Doppler Weather Radar - METNET - India Meteorological Department

B.1.4. Antenna system
a. Type - Feed Horn mounted on parabolic solid surface reflector.
b. Diameter - 8.6 meters i.e., 28 feet (nominal).
c. Beam Width- 0.95 degree pencil beam at 2800 MHz measured at 3 dB points.
d. Polarization- Linear Horizontal.
e. Side lobes 28 dB or better down from the main lobe to 12 degrees, 30 dB or lower
thereafter.
f. VSWR (Voltage Standing Wave Ratio) 1.15 : 1 maximum (with radome).
g. Safety Switch provided on antenna pedestal and at servo amplifier assembly.
h. Wave guide - Material – Aluminum.
The entire R. F plumbing shall be capable of operating satisfactorily at the prevailing
environmental conditions.
i. Type of pedestal -Elevation over azimuth.
B.1.5. Antenna scan details
B.1.5.1. Azimuth movements
a. Automatic mode 360 degrees continuous.
b. Manual mode -- Manually settable to any azimuth angle.
c. Azimuth rate Variable from 0 to 6 RPM.
d. Azimuth Accuracy 0.2 degrees or better.
e. Azimuth Resolution 0.1 degrees.
B.1.5.2. Elevation movement
a. Automatic mode - 1 degree to + 70 degrees.
b. Manual mode - 1 degree to +92 degrees.
c. Elevation speed in automatic mode Variable up to 5 scans per minute.
d. Elevation Speed in Manual mode Variable from 1 to 6 degrees per second.
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