图1:

图2:
图1是原始图层,想利用栅格计算器将0设置为空值后参与两个图层的平均运算,但用完栅格计算器里的setnull()函数和con()函数后图层的值会变大,请问各位大神怎么解决?
setnull语句为:SetNull("MOD11A2_2003201.LST_Day_1km.tif" == 0,"MOD11A2_2003201.LST_Day_1km.tif")
con语句为:Con(("MOD11A2_2003201.LST_Day_1km.tif" > 0),"MOD11A2_2003201.LST_Day_1km.tif" )