Download - Okinawa Validation Site in Japan
Okinawa Validation Site in Japan
Shinsuke Satoh1, Katsuhiro Nakagawa1,Yukari Shusse1, Yasushi Kitamura1,
Nobuhiro Takahashi2, Hiroshi Hanado3, Toshio Iguchi2, and Kenji Nakamura4
1 NICT Okinawa Subtropical Environment Remote-Sensing Center2 NICT Precipitation Radar Group3 JAXA GPM/DPR project team4 Hydrospheric Atmospheric Research Center (HyARC), Nagoya University
2nd International GPM Ground Validation Workshop28 September 2005, Taipei, Taiwan
Outline of the talk(1) Introduction of three main remote-sensors
in NICT Okinawa, Japan - Okinawa GV site located in subtropical maritime environment - Long-Range Ocean Radar (LROR) - 400 MHz-band Wind Profiler (WPR) - C-band polarimetric radar (COBRA)
(2) Application studies for TRMM/GPM GV - Okinawa Baiu Campaign Experiment 2004 (Okn-Baiu04) - DSD profile retrieval from 400 MHz WPR and other instruments - Rainfall type classification using COBRA polarimetric data - Comparison between TMI data and TB simulated from
COBRA data
NICT: National Institute of Information and Communications Technology (former name is CRL: Communications Research Laboratry)
Okinawa located in the sub-tropics
Monsoon Typhoon
Kuroshio Current
Typhoon
Asia Monsoon
25N
30N
35N
40N
45N
OkinawaMain Island
Okinawa is a good observation base in the subtropical maritime environment.
- Heat and water provided by Typhoon - High temperature sea water provided
by the Kuroshio current - Water circulation in the east Asia
Ishigaki and Yonaguni Is.
Three Remote-sensors in NICT Okinawa
Okinawa Subtropical Environment Remote-Sensing Center
Ogimi WPR Facilities
400 MHz-band Wind Profiler
Nago Radar Facilities
Weather Radar ( COBRA)
Ocean Radar
Yonaguni Ocean Radar Facilities
風
雨
海
YonaguniIshigaki
Onna
Ogimi
Nago
Network Data System
Zamami
:AWS
Long-range Ocean Radar< LROR Specificatons >
Radar Type FMICW Doppler RadarFrequency 9.2 MHzBand Width 55 kHz, 22 kHzTx Power 1 kW (Peak)Obs. Range 200 kmRange Resolution < 7 kmAntenna Type 16 elements array for DB
FBeam Width 8 – 10 degreesObs. Area 60 degreesObs. Interval > 30 min
Yonaguni Radar Facilities
Ishigaki Radar Facilities
First scatter signal current speed, wind directionSecond scatter signal wave height
Frequency of Bragg scattering
1st scattering
2nd scattering
Observation Range of the LROR
50 km
100 cm/s
122° E 123° E 124° E 125° E 126°24° N
25° N
26° N
27°
Taiwan
Depth 200m
Current Velocity V(cm/s)100 ≦ V75 ≦ V <10050 ≦ V < 7525 ≦ V < 500 ≦ V < 25
50 km
100 cm/s
122° E 123° E 124° E 125° E 126°24° N
25° N
26° N
27°
Taiwan
Depth 200m
Current Velocity V(cm/s)100 ≦ V75 ≦ V <10050 ≦ V < 7525 ≦ V < 500 ≦ V < 25
122.00
24.00
Yonaguni radar site
Kuroshio current
TAIWAN
Ishigaki radar site
200 km
05 Nov. 2004, 08:30JST11 Oct. 2004, 14:00JST
400 MHz-band Windprofiler< Other instruments at Oogimi >• 1.3 GHz-band Windprofiler
–1357.5MHz, 1 kw (peak), 2.1 x 2.1 m
• Doppler Sodar• GPS sonde• Ceilometer• Automatic Weather Station• Optical Rain Gage• Micro Rain Radar• 2D Video Distrometer
< 400 MHz WPR Specificatons >Radar Type Pulsed Doppler RadarFrequency 443.0 MHzPeak Power 20 kWAverage Power 2 kWPulse Length 1.33 / 2.0 / 4.0 usPRF 6.25 / 20 kHzAntenna Type 24 x 24 element crossed arrayAntenna Size 10.4 x 10.4 mBeam Width 3.3 degBeam Steerability AZ 0 - 360 deg EL 0 - 15 deg
