Carlos Augusto Morales Universidade de São Paulo - USP...

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CHUVA: Radar Status

Carlos Augusto Morales

Universidade de São Paulo - USP

Luiz Augusto Toledo Machado and Carlos Frederico Angelis

Instituto Nacional de Pesquisas Espaciais - INPE

Radar Manufacture: EEC

Specifications:

Dual Polarization – Simultaneous

PRF: 800 Hz

Number of Samples: 100

Gate width: 125 m (960 bins)

Antenna beam width: 0.5º

Volscans: 10 elevations from 0.5 – 12º and 2 elevations at 90º (every 10min.)

RHI along the MRR and ADMIRARI (every 10 min)

Measurements:

1st – 25th of March, 2010

Vertical Measurements – Time series

Evaluation of XPOL/CLA

• ZDR

• Zh X DSD (Joss and Thies)

• Zh x MRR

• Zh x TRMM

Mean ZDR = -0.054 dB Mean ZDR = -0.184 dB

Mean ZDR = 0.067 dB

DSD Comparisons

JOSS-Airport

Thies and MRR Vila

Thies UEMA

Rayleigh -12.58

X-Band -12.16

Bias +6.57

TRMM Comparisons

• Besides the DSD comparisons, we have evaluated the bias correction using

TRMM-2A25 measurements according to Anagnostou et al. (2001).

• CAPPIs: 5 x 5 km horizontal and 2 km vertical

• Stratiform region and above 7 km height

• Maximum range : 100 km

Matched Distributions

Attenuation Problem

Original TRMM at 2 km

TRMM-CAPPI at 3km

5x5 km res

XPOL/CLA at 3km

5x5 km res

Radial Extracted

for correction

0 20 40 60 80 100 120 140-20

-10

0

10

20

30

40

50

60

Distance from Radar (km)

Zh (

dB

Z)

Corrected for

Attenuation

TRMM -2A25

at 2km level

Without

Correction –

Raw data

Applying the attenuation correction scheme (Anagnostou et al., 2006) for

the 1 degree elevation ray;

XPOL has 0.125 km bin resolution.