GPS and Navigation Products

Multifrequency Real-Time GPS and GNSS Receivers

CRS has pioneered "software radio technology" for more than 15 years. We have developed and commercialized the world's first real-time software based GPS receivers. Our software GPS receivers have made direct use of software radio technology. These receivers proved to have superior performance and flexibility within modest costs. The technology for the development of such receivers is described here. The technology allows us to design and develop new architecture within a few months.

Several GPS receivers for specialized applications have been developed. (see Research & Development). These include block processing receivers, multipath mitigation, A/J receivers, precise test and position localization receivers, YMCA receivers, GPS/INS integrated systems, Direct Y-code acquisition, and pseudolites. Satellite-borne dual frequency receivers have also been developed.

These specialized receivers provide extreme accuracy and access to many intermediate parameters not normally available. They also provide flexibility and can be upgraded as the new waveforms and signals become available.

Prototypes of these receivers are available. We are constantly upgrading the receivers as new waveforms and signals are being defined. These include GPS-III waveforms, L5, as well as those for Galileo. Civilian Glonass receivers are developed and combined GPS/Glonass receivers will soon be available as a commercial off-the-shelf product.

Advanced Dual Frequency GPS Receiver is the software based real-time GPS receiver introduced in 2000. The receiver uses semi-codeless P code and provides extremely precise pseudoranges, phases, and navigational solutions at a rate up to 50 updates/sec.

An expanded version of this receiver with a built in calibrator has been widely used by ionospheric researchers for precise monitoring of ionosphere. The calibrator ensures that receiver bias is deterministically measured and eliminated. This provides sound measurement of absolute TEC, which is not available by using any other receivers. The receiver also provides independent L1, L2 amplitude and phase time series and spectra in real time.

Ultra-Tightly Coupled GPS/INS Receiver is based on our software receiver technology and is integrated with inexpensive MEMS-based Inertial Measuring Unit (IMU), closely within the GPS tracking loop. This novel architecture provides cm-level accuracy using civilian signals. The integration scheme allows the tracking loop bandwidth to be reduced (the dynamics is handled by the INS), thereby improving the SNR. It can also handle signal obscuration for limited durations.