Quality Evaluation of Onboard Dual Frequency Kinematic GPS Observations

An observation quality evaluation system for onboard dual frequency GPS is presented in this paper. We investigate how to evaluate the quality of onboard dual frequency kinematic GPS receiver using in-flight observations, and provide several indices of onboard observation quality evaluation. To come over high dynamic characteristics of onboard observations, we design an efficient method of outlier elimination and cycle slip detection. Then via linear combination of original observations, the kinematic observations noise is extracted, and the observation quality is evaluated. Further more, we provide an algorithm to compute the correlation of different types of observations, and analyze the relation between the observation quality and sightline direction. We achieve a series of reliable quality evaluation results by experiments on the data from CHAMP satellite and provide reasonable explanation. The results of CHAMP data analysis contribute to better understanding of receivers and applications of GPS.