Oogimi Windprofiler Facilities
400 MHz WPR 1.3 GHz WPR
DopplerSodar
Horizontal Winds ProfilesH
IGH
T (
km)
00 (SEP05) 06 12 18 00 (SEP06) 06 12JST
16
14
12
10
8
6
4
2
121110 9 8 7 6 5 4 3 2 1
HIG
HT
(km
)
m/s
m/s
(Typhoon Songda 2004)
00 06 12 18 00 12 18 06
(01APR – 02APR2004)
24JST
18
C-Band Okinawa Bistatic polarimetric RAdar (COBRA)
< COBRA Specifications >Frequency 5340 MHz
Peak power 250 kW×2 (Klystron)10 kW×2 (TWTA) COBRA+
Pulse width 0.5 / 1.0 / 2.0 s (Klystron)0.5 - 100 s (TWTA) COBRA+
PRF 250-3000 Hz, PRT 1 s stepstaggered PRF
Antenna 4.5 m parabola
Antenna gain 45 dBi (inc. radome)
Beam width 0.91 deg
Sidelobe level < -30 dB (AZ dir., one way)
< -28 dB (EL dir., one way)
Cross pol ratio > 36 dB (integ in a beam)
Tx Polarization H / V / +45 / -45 / LC / RC
Doppler estimation Pulse-pair / FFT
Range bin num > 2000
Antenna scan 0.5-10 rpm (PPI)0.1-3.6 rpm (RHI)
COBRA was installed on a mountain peak (343 m in ASL + 15 m tower) in Nago city, Okinawa Island.
Characteristic Functions of COBRATransmitting 6 kinds of polarization
(H, V, +45, -45, RC, LC) pulse by pulse, and receiving H and V simultaneously
• Attenuation correction• Precip. type classification• DSD estimation
Polarization Data
Bistatic Doppler Network
3D windobs area
150 km
Dual-Doppler analysis using main radar and bistatic receiver
Zamami
Bistaticscatter
Back-scatter
Zamami bistatic site (since Mar. 2005)
Typhoon Observation by COBRA
GMS IR Image
8km4km0km
0km 50km 100km 150km 200km 250km 300km
400km
40
0k
m
T0216 (SINLAKU)
12km
998hPa
2728293031
0102
0304
05
06
07
980975945935
935945
935940
940
945
08 970hPa
925hPa
998hPa
2728293031
0102
0304
05
06
07
980975945935
935945
935940
940
945
08 970hPa
925hPa
T0418 (SONGDA)
Okinawa Baiu Campaign Experiment
Okn-Baiu-04 (May 22 - June 9, 2004)
Simultaneous obs with TRMM and Aqua
<OBJECTIVES>4D-dataset of rain rate, DSD and hydrometeor type, etc for development and validation of satellites-based precipitation map
GPS Sonde Ka-band Doppler Radar by NIED
Ogimi site
COBRA RHI scan
COBRA volume scan
400 MHz WPRDoppler SodarMP-Ka
X-band Doppler Radarby Nagoya-univ.
< Ogimi WPR site >- Disdrometer- Micro Rain Radar (MRR)- 2D Video Distrometer (2DVD)- Optical Rain Gauge (ORG)- Microwave Radiometer (MWR)- Ceilometer- Doppler Sodar- Auto Weather Station (AWS)
Collaborated IOP experiment with- CREST-GSMaP (Osaka prefec univ)- CREST-LAPS (Nagoya Univ)
DSD profile retrieval from 400 MHz WPR data (1)
Pt : Received Power from turbulence
SD(v) : Doppler spectrum of raindrop
Pn : Noise level
* : Convolution integral
Sobs(v)=PtSt(v)+SD(v) * St(v)+Pn
2
20
2 2
)(exp
2
1)(
vv
vSt
SD(v)=C ・ N(D) ・ D6 ・d D/ dv
Turbulence echo spectrum St(v) is fitted by Gaussian function (V0 and are estimated)
DSD
21:36JST, 01JUN 2004
Falling Velocity of Raindrop (Gunn and Kinzer): V = 9.65 - 10.3exp(-0.6D)
Rain Echo
0.0001
0.001
0.01
0.1
1
10
-10 -8 -6 -4 -2 0Velocity (m/s)
SOBS ST SD*ST SD
H=2519 m
Turbulence Echo
(Air motion)
by Yasushi Kitamura
DSD profile retrieval from 400 MHz WPR data (2)
-8
-4
0
4
log1
0(N
(D))
6543210Diameter (mm)
ND(H=1522m) ND(H=2519m) ND(H=3517m)
-8
-4
0
4lo
g10(
N(D
))
20151050Diameter (mm)
ND(H=4514m) ND(H=5512m) ND(H=6510m)
< H=4 km
Drop Size Distribution
Air motion: V0=0
