Geological mapping by thermal inertia derived from long-term maximum and minimum temperatures of ASTER data

Thermal inertia is a geophysical quantity used to characterize geological features. Apparent Thermal Inertia (ATI) is an alternative quantity to be derived from remotely sensed data. Calculation of the conventional ATI requires acquisition of a pair of daytime and night-time images taken within a short time interval that is often difficult to fulfill by satellite remote sensing due to orbit constraints. In this study, we proposed Long-term ATI (LATI) as a new alternative ATI by taking advantage of the large ASTER data archive. Using the Cuprite area, Nevada, U.S., as a test site, ATI was calculated using an ASTER data pair obtained within 2 days. LATI was also calculated using a much further separated ASTER data pair; daytime on 5 August 2000 and night-time on 12 January 2012. These dates were chosen to represent the maximum and minimum yearly surface temperatures. There was a strong positive correlation between ATI and LATI. We can conclude that LATI is useful and superior to the conventional ATI, because the maximum and minimum land surface temperatures tend to converge on certain values and can be used to characterize surface geological features with minimal effects from temporal atmospheric and environmental conditions.

Automated summary

Thermal inertia is a geophysical quantity used to characterize geological features. In this study, a new alternative called Long-term ATI (LATI) was proposed by utilizing a large ASTER data archive. The results showed that there was a strong positive correlation between LATI and the conventional ATI, suggesting that LATI is a more useful and superior alternative for characterizing surface geological features.