Based on the meteorological data from 6 stations in Taiyuan, variation characteristics of precipitation, evaporation and temperature in recent 60 years were analyzed, and variation trends of the three meteorological e...
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Based on the meteorological data from 6 stations in Taiyuan, variation characteristics of precipitation, evaporation and temperature in recent 60 years were analyzed, and variation trends of the three meteorological elements in Taiyuan were detected with linear regression method and Mann-Kendall rank correlation method. The results indicate that annual precipitation in Taiyuan during 1951～2006 presented weak decreasing trend which has been obviously since 1990's with average decreasing rate of 13.03mm/10a;among four seasons, decreasing in autumn is the most significant for the rate of 6.13 mm/10a. Annual evaporation in Taiyuan showed obvious decreasing trend from 1970's, and the average rate is 16.28mm/10a, as for seasons, decreasing trend in summer to be the most significant as decreasing rate is 8.42 mm/10a. Annual average temperature presented evident increasing trend from 1980's with the warming rate of 0.38/10a, temperature increasing trend in winter to be more significant than in other seasons, and average rate is 0.61/10a.
TERRA MODIS band 31 was selected as the criterion for doing the radiometric cross-calibration of CBERS-02 IRMSS thermal band. From August to December, 2004, seven times day and night synchronous images of two sensors ...
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TERRA MODIS band 31 was selected as the criterion for doing the radiometric cross-calibration of CBERS-02 IRMSS thermal band. From August to December, 2004, seven times day and night synchronous images of two sensors passing through the Lake Qinghai and Lake Taihu were selected to obtain the cross-calibration data. TERRA MODIS band 31 data were used to conduct out the pupil radiance of CBERS-02 IRMSS band 9 based on the two sensors' spectrum matching, and then the DN values were picked-up from the IRMSS data in the same area. A new model to calculate the radiometric calibration coefficients was carried out in this study. The model is multi-points linear regression method with 7 times day and night synchronous images at different dates and locations. The radiometric cross-calibration coefficients are 8.0567 (gain, unit: DN/(W/m(2)/sr(1)/mu m(1))) and 47.892 (offset, unit: DN). Accuracy estimate of calibration coefficients was carried out. The results show that the calibration coefficients obtained from the linear regression method have a similar precision as TERRA MODIS band 31 ' s. The calibration coefficients can satisfy the quantitative applications of CBERS-02 IRMSS thermal data.
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