Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 172
Flash Flood Forecasting Over Complex Terrain: With an Assessment of the Sulphur Mountain NEXRAD in Southern California Appendix B Characteristics of the NEXRAD Radar Parameter or Feature Value or Description Radar System Range of Observation Reflectivity 460 km Velocity 230 km Angular Coverage Azimuth Full circle or sector Elevation Operational limits; –1° to +20° Antenna Type S-band, center-fed, parabolic dish Reflector aperture 8.54-m (28-foot) diameter; circular Beamwidth (one-way, 3 dB) 0.96° at 2.7 GHz; 0.88° at 3.0 GHz Gain 45.8 dB at 2.85 GHz (midband) Polarization Linear horizontal First side-lobe level –29 dB Steerability 360° azimuth; –1° to +45° elevation Mechanical limits –1° to +60° Rotation rate 30° s –1 (azimuth and elevation) Angular acceleration 15° s –2 (azimuth and elevation) Pointing accuracy ±0.2° Radome Type Fiberglass skin foam sandwich Diameter 11.89 m (39 feet.) RF Loss (two-way) 0.3 ± 0.06 dB over 2.7–3.0-GHz band Transmitter Type Master Oscillator Power Amplifier (MOPA) Frequency range 2.7–3.0 GHz Peak power output (nominal) 500 kW into antenna Pulsewidth (nominal) 1.57 μs (short pulse); 4.5 μs (long pulse) ± 4% RF duty cycle (maximum) 0.002
OCR for page 173
Flash Flood Forecasting Over Complex Terrain: With an Assessment of the Sulphur Mountain NEXRAD in Southern California Pulse Repetition Frequency Long pulse 322–422 Hz ± 1.7% Short pulse 322–1282 Hz ± 1.7% Waveform types Contiguous and batch (phase-coded build 8.0) Receiver Type Linear Tunability (frequency range) 2.7–3.0 GHz Bandwidth (3 dB) 0.63 MHz (short pulse); 0.22 MHz (long pulse) Phase control Selectable Receiver channels Linear output I/Q Dynamic range 95 dB max; 93 dB at 1-dB compression Minimum detectable signal –113 dBm (ORDA) Noise temperature 450 K (ORDA) Intermediate frequency 57.6 MHz Sampling rate 600 kHz (This remains the same for the I/Q samples; IF samples will be at 72 MHz) Signal Processor Type Programmable Parameters derived Reflectivity; mean radial velocity; Doppler spectral width Algorithms (respective) Power averaging; pulse-pair; single-lag correlation Accuracy (Standard Deviation) Reflectivity <1 dB Velocity and spectrum width <1 m s–1 Number of Pulses Averaged Reflectivity 6–64 Velocity and spectrum width 40–200 Range Resolution Reflectivity 1 km Velocity and spectrum width 0.25 km Azimuth Resolution Reflectivity 1° Velocity and spectrum width 1° Clutter canceller Gaussian Model Adaptive Processing Filter, Spectral Domain Clutter suppression 30–50 dB max Radar Product Generator (RPG) RPG processor 64-bit reduced instruction set (RISC) digital computer Shared memory 512-MB semiconductor memory Wide-band communication 1.544 Mbit s–1 data rate Narrow-band communication Up to 13 of 14,400/4,800 bit s–1 4-wire (1 may be 33,600 bit s–1 capable) 8 of 14,400/4,800 bit s–1 2-wire Up to 9 Wide Area Network (WAN) connections RPG Graphic Display Processor Principal user processor (PUP) 64-bit RISC digital computer
OCR for page 174
Flash Flood Forecasting Over Complex Terrain: With an Assessment of the Sulphur Mountain NEXRAD in Southern California Communications 14,400/4,800 bit s–1; 2- and 4-wire (maximum: 28 lines) Video Color, with split-screen and zoom features Mass storage Up to two 40-GB disks Other National Climatic Data Center (NCDC) National archive for NEXRAD data and other meteorological and climatological data. Level II archive Network interface located at the RPG. Digital base data are output from the Base Data Dissemination System (BDDS), which includes base reflectivity, mean radial velocity, and spectrum width. Data are sent electronically to the NCDC for permanent storage. (Completed nationwide in September 2004) Level III archive Interface is located at the RPG. A set of predetermined products defined in FMH-11 Part A is sent electronically to NCDC for permanent storage. (Completed nationwide in September 2004) National Weather Radar Network Consists of WSR-88D sites dispersed throughout the conterminous United States (CONUS) plus Department of Defense sites or non-CONUS Department of Transportation sites.
Representative terms from entire chapter: