Sponsored by internal Cornell funds
Project Participants: Mark L. Psiaki (PI), Hee Jung, and Steve Powell
This research is developing algorithms for use in a GPS software receiver. A software receiver is a device that uses very little electronic hardware in order to acquire and track GPS signals and to extract and use their navigation information. A minimal RF front end produces a digital data stream that gets input to a general-purpose microprocessor. The microprocessor then uses software to perform all of the remaining functions of a GPS receiver.
This approach allows one to apply sophisticated estimation and signal processing techniques to extract navigation information from the signals. Software receiver algorithms that are being developed apply a combination Kalman-filter/Smoother techniques and FFT-based block processing techniques to perform acquisition and tracking of very weak signals. This work will enable such things as
1) Ultra precise GPS measurements of the acceleration of a falling-sphere probe of the upper atmosphere.
2) GPS-based measurements of very strong ionospheric scintillations, ones that cause a traditional receiver to lose lock.
3) The use of GPS to do orbit determination for geostationary satellites, where the signals are 10 to 30 dB weaker than in terrestrial applications.
Future plans include the development of a dual frequency RF front end and a dual frequency software receiver.
Last updated 9 Feb. 2001