Noise Correction of Polarimetric Radar Measurements

Presence of noise corrupts polarimetric radar signatures when the observations are made under low signal to noise ratio conditions. Unlike reflectivity measurements, noise contamination could affect differential measurements yielding unrealistic signatures (such as Zdr and LDR) inconsistent with reflectivity values. Therefore, noise correction is necessary to extend the range of polarimetric radar observations. Though in principle noise correction is straightforward in practice it is not so, because the received noise temperature changes with precipitation condition and elevation angle. This paper presents variability of noise power with observation environment. Examples of noise corrected and uncorrected polarimetric radar measurements from CSU-CHILL are presented.