THE UNIVERSITY OF CALGARY Determining Heading and Pitch Using a Single Difference GPS/GLONASS Approach

iii This thesis presents an approach to combine GPS and GLONASS measurements, using a single differencing technique with a common frequency and time standard, to determine the heading and pitch parameters using a pair of non-dedicated GPS/GLONASS receivers. The theory behind the use of GPS for attitude determination is well known. Augmentation of GPS with GLONASS is not straightforward however. This is because the latter system, besides having other differences with the former system, employs the frequency division multiple access (FDMA) technique to distinguish the signals from different satellites. The fact that each GLONASS signal has its own slightly different frequency makes the double differencing (DD) of the carrier phase measurements no longer possible without modification. GPS uses the code division multiple access (CDMA) technique, which has a common frequency for all satellites, and hence does not experience the same problem. To get around this problem, the use of between-receiver single differencing (SD) of the carrier phase measurements is proposed. In this cas