Retrieval of Subpixel Fire Temperature and Fire Area using Simulated HJ-1B Data

Abstract

HJ-1B satellite is one of the small satellites in the constellation for disaster prediction and monitoring which will be launched in 2008. The infrared sensor, which is one of the payloads of HJ-1B satellite, contains the MIR and TIR channels. The improved capabilities of HJ-1B data offer an opportunity for the computation of subpixel fire temperature and fire area. The simulated HJ-1B MIR and TIR channel images are used in this paper for the algorithm test. Fires with various sizes and temperatures are simulated in a wide range of terrestrial biomes and climates conditions by MODTRAN 4. A bispectral method developed by L. Giglio and J. D. Kendall is adopted to retrieve the temperature and area of a subpixel fire within an otherwise homogeneous pixel. It is evident that HJ-1B satellite data are more sensitive to the smaller and the cooler fires than that of MODIS or AVHRR Data. For the HJ-1B data, if the fire area is about 450 m2 and fire temperature is about 1000 K, it can also offer a capability of retrieving the fire temperature and area in a relatively high accuracy. It has been demonstrated that the accuracy will increase with the growing fire area or temperature. By sensitivity analysis it has been found that the uncertainties of the retrieved fire temperature and area using HJ-1B data are about 10.0% and 30% at the given simulation condition.