Table 1 Processing strategy of multi-frequency and multi-GNSS PPP-RTK system
From: Principle and performance of multi-frequency and multi-GNSS PPP-RTK
Items | Strategies | ||
|---|---|---|---|
GNSS system | GPS, Galileo and BDS | ||
GNSS signals | GPS: L1, L2 and L5; Galileo: E1, E5a, E5b, E5 and E6; BDS: B1I, B2I and B3I | ||
Combination mode | Raw observations | ||
Data sampling interval | Server: 5 s; User: 1 s | ||
Elevation mask | 7° | ||
Minimum number of satellites | 4 | ||
Estimator | Sequential least squares | ||
Weight of observations | Elevation-dependent weight | ||
Phase wind-up effect | Corrected | ||
Satellite antenna phase center | Corrected by igs14.atx | ||
IFCB | Corrected by IFCB products | ||
Receiver antenna phase center | Corrected by igs14.atx | ||
Receiver clock | Epoch-wise estimated for each system and each frequency | ||
Phase ambiguities | EWL-WL-L1 cascade partial fixing | ||
Receiver coordinate | Server side | Fixed | |
User side | Estimated in the epoch-wise kinematic model | ||
Ionospheric delays | Server side | Epoch-wise estimated for each satellite | |
User side | Corrected by precise ionospheric corrections | ||
Tropospheric delays | Dry component | Modeled by Saastamoinen with Global Mapping function (GMF) | |
Wet component | Server side | Random-walk estimated | |
User side | Corrected by precise tropospheric corrections | ||