

Hobart, Tasmania · looking across the city by confidence class; orange where passes differ by more than 15 cm · Showcase
Products
Change and volumes
What moved, where, and how much: real change, beyond each pair's measured scatter at 95 % confidence, kept as its own layer.
A site is captured again to our specification, or an earlier survey brought in, and the two co-registered on ground that has not moved. Change is measured only where both captures are confident, so a volume is a measurement and not an artefact of misalignment.
Change is reported as maps, profiles and volumes by area, each with the confidence that supports it.
- On stable open ground, checked independently of the alignment, the 2011 survey agrees with the 2024 survey to a median −6 mm (NMAD 64 mm, 95th percentile 157 mm; 94.4 % within 15 cm): relative agreement between surveys, not absolute accuracy. Hobart 3D city model
Deliverables
- Elevation-change rasters with a significance threshold
- Cut / fill volumes by area or stockpile
- Cross-section profiles through time
- Change report with method and confidence
Applications
- Pit, dump and stockpile reconciliation
- Coastal erosion and accretion
- Landslip and subsidence monitoring
- Rehabilitation tracking


- 3 passes agree
- 2 passes agree
- Single pass
- Change detected
- Modelled
