Vaisala RVP900

Chapter 4 _____________________________________________________ TTY Nonvolatile Setups
VAISALA______________________________________________________________________ 113
These configurations specify whether noise correction are applied to the
dual-pol measurements.
PhiDP – Negate: NO , Offset:0.0 deg
You can configure the sign and offset corrections for Φ
DP
.
Polarimetric Attenuation Correction:Yes
This is to correct for intervening weather attenuation. It uses the change of
angle in DP . The tuning numbers are taken from the dualpol.conf file.
KDP computation – 0:LSQ, 1:Weighted LSQ, 2:Cubic Splines
Choose what kind of K
dp
computation you would like to use. "LSQ" means
a least square fit to a linear function. "Weighted LSQ" means a weighted
least square fit to a linear function. FIR filter coefficients are used as
weights. "Cubic Splines" means smoothing and numerical derivatives
calculation using a CSU’s "Adaptive estimation of specific differential
phase" algorithm.
KDP – LSQ Length: 4.00 km
For LSQ K
dp
computation, select the length here.
KDP – LSQ Weights(FIR) Width: 4.00 km
For Weighted LSQ K
dp
computation, select the FIR width here.
KDP – Standard Smoothing Factor: 0.10
KDP – Adaptive Smoothing Factor: 1.10
For cubic spline K
dp
computation: Smoothing factor for the first, non–
adaptive, stage of cubic splines processing. Then the smoothing factor for
the second, adaptive, stage of the cubic splines processing.
T/Z/V/W computed from: Co–Rcv:YES Cx–Rcv:NO
A typical installation might use H-Xmt:YES, V-Xmt:No, Co-Rcv:YES,
Cx-Rcv:NO. Including both transmissions will decrease the variance of
(T/Z/V/W); but most researchers prefer excluding V-Xmt because that is
more standard in the literature. Also, if your polarizations are such that the
main power is returned on the cross channel, then you will probably want
Co-Rcv:NO and Cx-Rcv:YES.