Accession Number:

ADA229762

Title:

Clutter Rejection for Doppler Weather Radars with Multirate Sampling Schemes

Descriptive Note:

Project rept.

Corporate Author:

MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB

Personal Author(s):

Report Date:

1990-12-11

Pagination or Media Count:

132.0

Abstract:

Reliable weather parameter estimates are required of radars such as the Terminal Doppler Weather Radar TDWR which will automatically detect hazardous weather phenomena in the vicinity of an airport. Velocity and range aliasing will degrade the quality of these estimates, as will contamination by ground clutter. For radars which operate at short ranges and at low elevation angles, as the TDWR will to detect windshears at the airport surface, clutter contamination is an especially severe problem. Multirate pulse trains can extend both the unambiguous velocity and range of a Pulsed Doppler Radar beyond those afforded by pulse trains with a constant intersample spacing but the usual properties of conventional clutter filter architectures change radically when applied to data collected with a multirate sampling scheme. The Pulse-Pair spectral moment estimators are presented, followed by a discussion of frequency domain clutter rejection techniques for Batch PRT Pulse Repetition Time sequences. The main topic of the report is clutter suppression for Staggered PRT sequences in which the PRT alternates from pulse to pulse. The Staggered PRT scheme has the advantage over the Batch PRT scheme of spatial coherency for estimates of the radar return signals autocorrelation function at the lags corresponding to the two PRTs. A time varying filter architecture with multiple transfer functions is presented and analyzed, and its interaction with the Pulse Pair estimators is explored. Three design techniques for Staggered PRT filters are assessed in the context of clutter suppression. The final section of the report summarizes the results for the Batch and Staggered PRT schemes.

Subject Categories:

  • Meteorology
  • Active and Passive Radar Detection and Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE