Efficient Dual-Frequency Ambiguity Resolution Algorithm for GPS-Based Attitude Determination

This paper discusses the benefits of using dual-frequency receivers for attitude determination applications. The ambiguity resolution performance, baseline, and attitude solution accuracy is compared between single and dual-frequency modes. Evaluation is performed both in static and kinematic environments. While the static data were collected in an open-sky environment, the two kinematic data sets were collected in “degraded” environments including partial blockages due to trees or overpasses. The level of dynamics observed during these tests is somewhat limited, as the vehicle often travels at constant speed, but is, however, representative of car navigation. Results indicate that for baselines as long as $10\mathrm{m}$ , the proposed WL/L1 cascaded ambiguity resolution scheme significantly outperforms its single frequency counterpart by providing faster and more reliable fixed ambiguity resolution. Assuming a correct ambiguity fix, dual frequency observations do not provide significant improvements in terms of baseline or attitude accuracy. However, the improved speed and reliability of the dual frequency ambiguity resolution algorithm does translate, especially in kinematic mode, into significant improvements in terms of attitude solution availability and reliability.