TWP/MMCR/C3 - Antenna gain/beamwidth uncertainty

Upon installing the KAZR at Darwin, we found that the antenna's subreflector was loose.  
Based on measurements from the manufacturer, a 0.001" change can change the antenna gain 
of approximately 1 dB.  This adds an uncertainty of 2 dBZ reflectivity measurements.  We 
measured slightly more than 0.100" off nominal position.  However the manufacturer does 
not measure the subreflector location for each antenna so we do not know how far off, if at 
all, the subreflector is from its position when it was characterized at the test range.

We have contacted CSIRO and are investigating the possibility of sending the antenna to 
their near-field antenna test range.  In several months we will also have a Ka-SACR at 
Darwin that will enable us to do a cross-calibration.

Until the antenna calibration can ascertained, I recommend data users consider the 

reflectivity uncertainty due to the possible antenna misalignment to be +/- 3dBZ.

• Raw data stream - documentation not supported

• Reflectivity
• RadarConstant
• RangeCorrectedPower

• CalibrationConstant
• RadarConstant