Viewsheds from Key Observation Points for Fort Union Trading Post National Historic Site (FOUS)

Visibility viewsheds incorporate influences of distance from observer, object size and limits of human visual acuity to define the degree of visibility as a...可视域（Visibility viewsheds）通过整合观测者与目标的距离、物体尺寸以及人类视觉敏锐度极限等影响因素，将可视程度定义为一种……