Vaisala RVP900 - Page 249

else
G = 0.1 + (N - 10000)/10000
This format is backward-compatible with the previous linear format for all values between
0.0 ... 0.1 dB/km and it extends the upper range of values from 0.65535 ... 5.6535. These
larger attenuation corrections are needed for very short wavelength radars.
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
---------------------------------------------------------------
| | | | | | | | | | | | | | | | |
| Threshold Control Flags for Differential Reflectivity(Zdr) | Input 18
|---------------------------------------------------------------|
See description for Input 11.
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---------------------------------------------------------------
| | | | | | | | | | | | | | | | |
| Signed Zdr Calibration Offset in 1/16 dB(GDR) | Input 19
|---------------------------------------------------------------|
When
dierential reflectivity is computed there is a possibility that radar asymmetries
introduce a bias in the Zdr values, that is, that Zdr is non-zero even when observing purely
spherical targets. This calibration
oset permits nulling out this eect. The GDR oset
accounts for the overall Tx/Rx gain imbalance between the two channels of the radar.
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
---------------------------------------------------------------
| | | | | | | | | | | | | | | | |
| Radar Wavelength in Thousandths of Centimeters | Input 20
|---------------------------------------------------------------|
The radar wavelength is used in the calculation of 16-bit velocity and width data, to convert
from Nyquist units to absolute physical units.
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---------------------------------------------------------------
| | | | | | | | | | | | | | | | |
| Signed LDR Calibration Offset in 1/100 dB(XDR) | XARG 1
|---------------------------------------------------------------|
The XDR
oset is used in the linear depolarization ratio equations, and is the dierential
receiver gain between the two channels. Unlike the GDR oset (used for Zdr), the gain
dierence does not depend on dierential transmit power.
Chapter 8 – Host Computer Commands
247