A standalone application to monitor the stability of a low cost maintenance free X-band mini weather radar, using ground clutter echoes

During the past years, the Remote Sensing Group of Polytechnic of Turin developed a prototype of a X-band mini weather radar capable to detect and measure rain with good performances. These radar systems may suffer some degradation due to external factors like temperature fluctuations: some adjustment shoul be automatically implemented through a periodic control procedure, in order to have continuosly correct rainfall estimation. An application to monitor the X-band mini weather radar is presented. The basis of the proposed methodology is to control the radar signal stability though a statistical analysis of clutter echoes coming from a multiplicity of ground target during clear sky days. It has been design as a standalone software which can be periodically run by a radar user and which can be fully integrated with the common radar control and signal processing software. The application allows two type of analysis: short term and long term period. The short term analysis tracks the variations of the mean clutter value in six concentric circular crowns around the radar, in order to take into account different type of clutter at different distances. It is useful to monitor the radar signal with respect to the temperature fluctuations. The long term analysis is based on an adapted version of the RCA (Relative Calibration Adjustment) proposed by D.S. Silberstein et. al. in an article published in 2008 (Journal of Atmospheric and Oceanic Technology) which works on the cumulative distribution function of radar reflectivity. The application has been already installed onboard on two radar and both the short term and the long term period analysis have been performed achieving good results.