Above the melting level, turbulence echo cannot be distinguished from snowfall echo
Sobs(v)=C・ N(D)・ D6・d D/dv142.0837.0 DV Snow falling vel:
8
7
6
5
4
3
2
Hei
ght
(km
)
500Z (dBZ)
21:36
-:WPR ○: COBRA
> H=4 km
4
2
0
-2
6543210
Diameter (mm)
MRR WPR
21:50-22:004
2
0
-2
6543210
Diameter (mm)
MRR WPR
21:40-21:50 4
2
0
-2
6543210
Diameter (mm)
MRR WPR
21:30-21:40
4
2
0
-2
6543210
Diameter (mm)
MRR WPR
21:20-21:304
2
0
-2
6543210
Diameter (mm)
MRR WPR
21:10-21:204
2
0
-2
log1
0(N
(D))
6543210
Diameter (mm)
MRR WPR
21:00-21:10
Comparison between DSDs derived from 400 MHz WPR and MRR
MMR: 1275 mWPR: 1223 m10 min average
1
4
15
HE
IGH
T (
km)
400
MH
z W
PR
MR
R
2DVD / Disdrometeron the ground
DSD measurement
3D Characteristics of Polarimetric Radar Variables (1)
Stratiform
Convective
Embedded
by YukariShusse
3D Characteristics of Polarimetric Radar Variables (2)
Stratiform Type
EL=0.5°EL=0.9°
EL=1.4°
EL=2.0°
EL=2.6°
EL=3.4°
BB
> 4 km: relative lower ZDR~ 4 km: weak correlation< 4 km: ZDR increase with Zhh
Convective Type Embedded Type
Upper layer: lower ZDR (1~1.5) in spread ZhhLower layer: higher ZDR (>2.5) in spread Zhh
< Zhh vs ZDR >
Upper layer: Lower ZDR in small ZhhLower layer: higher ZDR with larger Zhh
3D Characteristics of Polarimetric Radar Variables (3)
Spread distribution of larger hv (>0.99) up to upper layer
Stratiform Type Convective Type Embedded Type
< Zhh vs hv >
> 4 km: smaller hv~ 4 km: weak correlation< 4 km: hv increases with Zhh
BB
Upper layer: smaller hvLower layer: larger hv with larger Zhh
Coordinates for TMI footprint
COBRA beams
TRMM
COBRA
Sat. flight dir.
< Procedure >
COBRA R- data converts into the TMI footprint coordinates(40x60 km, 1x1 km reso.)
RTM calculation (Liu, 1998)- 0C level = 4.5 km (rain/graupel)- Relative humidity = 80%- adjust Z-R relationship- calc in vertical direction- calc in 1x1 km grid
TMI Antenna convolution and TB output
TMI TB simulated from COBRA data (1)
by Nobu Takahashi
TMI TB simulated from COBRA data (2)02Z, 2JUN2004
DIFF
A (Z=AR^B)
10 GHz V-pol
TB10v (COBRA-sim)TB10v (TMI)
DIFF (K)
TMI TB simulated from COBRA data (3)02Z, 2JUN2004
A (Z=AR^B)
19 GHz V-pol
TB19v (COBRA-sim)TB19v (TMI)
DIFF (K)
Okinawa Data Publication Server
http://sdkgwww.nict.go.jp/internal.html- Quick-look images for public seeing.- To download the raw data, the user ac
count is required (Ask me: “[email protected]” about an application form for the account).
The explanation is Japanese only until now
COBRA raw data have not been included on this server
Official Web Pageof NICT Okinawa
The last data of LROR
http://www2.nict.go.jp/dk/c218/
The last data (LROR, WPR, COBRA) are linked from Japanese page only
Summary• NICT Okinawa developed three main remote-sensor;
- Long-range Ocean Radar (LROR)- 400 MHz-band Wind Profiler (WPR)- C-band polarimetric radar (COBRA)
to measure the subtropical maritime phenomena.• All sensors are operated almost continuously until now
and in future.• The observation data are published through a web server• Some application studies for the TRMM/GPM algorithm de
velopment using the observation data are in progress. - DSD profile retrieval from WPR data - Rain type classification using COBRA polarimetric data - TB simulated from COBRA simultaneous obs data• Site calibration and physical calibration will carry out.