User's Manual

RVP8 User’s Manual

October 2005

TTY Nonvolatile Setups

3–11

Provide WSR88D legacy BATCH major mode: YES

Maximum range to unfold: 600.0 km

Low–PRF bins range averaged on each side: 2

Overlay power – Refl:5.0dB Vel:8.0dB Width:12.0db

LowSamps = ( 0.00000 x HiSamps ) + 6.00 :

LowPRF = ( 0.00000 x HiPRF ) + 250.00 :

This is actually a fully general implementation of a Lo/Hi Surveillance/Doppler PRF unfolding

scheme that provides all of the legacy features as special cases. The parameters are defined as

follows:

S The maximum range to unfold is given in km. This allows you to set an upper bound on

how many Doppler trips will be unfolded according to the echoes seen in the surveillance

data.

S The surveillance data set uses very few pulses and therefore is somewhat noisy. You may

choose the number of bins that will be range averaged from both sides of these bins to

provide a lower variance power estimate. A value of zero means “No averaging”, a

value of one would average three points total, etc.

S The unfolding algorithm flags obscured range bins according to three different power

thresholds for reflectivity, velocity, and width, and outputs these bits in the DB_FLAGS

data parameter. Each of these thresholds is specified in deciBels.

S The fundamental RVP8 operating parameters (PRF, Sample Size, etc) all apply to the

high PRF portion of the BATCH trigger waveform. The low PRF rate and sample size

are derived from these high values using a slope and offset. In the example shown

above, the slopes are both zero, so that the surveillance data will be fixed at 6-pulses and

250-Hz. Making the slopes nonzero would cause the low-PRF parameters to vary

automatically if desired.

These setup parameters are accessible through the DSP driver using the new entry points

dspw_batchSetup() and dspw_batchSetup(). These use the custom opcode that is defined

separately by each major mode, so you may find customUserOpcode_batch() to be a useful

model for how to build such things.

Polarization Params – Filtered:YES NoiseCorrected:YES

PhiDP – Negate: NO , Offset:0.0 deg

KDP – Length: 5.00 km

T/Z/V/W computed from: H–Xmt:YES V–Xmt:YES

T/Z/V/W computed from: Co–Rcv:YES Cx–Rcv:NO

The first question decides whether all polarization parameters will be computed from

filtered or unfiltered data, and whether noise correction will be applied to the power

measurements.

The second and third questions define the sign and offset corrections for

and the

length scale for KDP.

The fourth and fifth questions control how the standard parameters (Total

Reflectivity, Corrected Reflectivity, Velocity, and Width) are computed in a multiple

polarization system. Answering YES to H-Xmt and/or V-Xmt means that data from