ABSTRACT

Identification of terrain surface features can be done using approaches such as visual observation or remote sensing image processing. Accurate detection of survey targets at the ground level primarily depends on human visual acuity or sensor resolution, and then on acquisition geometry (i.e. the relative position and orientation between the surveyor and the terrain). Further, the delimitation of the observer’s viewshed boundary or of the sensor’s ground footprint is sometimes insufficient to ensure that all enclosed targets can be correctly detected. Size and orientation can hamper ground target visibility. In this paper we describe a new release of r.survey, an open-source spatial analysis tool for terrain survey assessment. This tool offers the necessary information to assess how terrain morphology is perceived by observers and/or sensors by means of three basic visibility metrics: 3D distance, view angle, and solid angle. It is also fully customizable, allowing single or multiple observation points, ground or aerial point of view, and size setting of the observed target, making it useful for many different purposes.

摘要

可以通过视觉观察或遥感图像处理等方法来识别地形表面特征。地面测量目标的准确检测主要取决于人的视力或传感器分辨率，然后取决于采集几何（即测量员与地形之间的相对位置和方向）。此外，观察者的视域边界或传感器的地面足迹的划界有时不足以确保可以正确检测所有封闭目标。尺寸和方向会妨碍地面目标的可见性。在本文中，我们描述了 r.survey 的新版本，这是一种用于地形测量评估的开源空间分析工具。该工具提供了必要的信息，以评估观察者和/或传感器如何通过三个基本可见性指标感知地形形态：3D 距离、视角和立体角。它也是完全可定制的，允许单个或多个观察点、地面或空中视角以及观察目标的大小设置，使其可用于许多不同的目的。