Cross-Comparative Analysis of GF-1 Wide Field View and Landsat-7 Enhanced Thematic Mapper Plus Data

Abstract

The wide field view (WFV) sensor on-board GF-1 satellite can acquire multi-spectral data with moderate spatial resolution, which holds great potential for monitoring the Earth's surface. This study assesses WFV data through cross-comparison of spectral band reflectances and vegetation indices with Landsat-7 Enhanced Thematic Mapper plus (ETM+) data. The four vegetation indices considered in this study are the normalized difference vegetation index (NDVI), the enhanced vegetation index (EVI), the ratio vegetation index (RVI), and the soil adjusted vegetation index (SAVI). The R2 between the WFV and ETM+ data were 0.82, 0.89, 0.92, and 0.80 for the blue, green, red, and near-infrared bands reflectance, and 0.90, 0.84, 0.83, and 0.91 for NDVI, EVI, RVI, and SAVI, respectively. The results displayed a high correlation between the spectral reflectances and vegetation indices of the two sensors’ data, which indicated the reliability of the WFV data. Furthermore, the WFV data were better than the ETM+ data with regards to spatial and temporal resolutions.