Bernese GPS Software Version 5.0 - Bernese GNSS Software

12.4 Estimation of Deterministic Ionosphere Models
observed in a rapid-static mode [Schaer, 1994]. The formal accuracy of the coordinates/
ambiguities is plotted with solid/dotted lines. We may recognize in Figure 12.4 that (a) the
transition essentially takes place when the a priori sigma of the SIPs is of the same order
of magnitude as the a priori measurement noise (assumed to be 4 millimeters) and that
(b) for a very big a priori sigma, the 8 dotted curves showing the formal accuracy of the
L1/L2 ambiguities go to infinity. Note that this particular scenario is based on a 5-satellite
constellation.
12.4 Estimation of Deterministic Ionosphere Models
12.4.1 Local Ionosphere Models
Local ionosphere models (type-1 models) according to Eqn. (12.11) may be estimated with
program IONEST (”Menu>Service>Ionosphere tools>Local ionosphere model estimation”). The processing
steps RXOBV3 and CODSPP are presupposed.
In panel “IONEST 1: Filenames” (Figure 12.5), you decide whether you want to analyze the
geometry-free linear combination of either CODE or PHASE observations. We recommend to
analyze PHASE observations. At “Phase observations” or “Code observations”, one or more zerodifference
observation files may be selected. If you want to derive more than one ionosphere
model per session, you have to concatenate/split up the observation file(s) into the desired
Figure 12.5: Filenames for IONEST.
Bernese GPS Software Version 5.0 Page 263