Pulse compression for weather radars

Abstract

Abstract-Wideband waveform techniques, such as pulse compression, allow for accurate weather radar 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. A simulation procedure has been developed to accurately describe the signal returns from distributed weather targets, with pulse compression waveform coding. This procedure is unique and improves on earlier work by taking into account the effect of target reshuffling during the pulse propagation time which is especially important for long duration pulses. The simulation procedure is capable of generating time series from various input range profiles of reflectivity, mean velocity, spectrum width, and SNR. Results from the simulation are used to evaluate the performance of phasecoded pulse compression in conjunction with matched and inverse compression filters. The evaluation is based on comparative analysis of the integrated sidelobe level and Doppler sensitivity after the compression process. Pulse compression data from the CSU-CHILL radar is 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 levels that are acceptable for operational and research applications.

Weather Radar Network With Pulse Compression of Arbitrary Nonlinear Waveforms: Ka-Band Test-Bed and Initial Observations

“…The frequency modulation makes the carrier frequency of the transmit waveform swept in a time domain. It is known to yield good range sidelobe performance comparing other methods [3]. Pulse compression has not been widely employed in weather radar primarily due to unignorable range sidelobes.…”

“…Meanwhile, various researchers have tried to use pulse compression technique in weather radar [3][4][5][6][7]. It transmits long modulated pulses and compresses corresponding echo signals, resulting in finer range resolution with the lower peak power.…”

Improving weather radar observations using pulse‐compression techniques

“…By appropriate compression filtering in the receiver, this modulation can be unwound and the pulse compressed producing data of fine-range resolution. Thus, the compressed waveform has a time resolution of 1/B seconds and a theoretical range resolution of c/2B m (Keeler, 1995;Mudukutore et al, 1998), denoted here as r B :…”

“…Since then, more engineering and technical aspects have been investigated by Bucci and Urkowitz (1993), Keeler (1995) and Mudukutore et al (1998), among others. Meteorological research carried out using this technique include studies of clear-air wind shear using high power radar (Browning et al, 1978), cloud observations with millimetric radar (Sekelsky and McIntosh, 1996;Clothiaux et al, 2000;Uttal and Kropfli, 2001) or airborne radar precipitation observations (Girardin-Gondeau et al, 1991;Durden et al, 1994;Tanner et al, 1994).…”

Decoding of Barker-coded incoherent scatter measurements by means ofmathematical inversion

“…Key et al, 1959;Rihaczek and Golden, 1971;Mudukutore et al, 1998; see also the textbook by Blinchikoff and Zverev, 1987). Decoding Barker coded incoherent scatter measurements without sidelobes can be made using an infinitely long filter.…”