Benefits of Combined GPS/GLONASS Processing for High Sensitivity Receivers

摘要

This thesis presents a comprehensive study on the advantages of using combined processing of the Global Positioning System (GPS) and the Global Navigation Satellite System (GLONASS) for receivers in comparison with a GPS-only receiver in degraded signal environments. Existing commercial High Sensitivity (HS) GPS receivers suffer significant degradations in many environments such as in indoor environments and urban canyons due to restricted visibility of available satellites. Even if a sufficient number of satellites are available, the geometric Dilution of Precision (DOP), the noise and multipath can often be large, leading to large errors in position. Currently there are more than twenty-four active GLONASS satellites in orbit. It is therefore advantageous to concentrate on combining the GPS and GLONASS measurements to achieve more reliable and accurate navigation solutions.;In this research, data was collected in an indoor environment and in urban canyons. A software receiver, namely GSNRx(TM) was used to process the data in both standard and high sensitivity modes. The analysis studies the benefits of combined HS GPS/GLONASS processing in terms of measurement availability, pseudorange degradation, signal power degradation, navigation solution availability, residual analysis, positioning accuracy and DOP. The combined use of GLONASS and GPS provides significant improvement in all of the above performance measures. Recommendations for future work are made for improvements.