Recent advancements on range ambiguity characterization and mitigation for the NASA D3R

The NASA dual-frequency, dual-polarization, Doppler radar (D3R) is a weather radar operating at 13.91 GHz (Ku-band) and 35.56 GHz (Ka-band). The operational range of the D3R is 40 km, this relatively short operating range, along with the high sensitivity of D3R, are susceptible to increased observation of range ambiguous echoes, also referred to as “second-trip echoes”. In this work, by leveraging a staggered pulse repetition period and random transmitted phase codes, two methods are developed to detect and dealias the second trip contamination for the operational use with the D3R. Using these methods, the overlapping echoes are separated, and unambiguous range of the D3R is increased. Weather signals are simulated and used to quantitatively characterize the performance of moment estimator over a wide range of realistic weather scenarios. The D3R's Ku-band observations are presented to demonstrate the performance of algorithm with and without overlapping echoes from different ranges.