Real-Time Carrier Phase Ambiguity Resolution for High-Dynamic Vehicles

Award Information
Agency: Department of Defense
Branch: Air Force
Contract: N/A
Agency Tracking Number: 25914
Amount: $78,649.00
Phase: Phase I
Program: SBIR
Solicitation Topic Code: N/A
Solicitation Number: N/A
Solicitation Year: N/A
Award Year: 1994
Award Start Date (Proposal Award Date): N/A
Award End Date (Contract End Date): N/A
Small Business Information
14960 Woodcarver Road
Colorado Springs, CO 80921
United States
HUBZone Owned: No
Woman Owned: No
Socially and Economically Disadvantaged: No
Principal Investigator
 Mr. Frank Van Diggelen
 (719) 481-4877
Business Contact
Phone: () -
Research Institution

To achieve real-time ambiguity resolution (AR) in a high-dynamic environment, an algorithm is needed that is robut to cycle-slips and requires the minimum possible number of consecutive measurements before correctly resolving the ambiguities. The problem with existing AR algorithms is that they require many consecutive measurements over a long period of time and/or a significantly changing satellite geometry. An innovative tehcnique is described which uses FDI equivalence and the optimal integer search space. The number of searches required to resolve ambiguities is significantly reduced over existing techniques. Furthermore, the technique of FDI equivalence is shown to be highly efficient in discarding false ambiguities. These two features of the proposed technique mean that when satellite visibility is good and measurement noise is low, the ambiguities can be resolved immediately after a single measurement from each channel. When visibility is reduced or noise is large, the technique can be enhanced to minimize the number of consecutive measurements required before the ambiguities are correctly resolved. The ambiguity resolution algorithm is designed to operate with an autonomous integrity algorithm developed by NAVSYS which produces a real-time check of the validity of GPS data. This algorithm is capable of performing real-time cycle-slip detection and repair. The performance of the ambiguity resolution algorithm will be enhanced and validated through simulation under the Phase I contract. Under Phase II a prototype system will be delivered for flight tests.

* Information listed above is at the time of submission. *

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