Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging...
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![Page 1: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/1.jpg)
Jan 28, 2008 Symposium on Imaging
Ground-based and Space-based Radar Precipitation
Imaging
V.Chandrasekar
Colorado state University
January 28, 2008
![Page 2: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/2.jpg)
Jan 28, 2008 Symposium on Imaging
Introduction
• CSU-CHILL radar
- PPI (Plan Position Indicator) scan - RHI (Range Height Indicator) scan
• Tropical Rainfall Measurement Mission (TRMM) - Precipitation Radar (PR)
![Page 3: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/3.jpg)
Jan 28, 2008 Symposium on Imaging
CSU-CHILL radar : New antenna installation
![Page 4: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/4.jpg)
Jan 28, 2008 Symposium on Imaging
Example of PPI scan
![Page 5: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/5.jpg)
Jan 28, 2008 Symposium on Imaging
Example of RHI scan
![Page 6: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/6.jpg)
Jan 28, 2008 Symposium on Imaging
The received signal corresponds to resolution volume determined by the transmit pulse width
& beam width
Bcx rR : Resolution Range-Cross
Backscattered signal in weather radars is from distributed target
Cross range resolution is dependent on the antenna beam width and range
![Page 7: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/7.jpg)
Jan 28, 2008 Symposium on Imaging
2
2ln8
2
2ln8
2ln24
BB
Be erferff
widthbeam antenna dB 3
cyclen integratio onein Azimuth
B
![Page 8: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/8.jpg)
Jan 28, 2008 Symposium on Imaging
r0,0,0 r,, r2
Wn r 2 f 2 ,0
f 2 ,0 dsin drd
f 2 0, f 2 0, d d
If a r,, r2
Wn r 2 f 2 ,0
f 2 ,0 dsin drd
r0,0,0 a f 2 0, 0 f 2 0, d d
![Page 9: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/9.jpg)
Jan 28, 2008 Symposium on Imaging
Intrinsic backscattering properties of hydrometeor is described by the backscattering covariance matrix
Intrinsic backscattering properties of hydrometeor in a linear polarization basis enables the measurements such as size, shape and spatial orientation
++
+
++
+
++ +
+--
----
- - -- 2max
cTr
Tv
4max
Waveform Coding at CSU-CHILL radar
![Page 10: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/10.jpg)
Jan 28, 2008 Symposium on Imaging
vhS
hhS
hvS
vvS
Ev
Eh
Backscattered signal from horizontal polarization
Backscattered signal from vertical polarization
Backscattering covariance matrix is given by
2
2
2
2
222
2
vvhvvvhhvv
vvhvhvhhhv
vvhhhvhhhh
BSA
SSSSS
SSSSS
SSSSS
Waveform Coding at CSU-CHILL radar
![Page 11: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/11.jpg)
Jan 28, 2008 Symposium on Imaging
The received signal in the two polarization channels can be written as
Tvvvhhvhh VVVVz
2
2
2
2
vvhvvvvhvvhhvv
vvhvhvvhhvhhhv
vvvhhvvhvhhhvh
vvhhhvhhvhhhhh
T
VVVVVVV
VVVVVVV
VVVVVVV
VVVVVVV
EE Kzz
The covariance matrix of the received signal is given by
Dual ChannelDigital
Waveform Generator
REF OSCILLATOR
H-Transmitter
V-Transmitter
V- Receiver
H- Receiver
DuplexerSTALO
H
V
Waveform Coding at CSU-CHILL radar
![Page 12: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/12.jpg)
Jan 28, 2008 Symposium on Imaging
Reflectivity from (a) Alternate mode (20:34:00 UTC) (b) Walsh coded
simultaneous mode (20:28:51 UTC). Data collected by CSU-CHILL on May 29, 2007
LDR estimated from (a) Alternate mode (20:34:00 UTC) (b) Walsh coded simultaneous mode
(20:28:51 UTC). Data collected by CSU-CHILL on May 29, 2007
Waveform Coding at CSU-CHILL radar
![Page 13: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/13.jpg)
Jan 28, 2008 Symposium on Imaging
Networked System Processing
KSAO
KRSPKLWE
KCYR
![Page 14: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/14.jpg)
Jan 28, 2008 Symposium on Imaging
UNFILTERED FILTERED
Tornadic circulation feature; wind speeds greater than 40 m/s (90 mph)
Networked System Processing
![Page 15: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/15.jpg)
Jan 28, 2008 Symposium on Imaging
Networked System Processing
Measurement at each radar node
Networked retrieval
![Page 16: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/16.jpg)
Jan 28, 2008 Symposium on Imaging
Reflectivity retrieval in a networked radar environment: Demonstration
from IP-1 radar network
![Page 17: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/17.jpg)
Jan 28, 2008 Symposium on Imaging
KTLX
Before After
May 7, 2007 CSE
![Page 18: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/18.jpg)
Jan 28, 2008 Symposium on Imaging
May 8, 2007 CSE
KTLX
Before After
![Page 19: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/19.jpg)
Jan 28, 2008 Symposium on Imaging (Adopted from TRMM data user handbook, 2001)
TRMM : Tropical Rainfall Measurement Mission - Joint mission between NASA and JAXA - Observing precipitation over tropical regions between 37oS and 37oN - Satellite was lunched in 1997
PR : Precipitation Radar (installed on TRMM) - 13.8 GHz Ku-band radar - Horizontal resolution at nadir : 4.3 km. ( 5 km. postboost) - Range resolution : 250 m. - Swath width : 215 km. ( 245 km postboost) - Altitude : 350 km. ( 402.5 km postboost) Note : TRMM was boosted in altitude in August 2001
215 km.
A hurricane in TRMM-PR track
TRMM-PR : orbital and observatory characteristics
![Page 20: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/20.jpg)
Jan 28, 2008 Symposium on Imaging
Ground and Space-based radar volume matching
• Performance and system cross validation
![Page 21: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/21.jpg)
Jan 28, 2008 Symposium on Imaging
Effective vertical resolution = xr + xb
= h*cosθ + r θB sin θ
Effective horizontal resolution = hr + hb
= h*sinθ + r θB cos θ
Geometry of pulse volume and resolution degradation effect of space-based radar measurement.
to surface
![Page 22: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/22.jpg)
Jan 28, 2008 Symposium on Imaging
Geometric distortion in the space-base radar imagecaused by platform motion
![Page 23: Jan 28, 2008Symposium on Imaging Ground-based and Space- based Radar Precipitation Imaging V.Chandrasekar Colorado state University January 28, 2008.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5e5503460f94a3d36f/html5/thumbnails/23.jpg)
Jan 28, 2008 Symposium on Imaging
Difference in resolution between space and ground-based radar images
NEXRAD : KAMX Miami, FL TRMM-PR
• A couple example from simultaneous observations between NEXRAD and TRMM
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Jan 28, 2008 Symposium on Imaging
NEXRAD : KEVX , Red Bay/Eglin, FL TRMM-PR
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Jan 28, 2008 Symposium on Imaging
3-D volume matching and shifting based on GR and SR resolution volumes
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Jan 28, 2008 Symposium on Imaging
Matched and Aligned images between SR and GR
GR SR
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Jan 28, 2008 Symposium on Imaging
Matched images of a tropical storm in Bay of Bengal
GR (SHAR, India)
SR (TRMM-PR)
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Jan 28, 2008 Symposium on Imaging
Summary
• The Radar research group works on a variety of problems all the way from
• Design and development of imaging sensors
• Analysis of images for interpretation and • Cross validation of images from multiple
platforms • Developing hardware, theory algorithms
and and novel applications