Abstract: Spaceborne active differential absorption is the more accurate monitoring of global carbon dioxide technology. The atmospheric pressure, temperature, humidity, surface reflectivity and the linewidth in the hardware system, the filter bandwidth and other factors have a great impact on the inversion error, the overall error reaches to 1ppmv range. In this paper, the error caused by the variation of surface reflectance is mainly studied. The influence of the spot size and the distance of the spot on the error is discussed in detail in different terrain. The experimental results show that the larger the spot size, the smaller the inversion error. The larger the separation distance, the greater the inversion error. In a single terrain error is small, while the more complex terrain error (such as: man-made), error control in the 1ppmv range, but cannot be ignored.

Key words: differential absorption