Interdisciplinary Distinguished Lecturer: Dr. Svetlana Bachman

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Weather Radar

Dr. Svetlana Bachman, Researcher
University of Oklahoma

Dr. Svetlana Bachman spoke on Friday, January 18th, 2008 at 12:30PM in Engineering Building II, Room 1230

A novel method for suppression of ground clutter
(GC) in weather radar is presented. The novel identi?cation
scheme is entirely phase based, unlike power-based schemes that
are generally used. GC contributions to the Doppler spectrum are
identi?ed from the differential phase between complex spectral
coef?cients of two spectra estimated for odd- and even-indexed
half-sequences of the original time series. Phase values near zero
are used as indicators of clutter contributions for Doppler bins
close to zero velocity. Indicated Doppler bins are notched from the
original spectrum, and the moments are then obtained. The identi-
?cation scheme is motivated by spectra of an electronically steered
phased array of the National Weather Radar Testbed (NWRT)
and requires a suf?cient number of pulses/samples for spectral
analyses. However, the method can be used with a mechanically
steered antenna with an appropriate adjustment compensating
smearing due to antenna rotation. The method was tested on
several NWRT data sets obtained in clear air and in precipitation.
One example of clutter-?ltered power in precipitation is shown
here. There is no baseline for comparison, as the NWRT does
not have clutter ?ltering at the present time. Nonetheless, for
a comparison of power- and phase-based identi?cation schemes,
a power-based clutter ?lter similar to the one used by the National Weather Service on the network of mechanically steerable
Weather Surveillance Doppler radars WSR-88Dâs is implemented
on NWRT and used as a preliminary baseline for comparison.