where LST
min
and LST
max
correspond to 240 and 340 K respectively, which allowsorthonormalizing the NDVI–LST space. LST
max
also corresponds to the upper limitof the thermal range of AVHRR, and LST
min
has been chosen in order to normalizeinaccuracies in NDVI and LST parameters to 1–2% of their respective range.