Download - Epochs
Epochs
1 2 3 4 5 Hours
20
0 mm
-20
Elevation angle and phase residuals for single satellite
Simple geometry for incidence
of a direct and reflected signal
Multipath contributions to observed phase for an antenna at heights (a) 0.15 m, (b) 0.6 m, and (c ) 1 m. [From Elosegui et al, 1995]
Antenna Phase Patterns
Top: PBO station near Lind, Washington.
Bottom: BARD station CMBB at Columbia College, California
Left: Phase residuals versus elevation for Westford pillar, without (top) and with (bottom) microwave absorber.
Right: Change in height estimate as a function of minimum elevation angle of observations; solid line is with the unmodified pillar, dashed with microwave absorber added
[From Elosequi et al.,1995]
Correlation between estimates of height and zenith delay as function of minimum elevation angle observed (VLBI, from Davis [1986])
Uncertainty in estimated height as function of minimum elevation angle observed
(VLBI, from Davis [1986]; dotted line with no zenith delay estimated)
GPS adjustments to atmospheric zenith delay for 29 June, 2003; southern Vancouver Island (ALBH) and northern coastal California (ALEN). Estimates at 2-hr intervals.