用FY-1C两个近红外太阳反射光通道的观测数据反演水汽总含量  

REMOTE SENSING OF TOTAL COLUMN PERCEPTIBLE WATER VAPOR WITH TWO SUN REFLECTANCE CHANNELS OF FY-1C SATELLITE

作　　者：张弓[1] 许健民[1] 黄意玢[1] 

机构地区：[1]国家卫星气象中心,北京100081

出　　处：《应用气象学报》2003年第4期385-394,共10页Journal of Applied Meteorological Science

摘　　要：FY 1C极轨气象卫星扫描辐射仪第 1 0通道的观测波长为 0 .90～ 0 .965 μm ,位于弱水汽吸收区 ,邻近的第 2通道观测波长为 0 .84～ 0 .89μm ,位于大气窗区。该文根据R .Frouin提出的算法 ,用FY 1C资料实现了近红外水汽吸收区和窗区两个通道联合反演水汽总含量。所用的反演关系式为r =exp(B -A m)。其中 ,水汽吸收区与窗区两个通道的反射率之比r可以从卫星测值中求出 ;在探空站所在的地方 ,沿光路的水汽总含量m为己知量 ,可以用统计方法求出系数A和B ;在没有探空站的地方 ,可以根据系数A和B ,用反演关系式求m。影响系数A的因素主要是大气的温、压、湿廓线和仪器的通道响应函数 ,影响系数B的因素是地表反射率。由于这些对反演关系式中的系数取值有影响的因素随时间和地点有变化 ,对不同地区和时段的探空站分别进行统计 ,得到不同的系数进行反演 ,取得了较好的效果。另外 ,还用质量控制手段控制了定位误差可能带来的影响。独立样本真实性检验表明 ,反演值和探空测值之间的偏差约为 1 5 %～ 2 0 % ,相关系数在 90 %以上。Remote sensing of the total column perceptible water vapor with the imaging spec trometer on the FY-1C polar orbiting satellite is realized based on the algor ith m suggested by R. Frouin et al. (1990). With the two sun reflectance channels (a water absorption channel and a window channel), the total column perceptible wa ter vapor is derived. The water absorption channel is at the wavelength of 0.90 to 0.965μm, and the window channel at 0.84 to 0.89μm. The basic formula used i s:r=exp(B-Am). In the formula,r, the ratio of observation values between the water absorption channel and the window channel, is known. At the locations around radiosonde stations, the total water vapor amount along th e observation path is also known. Coefficients A and B can be derived by means of the statistic method. At other locations far from radio sonde stations , m is calculated with coefficients A and B. Factors affecting A are the atmospheric profiles of temperature, pressure and humidity and the channel response function of the imaging spectrometer. The factor affecting B is the surface reflectance. Those factors are time- and location-related. Statistic ca lculation is performed respectively at different time periods and locations. The possible errors that otherwise may be introduced from the incorrect navigation of the images are limited by the quality control measure. Reality examination wi th independent radiosonde samples shows that the bias is about 15% to 20%, and t he correlation coefficient is above 90%.

关 键 词：FY-1C气象卫星 水汽总含量 太阳反射光通道 反演 

分 类 号：P426[天文地球—大气科学及气象学] P414.5