FY-3C VIRR和Terra MODIS NDVI产品在湘赣地区的一致性

卫星遥感是监测大范围植被动态变化最有效的手段。随着中国遥感技术的发展,国产风云卫星也逐渐应用于植被变化研究,但有关国产风云卫星刻画植被动态变化表现方面仍不明晰。比较了国产风云卫星(FY-3C VIRR)和美国Terra卫星(MODIS)的归一化植被指数(normalized difference vegetation index, NDVI)产品在湖南省和江西省的时空一致性。结果表明：(1)两种卫星NDVI产品的空间分布与年、季、月的变化特征在湘赣地区有较好的一致性,江西省NDVI整体高于湖南省;(2)FY-3C和MODIS年均NDVI都呈现出2018年高于2017年和2019年的情况,基于MODIS的湘赣地区三年的年均NDVI(0.58)高出FY-3C(0.36)约60%;(3)FY-3C NDVI在各季节都整体低于MODIS NDVI,其中冬季差异最大,基于MODIS NDVI均值(0.42)约是FY-3C(0.21)的2倍,其余季节MODIS高出FY-3C约50%;(4)FY-3C NDVI与MODIS NDVI月变化趋势基本一致,二者年最大NDVI差异变化不大且较为稳定,年最小...

Consistency of FY-3C VIRR-NDVI and Terra MODIS-NDVI products in Hunan and Jiangxi provinces of China

Satellite remote sensing is the most effective means of monitoring the vegetation dynamic over large-scale. With the development of remote sensing technology in China, domestic Fengyun satellites has been gradually applied to the study of vegetation change. However, the performance of Fengyun satellites in depicting the vegetation dynamic is still unclear. The spatial and temporal consistency of normalized difference vegetation index (NDVI) products retrieved from FY-3C VIRR (FY-3C) and Terra MODIS (MODIS) was compared over Hunan and Jiangxi provinces. The results showed as follows. High consistence in spatial distribution and temporal dynamic (i.e., annual, seasonal, and monthly) are characterized by FY-3C and MODIS NDVI products. Regional averaged annual mean NDVI of Jiangxi province is higher than that of Hunan province. The annual mean NDVI of 2018 is higher than that of 2017 and 2019 in both FY-3C and MODIS NDVI products. Three years regional averaged annual mean NDVI in Hunan and Jiangxi Provinces based on MODIS (0.58) is 60% higher than of FY-3C (0.36). FY-3C NDVI is lower than that of MODIS NDVI in all seasons with the largest difference occurred in winter. MODIS NDVI (0.42) is twice higher than FY-3C NDVI (0.21) in winter and this magnitude is about 50% in the rest seasons. The monthly variation of FY-3C NDVI and MODIS NDVI is also consistent. The difference is stable and small in annual maximum NDVI but larger in annual minimum NDVI (the annual minimum NDVI based on MODIS is about 100% higher than that of FY-3C). Scientific reference for the ability of domestic Fengyun satellites to detect vegetation dynamic characteristics in typical areas is unraveled in this study.