Reference
Glossary — surveying & geospatial terms
Definitions of key surveying, CAD, and geospatial terminology used across our services.
A
B
- Balady PlatformSaudi Arabia’s e-government municipal-services platform through which surveying decisions and building permits are processed, requiring survey deliverables in specific formats and standards.
- Bathymetric SurveyMeasurement of water-body depths in rivers, ports, and lakes using sonar equipment, producing seabed maps used for port design and submarine pipeline routing.
- BIMBuilding Information Modeling — a digital methodology for representing buildings as 3D models carrying complete engineering information per element, used across the project lifecycle.
C
- CADComputer-Aided Design — software for digitally creating and editing engineering drawings (AutoCAD being the most known), used to produce architectural, structural, and MEP drawings.
- CadastreAn official register documenting parcel boundaries, areas, and ownership within a national coordinate reference system — the foundation of land-registration and urban-planning systems.
- Contour LineLines on a map connecting points at the same elevation, used to visually represent terrain shape. The spacing between lines is the "contour interval", typically 25 cm to 2 m depending on terrain.
D
- DatumA reference frame defining the origin and axes for measuring coordinates on Earth. WGS84 is the most widely used globally, with many countries adopting a local datum for national projects.
- DWGThe native CAD file format for AutoCAD — the industry-standard format for exchanging engineering drawings between teams.
- DXFDrawing eXchange Format — an open CAD interchange format used to move drawings between different CAD applications (AutoCAD, BricsCAD, ZWCAD) while preserving layers and dimensions.
E
G
- GeoidAn imaginary surface representing mean sea level extended under landmasses, used as the elevation reference in surveying. It differs from the Earth ellipsoid because of local gravity variations.
- GISGeographic Information System — software for storing, analysing, and displaying spatial data, used in urban planning, asset management, risk analysis, and spatial decision-making.
- GNSS / GPSSatellite navigation systems for precise positioning. The American GPS is most known, alongside Russian GLONASS, European Galileo, and Chinese BeiDou — modern survey-grade receivers use all four simultaneously for accuracy.
I
L
- Land SubdivisionDividing a land parcel or building into independent, individually-registrable parcels or units, with an approved subdivision plan and an area-and-coordinate schedule per unit.
- LiDARLight Detection and Ranging — a method using laser pulses to measure distances, deployed ground-based or airborne to produce high-accuracy 3D maps of terrain, buildings, and vegetation.
M
O
P
- PhotogrammetryThe science of extracting measurements and 3D models from overlapping photographs, widely used with drone flights to produce Orthomosaics and DSM/DTM models of sites.
- Point CloudA set of millions of 3D points (X,Y,Z) representing the surface of an object or site, captured by laser scanner or photogrammetry, used as the base for BIM models and drawings.
Q
S
- Shop DrawingDetailed execution drawings prepared by the contractor or fabricator to elaborate design elements before construction, including precise dimensions, installation methods, and materials.
- Surveying DecisionA certified surveying document issued by the competent authority (e.g. municipalities via the Balady platform in Saudi Arabia) that fixes a parcel’s boundaries, dimensions, and area — a prerequisite for issuing building permits.
T
- Topographic SurveyThe measurement and recording of natural terrain and existing features on a land parcel, producing a contour map with precise coordinates used for engineering design and permits.
- Total StationA surveying instrument combining electronic angle and distance measurement, used in topographic surveys and construction setting-out at centimetre accuracy.