Abstract: Newton's iteration method was the common algorithms on the sub-pixel decompound of the forest fire.The computing precision of the fire area lied on the estimating precision of background temperature,when the estimating error of the background temperature(Tbg) was to 0.5～1K,one times difference of the fire area to pixel size percent(Af) would caused.The genetic algorithms has the capability of entirely optimizing,with the background temperature(Tbg),fire temperature(Tf) and fire area percent(Af) as the optimizing variables.The RAGA genetic algorithms were used to optimize the entire results of radiance balance equations on the sub-pixel decompound.The result indicated that the equations evaluation precision was two orders of magnitude higher than the Newton's iteration method.Finally,three forest fire areas in Muli County of Sichuan Province was estimated with the RAGA respectively to provide the important references for putting out of the forest fires.

Key words: Remote sensing, Remote sensing, Sub-pixel decompound, Genetic algorithm, Area of forest fire