地表反射率对星载差分吸收二氧化碳反演的影响

Effect of surface reflectance on retrieval of spaceborne differential absorption carbon dioxide

星载主动式差分吸收是目前较为精准监测全球二氧化碳的方法。大气中气压、温度、湿度、地表反射率及硬件系统中线宽、滤波器带宽等对反演误差都有影响,其中地表反射率对反演误差有着不可忽视的影响。实验结果表明光斑足迹越小、间隔距离越大、地貌越复杂,反演误差就会越大。在光斑直径为100 m、距离间隔为10 m时,6种地貌的绝对误差在0.0215×10^(-6)~0.2134×10^(-6),控制在1×10^(-6)之内,这对实际硬件参数设计有一定参考意义。

Spaceborne active differential absorption is a more accurate method to monitor global carbon dioxide. The atmospheric pressure, temperature, humidity, surface reflectivity and the hardware system linewidth, filter bandwidth and so on all have influence on retrieval error. Among them, the surface re- flectivity has unnegligible influence on retrieval error. Experimental results show that the spot footprint is smaller, separation distance is bigger, and geomorphology is more complex, the retrieval error will be bigger. When the spot diameter is 100 m and distance interval is 10 m, the absolute error of six geomorphies ranges from 0.0215 ×10^（-6） to 0.2134 ×10^（-6）, which is controlled within 1×10^（-6） It has certain reference significance to the actual hardware design.