Evaluation of the NCEP and MODIS Atmospheric Products for Single Channel Land Surface Temperature Retrieval With Ground Measurements: A Case Study of HJ-1B IRS Data

Abstract

In this paper, two atmospheric profile sources were assessed for land surface temperature (LST) retrieval purposes for the HJ-1B IRS (Infrared Scanner) single-channel thermal infrared (TIR) data. One profile source is the National Center for Environmental Prediction (NCEP) operational global analysis data, and the other source is the Moderate Resolution Imaging Spectroradiometer (MODIS) atmospheric profiles product (MOD07). The atmospheric profiles were used as the input to the MODTRAN 4 radiative transfer model to calculate the atmospheric parameters involved in LST retrieval. The LST retrievals from the HJ-1B IRS data were compared with ground measured temperatures obtained from a series of field campaigns in Hebei province, China, from May to September of 2010. Ground measurements were performed over four land-cover types: bare soil, full-cover wheat, full-cover corn, and water surfaces. A total of 11 points of measurements was collected over a period of eight days. The results indicate that the LST derived from HJ-1B IRS data using either the NCEP or MOD07 profiles showed good agreement with the ground LSTs, with an root mean square error (RMSE) of 1.16 and 1.21 K for the NCEP and MOD07, respectively. In addition, we found that the MOD07 profiles may cause greater error for the atmospheric parameters estimation in the TIR domain for the regions of higher altitude due to a lack of data at the lower altitude levels. Thus, we proposed a method for combination of the MOD07 and NCEP profiles for LST retrieval. The results show that the combined profile is able to produce more reliable results than the use of only one type of profile because the combination offers both high spatial resolution and the necessary level of accuracy. This result implies that the combined profiles may be highly useful for accurate LST retrieval when local soundings are not available and particularly for sensors with only one thermal channel.