The fractional coverage of the illuminated vegetation (IV), illuminated soil (IS), shaded vegetation (SV), and shaded soil (SS) are four essential structural parameters (f_IV, f_IS, f_SV, and f_SS) describing the vegetation canopy. Their correct estimation can help improve the monitoring of vegetation growth. In this study, we propose and evaluate four coastal/aerosol-band-based vegetation-shadow indices (CVSIs) using the normalized difference of top-of-atmosphere (TOA) reflectance in the coastal/aerosol band and in the blue, green, red, and near-infrared (NIR) bands. We used the four CVSIs to evaluate the illumination conditions of the vegetation-soil canopy for two cases: shadows produced by vegetation and shadows produced by mountains. We also evaluated the combined use of linear spectral mixture analysis (LSMA), CVSIs, and the normalized difference vegetation index (NDVI) to estimate f_IV, f_IS, f_SV, and f_SS. The results led to several conclusions: (i) the effects of atmospheric path radiation mainly influence the optical bands, resulting in the coastal/aerosol-band TOA reflectance exceeding the TOA reflectance of the blue, green, red, and near-infrared bands; (ii) CVSIs can be used to evaluate the illumination conditions of the vegetation-soil canopy; (iii) the proposed strategy produces reasonably accurate estimates of f_IV, f_IS, f_SV, and f_SS (n = 191,268; R² = 0.830–0.981; mean absolute error = 0.053–0.098; root mean square error = 0.063–0.126). Maps of f_IV, f_IS, f_SV, and f_SS are consistent with maps of the actual field illumination conditions.

光照植被 (IV)、光照土壤 (IS)、阴影植被 (SV) 和阴影土壤 (SS) 的部分覆盖率是四个基本结构参数（f _IV、f _IS、f _SV和f _SS) 描述植被冠层。他们的正确估计有助于改进对植被生长的监测。在这项研究中，我们使用沿海/气溶胶波段和蓝色、绿色、红色和近红外 (NIR) 波段。我们使用四种 CVSI 来评估两种情况下植被-土壤冠层的光照条件：植被产生的阴影和山脉产生的阴影。我们还评估了线性光谱混合分析 (LSMA)、CVSI 和归一化差异植被指数 (NDVI) 的组合使用，以估计f _IV、f _IS、f _SV和f _SS。结果得出几个结论：（i）大气路径辐射的影响主要影响光波段，导致沿海/气溶胶波段TOA反射率超过蓝色、绿色、红色和近红外波段的TOA反射率；(ii) CVSI 可用于评估植被-土壤冠层的光照条件；(iii) 提议的策略对f _IV、f _IS、f _SV和f _SS产生合理准确的估计（n  = 191,268；R ²  = 0.830–0.981；平均绝对误差 = 0.053–0.098；均方根误差 = 0.063– 0.126）。f _{IV 的}地图、f _IS、f _SV和f _SS与实际现场照明条件图一致。