Accession Number : AD0715884

Title :   Special Radar Projects at the National Severe Storms Laboratory. The 'R'-Meter.

Descriptive Note : Final rept. 1 Jul 68-1 Apr 70,

Corporate Author : NATIONAL SEVERE STORMS LAB NORMAN OKLA

Personal Author(s) : Sirmans,Dale

Report Date : SEP 1970

Pagination or Media Count : 31

Abstract : The power returned from a random distribution of scatterers moving relative to each other fluctuates about its mean at a rate proportional to the width of the velocity spectrum. The average crossing rate can be observed with an incoherent radar and the velocity spectrum width inferred if the spectra are not spuriously broadened by system instability. However, tolerable levels of stability are not normally achieved in practice with most incoherent radar systems such as the WSR-57 and the CPN-18. Another source of error in crossing rate measurements is receiver noise; this limits quantitative measurement of the crossing rate to signals whose mean is 20 dB or more above the noise unless a correction is made. Relationships among crossing rate, meteorological parameters, and radar characteristics are derived for several models of interest. Crossing-rate-processing of radar echo data continues to be an attractive concept, although further consideration of attendant problems is indicated. (Author)

Descriptors :   (*THUNDERSTORMS, WIND), (*METEOROLOGICAL RADAR, *WEATHER FORECASTING), RADAR CROSS SECTIONS, VELOCITY, SCATTERING, X BAND, S BAND, RADAR SIGNALS, DOPPLER RADAR, STABILITY, DATA PROCESSING, NOISE(RADAR), RADAR RECEIVERS, PROBABILITY

Subject Categories : Meteorology

Distribution Statement : APPROVED FOR PUBLIC RELEASE