Irregular urban heat island footprint extraction method based on angle segmentation

The invention provides an irregular urban heat island footprint extraction method based on angle segmentation. Firstly, based on a multi-source remote sensing image, the surface temperature is inverted, a city built-up area is extracted by using a dynamic threshold dichotomy, and then the city form is measured and calculated. Secondly, a plurality of buffer rings with the interval of 1 km are drawn from the boundary of the urban built-up area, the built-up area and the buffer rings of the built-up area are divided into sixteen quadrants at equal angles, then the average temperature on each ring is counted, a temperature curve is drawn, and abnormal quadrants are removed; thirdly, integrating the residual quadrant temperature curves, and fitting a footprint extension distance and a background temperature value by using an exponential decay model; and finally, according to the extension distance obtained by fitting and the background temperature value, jointly constraining the heat island influence range, and o