Topographic and contour survey. Drone + ground control.
Orbital captures site topography across South East Queensland — terrain elevation, contour lines, surface features and volumetric data — using drone photogrammetry combined with GNSS RTK ground control and total station verification of critical features. The deliverable lands in your civil design software in your project’s coordinate system, ready for design, earthworks planning and volumetric calculation.
What we deliver
- Digital Elevation Model (DEM) — raster of surface elevation at sub-metre resolution across the captured area.
- Contour lines — drafted to your chosen interval (typically 0.25m, 0.5m or 1.0m depending on terrain and project).
- Survey-grade ground control — every deliverable tied to GDA2020 Zone 56 (or AHD where the project requires) via GNSS RTK ground control points captured at the time of survey.
- Total station verification of critical features — building corners, kerbs, drainage points, control monuments, anywhere sub-survey-grade accuracy is required beyond the drone’s typical performance.
- Hillshade rendering and 3D terrain visualisation — useful for client review and presentation.
- Volumetric calculations — cut and fill quantities, stockpile volumes, before-and-after comparison for earthworks.
- CAD deliverable — DWG and PDF with contours drawn as polylines on dedicated layers, ready for direct import into Civil 3D, MicroStation, MagiCAD, AutoCAD or 12d.
- Survey report — methodology, accuracy statement, ground control documentation, coordinate system confirmation.
How we survey topography
Drone photogrammetry capture
Most modern topographic surveys are most efficiently captured via UAV photogrammetry, particularly for sites larger than half a hectare or with limited ground access. The drone flies a planned grid above the site capturing hundreds of overlapping high-resolution photographs, which the photogrammetry pipeline processes into a dense 3D point cloud and DEM.
Photogrammetry captures the terrain surface accurately under most outdoor conditions — open ground, hard surfaces, low vegetation, infrastructure. Where dense vegetation needs to be penetrated to capture the ground surface beneath, we supplement the drone capture with total station survey of the ground beneath canopy, or scope a ground survey for the affected area. We tell you up front at scoping whether the site suits drone-only capture or needs the supplement.
GNSS RTK ground control
Surveyed ground control points are placed across the site before flight and captured to GDA2020 Zone 56 with our GNSS RTK kit. These provide the survey-grade reference frame that ties the drone-captured terrain to absolute coordinates. The number of control points scales with site size and required accuracy — we calculate the right density for each scope.
Total station verification
Where specific features require accuracy beyond the drone’s typical performance — small drainage features, services exposed to ground, critical infrastructure points — we capture them with total station as part of the same survey. The combined dataset gives drone-grade coverage of the broad terrain with sub-centimetre accuracy on the elements that need it.
Coordinate systems and project compatibility
All deliverables land in GDA2020 Zone 56 by default, with AHD heights. Where the project uses MGA94 (the older datum) or a local coordinate system, we transform accordingly. Confirm the project’s coordinate system at scoping and the deliverable lands ready to import.
Where topographic survey earns its place
Civil design and earthworks
Site preparation, road design, drainage, retaining walls, slab design on sloping sites — every civil scope starts with accurate terrain data. A topographic survey done well saves design rework and earthworks variation claims.
Subdivisions and development applications
Council development applications typically require topographic survey of the existing site, contoured to a defined interval, with key features (boundaries, easements, existing buildings, vegetation) captured. We deliver to council submission requirements.
Earthworks volumetric calculations
Stockpile measurement, cut-and-fill estimates, dirt-moving program verification, before-and-after comparison. The drone-based capture method is fast, safe and significantly more accurate than ground-based measurement on large or hazardous sites.
Architect and landscape design context
Slope analysis, drainage modelling, grading design, terrace and retaining feature design — all benefit from accurate site contours rather than the indicative contours that appear on planning maps.
Integration with underground services and built structures
Our topographic surveys integrate with underground service locating, drone orthomosaic, and point cloud capture of existing structures on the same project. Above-ground terrain + below-ground services + existing buildings — one coordinated deliverable, one coordinate system.
Why Orbital for topographic survey
Twenty-three years of survey-grade spatial work in South East Queensland. CERTLOC and NULCA-credentialled foundation. We treat the topographic capture as one component of a larger spatial deliverable rather than a standalone surveying service — which means it integrates seamlessly with locating, drone mapping, point cloud and any AS 5488 work on the same project.
Most pure-surveying firms can’t deliver the integrated above-and-below-ground spatial package. Most drone-mapping operators don’t have the survey discipline. Orbital sits at the intersection: drone capture with surveyor discipline, integrated with twenty-plus years of locating expertise. That’s the spatial-intelligence specialist positioning in operation.
Frequently asked questions
Are you registered surveyors?
Orbital captures and delivers topographic data to engineering specifications. Where the deliverable needs to be signed off by a Registered Cadastral Surveyor (e.g. for legal boundary, certified plan of survey, or formal land tenure work), we coordinate with a Queensland-registered surveyor as part of the engagement. For engineering, civil, architectural and design-context use, our deliverables are typically used directly without separate sign-off.
What accuracy do you achieve?
Drone photogrammetry with surveyed ground control typically achieves vertical accuracy of ±30–50mm and horizontal accuracy of ±20–30mm across the captured area, depending on flight height and ground control density. Critical features captured with total station are recorded to sub-10mm accuracy. We state the accuracy budget for each scope in writing.
What contour interval should I specify?
Depends on the use. Civil design typically uses 0.25m or 0.5m intervals; broader planning work uses 1.0m. Hilly or steeply sloping sites may need finer intervals at critical zones. We’ll recommend an interval at scoping based on the terrain and the design work the survey is supporting.
Can the topographic survey include the underground services?
Yes — that’s exactly what an AS 5488 + topographic + drone mapping integrated scope delivers. Above-ground terrain captured to engineering grade. Below-ground services located and designated by AS 5488 quality level. One coordinated deliverable, one coordinate system. Common scope on civil and infrastructure work.
Can you handle vegetated sites?
Yes for moderate vegetation — drone photogrammetry captures the canopy top where vegetation is dense, which suits some use cases (orthomosaic, vegetation extent mapping, hard-surface terrain). Where the brief requires the ground surface beneath dense canopy, we supplement the drone capture with total station survey of the affected area, or scope a ground survey for those zones. We confirm the right method per site at scoping.
What’s the cost?
Per scope. Variables: site size, contour interval, ground control density, integration with other Orbital services, total station verification requirements. Send us the brief and site address; we’ll come back with a fixed-price quote, usually within 48 hours.
Related services
- Drone mapping and orthomosaic
- Point cloud capture
- Underground service locating
- AS 5488 Subsurface Utility Engineering
Tell us about the site and the design work it’s supporting.
Send us the brief and a site address. We’ll come back with a fixed-price scope, recommended capture method, contour interval and integration with any locating or aerial work also needed.