خلاصة:
Land surface temperature (LST) is a significant parameter for many applications. Many studies have proposed various algorithms, such as the split-window method, for retrieving surface temperatures from two spectrally adjacent thermal infrared bands of satellite data. Each algorithm is developed for a limited study area and application. In this paper, as part of developing an optimal split-window method in the southeast of Tehran province, Iran, four commonly applied algorithms to retrieve the LST from AVHRR were compared. This study was carried out in a wheat farm site located in the Pakdasht Agricultural Region. Measurements of LST over the farm were made with a manual infrared radiometer at the time of NOAA overpass for 18 days of May to June 2004. These days were cloud free over the study area. A total of 18 NOAA images were acquired for the days that LST measurements were made. The temperatures derived by the different split-window algorithms were compared to ground truth measurements. The performance of the split window algorithms was checked with three statistical indices: root mean square error (RMSE), mean bias error (MBE) and coefficient of determination (R2). The results showed that the Ulivieri split-window algorithm produced the lowest value of RMSE and MBE (2.71 and 0.26 K, respectively) and its highest value of R2 (0.92) gave more accurate results than the other algorithms.
ملخص الجهاز:
Comparison of Some Split-window Algorithms to Estimate Land Surface Temperature from AVHRR Data in Southeastern Tehran, Iran S.
Many studies have proposed various algorithms, such as the split-window method, for retrieving surface temperatures from two spectrally adjacent thermal infrared bands of satellite data.
In this paper, as part of developing an optimal split-window method in the southeast of Tehran province, Iran, four commonly applied algorithms to retrieve the LST from AVHRR were compared.
Various authors suggested split-window methods including non- uniform emissivity to estimate LST (Price, 1984; Becker and Li, 1990; Prata and Platt, 1991; Kerr et al.
Yang and Yang (2006) modified Becker split window LST algorithm for NOAA-16/17 AVHRR data.
To obtain LST values that are comparable with those obtained using split window algorithms, measurements of surface temperature over the farm were carried out simultaneously over 30 minutes, centered about the time of the satellite overpass.
If Tr is the radiometric temperature measured by a thermal infrared radiometer, the equation used to determine the true land surface temperature (Ts) is:The objective of this study was to compare various split-window algorithms for retrieving B(Tr ) ε B(Ts ) (1 ε) Fd / π (1)surface temperature for a agricultural land located in southeast of Tehran province, Iran and, then, to select the most accurate model.
Accurate land surface temperature retrieval from AVHRR data with use of an improved split window algorithm.
A split-window algorithm for estimating land surface temperature from satellites.
A comparative study of algorithms for estimating land surface temperature from AVHRR Data.