G05 GNSS++: Emerging Technologies and Applications

IAG (Geodesy)

25-Jun-2015, 15:00 - 16:30

Abstract content:

Real-time troposphere delay modeling using GNSS Precise Point Positioning and IGS-RTS products

The availability of IGS Real-Time Service (RTS) products makes Precise Point Positioning (PPP) a very powerful technique to process GNSS (Global Navigation Satellite System) signals in real-time. There are still, however, some limitations of PPP. A significant change in satellite geometry is required to efficiently de-correlate troposphere delay, receiver clock offset, and receiver height.
Wroclaw University of Environmental and Life Sciences (WUELS) is developing regional troposphere delay models to support numerical weather prediction (NWP) models and PPP-RTK positioning. The fully operational model works in near real-time (NRT) regime over area of Poland. Although the latency of NRT model is sufficient for NWP, a minimum latency is required to support precise positioning. One possibility is to provide a short forecast of ZTD using the distribution of meteorological parameters. Another option is to take advantage of IGS real-time service (RTS) and reduce the latency of estimated ZTD to minimum.
Using the original GNSS-WARP software, a number of Polish EPN stations was processed in a simulated real-time conditions over one week long test campaign. The resulting ZTDs were compared to ZTDs obtained with NRT strategy. The mean error of estimated ZTD was 3.0mm, mean value of residuals was -9mm, with standard deviation of 13mm. The residuals with respect to reference solutions exceed 20mm in some epochs. Although the accuracy of the obtained results is not enough even for NWP support, the advantage of the presented solution is the low-latency and high-temporal resolution of derived ZTD.

T. Hadas1, J. Kaplon1, J. Bosy1.
1Wroclaw University of Environmental and Life Sciences, Institute of Geodesy and Geoinformatics, Wroclaw, Poland.


PPP     Real-Time     IGS RTS     troposphere     ZTD