Night Microphysics RGB
Alternative names: Fog RGB, Fog/Low Clouds RGB
Main applications (Nighttime)
- Detection of clouds, with emphasis on fog and low-level clouds.
- Detection of moisture boundaries in cloud-free areas.
- Dust detection.
- Variants with different tuning for tropical regions are available (see below).
- The RGB performs poorly in twilight conditions and in very cold environments.
- The current FCI-based recipe has a known limitation: saturation for some low clouds. Further tuning is planned to address this issue in future updates.
RGB Recipes by Satellite Instrument
MSG SEVIRI Night Microphysics RGB
| Colour beam |
Channel (difference) |
Range min |
Range max |
Unit |
Gamma |
| Red |
IR12.0 -- IR10.8 |
-4 |
+2 |
K |
1.0 |
| Green |
IR10.8 -- IR3.9 |
0 |
+10 |
K |
1.0 |
| Blue |
IR10.8 |
243 |
293 |
K |
1.0 |
MTG FCI Night Microphysics RGB
Agreed upon at the online workshop 2026-05-13
Proposed (M.A. Martinez, 2025, M. Putsay, 2026)
Tuned for mid-latitudes.
| Colour beam |
Channel (difference) |
Range min |
Range max |
Unit |
Gamma |
| Red |
IR12.3-10.5 |
-7.1 |
+2.4 |
K |
1.0 |
| Green |
IR10.5 -- IR3.8 |
-2.9 |
+6 |
K |
1.0 |
| Blue |
IR10.5 |
242.2 |
293.1 |
K |
1.0 |
GOES ABI Night Microphysics RGB
| Colour beam |
Channel (difference) |
Range min |
Range max |
Unit |
Gamma |
| Red |
IR12.3 -- IR10.3 |
-6.7 |
+2.6 |
K |
1.0 |
| Green |
IR10.3 -- IR3.9 |
-3.1 |
+5.2 |
K |
1.0 |
| Blue |
IR10.3 |
243.6 |
292.7 |
K |
1.0 |
Himawari AHI Night Microphysics RGB
| Colour beam |
Channel (difference) |
Range min |
Range max |
Unit |
Gamma |
| Red |
IR12.4 -- IR10.4 |
-7.5 |
+3 |
K |
1.0 |
| Green |
IR10.4 -- IR3.9 |
-2.9 |
+7 |
K |
1.0 |
| Blue |
IR10.4 |
243.7 |
293.2 |
K |
1.0 |
FY-4 AGRI Night Microphysics RGB
| Colour beam |
Channel (difference) |
Range min |
Range max |
Unit |
Gamma |
| Red |
IR12.0 -- IR10.8 |
-4 |
+2 |
K |
1.0 |
| Green |
IR10.8 -- IR3.75 |
0 |
+10 |
K |
1.0 |
| Blue |
IR10.8 |
243 |
293 |
K |
1.0 |
Variants for Tropical Regions
Tropical regions require adjusted tuning due to a higher tropopause and increased atmospheric moisture, which affect radiance signals particularly in the mid- and long-wave infrared channels. For this reason, the RGB stretching ranges are modified accordingly.
MSG SEVIRI Night Microphysics RGB -- for tropics
| Colour beam |
Channel (difference) |
Range min |
Range max |
Unit |
Gamma |
| Red |
IR12.0 -- IR10.8 |
-4 |
+2 |
K |
1.0 |
| Green |
IR10.8 -- IR3.9 |
0 |
+5 |
K |
1.0 |
| Blue |
IR10.8 |
273 |
300 |
K |
1.0 |
MTG FCI Night Microphysics RGB -- for tropics
| Colour beam |
Channel (difference) |
Range min |
Range max |
Unit |
Gamma |
| Red |
IR12.0 -- IR10.5 |
-7.1 |
+2.4 |
K |
1.0 |
| Green |
IR10.5 -- IR3.8 |
-2.9 |
+1.1 |
K |
1.0 |
| Blue |
IR10.5 |
273 |
300 |
K |
1.0 |