Atmospheric Winds and Rain Obs - ofcm.gov session2...(60 rpm) Simultaneous, MultiBeam-...
Transcript of Atmospheric Winds and Rain Obs - ofcm.gov session2...(60 rpm) Simultaneous, MultiBeam-...
60th IHC – Mobile, Alabama 20 – 24 March 2006
Atmospheric Winds and Rain Obs - Coming to Your Neighborhood Soon!
OUTLINE
Problem Definition ABL and Surface Wind Fields Precipitation Next Steps Acknowledgements:
NOAA AOC (Sean McMillan)
60th IHC – Mobile, Alabama 20 - 24 March 2006
Project Objectives Develop an operational system for
continuously mapping:
Lower ABL wind field.
Ocean surface wind field.
Precipitation field. Within tropical cyclones and rain bands.
60th IHC – Mobile, Alabama 20 - 24 March 2006
IWRAP Measurement Technique
Conical Scan (60 rpm)
Simultaneous, Multi-Beam Doppler/Reflectivity
Profiling
Specifications
Frequency: C-band & Ku-band Polarization: VV, HH Beam Incidence Angles: 30, 35, 41.5, 50 Altitude Range: 500 – 8000 m Range Resolution: 15, 30, 60 & 120 m
Swath Coverage ~ 55 deg. Incidence Proportionally not to scale.
60th IHC – Mobile, Alabama 20 - 24 March 2006
IWRAP Wind Products Tangential Winds – 13 Sept. 2003, Inbound Leg
Radial Winds – 13 Sept. 2003, Inbound Leg
30 35 40 45 50 55 60 65 Radial distance from storm center (km)
30 35 40 45 50 55 60 65 Radial distance from storm center (km)
kts
160
120
80
40
kts
40
0
-40
-60
Alti
tude
(m)
1000
300
2000
Alti
tude
(m)
1000
300
2000
60th IHC – Mobile, Alabama 20 - 24 March 2006
Volume Backscatter Profiles: - Ocean Surface Backscatter Contamination
Outer Side
Nadir Side
θo
Range Gate
(N)(N)
Range Gate
(N-1)
(N-1) (N)
(N-1)
Alti
tude
Distance from Aircraft Track
Antenna Pattern Main Lobe
Incidence Angle
Nadir Side OuterSide
Gai
n (d
Bi)
θo
(N-1)
(N)
Range Gates (N & N-1)
60th IHC – Mobile, Alabama 20 - 24 March 2006
Volume Backscatter Profile (with Surface Contamination)
Ocean Surface
Echo
Ocean Surface
Contamination
60th IHC – Mobile, Alabama 20 - 24 March 2006
Doppler Spectral Profile
Ocean Return
Return from Precipitation / Winds
22 September 2005 – 19:55 GMT
1493 1217 942 667 391 116 -159 Altitude (m)
220
110
0
-110
-220
Rad
ial D
oppl
er V
eloc
ity (k
ts)
dB
-5
-10
-15
-20
-25
60th IHC – Mobile, Alabama 20 - 24 March 2006
Lower Atmospheric Boundary Layer
Ocean Return
Return from Precipitation / Winds
22 September 2005 – 19:55 GMT
380
250
120
-10
-140
Alti
tude
(m)
Radial Doppler Velocity (kts) -220 -110 0 110 220
dB
20
15
10
5
Spectral Filtering Algorithm
22 September 2005 – 19:55 GMT
Precipitation Profile to Surface
Surface
Ocean Surface Backscatter
60th IHC – Mobile, Alabama 20 - 24 March 2006
Volume Backscatter Profile - Spectral Filtering Applied
60th IHC – Mobile, Alabama 20 - 24 March 2006
ABL Profile with Spectral Filtering Al
titud
e (m
)
Wind Speed (kts) 0 20 40 60 80 100
1000
100
60th IHC – Mobile, Alabama 20 - 24 March 2006
Further Improvements: - Leading to an Operational Solution
More efficient antenna design – ~15 % reduction in beamwidth – 4 db gain improvement
Unique Single RF Channel Design – 10 dB improvement in sensitivity. – Smaller, lighter and less expensive.
Frequency Diversity Doppler technique – Decouples range and Doppler ambiguities.
60th IHC – Mobile, Alabama 20 - 24 March 2006
Next Step: - Advanced Wind and Rain Airborne Profiler
Proposed SBIR Phase II Develop AWRAP system
– Real-time spectral processor Map ABL winds to within ~ 50 m of surface. Map ocean surface wind field in the presence of precipitation.
– New transceiver & antenna 15 dB more sensitive (~15 dBZ minimum reflectivity) One-third the components.
60th IHC – Mobile, Alabama 20 - 24 March 2006
Our Mission Statement
A Happier, Smarter, Better World ! Advances in technology are, and will continue to, bring the research, forecast, emergency management and operational communities closer together.
The end result, we all become smarter quicker and the public receives better and better and better forecasts ! ! !
60th IHC – Mobile, Alabama 20 - 24 March 2006
NASA IIP HIWRAP
NUMBER 5
NASA High Altitude Wind and Rain Profiler Highlights
- 60+ kft flight altitude - Design for Global Hawk UAV - Map winds from troposphere to the surface. - Clouds and precipitation. - Modular design for transition to other aircraft. -Long duration mission (24+ hrs) - Solid-state design reduces fabrication and operational costs
60th IHC – Mobile, Alabama 20 - 24 March 2006
Lower Atmospheric Boundary Layer
Ocean Return
Return from Precipitation / Winds
22 September 2005 – 19:55 GMT
380
250
120
-10
-140
Alti
tude
(m)
Radial Doppler Velocity (kts) -220 -110 0 110 220
dB
20
15
10
5
Original Measurements
Spectral Filtering Algorithm
22 September 2005 – 19:55 GMT
Precipitation Profile to Surface
Surface
-220 -110 0 110 220
Radial Doppler Velocity (kts)
380
250
120
-10
-140
Altit
ude
(m)
60th IHC – Mobile, Alabama 20 - 24 March 2006
IWRAP Wind Products (cont.) Divergence – 13 Sept. 2003, Inbound Leg
Vorticity – 13 Sept. 2003, Inbound Leg
30 35 40 45 50 55 60 65
30 35 40 45 50 55 60 65 Radial distance from storm center (km)
m/s
0.4
0.2
0.0
-0.2
-0.4
4 2 0 2
-4
Alti
tude
(m)
1000
300
2000
Alti
tude
(m)
1000
300
2000
x10-3 s-1
60th IHC – Mobile, Alabama 20 - 24 March 2006
Precipitation Retrievals
(modified)