In 2015 APEM was contracted to generate highly accurate topographic data for earthworks calculations for the Aberdeen Western Peripheral Route (AWPR), using repeat high definition aerial surveys.

At 58 km in length the AWPR was the largest road scheme under construction in the UK at that time.

What we did

We used specialist cameras mounted in a twin engine aircraft to generate both detailed imagery and an accurate height model at regular intervals during the project’s two-year construction phase.

This approach is a completely novel way of managing volumes such as stockpiles, embankments and cuttings. APEM’s specially designed survey aircraft allowed the entire length of the 58 km route to be surveyed in a single day, which is not possible using unmanned aerial vehicles or traditional ground surveys due to the size of the project area.

Having fewer people on the construction site also brings significant health and safety benefits.

Using advanced photogrammetry software and a network of ground control points, APEM produced high density, highly accurate topographic data from the aerial surveys. High resolution (7cm GSD) ortho-photos were also produced.

We used powerful computers and in-house image processing protocols to produce the images and height map for the entire route within one week of the survey flight. The CAD-ready datasets allowed AWPR surveyors to produce 3D models and cross sections for visualisation and analysis before calculating the required earthworks volumes.

The up-to-date aerial photos also proved valuable in site meetings, showing that operations had commenced in specific areas or illustrating constraints affecting the works.

Measuring earthworks from the air produced a true ‘snap-shot’ of the project not achievable by other methods. Quantities were reported on schedule, allowing earthworks teams to monitor progress of the works.

The Results

  • Full coverage of the entire 58 km project in a single day
  • Highly accurate topographic data for whole site produced within seven days of survey
  • Rapid calculation of earthworks volumes using CAD-ready data
  • Ortho-images provided added value
  • Reduced health and safety risks
  • Avoided the issues that limit the use of UAV’s
  • Fast, safe, accurate and cost-effective.