YIBL (25001M001) IGS station web page
The YIBL IGS station in located in western Oman near the town of Fahud, Oman. The site is operated by Petroleum Development Oman (PDO), which is the premier hydrocarbon exploration and development company in the Sultanate of Oman. Data from the site are available from July 13, 2003 (GPS Week number 1227).
The location of the site in Oman is shown in Figure 1. It is expected that the site will be on the Arabian plate.
Figure 1: Location map of the YIBL IGS site showing expected ITRF 2000
motion. The McClusky
et al. [Geophys. J. Int, 2003] Euler pole for the Arabian Plate, predicts
the velocity of YIBL will be North 30.5 mm/yr, East 35.2 mm/yr.
Site construction
The monument at the site is a SCIGN style short-braced monument constructed from the basic design shown in Figure 2.
Figure 2: Basic construction design of the YIBL monument. (Full size
figure).
Below, photographs of the site are shown looking in the north, east, south and west cardinal directions.
View looking north at YIBL (The fence is about 1-m high). The solar panels, east of the monument, are facing south. The data from the site transmitted using an Intuicom system to central location west of the site. The continuously operating telemetry system was installed and is monitored by Condor. The PDO Geomatics department constructed of the site.
View looking east at YIBL
View looking south at YIBL
View looking west at YIBL
Details inside the enclosure showing the Ashtech Micro-Z receiver and Intuicom radio inside the passive cool box.
Results from site
Here we show some of the characteristics of the site.
Atmospheric delay estimates
The above plot shows the "wet" atmospheric delays at the YIBL site. The dark blue closed circles with light blue error bars are GPS estimates. The red line show values (every 6 hours) obtained from the analysis of the National Center for Environmental Prediction (NCEP) 3-D global weather assimilation model. An average hydrostatic ("dry") delay is computed from the NCEP surface pressure at Yibal and is removed from both the GPS and model estimates. Despite this site being in a desert, at times, the wet delay is same magnitude as that found in tropical regions.
Phase residual plots: Sky-map view.
The plot above shows typical dual-frequency corrected phase residuals from the YIBL site. The root-mean-square (RMS) scatter of the residuals is 6.3 mm. The plots are shown in 4-hr intervals and show a sky projection of the residuals. In each frame, North is to the right and east is up. The center of each circle is the zenith direction, and the circle corresponds to 0-deg elevation (results are shown to 10 degree elevation). The residuals are plotted normal to the tracks of the satellites across the sky with green areas being positive residuals and yellow areas being negative residuals. The thick short red lines in each frame show the size of 19 mm residual. Blue-colored lines on the satellite tracks show times when data were available but were not used in the GPS processing. (These times are generally for data between the minimum tracking elevation angle at the site of 5 degrees and the processing cutoff of 10 degs).
Phase residual plots: Histograms and elevation angle dependence.
Histograms of the phase residuals binned in 10-deg elevation bins and, in the lower portion of the figure, dual-frequency phase residuals for 24-hours of data shown as a function of elevation angle. The elevation angle plot, the thick red line near zero is the average residual as a function of elevation angle. The yellow dots (which appear to lie on the green lines) are the RMS scatter of residuals as a function of elevation angle. The green lines are a fit to the yellow dots using an inverse sine of elevation angle model. The model and coefficients are shown at the top of the plot. The thin red horizontal lines show the 1-sigma bounds based on the RMS scatter.