A new mains water pipeline, 530 hectares of testing terrain and a drone survey built to handle both.
The project required the collection of high density, colourised Light Detection and Ranging (LiDAR) data and ortho-imagery in a semi-rural area near Wirrina Cove, South Australia, to provide natural surface levels supporting the design of a new mains water pipeline from Normanville to Wirrina Cove. The total capture area was 530 hectares.
The survey was carried out by David Topfer, Director at Engineering Surveys, a long standing Aptella customer who has built his fleet around equipment supplied by Aptella, including the DJI Matrice 400 and Zenmuse L3 LiDAR used on this project, alongside Global Navigation Satellite System (GNSS) and total station equipment.
“Support was the main reason we chose Aptella for our RPA [remotely piloted aircraft] needs, and it’s paid off. Their training got us productive quickly, and Yamila and the team always respond when we need help. On the Normanville to Wirrina Cove project, I had the Matrice 400 and L3 up and running fast, and I was confident in the data straight out of the box.”
David Topfer, Director, Engineering Surveys
Challenges included steep and variable terrain (ranging from 0 to 140m within a single flight corridor), including cliff areas, windy conditions, and visibility limitations over steep rolling hills.
Long grasses and dense tree canopy across paddocks made LiDAR a more suitable solution than photogrammetric modelling.
The total area covered was 530 hectares across three mission areas and five flights. The maximum area covered per full battery varied depending on wind conditions and mission geometry. Generally, when flying at 110m altitude, up to approximately 165 hectares were
captured over a 35-minute flight.
Due to the undulating terrain, mission settings were configured to AGL with Real-Time Follow enabled, which effectively maintained the required altitude above ground level. Flight lines were aligned parallel to cliff faces to minimise sudden elevation changes along the flight path.
Mission Settings Summary:
Payload Settings:
These payload settings were selected to optimise the accuracy of processed LiDAR data, particularly on road surfaces.
For positioning, network RTK was used, with the nearby Continuously Operating Reference Station (CORS) base 5YAN Yankalilla within 10km of the furthest mission area, under a Custom Network RTK service. Approximately 12 ground control points were established within each mission area using internet corrected GNSS, distributed evenly and selected on smooth, regular surfaces, typically bitumen. Sprayed white crosses on bitumen were also used during post processing to verify X, Y, Z conformance and traditional survey teams collected check shots across roads, processed in DJI Terra as checkpoints.
Important Note: Distance to the CORS base should not exceed 15km for any mission area. Flying beyond this range can appear correctly georeferenced in the flight lines, but reconstruction in DJI Terra may fail.
Important Note: Distance to the CORS base should not exceed 15km for any mission area. Flying beyond this range can appear correctly georeferenced in the flight lines, but reconstruction in DJI Terra may fail.
Final Ground Control Point (GCP) accuracy was generally within 30mm, with the vast majority of check points falling within 40mm and a small number of outliers reaching 80mm height deviation. With a 16 point return density, the LiDAR provided excellent coverage beneath tree canopies and through dense low vegetation, something photogrammetric methods alone could not achieve.
The Zenmuse L3 also delivered efficiency gains through its dual 100MP oblique cameras, capturing LiDAR and ortho-imagery simultaneously. Reduced overlap requirements, 40% side overlap compared to the traditional 70%, meant each mission needed to be flown only once to generate multiple deliverables.
Impact
The Zenmuse L3’s ability to combine LiDAR and ortho-imagery in a single flight delivered significant time savings over traditional methods, while the Matrice 400 demonstrated excellent stability in winds up to 12 m/s. The platform’s full colour cameras, covering front, rear, left, right and downward views, added real time situational awareness over sensitive cliff and coastal terrain.
For David, the project reflects a wider pattern in how he has built out his survey capability. Since becoming an Aptella customer, he has been trained by Yamila Fernandez, Lead Technical Consultant for the Reality Capture team and her colleagues, who have continued to support him ever since. Projects like Normanville to Wirrina Cove show that training and support translating directly into results in the field.
