Doppler Weather Radar - METNET - India Meteorological Department

SA9-15 Current at position 15 of A1SA9 with the PRF 322Hz and narrow pulse.
C.2 Calibration procedure for dynamic range
ZAUTO
This is a command used in the RCP8 to find the dynamic range value. In this method, we first
measure the total noise level of the Signal processor by measuring the equivalent dBZ input with
no test Signal inserted. We will then insert the internal CW test Signal into the input of the
Receiver Protector. The test Signal amplitude will be sequentially adjusted in 1 dB steps over
the full 103 dB Range of the test attenuator. The received equivalent dBZ level for each
attenuator step is recorded to hard disk. The dynamic Range from 1 dB above the noise level to
1 dB above the 1 dB compression level is then calculated automatically and the Dynamic Range
value is displayed on the screen.
Configuration for measuring dynamic range is shown below. The internal RF Generator along
with the 7 Bit Attenuator will generate a set of 104 Signal level steps at 1dB per step. This
stepped Signal is input to the directional coupler on the Receiver Protector, passes through the
normal receive channel and is measured by the RVP8 Signal Processor.
4.3. Test procedure
(1) Type the “zauto” command
Figure C.2. Configuration of Dynamic Range test
(2) Select Pulse Width 2.0 as shown below in Figure 3.
(3) Click the “AutoCal” button to start calibration automatically from the Zauto menu.
The zauto utility steps through a series of signal values and plots the points. Finally the
Dynamic Range is shown in the Results area of the zauto display. Enter the result on the
data sheet and include a screenshot as Attachment 7, Figure 9.
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