1. APPLICATIONS OF METEOSAT SECOND GENERATION (MSG)
RGB IMAGES: PART 05
RGB COMPOSITES WITH CHANNEL 12 AND THEIR INTERPRETATION
Author: Jochen Kerkmann (EUMETSAT)

2. PART 5:
RED-GREEN-BLUE COLOUR COMPOSITES WITH CHANNEL 12 (HRV) AND THEIR INTERPRETATION

3. RGBs with the HRV Channel: Introduction
In order to preserve the high resolution of the HRV channel, it should be assigned to 2 colours
The HRV has a three times higher resolution than the other channels, i.e. a zoom factor of 3 is needed for the IR channels

4. Recommended Schemes for RGB Image Composites with Channel 12 (HRV)
RGB Composite Applications Time
RGB 12,12,09i: Clouds, Convection Day
RGB 03,12,12: Snow, Fog Day
RGB 12,12,04-09: Severe Storms Day 1. 2. 3.

5. (similar to traditional NOAA AVHRR 1,2,4)
1. RGB 12,12,09i
("HRV Clouds")
(similar to traditional NOAA AVHRR 1,2,4)
R = Channel 12 (HRV)
G = Channel 12 (HRV)
B = Channel 09i (IR10.8i)
Applications:
Clouds, Convection

6. 1. RGB 12,12,09i ("HRV Clouds") Recommended Range and Enhancement:
Beam Channel Range Gamma Gamma2
Red 12 (HRV) 0 …+100 %
Green 12 (HRV) %
Blue 09i (IR10.8i) K
Note: no Gamma correction needed for HRV channel if solar zenith angle
correction is performed (as described on slide 7 of "Conversion from Counts to Radiances")

7. Ch.12
HRV
Ch.09i
IR10.8i

8. Colour Interpretation of RGB 12,12,09i Images

9. Comparison HRV vs RGB 12,12,09i MSG-1, 13 June 2003, 14:00 UTC
The RGB 12,12,09i helps to detect thin Ci clouds and to distinguish between thick Cb clouds and Ci anvils

10. 2. RGB 03,12,12 ("HRV Fog") R = Channel 03 (NIR1.6)
G = Channel 12 (HRV)
B = Channel 12 (HRV)
Applications:
Snow, Fog

11. 2. RGB 03,12,12 ("HRV Fog") Recommended Range and Enhancement:
Beam Channel Range Gamma Gamma2
Red 03 (NIR1.6) 0 …+70 %
Green 12 (HRV) %
Blue 12 (HRV) %
Note: no Gamma correction needed for HRV and NIR1.6 channels if solar zenith angle correction is performed (as described on slide 7 of "Conversion from Counts to Radiances")

12. Ch.03
NIR1.6
Ch.12
HRV

13. Colour Interpretation of RGB 03,12,12 Images

14. The RGB 03,12,12 helps to distinguish between fog and snow
Comparison HRV vs RGB 03,12,12
MSG-1, 24 February 2003, 11:00 UTC
The RGB 03,12,12 helps to distinguish between fog and snow

15. 3. RGB 12,12, 09-04 ("HRV Severe Storms")
R = Channel 12 (HRV)
G = Channel 12 (HRV)
B = BTD (IR10.8-IR3.9)
Applications:
Severe Storms

16. 3. RGB 12,12,09-04 ("HRV Severe Storms")
Recommended Range and Enhancement:
Beam Channel Range Gamma Gamma2
Red 12 (HRV) 70 …+100 %
Green 12 (HRV) %
Blue IR10.8-IR K
Note: no Gamma correction needed for HRV channel if solar zenith angle
correction is performed (as described on slide 7 of "Conversion from Counts to Radiances")

17. Ch.12
HRV
Ch.
09-04

18. Colour Interpretation of RGB 12,12,09-04 Images

19. Comparison HRV vs RGB 12,12,09-04 MSG-1, 13 June 2003, 14:00 UTC
The RGB 12,12,09-04 helps to detect the most vigorous storms (with the strongest updrafts)