GNSS observable-specific phase biases for all-frequency PPP ambiguity resolution

Abstract An unwritten rule to resolve GNSS ambiguities in precise point positioning (PPP-AR) is that users should follow faithfully the frequency choices and observable combinations mandated by satellite clock phase bias providers. Switching other frequencies of measurements requires clocks be converted, albeit a roundabout way, agree with new code biases. Satellite biases, on hand, are prescribed conventionally as wide-lane narrow-lane combinations, which prevents from resolving case multi-frequency observables. We therefore develop an approach compute observable-specific biases (phase OSBs) concert legacy, but ambiguity-fixed, enable PPP-AR over any at user end, i.e. , all-frequency PPP-AR. In particular, OSBs baseline ( e.g. L1/L2 for GPS E1/E5a Galileo) estimated decoupling pre-aligned clocks; then re-estimated holding pre-resolved undifferenced frequencies; finally, all third-frequency determined introducing ambiguity-fixed above. used global network GPS/Galileo data month verify this approach. dual-frequency using L1/L2, L1/L5, Galileo E1/E5a, E1/E5b, E1/E5 E1/E6 signals, 95% ambiguity residuals were within ±0.25 ±0.15 cycles, respectively, after OSB corrections raw measurements. As result, fixing rates reached around tests, though it was only aligned pseudorange applied throughout. stress key computing such have same datum clocks.