Photogrammetry Services
Photogrammetry is a measurement technique that derives 3D geometry from overlapping photographs using computational triangulation. Brisbane Point Cloud delivers aerial and close-range photogrammetry for terrain mapping, facade documentation, and visual inspection across Australia.
Capabilities
What we deliver
- Aerial photogrammetry from UAV platforms at 1-5cm ground sample distance
- Close-range photogrammetry for facades, monuments, and small objects
- Ortho-mosaic production with radiometric correction and seamline editing
- Dense point cloud generation from multi-view stereo matching
- Textured 3D mesh models for visualisation and measurement
- Change detection by comparing multi-epoch image datasets
Equipment Used
Deliverables
- Ortho-mosaic imagery (GeoTIFF, ECW)
- Digital surface model (DSM) and digital terrain model (DTM)
- Dense photogrammetric point cloud (LAS/LAZ)
- Textured 3D mesh (OBJ, FBX, 3D Tiles)
- Volume calculation reports from surface models
Our Process
How we work
Mission Design
We calculate the required flying height, overlap, and camera settings to achieve your specified ground sample distance. Ground control points are planned for the site geometry.
Image Capture
Our CASA-certified pilots fly the photogrammetry mission with calibrated cameras. Images are captured with 75-80% forward overlap and 65-70% side overlap to ensure full stereo coverage.
Aerotriangulation
Images are aligned using structure-from-motion algorithms. Ground control points constrain the solution to survey accuracy. Bundle adjustment optimises camera positions and lens parameters.
Product Generation
Dense matching produces a 3D point cloud or mesh. Ortho-mosaics, surface models, and volumes are derived from the reconstructed geometry. All products include accuracy metadata.
FAQs
Common questions
What is photogrammetry and how is it different from LiDAR?
Photogrammetry extracts 3D measurements from photographs by identifying common features across multiple overlapping images and triangulating their 3D positions. LiDAR directly measures distance using laser pulses. Key differences: photogrammetry produces high-resolution visual texture (colour imagery) and is generally lower cost for aerial surveys, but requires good lighting and visible surface texture. LiDAR works in any lighting condition, penetrates vegetation, and achieves higher geometric accuracy for engineering measurement. Photogrammetry accuracy depends on ground sample distance (pixel size) and control quality; typical aerial photogrammetry achieves 2-3x GSD accuracy (e.g., 2cm GSD yields 4-6cm positional accuracy).
When should I choose photogrammetry over LiDAR?
Photogrammetry is the better choice when: you need high-resolution visual imagery (ortho-mosaics for planning, marketing, or visual inspection), the site has good surface texture and lighting, moderate accuracy (5-10cm) is acceptable, or budget is a primary constraint. It excels at producing visual basemaps, textured 3D models for client presentations, and facade documentation where colour information matters. LiDAR is preferred for engineering-grade accuracy, vegetation penetration, indoor surveys, or situations requiring measurement in poor lighting. We often recommend combining both on the same UAV flight.
What ground sample distance can you achieve?
Ground sample distance (GSD) depends on flying height and camera sensor. With our DJI Matrice 4T at 60m AGL, we achieve approximately 1.5cm GSD. At 80m AGL, approximately 2cm GSD. The DJI Mini 5 Pro achieves similar GSD at lower heights due to its smaller sensor. For close-range facade photogrammetry, GSD can be as fine as 1-2mm when photographing from 5-10m distance. Finer GSD requires lower flight altitudes, which increases flight time and image count. We recommend the minimum GSD that meets your accuracy and detail requirements to optimise cost.
How many ground control points are needed?
For a standard aerial photogrammetry survey, we place a minimum of 5 ground control points (GCPs) distributed around the site perimeter and centre. Larger sites (over 10 hectares) require additional GCPs at approximately 200-300m spacing. We also place independent check points (not used in processing) to verify achieved accuracy. GCPs are surveyed using GNSS RTK with typical positional accuracy of +/-10mm horizontal and +/-15mm vertical. For projects requiring only relative accuracy (e.g., volume calculations between two epochs), fewer GCPs may be acceptable.
Can photogrammetry work under tree canopy?
No. Photogrammetry requires direct line-of-sight to surfaces. Dense vegetation canopy blocks the camera view of the ground, making it impossible to reconstruct ground surface beneath trees. For vegetated sites where ground topography is needed, LiDAR is the appropriate technology because multiple laser returns can penetrate gaps in the canopy. However, photogrammetry can map the canopy surface itself accurately, which is useful for vegetation height modelling and canopy cover assessment.
What weather conditions are required for photogrammetry?
Photogrammetry requires consistent lighting across all images. Optimal conditions are overcast or uniformly cloudy skies, which provide diffuse lighting without harsh shadows. Direct midday sun creates strong shadows that can confuse matching algorithms and cause artefacts in ortho-mosaics. Rain, fog, and heavy haze degrade image quality and must be avoided. Wind must be within UAV operating limits (typically below 35km/h). We schedule missions for appropriate conditions and reschedule at no cost if weather is unsuitable on the planned day.
Get a quote for photogrammetry services
Tell us about your project and we will provide a fixed-price proposal within one business day.