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Fire Detection with the ATSR-2 Sensor. By Kurt Fischer ME 449. Table of Contents. 1) Introduction 2) Background on thermal radiance 3) Background on fire radiance 4) How the ATSR senses fires 5) Summary. Introduction.
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Fire Detection with the ATSR-2 Sensor By Kurt Fischer ME 449
Table of Contents 1) Introduction 2) Background on thermal radiance 3) Background on fire radiance 4) How the ATSR senses fires 5) Summary
Introduction • Objective: To provide a concise explanation on how the ATSR-2 sensor, on the ERS-2 satellite, detects fires. • Rational: This was done in order to achieve a better understanding in the interpretation of the ATSR data using the Voyager browser program. • This collection of information was gathered from internet research that focused on NASA’s remote sensing tutorial web site , and the European Space Agency’s web site concerning the ATSR World Fire Atlas.
Thermal Radiance Background • Objects of different temperature radiate different wavelength bands • These different bands have different maximum relative intensities • When the temperatures differ by ~500*C, these maximum relative intensities differ by an order of magnitude • This large difference allows fires to standout from the background See http://rst.gsfc.nasa.gov/sect9/sect9_2.html
Fire Radiance Background • A fire’s temperature can range from 400 K to 1000 K • The respective maximum relative intensity occurs ~2-5μm • This gives the optimum wavelength to use in order to see the fire • The channel that is used on the ATSR-2 to detect fires is at 3.7μm
Satellite Sensing of Fires Here is an example of two signals that would saturate the sensor • The satellite first views a pixel (~1km2) using the channel at 3.7 μm • It makes a record of the fire when a signal saturates the sensor • The signal’s intensity must be high enough in order for saturation to occur • Intensity is a function of temperature and area • Saturation first occurs at around 320 K (given a large enough area) • Must be done at night to avoid solar reflectance which would cause artefact signals • Clouds will block the signal from fires See http://esapub.esrin.esa.it/eoq/eoq50/arino50.htm
Summary Be more specific!! Fires can be detected because of their higher temperature (400-1000K????) relative to it’s surroundings. The high temperature radiates a wavelength band with a maximum relative intensity occurring at a 3-5 um??? unique wavelength. The sensor, which is tuned to 3-5 um???, can detect fires because the radiance is much greater than that of the background. The sensor has limitations include: - solar glare fires can only be detected at night occur at night because solar reflectance will cause false signals and - cities, - clouds will block the sensor from seeing the fire. - non-fire signal ???