Rapid remote sensing identification and flux estimation method and system for near-surface methane abnormal emission

The invention provides a rapid remote sensing recognition and flux estimation method and system for abnormal emission of near-surface methane. The method comprises the following steps: calculating unit absorption characteristic spectrums of near-surface methane and other trace gases by utilizing a radiation transfer model; screening an optimal channel for near-surface methane increment inversion; constructing a spectrum similar pixel set and a reference background spectrum of the pixel to be inverted; carrying out optimization iteration inversion on the near-surface methane increment by utilizing a matched filtering method; identifying methane point source discharge ports and methane point source discharge smoke plumes by using a morphological operation method; and calculating the emission flux of the methane point source in combination with the wind field information of the methane point source emission port. The method can be used for rapid remote sensing identification and flux estimation of abnormal near-