Bernese GPS Software Version 5.0 - Bernese GNSS Software

14.2 Precise Clock Estimation
Figure 14.2: Example for selecting the reference clock in the GPSEST program panel.
DCB, where yyyy is the 4-digit year and yymm the 2-digit year and month for the session you
are processing). We refer to Chapter 13 for more details about the differential code biases.
14.2.2 Selection of the Reference Clock
The input panel for the clock estimation in GPSEST is displayed in Figure 14.2. You have
the possibility to select one or more station or satellite clocks as reference for the clock
estimation in options “REFERENCE STATIONS” and “REFERENCE SATELLITES” respectively.
There are two ways to realize the reference clock in GPSEST:
• No clock corrections are estimated for the selected reference clock(s). The a priori
values are kept fixed. Select REFERENCE FIXED in option “Type of datum definition”.
If either “Receiver clock offsets” or “GNSS clock offsets” are selected for estimation in
panel “GPSEST 5.1: Setup of Parameters and Pre-Elimination 1” all clocks of the other type
(satellite or receiver) are not setup for estimation and are kept fixed as reference.
• Clock corrections are estimated for all clocks including the reference clock(s). Instead
of fixing the reference clock the sum of the estimates for all selected reference clocks
is set to zero by selecting ZERO-MEAN CONDITION in option “Type of datum definition”.
Fixing a reference clock makes sense, e.g., when you want to get the clock corrections with
respect to a specific receiver clock. If the receiver clock for this particular station is not
synchronized with CODSPP the resulting clock corrections for this reference clock are set
Bernese GPS Software Version 5.0 Page 293