Ka-Band Precipitation Radar (KPR)

KPR is a compact Ka-band Precipitation Radar and radiometer for measuring vertical profiles of reflectivity and Doppler velocity. Key features of the instrument are: a pair of flat-plate array antennas pointing in the zenith and nadir directions, 10 W peak power solid state transmitter amplifier and a low-loss switch network. KPR includes an integrated noise source and ambient load for sky brightness temperature measurements and radiometric calibration of its receiver. The instrument is packaged to install in a standard (6″ ID x 24″ L) PMS probe canister.

Frequency:   35.6 GHz
Transmitter:   10 W solid state power amplifier
Antennas:   14 cm flat-plate array, 4.5 deg. beam-width
Pulsing:   Interleaved short RF and linear FM pulses
Range Resolution:   30, 75, 100 or 150 m
Delta T:   1 K @ 200 ms integration (5 Hz data rate)
Rec. Noise Temp.:   440 K
Radomes:   Matched Rexolite window
Weight:   25 lb (40 lb with canister)
Power:   50 W AC; 100 W  28 VDC
Example Data




(Click on image to see it in high resolution.)

KPR combined short pulse – chirped long pulse reflectivity (top), Doppler velocity (middle – uncorrected for aircraft motion) and Doppler velocity spectrum width (bottom – uncorrected for aircraft motion induced spectrum width bias) images collected on September 4, 2016 near Laramie Wyoming from the Univ. of Wyoming King Air research aircraft. The aircraft was flying approximately 3 km above ground and 2 km above the melting layer, while collecting data using alternating pulse pairs from the zenith and nadir pointing antennas at 30 m range resolution.