DualPolProcessing.md

Dual-Polarization Processing in LROSE

In this document we illustrate some of the basic operations that the Radx apps in LROSE can perform for dual-polarization processing.

In these examples we are using some data from the NCAR S-Pol radar at the site near Hays, Kansas during the PECAN field project in 2015.

The measured fields

• DBZ
• ZDR
• RHOHV
• PHIDP
• TEMP

DBZ

PPI

RHI

ZDR

RHI

RHOHV

RHI

PHIDP

RHI

TEMPERATURE

RHI

The derived fields

• KDP
• PID (Particle ID, Hydrometeor type)
• PRECIP RATE

KDP

We compute KDP from PHIDP.

It is defined as the slope of PHIDP in range, divied by 2.

KDP can be noisy - considerable smoothing and other filtering is required for good results.

RHI

We compute PDI from the above dual-pol fields, in addition to temperature

PID

PID is computed using a fuzzy-logic approach.

RHI

Precip rate

Precip rate may be computed using DBZH, Z/ZDR and KDP.

RATE_ZH

PPI

RATE_Z_ZDR

PPI

RATE_KDP

PPI

RATE_HYBRID

A hybrid rate may be estimated using a combination of the computed rates.

PPI