Transcript RGB part 06 - NOT recommended RGB colour composites

APPLICATIONS OF
METEOSAT SECOND
GENERATION (MSG)
RGB IMAGES: PART 06
NOT RECOMMENDED RGB
COLOUR COMPOSITES
Author:
Version 1.0, 30 June 2004
Jochen Kerkmann (EUMETSAT)
[email protected]
PART 6:
NOT RECOMMENDED RED-GREENBLUE COLOUR COMPOSITES
Version 1.0, 30 June 2004
Channel Selection
• The selection of the channels to be combined in a RGB
composite should be based on the physical properties
represented by the channels (e.g. IR10.8 provides cloud top
temperature, VIS0.6 provides cloud optical thickness,
VIS0.8 provides "greeness" of vegetation etc…)
• It does not make sense to combine channels that represent
the same physical property!
Version 1.0, 30 June 2004
(Cloud) Physical Properties represented
by the MSG Channels
VIS0.6:
VIS0.8:
optical thickness and amount of cloud water and ice
optical thickness and amount of cloud water and ice
"greeness" of vegetation
NIR1.6, IR3.9r:
particle size and phase
WV6.2, WV7.3:
mid- and upper level moisture
IR8.7, IR10.8, IR12.0: top temperature
IR8.7 - IR10.8:
IR12.0 - IR10.8:
IR3.9 - IR10.8:
IR13.4 - IR10.8:
WV6.2 - IR10.8:
Version 1.0, 30 June 2004
phase and optical thickness
optical thickness
optical thickness, phase, particle size
top height
top height, overshooting tops
Not Recommended Schemes for
RGB Image Composites
1.
RGB 01,02,09i: although known from AVHRR, this combination duplicates
the visible information. It is better to create RGB 12,12,09 instead.
2.
RGB 04i,09i,10i: also known from AVHRR (night-time), but duplication of cloud
top temperature information. It is better to use the RGB
10-09,09-04,09 during night-time.
3.
RGB 07i,09i,10i: combines three times the top temperature information; the resulting
image will not have many colours. It is better to use the brightness
temperature differences (e.g. RGB 10-09,09-07,09).
4.
RGB 05i,08i,11i: combines three sounding channels, which are not useful for
cloud observation. Again, it is better to combine these channels with
other channels to get relevant physical properties (e.g 05-09 (top
height); 05-06 (top height, WV structure); 06-11 (SO2
concentration)).
Version 1.0, 30 June 2004
1. Not Recommended RGB 01,02,09
RGB 01,02,09i (not recommended)
RGB 12,12,09i (recommended)
MSG-1, 13 June 2003, 14:00 UTC
Version 1.0, 30 June 2004
2. Not Recommended RGB 04i,09i,10i
RGB 04i,09i,10i (not recommended)
RGB 10-09,09-04,09 (recommended)
MSG-1, 03 February 2004, 03:00 UTC
Version 1.0, 30 June 2004
3. Not Recommended RGB 07i,09i,10i
RGB 07i,09i,10i (not recommended)
RGB 10-09,09-07,09 (recommended)
MSG-1, 26 May 2004, 12:00 UTC
Version 1.0, 30 June 2004
4. Not Recommended RGB 05i,08i,11i
RGB 05i,08i,11i (not recommended)
RGB 05-06,04-09,03-01 (recommended)
MSG-1, 08 September 2003, 12:00 UTC
Version 1.0, 30 June 2004