Remote Sensing of (Alaskan boreal)

Wildfires (with Satellites) – ���Why and How?

Chris Waigl 2013-08-08, G&G Remote Sensing lunch seminar UAF

Chris Waigl,– cwaigl@alaska.edu – Remote sensing of (boreal) wildfires (with satellites): Why and how? – 2013-08-08 2

What’s special about Alaska (and the whole boreal zone)?

Image: Alaska Climate Research Center

Chris Waigl,– cwaigl@alaska.edu – Remote sensing of (boreal) wildfires (with satellites): Why and how? – 2013-08-08 3

Why? Global (or regional) fire maps

NASA MODIS Global Firemap - July 10-19, 2013

Chris Waigl,– cwaigl@alaska.edu – Remote sensing of (boreal) wildfires (with satellites): Why and how? – 2013-08-08 4

How is it spreading? Where does the smoke go?

Steward Creek 2 fire 2013- Alaska Fire Service

Chris Waigl,– cwaigl@alaska.edu – Remote sensing of (boreal) wildfires (with satellites): Why and how? – 2013-08-08 5

How severe is it? How is it impacting the ecosystem? à Ecology

Steward Creek 2 fire 2013- Image Alaska State Parks

Chris Waigl,– cwaigl@alaska.edu – Remote sensing of (boreal) wildfires (with satellites): Why and how? – 2013-08-08 6

How? Passive remote sensing from polar-orbiting satellites

For example, MODIS

!   36 bands: 20 reflective visible and short-wave infrared (250-500m resolution), 16 emissive mid and thermal IR1000m

!   Up to 8 “good” images of Alaska / day

Trade-off between resolution in time and space: http://www.youtube.com/watch?v=V0hsCD4qZMk

Chris Waigl,– cwaigl@alaska.edu – Remote sensing of (boreal) wildfires (with satellites): Why and how? – 2013-08-08 7

We measure the intensity of radiation emitted by the fire

Chris Waigl,– cwaigl@alaska.edu – Remote sensing of (boreal) wildfires (with satellites): Why and how? – 2013-08-08 8

Landsat (July 7, 2009)

Chris Waigl,– cwaigl@alaska.edu – Remote sensing of (boreal) wildfires (with satellites): Why and how? – 2013-08-08 9

Zooming in…

Chris Waigl,– cwaigl@alaska.edu – Remote sensing of (boreal) wildfires (with satellites): Why and how? – 2013-08-08 10

Time series: July 4-7, 2009, MODIS over Landsat

Chris Waigl,– cwaigl@alaska.edu – Remote sensing of (boreal) wildfires (with satellites): Why and how? – 2013-08-08 11

2004 Boundary Fire – MODIS Terra

What’s in a pixel? •  shape •  overlap •  distortion

1 px = 1 x 1 km

at nadir (= looking straight down)

Chris Waigl,– cwaigl@alaska.edu – Remote sensing of (boreal) wildfires (with satellites): Why and how? – 2013-08-08

2004 Boundary Fire – simultaneous ASTER image

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1 px = 30 x 30 m

Chris Waigl,– cwaigl@alaska.edu – Remote sensing of (boreal) wildfires (with satellites): Why and how? – 2013-08-08

2004 Boundary Fire – sub-pixel fire temperature���= temperature of the portion of the pixel that is actually on fire

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Chris Waigl,– cwaigl@alaska.edu – Remote sensing of (boreal) wildfires (with satellites): Why and how? – 2013-08-08

Different method: Active remote sensing with microwaves (radar backscatter - SAR)

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new burn

old fire scar

Chris Waigl,– cwaigl@alaska.edu – Remote sensing of (boreal) wildfires (with satellites): Why and how? – 2013-08-08

Overlaying MODIS hotspot pixels on SAR

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Chris Waigl,– cwaigl@alaska.edu – Remote sensing of (boreal) wildfires (with satellites): Why and how? – 2013-08-08

Different method: Thermal aerial imagery

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Chris Waigl,– cwaigl@alaska.edu – Remote sensing of (boreal) wildfires (with satellites): Why and how? – 2013-08-08

Thanks!

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Lime River fire 2013- Alaska Fire Service

Data and imagery courtesy of: •  Alaska Fire Service/AICC •  U.S. Geological Survey •  NASA’s Earth-Sun System Division •  Martin Stuefer

•  Alaska Climate Research Center •  Alaska Satellite Facility/SAR Data Center •  Alaska State Parks