Evaluation Analysis of Landsat Level-1 and Level-2 Data Products Using In Situ Measurements
Evaluation Analysis of Landsat Level-1 and Level-2 Data Products Using In Situ Measurements
复制标题
利用原位测量对 Landsat 1 级和 2 级数据产品进行评估分析
DOI：
10.3390/rs12162597
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
L. Leigh
中科院分区：
文献类型：
--
作者：
C. T. Pinto;Xin Jing;L. Leigh
陆地卫星1级产品以量化和校准的缩放数字数（DN）形式交付。1级DN数据可以应用辐射重新缩放系数重新缩放到大气层顶（TOA）反射率。目前，一级产品是大地卫星传感器的标准数据产品。较新的2级数据产品包含表面反射率值，即，在没有大气影响的情况下，这些产品将在地面测量反射率;在不久的将来，预计这些产品将成为大地卫星传感器的标准产品。本文的目的是提出一个辐射性能评价的1级和2级数据产品的Landsat-7增强型专题制图仪（ETM+）和Landsat-8业务陆地成像仪（OLI）传感器。TOA反射率和派生的表面反射率值从这两个数据产品进行了评估，并在原位测量位于土耳其，巴西，智利，美国，法国和纳米比亚的8个测试站点进行了比较。结果表明，ETM+和OLI Level-1 TOA反射率数据和现场测量值之间的一致性分别为3.9%至6.5%和3.9%至6.0%，在所有光谱波段。在较短的波长波段，原位测量结果与2级表面反射率数据产品之间的一致性持续下降，在较长的波长波段略好。两个Landsat传感器的2级地表反射率数据的平均绝对误差百分比为3.3%至10%。在现场收集的数据在短波长光谱带与2级数据的显着衰减的协议表明在一些网站的气溶胶浓度的检索问题。相比之下，结果表明在中红外光谱中对水蒸气的估计相当准确。最后，尽管在两个传感器中可见光谱区的2级数据产品（与1级数据相比）的可靠性较低，但Landsat-8 OLI 2级显示出与Landsat-7 ETM+2级数据相同的所有光谱带表面反射率产品的改进。
Landsat Level-1 products are delivered as quantized and calibrated scaled Digital Numbers (DN). The Level-1 DN data can be rescaled to Top-of-Atmosphere (TOA) reflectance applying radiometric rescaling coefficients. Currently, the Level-1 product is the standard data product of the Landsat sensors. The more recent Level-2 data products contain surface reflectance values, i.e., reflectance as it would be measured at ground level in the absence of atmospheric effects; in the near future, these products are anticipated to become the standard products of the Landsat sensors. The purpose of this paper is to present a radiometric performance evaluation of Level-1 and Level-2 data products for the Landsat-7 Enhanced Thematic Mapper Plus (ETM+) and Landsat-8 Operational Land Imager (OLI) sensors. TOA reflectance and derived surface reflectance values from both data products were evaluated and compared to in situ measurements from eight test sites located in Turkey, Brazil, Chile, the United States, France, and Namibia. The results indicate an agreement between the ETM+ and OLI Level-1 TOA reflectance data and the in situ measurements of 3.9% to 6.5% and 3.9% to 6.0%, respectively, across all spectral bands. Agreement between the in situ measurements and both Level-2 surface reflectance data products were consistently decreased in the shorter wavelength bands, and slightly better in the longer wavelength bands. The mean percent absolute error for Level-2 surface reflectance data ranged from 3.3% to 10% for both Landsat sensors. The significant decay in agreement with the data collected in situ in the short wavelength spectral bands with Level-2 data suggests issues with retrieval of aerosol concentration at some sites. In contrast, the results indicate a reasonably accurate estimate of water vapor in the mid-infrared spectrum. Lastly, despite the less reliable performance of Level-2 data product in the visible spectral region (compared with Level-1 data) in both sensors, the Landsat-8 OLI Level-2 showed an improvement of surface reflectance product over all spectral bands in common with the Landsat-7 ETM+ Level-2 data.