Winds and height assignment

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Winds and height assignment

• 11 October 2006
• CIMSS/UW, Madison,WI

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Outline

• AMV height assignment overview
• AMV height assignment methods CIMSS and
  EUMETSAT
• Cloud Top Heights Retrieval Methods
• Open discussion and do not Know-How exchange

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Overview of the satellite winds derivation
algorithm
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CIMSS Height assignment methods (1)
ARA1/2/3 HARA1 HARA2 IR (microns!!!)IR
WV H2O,WIN,CO2,BASE WV IR WV H2O, HIST
VIS IR (at same sp.res.) n/a
WIN,CO2,BASE Nieman et al.,JAM, 1993 1.
H2O-Intercept Method (H2O) 2. Infrared Window
(IRW) Channel Method (WIN) 3. CO2 Slicing (or
CO2-IRW) Method (CO2) 4. Water Vapor Histogram
Method (HIST) 5. Cloud Base Method (BASE)
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CIMSS Height assignment methods (2)
Best" height assignment value selection 1.The
lowest pressure (highest altitude) value of all
of the calculated height values is used as the
final wind vector pressure height assignment
value. 2.If WIN is selected as best, but a
valid BASE height is available, the BASE height
will be used instead.
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EUMETSAT Height assignment methods
For clouds (VIS, IR and WV channels)1. EBBT IR
Window (for VIS and IR channels), or WV for WV
ch.2. Semi_transparency Correction (6.2
channel)3. Semi_transparency Correction (7.3
channel)4. IR/WV Ratio method (6.2 channel)5.
IR/WV Ratio (7.3 channel)6. CO2 Absorption (10.8
channel) representative radiance method7. CO2
Absorption (10.8 channel) sampled radiance
arithmetic method8. CO2 Absorption (12.0
channel) representative radiance method9. CO2
Absorption (12.0 channel) sampled radiance
arithmetic method 10.RFF adjusted height.
(???) For clear sky scenes (WV channels)1.
EBBT WV Window2. Normalised Total Cumulative
Contribution Function (10 level)3. Normalised
Total Cumulative Contribution Function (50
level)4. Normalised Total Cumulative
Contribution Function (90 level)5. Normalised
Total Contribution Function (maximum level)
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CTH retrieval algorithms

• GOES
• Sounder CTH (T.Schriner), VISST CTH (P. Minnis)
  (spatial and temporal resolution/coverage)
• Accuracy S.Bedka, P.Heck
• MODIS
• Operational 5km, 1 km (M.Pavolonis, R.Frey,
  H.Zhang)
• Polar AMV HA D.Santek, J.Key
• Stereo HA GOES (F.Lu), MISR
• What else???

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Discussion and do not Know-How exchange

• -Tracking one channel image, height assigning
  another channel image
• -Level vs. Layer assignment
• -Uncertainty introduced by model guess
  BT-gtPress, Press-gtH, WIN and HIST methods
• -Spatial resolution would it be a factor?
• ?(Hi , i1,5) ? ? (H with/w_out RFF) ? ? (H
  level/layer) ???
• Updated HAM for GOES??? What channels do we
  have???
• CO2 with new channels is this a hope?

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Add

• GOES-MISR-MODIS CTH comparison
• ASTER-MISR-MODIS comparison