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Fast-acquisition/weak-signal-tracking gps receiver for heo
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Sirotzky, Steve Wintemitz, Luke Boegner, Greg |
| Copyright Year | 2004 |
| Description | A report discusses the technical background and design of the Navigator Global Positioning System (GPS) receiver -- . a radiation-hardened receiver intended for use aboard spacecraft. Navigator is capable of weak signal acquisition and tracking as well as much faster acquisition of strong or weak signals with no a priori knowledge or external aiding. Weak-signal acquisition and tracking enables GPS use in high Earth orbits (HEO), and fast acquisition allows for the receiver to remain without power until needed in any orbit. Signal acquisition and signal tracking are, respectively, the processes of finding and demodulating a signal. Acquisition is the more computationally difficult process. Previous GPS receivers employ the method of sequentially searching the two-dimensional signal parameter space (code phase and Doppler). Navigator exploits properties of the Fourier transform in a massively parallel search for the GPS signal. This method results in far faster acquisition times [in the lab, 12 GPS satellites have been acquired with no a priori knowledge in a Low-Earth-Orbit (LEO) scenario in less than one second]. Modeling has shown that Navigator will be capable of acquiring signals down to 25 dB-Hz, appropriate for HEO missions. Navigator is built using the radiation-hardened ColdFire microprocessor and housing the most computationally intense functions in dedicated field-programmable gate arrays. The high performance of the algorithm and of the receiver as a whole are made possible by optimizing computational efficiency and carefully weighing tradeoffs among the sampling rate, data format, and data-path bit width. |
| File Size | 89407 |
| Page Count | 2 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20110020459 |
| Archival Resource Key | ark:/13960/t4km4818h |
| Language | English |
| Publisher Date | 2004-12-01 |
| Access Restriction | Open |
| Subject Keyword | Space Communications, Spacecraft Communications, Command And Tracking Satellite Guidance Spacecraft Orbits Navigation Satellites Satellite Tracking Global Positioning System Receivers Signal Processing Space Navigation Signal Detection Earth Orbits Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
