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Comparison of urban heat island retrieval method from Landsat TM thermal data

Landsat TM/ETM+ data have been proved a useful tool to measure urban heat island (UHI) effect. In this paper, five methods - DN value or at-sensor brightness temperature, land surface temperature (LST) retrieved by spectral emissivity correction, mono-window algorithm, generalized single-channel method with and without near-surface temperature, to denote the spatial distribution of the UHI effect from the thermal band of ETM+ data are compared. The land surface emissivity (LSE) values required to retrieve LST was estimated from the NDVI Thresholds Methods, combing with the other six bands provided by the ETM+ data. Finally, we presented a comparison between the five temperatures retrieved by the five algorithms over Nanjing City. The results showed that the three methods of mono-window algorithm and the generalized single-channel method with or without near-surface temperature obtained the similar UHI effect results; DN value also owned high correlation coefficient with LSTs by the three mono-channel methods, so it could be used to denote the spatial variation of UHI effect in some degree; and the value of spectral emissivity corrected LST was much different with that from other four methods.