The ground system improves the aircraft positional accuracy by recording 1-sample-per-second raw gps pseudorange, carrier phase, and carrier doppler frequency data (RANGECMP log) at a fixed and known location for use in post-flight processing.
Raw gps satellite pseudorange and carrier data for post processing. Output at 1 sample per second.
Overall estimate of uncertainty: After post-processing, the best-case horizontal uncertainty is 1 cm + 1 ppm of the baseline between ground station and aircraft for baselines up to tens of kilometers. Vertical uncertainty is a few times greater than horizontal uncertainty.
Response time: 10 samples per second (from aircraft rangecmp log)
