Question

Describe the reference system of Survey of India topographical maps.

Answer 1

The reference system of Survey of India topographical maps is based on the geographical coordinate system, which uses latitude and longitude to specify precise locations. The maps feature a network of parallels (latitude) and meridians (longitude), allowing users to determine the exact position of any point on the Earth’s surface. Sheets are organised into 4° × 4° quadrangles, each subdivided into 1° × 1° degree sheets and further split for larger scales. Grid references are marked on the maps at regular intervals, typically 1’, 2’, or 5’, and contour lines provide elevation data referenced to mean sea level. This system ensures accurate location referencing for diverse applications, from land use planning and defence to environmental studies.