A generalized single‐channel method for retrieving land surface temperature from remote sensing data

TLDR

Many algorithms for retrieving land surface temperature have been developed, but each is tailored to a specific thermal sensor, preventing cross‑sensor application. The authors aim to develop a generalized single‑channel algorithm that relies solely on total atmospheric water vapour and the channel’s effective wavelength, assuming known emissivity. The algorithm applies to thermal sensors with a full‑width half‑maximum of about 1 µm, requiring no in‑situ radiosoundings or effective mean atmospheric temperature values. Validation across AVHRR, ATSR‑2, and Landsat TM sites shows root‑mean‑square deviations below 2 K (AVHRR, ATSR‑2) and below 1.5 K (Landsat TM), demonstrating the method’s accuracy and cross‑sensor applicability.

Abstract

Many papers have developed algorithms to retrieve land surface temperature from at‐sensor and land surface emissivity data. These algorithms have been specified for different thermal sensors on board satellites, i.e., the algorithm used for one thermal sensor (or a combination of thermal sensors) cannot be used for other thermal sensor. The main goal of this paper is to propose a generalized single‐channel algorithm that only uses the total atmospheric water vapour content and the channel effective wavelength (assuming that emissivity is known), and can be applied to thermal sensors characterized with a FWHM (Full‐Width Half‐Maximum) of around 1 μm actually operative on board satellites. The main advantage of this algorithm compared with the other single‐channel methods is that in‐situ radiosoundings or effective mean atmospheric temperature values are not needed, whereas the main advantage of this algorithm compared with split‐window and dual‐angle methods is that it can be applied to different thermal sensors using the same equation and coefficients. The validation for different test sites shows root mean square deviations lower than 2 K for AVHRR channel 4 (λ ≈ 10.8 μm) and ATSR‐2 channel 2 (λ ≈ 11 μm), and lower than 1.5 K for Landsat Thematic Mapper (TM) band 6 (λ ≈ 11.5 μm).