风云气象卫星-4A陆表温度数据在四川省境内的真实性评价

Authenticity Evaluation of Land Surface Temperature Data of FY-4A in Sichuan Province

陆表温度数据是地球环境监测的重要指标,是衡量地球表面与大气层之间稳定性的重要参数。基于FY-4A陆表温度产品,结合8个地面站点温度数据、MODIS陆表温度产品的66组数据,探究FY-4A陆表温度产品在四川地区的精度及其影响因素。结果显示:与地面站点温度数据的平均误差、平均绝对误差、均方根误差和相关系数分别为-6.39 K、6.81 K、9.10和0.945,其中地形平缓区优于地形起伏区。FY-4A陆表温度产品与MODIS陆表温度产品的平均误差、平均绝对误差、均方根误差和相关系数分别为-0.585 K、2.625 K、3.49和0.931,其中夜间优于日间,各季节相关性不同,且普遍存在低估现象;在空间差异上整体呈现东部优于西部的特征,成都平原精度高,在四川省西部地形起伏明显地区的精度有所下降。对17种土地利用类型验证结果表明,农田与自然植被类型的陆表温度产品精度明显优于常绿阔叶林类型。

Land surface temperature(LST)data is a crucial indicator for monitoring the Earth’s environment and measuring the stability between the Earth’s surface and atmosphere.Based on FY-4A LST products,combined with the LST of 8 meteorological stations and 66 groups of MODIS LST products,this paper explores the accuracy and influencing factors of FY-4A LST products in Sichuan.The results indicate that the average error,the average absolute error,the root mean square error and the correlation coefficient between the temperature data and the ground station are-6.39 K,6.81 K,9.10 and 0.945,among which the flat terrain area is better than the undulating terrain area.The average error,the average absolute error,the root mean square error and the correlation coefficient between FY-4A LST product and MODIS LST product are-0.585 K,2.625 K,3.49 and 0.931.Among them,Nighttime results are better than daytime,and the correlation of each season is different,and underestimation is common.In terms of spatial difference,the East is better than the West as a whole.The accuracy of Chengdu Plain is high,but it decreased in the area with obvious topographic relief in the west of Sichuan Province.The verification results of 17 land use types show that the accuracy of LST products of farmland and natural vegetation types is significantly better than that of evergreen broad-leaved forest types.