| Wideband waveform techniques, such as pulse compression, allow for accurate weather measurements in a short data acquisition time. However, for extended targets such as precipitation systems, range sidelobes mask and corrupt observations of weak phenomena occurring near areas of strong echoes. Therefore, sidelobe suppression is extremely important in precisely determining the echo scattering region. Dual-polarization parameters provide valuable insight into the cloud microphysics and improved rainfall rate estimates. A simulation procedure has been developed here to describe the signal returns from a random fluctuating medium such as distributed weather targets with pulse compression waveform coding, for both single and dual polarization operation. The simulation procedure allows for generation of a frequency or phase modulated transmit waveform and is capable of generating time series from various test profiles for reflectivity, velocity, spectrum-width and signal-to-noise ratio with range. For dual-polarization simulation, in addition to the parameters listed above, range profiles for the differential reflectivity {dollar}Zsb{lcub}DR{rcub}{dollar}, and the complex correlation coefficient at lag zero {dollar}rhosb{lcub}HV{rcub}{dollar}(0) can also be specified. Results from the simulation are used to evaluate the performance of various pulse compression techniques such as Barker phase codes, complementary codes, etc., and various compression filters such as matched filters, inverse filters, and their Doppler tolerant implementations. The evaluation is based on comparative analysis of the integrated sidelobe level and Doppler sensitivity after the compression process. Pulse compression data from CSU-CHILL and Eldora testbed radars have been analyzed. The results from simulation and the data analysis show that pulse-compression techniques indeed provide a viable option for faster scanning rates while still retaining good accuracy in the estimates of various parameters that can be measured using a pulsed-Doppler radar. Also, it is established that with suitable sidelobe suppression filters, the range-time sidelobes can be suppressed to very low levels. |
