Principals of Radar
F
NWS Radar Characteristics 28 foot dish Pulse Width 0.95° Peak Power 750kW –Avg. Power 1.5kW Discrete Pulse Transmissions Pulse length: –1.5 µsec.; or about 250 meters(0.13 nm). Pulse volume is 250 meters by 1 degree in azimuth. Radar Range: –Reflectivity = 248 nm –Velocity = 124 nm Volume Coverage Patterns (Clear Air vs. Precipitation Mode) –10 minutes vs 5 minutes Doppler and Surveillance Channels 3 Base Data Products –Reflectivity –Velocity –Spectrum Width
RADAR PRODUCT GENERATOR (RPG) RADAR DATA ACQUISITION UNIT (RDA) F
BACKSCATTERED ENERGY TARGET BACKSCATTERED ENERGY TRANSMITTED PULSE RADAR F
REFLECTIVITY LARGER PARTICLES - HIGHER REFLECTIVITY SMALLER PARTICLES - LOWER REFLECTIVITY F
15 TO 29LIGHT 30 TO 39MODERATE 40 TO 44HEAVY 45 TO 49VERY HEAVY 50 TO 54INTENSE 55 AND ABOVEEXTREME WSR-88D DBZ RANGES (I.E., REFLECTIVITY) PRECIPITATION INTENSITY F
VOLUME COVERAGE PATTERN F
VOLUME COVERAGE PATTERN (VCP) 11 F HORIZONTAL RANGE (NM) HEIGHT (K FT)
VOLUME COVERAGE PATTERN (VCP) 21 HORIZONTAL RANGE (NM) HEIGHT (K FT) F
F
VOLUME COVERAGE PATTERN (VCP) 31 AND 32 HORIZONTAL RANGE (NM) HEIGHT (K FT) F
F
CREATING COMPOSITE REFLECTIVITY F
THE DISPLAYED VALUE ON THE COMPOSITE REFLECTIVITY IMAGE IS: 50 COMPOSITE REFLECTIVITY F
F
CONE OF SILENCE F º19.5°
CONE OF SILENCE F HORIZONTAL RANGE (NM) HEIGHT (K FT)
Cone Of Silence F
F
F ECHO TOP PRODUCT “STAIR-STEPPED” APPEARANCE ECHO TOP INDICATED ON PRODUCT ECHO
F MAX K FT: 39
F
F
FREEZING LEVEL HIGH REFLECTIVITY BAND FORMATION OF BRIGHT BAND 0ºC F
F BASE REFLECTIVITY DEGREESBASE REFLECTIVITY DEGREES BASE REFLECTIVITY DEGREESBASE REFLECTIVITY DEGREES 25NM 50NM
FREEZING LEVEL HIGH REFLECTIVITY BAND 0ºC 0.5° 1.5° 2.4° 3.5° F BRIGHT BAND AND ELEVATION ANGLE
FINE LINE F
GROUND CLUTTER F
ANOMALOUS PROPAGATION (AP) F
HIGH REFLECTIVITY VALUES F
LOW ECHO TOPS F
F
F
F
BASE REFLECTIVITY 0.5 DEGREES DECEMBER 28TH, 1998 F
The End Questions???