There are several advantages to using very accurate clocks such as atomic clocks with global navigational satellite systems (GNSS) receivers CSACs (chip scale atomic clocks), which became commercially available several years ago, are easily integrated with GNSS receivers, and therefore, there have been many studies involving the use of CSACs with GNSS receivers. In this study, we attempt to realize fast re-tracking for short signal losses in urban areas by incorporating a CSAC with a SDR (software defined receiver). We focus on the robustness of the carrier phase, and perform experiments involving static tests. The results obtained showed that there are only slight differences between normal tracking and Doppler-aided tracking.

Keywords: Doppler aiding, GNSS, tracking loop, software receiver, SDR