Advances in Positioning and Reference Frames pp 93-100 | Cite as
Processing Strategies for Regional GPS Networks
Abstract
At the Center for Orbit Determination in Europe (CODE), one of the IGS Analysis Centers, we are routinely processing the GPS data of a dense European network. In order to improve the height estimates and, very strongly coupled therewith, the modelling of the troposphere for this network, we decided to include low-elevation data into the processing, something that has been done in VLBI analyses for a long time. An appropriate mapping function, the option to weight the observations according to the elevation angle, and the estimation of troposphere gradients were implemented to make best use of the data at low elevations. Problems may arise from phase center variations, multipath, and the troposphere.
143 days have been processed so far using the new processing options and data down to 5 degrees elevation. Comparing the results to a standard 15-degree elevation cut-off solution shows, that the use of low-elevation data together with an elevation-dependent weighting of the observations reduces the scatter in the height estimates by about 20–30 percent. The estimation of tropospheric gradient parameters improves the repeatability in the horizontal site coordinates by a factor of two for sites successfully tracking down to 10 degrees and below.
Keywords
Ambiguity Resolution Troposphere Zenith Delay Zenith Delay Phase Center Variation Troposphere GradientPreview
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