中国遥感卫星辐射校正场气溶胶光学特性观测研究

MEASUREMENTS AND STUDY OF AEROSOL OPTICAL CHARACTERISTICS IN CHINA RADIOMETRIC CALIBRATION SITES

1999年 6月 2 8日～ 7月 1 9日在敦煌场 ,7月 2 5日～ 7月 31日在青海湖水面场进行了一次大规模综合野外测量试验 ,其中采用 3台先进的法国CIMEL太阳辐射计对两个场地大气光学特性进行了系统全面测量 ,获得大量晴空天气条件下的大气光学数据。利用Langley法处理气溶胶通道数据得到气溶胶光学厚度及其光谱变化。测量结果显示 550nm波长平均气溶胶光学厚度分别为 0 .1 2、0 .1 8,由气溶胶光学厚度的波长变化得到气溶胶Junge参数分别为 2 .6、3.0 ,并与几种典型气溶胶类型比较。结果表明两地在晴空天气里 ,气溶胶含量较小 ,符合遥感卫星传感器辐射定标的大气条件。

A field measurement campaign was conducted in Dunhuang and Qinghai Lake sites in July 1999. Three CIMEL sun photometers were used to measure the optical characteristics of the atmosphere at the two sites, and a great deal of data about atmospheric optical characteristics in the clear condition were obtained. Data from aerosol bands of sun photometers are used, by means of the Langley method, to determine aerosol spectral optical depths. The results show that the aerosol optical depth (AOD) at 550 nm at the two sites is 0.125 and 0.18 respectively . ν (Junge aerosol size distribution parameter) derived from spectral variation of AOD is 2.6 and 3.0 respectively. These values are compared with several typical aerosol models. All results show that the aerosol concentration at the two sites is small and suitable for in flight calibration for remote sensing satellite sensors.