Analysis of the moderate resolution imaging spectroradiometer contextual algorithm for small fire detection
Authors: | W. Wang, J.J. Qu, X. Hao, Y. Liu |
Year: | 2009 |
Type: | Scientific Journal |
Station: | Southern Research Station |
DOI: | https://doi.org/10.1117/1.3078426 |
Source: | Journal of Applied Remote Sensing Vol.3. |
Abstract
In the southeastern United States, most wildland fires are of low intensity. A
substantial number of these fires cannot be detected by the MODIS contextual algorithm. To
improve the accuracy of fire detection for this region, the remote-sensed characteristics of
these fires have to be systematically analyzed. Using an adjusted algorithm, this study
collected a database including 6596 remote-sensed fire pixels in 72 MODIS granules, of
which 3809 fire pixels are missed by the MODIS contextual algorithm. The statistical
distributions of the sensor~observed fire reflectance and brightness temperature at relevant
spectral channels are analyzed. The study explains the reasons that the detection of low
intensity fires by the MODIS contextual algorithm is significantly influenced by view angles,
especially when view angles are greater than 40 degrees. This paper discusses and suggests
several aspects which could improve regional detection of low intensity fires. The results
indicate that I) the R2 threshold R2 < 0.3 is still valid for detecting low intensity fires omitted
by the MODIS contextual algorithm; 2) the threshold T~ > 310 K is too high, and a lower
threshold of T, > 293 K should be adopted instead; 3) the threshold 1>T> 10 K is also too
high, and both algorithms that use it risk omitting small fires because of this threshold.