Evaluation of the Use of High Rate Tracking Data for Jason-3 GPS-Based Precise Orbit Determination
Event: 2020 Ocean Surface Topography Science Team Meeting (virtual)
Session: Precision Orbit Determination
Presentation type: Type Forum
The GPS receiver onboard Jason-3 provides dual-frequency (L1 and L2) phase and pseudorange tracking data every 10 seconds. Our prior Jason-3 GPS-based precise orbit determination (POD) solutions have typically been based on 5-minute sampled ionosphere-free phase (LC) and carrier-smoothed ionosphere-free pseudorange (PC) tracking data. This heritage approach is based on the assumption that the 5-minute clock bias estimates for the GPS constellation have superior accuracy compared to higher temporal resolution estimates. In this presention we investigate the use of 30-second sampled LC and carrier smoothed PC data for Jason-3 POD, given that the accuracy of 30-second estimates of the GPS constellation clock biases have improved from when our heritage approach was first adopted. Orbit differences of POD solutions determined from 30-second data with respect to those from 5-minute data are non-negligible. They have a distinct 60-day period with peak-to-peak variations of up to 3, 0.1, and 6 mm in the radial, cross-track, and along-track components, with some sensitivity to data weighting. We consider the usual suite of internal metrics (post-fit residuals, day-to-day consistency as measured by overlaps of daily solutions), and the independent metric from withheld satellite laser ranging residuals. We also present updated results of the in-flight tracking performance of the Jason-3 GPS receiver.