Three radars were used throughout the two-year study period. During the Winter 2001 field project, data from only one radar was available, the C-Band (5-cm wavelength) Doppler radar located at the Al Dhafra Air Force Base . In March 2001, the radar at Dubai International Airport came online after network limitations were solved. In 2002, the DWRS mobile radar began operations at the Al Ain International Airport.Nominal Parameters of the UAE Radars
|Polarization||Horiz.||Horiz & Vert.||Horiz & Vert.|
|Antenna beamwidth (°)||1.10+||0.93||2.25|
|Antenna gain (dB)||43||46||38|
|Transmitter power (kW)||250||300||300|
In order to collect high-quality radar data that would satisfy the requirements for general forecasting, aviation forecasting, and the rainfall studies, a new volume scan strategy was developed and implemented. View scan strategy
Slight changes to the number of samples and the scan rate allowed for a volume repeat time of 6 min, which was utilized on the Al Dhafra radar for the 2001 winter project. The scan strategy was changed to the above parameters for the Al Dhafra and Dubai radars during the 2001 summer project (e.g., volume scans every 10 min). Subsequent investigation into dropouts of radar data showed that the EEC processor speed was not fast enough to allow for the theoretical scan rate, and therefore the scan rate was decreased to 17-18° s-1. This resulted in longer volume scan times, but still shorter than the volume repeat time of 10 min.
One complicating feature of the radar data in the UAE is "clutter", caused mainly by anomalous propagation (AP). Normal ground clutter and sea clutter is exaggerated during periods of AP, which commonly occurs when the nocturnal inversion develops with a high moisture gradient near the surface. Accurate rainfall estimates require the implementation of an algorithm or special scan strategy to eliminate or at least minimize this phenomenon. A radar data quality enhancement study was completed in October 2002, although the resulting algorithm continues to be fine tuned for the UAE environment. View information about our data quality enhancement efforts