由于冠层叶片群体效应,在1km的空间尺度上遥感获取浓密植被陆面温度与气温近似相等。根据这个原理对利用遥感手段获取气温进行了尝试,提出利用NDVI-Ts空间获取气温的方法,计算气温空间分布模式,同时对Prihodko和Goward提出的气温遥感获取模型(简称P-G模型)进行试验并与NDVI-Ts空间法进行了对比。根据Parton和Logan提出的气温尺度转换模型,利用气象站观测最高气温和最低气温获取Terra卫星过境时刻气温作为“测定值”,对遥感获取的气温进行检验,得到以下结论:P-G模型计算气温与观测结果相比偏高,而NDVI-Ts法计算结果偏低,但是其总体误差范围相当,大约为 4℃;与P-G模型相比,尽管NDVI-Ts空间法获得的气温在精度上对P-G模型没有多大的改善,但这种方法能够更加充分利用遥感获取的信息,而且在计算机运算效率上也有很大的改进,NDVI-Ts空间法相对于P-G模型具有一定优势。

Because of the colony effectof leafs in canopy, the complexmixture ofsunlit, partly shaded and fully shaded\nleafs causes the phenomenon thatradianttemperature fordense canopy are equal to the air temperature approxmi ately. And\nbased on the fact, we try to retrieve the air temperature from combined reflected solarand emitted terrestrial radiationwith\nNDVI-Tsspace. The air temperature at the tmi e ofsatellite passing throughwas estmi ated from themaxmi um andminmi um\nair temperaturemeasured in situwith Parton& Loganmodel andwe stillnamed it as“measured”air temperature. Then\nthe results fromNDVI-Tsspace and P-Gmethodwere validatedwith“measured”air temperature. The results showed that:\nthe air temperatures estmi ated from remotely sensed mi agewith P-G modelwere higher and the ones fromNDVI-Tsspace\nwere lower than“measured”averagely. But the remotely sensed air temperature estmi ated from the twomethods is allwith\nabout+4℃error comparedwith the“measured”air temperature. Although theNDVI-Tsspacemethod doesn’t mi prove\nP-G model from the error scale, theNDVI-Tsspace method is superior to P-G model because the former has used the\nremotly sensed infomationmuch fully than P-G model and has higher operation efficiency.