Table 1 Summary of PPP processing models and strategies

Observations

Pseudorange and carrier phase on GPS L1 and L2

Observation weighting

Elevation-dependent weight

Sampling interval

5 s

Elevation mask angle

5°

Satellite orbit

Fixed using the products from the International Global Navigation Satellite System Service (IGS)

Satellite clock

Fixed using the products from the IGS

Phase wind-up effect

Applied

Site displacement

Applied

Phase center offset and variation

IGS14.atx

Ionospheric delay

First-order effect eliminated by ionospheric-free linear combination

Tropospheric delay

Estimated with the coordinates

Ambiguity resolve

Estimated as real numbers

Receiver coordinates

Estimated in kinematic mode