1. VIIRS and the Fort McMurray Fire VISIT Satellite Chat (18 May 2016)
Curtis Seaman, CIRA

2. Outline Look at VIIRS imagery of Fort McMurray Fire
Discuss “saturation” and “fold-over”
Introduce “Fire Temperature RGB”
References

3. Spatial Resolution (m) @ nadir
VIIRS Bands for Fires
VIIRS Band
Central Wavelength
(μm)
Band Explanation
Spatial Resolution nadir M1
0.412
Visible/
Reflective
750 m M2
0.445 M3
0.488 M4
0.555 M5
0.672 M6
0.746
Near IR M7
0.865 M8
1.240
Shortwave IR M9
1.378
M10
1.61
M11
2.25
M12
3.7
Medium-wave IR
M13
4.05
M14
8.55
Longwave IR
M15
10.76
M16
12.01
DNB
0.7
Visible / Reflective
750 m across full scan I1
0.64
375 m I2
0.87 I3 I4
3.74 I5
11.45
VIIRS has 9* bands that detect fires/flares/hot spots
M-12, M-13, I-4 are best for fire detection
M-11 detects moderately active fires
M-10, I-3, M-15, I-5 detect only the hottest, largest fires
DNB detects visible light from fires at night

4. Brightness Temperature (K)
M-13 vs. I-4
M-13
I-4
Warmest pixel: 487 K
“Cold” pixels near the center of the fire are due to saturation and “fold-over”.
750 m resolution
375 m resolution
20:20 UTC 3 May 2016
I-4 is higher resolution, but has a low saturation point (367 K)
M-13 is a dual-gain band with a high saturation point (+600 K)
Brightness Temperature (K)

5. Fire Temperature RGB
Fire Temperature RGB combines the short/mid-wave IR bands to aid fire detection
M-10 (1.61 µm), M-11 (2.25 µm) and M-12 (3.7 µm)
Hot spots detected in M-12 show up red
Hot spots detected in both M-12 and M-11 appear orange to yellow
Hot spots detected in all three bands appear white (maybe even bluish if fold-over is present in M-12)
20:20 UTC 3 May 2016
Liquid clouds appear blue, ice clouds appear dark green, bare ground appears purple/maroon, snow/ice/water appear black

6. Fort McMurray Fire (3-7 May 2016)

7. 20:45 UTC 7 May 2016

8. 20:00 UTC 15 May 2016

9. 19:40 UTC 16 May 2016

10. 19:20 UTC 17 May 2016

11. References Seeing the Light: VIIRS in the Arctic Blog:
VIIRS Imagery and Visualization Team Blog: