The thermal infrared channel (IRS4) of HJ-1B satellite obtains view zenith angles (VZA) up to ±33°. The view angle should be taken into account when retrieving land surface temperature (LST) from IRS4 data. ...The thermal infrared channel (IRS4) of HJ-1B satellite obtains view zenith angles (VZA) up to ±33°. The view angle should be taken into account when retrieving land surface temperature (LST) from IRS4 data. This study aims at improving the mono-window algorithm for retrieving LST from IRS4 data. Based on atmospheric radiative transfer simulations,a model for correcting the VZA effects on atmospheric transmittance is proposed. In addition,a generalized model for calculating the effective mean atmospheric temperature is developed. Validation with the simulated dataset based on standard atmospheric profiles reveals that the improved mono-window algorithm for IRS4 obtains high accuracy for LST retrieval,with the mean absolute error (MAE) and root mean square error (RMSE) being 1.0 K and 1.1 K,respectively. Numerical experiment with the radiosonde profile acquired in Beijing in winter demonstrates that the improved mono-window algorithm exhibits excellent ability for LST retrieval,with MAE and RMSE being 0.6 K and 0.6 K,respectively. Further application in Qinghai Lake and comparison with the Moderate-Resolution Imaging Spectroradiometer (MODIS) LST product suggest that the improved mono-window algorithm is applicable and feasible in actual conditions.展开更多
Satellite images are used extensively in studying the urban heat island(UHI)phenomenon.We evaluated the suitability of thermal infrared(TIR)data from the HJ-1B satellite for detecting UHI using a case study in Beijing...Satellite images are used extensively in studying the urban heat island(UHI)phenomenon.We evaluated the suitability of thermal infrared(TIR)data from the HJ-1B satellite for detecting UHI using a case study in Beijing.Two modified algorithms for retrieving the land surface temperature(LST)from HJ-1B data were tested.The results were compared with LST images derived from a Landsat TM thermal band and the MODIS LST output.The spatial pattern of UHI generated using HJ-1B data matched well with that produced using TM and MODIS data.Of the two algorithms,the mono-window algorithm performed better but further tests are necessary.With more frequent coverage than TM and higher spatial resolution than MODIS,the HJ-1B TIR data present a unique opportunity to study thermal environments in cities in China and neighboring countries.展开更多
基金Under the auspices of Opening Funding of State Key Laboratory for Remote Sensing ScienceNational High-tech Research and Development Program (863 Program) (No. 2007AA120205, 2007AA120306)
文摘The thermal infrared channel (IRS4) of HJ-1B satellite obtains view zenith angles (VZA) up to ±33°. The view angle should be taken into account when retrieving land surface temperature (LST) from IRS4 data. This study aims at improving the mono-window algorithm for retrieving LST from IRS4 data. Based on atmospheric radiative transfer simulations,a model for correcting the VZA effects on atmospheric transmittance is proposed. In addition,a generalized model for calculating the effective mean atmospheric temperature is developed. Validation with the simulated dataset based on standard atmospheric profiles reveals that the improved mono-window algorithm for IRS4 obtains high accuracy for LST retrieval,with the mean absolute error (MAE) and root mean square error (RMSE) being 1.0 K and 1.1 K,respectively. Numerical experiment with the radiosonde profile acquired in Beijing in winter demonstrates that the improved mono-window algorithm exhibits excellent ability for LST retrieval,with MAE and RMSE being 0.6 K and 0.6 K,respectively. Further application in Qinghai Lake and comparison with the Moderate-Resolution Imaging Spectroradiometer (MODIS) LST product suggest that the improved mono-window algorithm is applicable and feasible in actual conditions.
基金supported by Startup Fund for Talented Scholars,Beijing Forestry University(Grant No.0001115000)State Key Laboratory of Remote Sensing Science Open Fund(Grant No.2009KFJJ021)+1 种基金sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal UniversityNational Key Technology Research and Development Program of China(Grant No.2009AA12200101)
文摘Satellite images are used extensively in studying the urban heat island(UHI)phenomenon.We evaluated the suitability of thermal infrared(TIR)data from the HJ-1B satellite for detecting UHI using a case study in Beijing.Two modified algorithms for retrieving the land surface temperature(LST)from HJ-1B data were tested.The results were compared with LST images derived from a Landsat TM thermal band and the MODIS LST output.The spatial pattern of UHI generated using HJ-1B data matched well with that produced using TM and MODIS data.Of the two algorithms,the mono-window algorithm performed better but further tests are necessary.With more frequent coverage than TM and higher spatial resolution than MODIS,the HJ-1B TIR data present a unique opportunity to study thermal environments in cities in China and neighboring countries.
