Figure 8 - The differences between the results of (epoch to epoch) GNSS and
differential levelling as well as mean values and standard deviations of the
differences for three baselines in (a) and L1 DDR values for P1 - P4 in (b).
Furthermore, the L1 DDR values for baseline P1- P4 are shown in Figure 8(b).
Between 12:25 UT and 12:50 UT, the maximum phase residual for the baseline P1-
P4 is about 30 mm which is approximately 1/6 of an L1 cycle. One should also note
that the mean values and the standard deviations are below 1 cm for the height
differences from P2-P4 and P3-P4, see Figure 8(a). Moreover, the L1 DDR values for
P2-P4 and P3-P4 are significantly less scattered according to the ones for P1- P4. But,
we can not show the residuals for all the sessions due to the lack of space.
From Table 4, it is clear that 10-min rapid static solutions corresponding to the
period between 12:30 and 13:30 appear as spoiled for the baseline P1-P4, see the 3rd
interval in Table 4. The few sessions for which this accuracy could not be obtained,
corresponding to the sessions of bad satellite geometry and multipath effect on the
site P1 where the ambiguities could not be fixed. Thankfully, the rapid static
solutions of 30-min do not expose such disturbances occurring at the same periods.
The solutions for the baselines P2-P4 and P3-P4 do not include this kind of
contamination since they are significantly far from the multipath environment on the
site P1.