NOAA-AVHRR资料反演地温与地面实测值的对比分析

A COMPARISON AND ANALYSIS OF LAND SURFACE TEMPERATURES FROM REMOTE SENSING AND OBSERVATION STATIONS

对遥感反演和地面实测2种方法获得的地温数据进行对比。首先,用NOAA-AVHRR第4、5波段数据和NASAPathfinder地温计算模型计算出中国1999年1月的最高月地温;然后,将其与同期267个气象站的实测月最高地温值进行比较。结果为:遥感反演地温与地面实测月最高地温的线性相关系数为0.86,标准差为5.6℃,反演值比实测值平均偏低2.8℃。用实测地温数据对遥感反演地温值进行线性修正,修正后的反演值与实测值的线性相关系数为0.86,标准误差由修正前的5.6℃变为5.2℃,平均误差由修正前的4.9℃变为4.1℃,平均偏低值由修正前的2.8℃变为0.1℃。修正后的遥感反演地温与实际值更加接近。

By comparing monthly maximum Land Surface Temperature (LST) of January 1999 retrieved from NOAA-AVHRR data with the result from ground observation, it is found that there is a correlation coefficient of 0.86 with a standard deviation of 5.6℃ between the monthly maximum LSTs from remote sensing and those from ground observation. Monthly maximum LSTs retrieved from remote sensing are generally 2.8℃ lower than those from ground observation. It is necessary to revise LSTs retrieved from remote sensing to reduce the mean deviation between them and LSTs from ground observation without any delay. After the revision of the monthly maximum LSTs retrieved from remote sensing, the correlation coefficient between the modified monthly maximum LSTs retrieved from remote sensing and LSTs from ground observation remains 0.86, the standard deviation is reduced from 5.6℃ to 5.2℃, and the mean deviation decreases from 4.9℃ to 4.1℃. Although the modified monthly maximum LSTs retrieved from remote sensing remain lower than those from ground observation, the mean deviation is reduced from 2.8℃ to 0.1℃.