89th American Meteorological Society Annual Meeting

Wednesday, 14 January 2009
Range overlaid staggered PRT
Hall 5 (Phoenix Convention Center)
David A. Warde, CIMMS/Univ. of Oklahoma, Norman, OK; and S. M. Torres
Poster PDF (223.0 kB)
Limitations in resolving both range and velocity unambiguously arise from uniform sampling as is typically done in Doppler weather radars. If the sampling period or pulse repetition time (PRT) is made large for extended range coverage, no overlaid conditions occur, but Doppler velocity measurements become ambiguously aliased. Conversely, if the PRT is made small to unambiguously resolve velocities, range-overlaid signals become more likely. Staggered Pulse Repetition Time (SPRT) has been shown to mitigate range and velocity ambiguities by decreasing velocity aliasing while extending the radar coverage. In other words, with the proper choice of PRTs, SPRT can eliminate the occurrence of overlaid echoes without sacrificing velocity aliasing. However, the performance of the SPRT algorithm to accurately dealias Doppler velocities deteriorates as the spectrum width of the weather signal increases in relation to the Nyquist interval. By allowing some overlaid signals to occur, shorter PRTs can be used to increase the SPRT dealiasing performance.

In this paper, we explore the use of range-overlaid SPRT as a means to improve the quality of Doppler velocity estimates. Additionally, we present a method to recover velocities beyond the unambiguous range of the standard SPRT algorithm.

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