The advantages of the original combination over narrow lane combinations in multi-frequency GNSS orientating

摘要

The narrow lane carrier phase combinations, especially in the case of short baseline, are commonly used to obtain high orientating accuracy using the multi-frequency GNSS (Global Navigation Satellite System) due to their ability to mitigate measurement noise and multipath. However, after reviewing the errors in solutions of NL (narrow lane) combinations and the original combination (combine carrier phase data independently), it is found that the original combination always has a better performance than all NL combinations with positive coefficients regardless of which navigation system is used and how many frequencies are used. To achieve this, the observation equations of linear combination and original combination are first considered with emphasis on the relevant errors and the measurement noise mitigating ability. Then this paper derives the solutions of those combinations and focuses on their performance comparison in aspects of solution accuracy and systematic errors. Finally, the theoretical developments are verified with BDS data and the advantages of the original combination are summarized and discussed.