TWP/MMCR/C3 - Antenna gain/beamwidth uncertainty
|DataStreams:||twpmmcrspecmomC3.a0, twpmmcrmomC3.00, twpmmcrmomC3.b1|
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.