A Topographical Survey is an accurate depiction of a site. That site could be property, an area of land or a defined boundary. This is scaled and detailed according to the spatial considerations and is the summary of the on-site data capture processes.
The purpose is to gather spatial information relating to the site (natural and man-made land features). This can often be related to national Ordnance Survey grid and datum information (often using GPS) and is surveyed by point. It is typically accepted that points are positioned in three dimensions which facilitates ground modelling and visualisations to be produced from the topographical survey.
Additional information can often be integrated into topographical surveys which assists a design team in taking account of the necessary and relevant site constraints. This can include site sections through particularly diverse gradient transects, spot heights of surrounding land and site features, i.e. neighbouring properties to assess overlooking, underground utilities information (from radar tracing and integrating utility records data).