NOAA/AVHRR
satellite data can be able to provide valuable means of determining the extent
of burning areas and of estimating emission pollutant sources in time and
space. As a part of the project,
the development of a spatially and temporally explicit method for quantifying
emission from wildfires and prescribed fires, funded by Air Resources Board,
California Environmental Protection Agency, an integrated technique as an
alternative method for wildfire mapping for California, using
NOAA-14/AVHRR/HRPT data was developed.
The technique consists of two parts. The first part is developing an appropriate active fire
detection algorithm that combines strengths of fixed multi-channel threshold
algorithm and adaptive thresholds of contextual algorithm. In the second part, mapping of
wildfires for California during the fire season, July through October, 1999,
was conducted under considering the hotspot detection results and NDVI
decreasing. In this study, a
dynamic algorithm for hotspot detection and burned scar mapping was also
developed. The dynamic here means
use of daily or near daily AVHRR data and compare the data values (both
individual band values and NDVI) acquired from two continual days. The
algorithm mainly includes four steps: (1) removing cloud pixels, replaced with
a pixel value and a pixel label acquired on the previous day; (2) detecting
hotspots through evaluating NDVI decreasing to those potential fire pixels; (3)
labeling pixels as burnt scars (recent or old) through evaluating NDVI decreasing
to those cooler pixels (related to hotspots); and (4) eliminating single pixels
through examining the properties of its neighbor pixels. Both wildfire-mapping techniques proved
to be reliable and feasible.
Please go back my main homepage