Accession Number:

ADA209478

Title:

Dual-Beam Autocorrelation Based Wind Estimates from Airport Surveillance Radar Signals

Descriptive Note:

Project rept.

Corporate Author:

MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB

Personal Author(s):

Report Date:

1989-06-21

Pagination or Media Count:

49.0

Abstract:

This report describes an efficient, autocorrelation based algorithm for estimating low altitude radial winds using signals from the two receiving beams of an airport surveillance radar ASR. The approach seeks to achieve the accuracy demonstrated previously for spectral domain dual beam velocity estimators with significantly reduced computational requirements. Fundamental to the technique is the assumption that the power spectrum measured with an airport surveillance radars broad elevation beam can be fitted by a two component Gaussian model. The parameters of this model are estimated using measured low- order autocorrelation lags from the low and high beam received signals. The desired near surface radial velocity estimate is obtained directly as one of these parameters - the center frequency of the low altitude Gaussian spectrum component. Simulated data and field measurements from Lincoln Labs experimental ASR-8 in Huntsville, Al, were used to evaluate the accuracy of the autocorrelation based velocity estimates. Monto Carlo simulations indicate that biases relative to the near surface outflow velocity in a microburst would be less than 2.5 ms unless the microblast were distant range 12 km or very shallow depth of maximum wind speed layer 50 m. Estimate standard deviations averaged 0.5 ms after the spatial filtering employed in our processing sequence. The algorithms velocity estimate accuracy was sufficient to allow for automatic detection of measured microbursts during 1988 with a detection probability exceeding 0.9 and a false alarm probability less than 0.05.

Subject Categories:

  • Meteorology
  • Active and Passive Radar Detection and Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE