For most projects — design and construction of territorial infrastructure, master plans, property rights, landscape design and more — an accurate topographic base is required, namely a topographic map or plan of the work area. Maps and plans are the key deliverable of topographic and geodetic field and office work known as topographic survey. Since the layout of underground utilities is an important component of a topographic plan, mapping these infrastructure elements is a critical part of the workflow.
Depending on scale, topographic maps and plans contain terrain features, relief, vegetation, buildings and structures, street networks, above‑ground and underground utilities (pipelines, cables, sewers) and other natural and man‑made objects. The survey scale is chosen to match the task.
Traditionally, surveys were performed by field geodetic methods and remote sensing. Today these same methods are applied at a new level using modern geomatics. Electronic total stations are used for linear‑angular measurements; GNSS (including real‑time RTK) is used for point positioning. Network GNSS services greatly improve efficiency. Remote sensing methods have advanced: digital imaging is ubiquitous, high‑resolution satellite imagery and UAV (drone) imagery are common. For large‑scale plans, especially on fast‑changing sites, terrestrial laser scanning is effective. High‑sensitivity cable/pipe locators are used to detect and map underground utilities.
Utility detection uses advanced locating equipment. Two horizontal and one vertical antenna with a powerful transmitter and digital signal processing allow quick, accurate detection even in congested utility corridors. With one button, burial depth is determined; current direction and magnitude help distinguish the target utility. Combined with GPS, detected defects and damages are shown on plan and profile in real time.