2026-04-27 · 8 min read
Singapore's subsurface utility records are largely a paper inheritance — sketches, hand-tape offsets, marginalia on engineering drawings. The shift to a digital, geo-anchored, QL-A-grade record is happening one trench at a time. This is the methodology Easepect deploys, now in production with the Singapore Land Authority.
The capture stack
Three components. No tripod. No survey crew on call.
- iPhone Pro with LiDAR (12 Pro through latest) running PIX4Dcatch.
- Emlid Reach RX (or RS3) RTK rover paired over Bluetooth.
- SiReNT NTRIP corrections piped to the Reach via mobile data — setup guide here.
Total kit weight under 2 kg. A site engineer can carry the lot. No tripod tip-over risk; the Sicher MiniPro is for the heavier gear that stays in the office.
The four-step workflow
- Scan the open trench. Crew walks the trench end-to-end. PIX4Dcatch records LiDAR depth + photogrammetry imagery + a centimetre RTK fix on every captured frame. Scan time for a typical 50-metre trench: 5–10 minutes.
- Cloud process. Multi-upload to PIX4Dcloud (resilient to patchy site coverage). Automated photogrammetric processing produces a georeferenced point cloud, orthophoto and 3D mesh. Output ready in 1–4 hours.
- Vectorise to GIS. PIX4Dmatic densifies the cloud; PIX4Dsurvey extracts vector features — pipe centrelines, valves, joints, manhole rims — with full attributes. Export as Shapefile, GeoPackage, DWG or IFC.
- Publish & AR overlay. Push the layer to ArcGIS Online or your asset registry. Crews on later visits scan a QR / GCP marker and PIX4Dcatch's AR view re-projects the buried network through the closed surface. X-ray vision.
What QL-A actually means here
ASCE 38-22 and PAS 128:2022 reserve QL-A — Quality Level A — for utilities that have been physically exposed and precisely measured. PIX4Dcatch + RTK in an open trench delivers exactly that: every visible utility, captured under RTK fix, at sub-5 cm absolute accuracy. The capture is timestamped, geometrically anchored to SVY21 and signed off in partnership with a licensed surveyor.
Who runs the capture
This is the operationally important shift. Traditional subsurface survey requires a tripod-mounted total station and a Registered Surveyor. PIX4Dcatch + RTK works with a site engineer, a foreman, an inspector — anyone with two-day training. The licensed surveyor reviews and signs off the deliverable rather than attending every visit. Cost-per-utility-record drops materially as the programme scales.
AR overlay — the post-cover use case
Once the trench is backfilled the captured network does not disappear. PIX4Dcatch can load the network as a DXF or IFC AR overlay. The crew on a later visit scans a known georeferenced marker on the closed ground (or a Pix4D Autotag) and the model snaps into place — buried pipes appear in the camera view exactly where they sit underground, projected through the surface.
This is an enormous safety win: the next excavation crew sees the network in-context before they break ground.
GIS publishing — straight into ArcGIS Online
PIX4Dcloud has a direct ArcGIS Online publish integration. The vectorised network from PIX4Dsurvey lands as a feature layer in your Esri environment with the full attribute schema — pipe size, material, depth, capture timestamp, surveyor sign-off, photo references. For non-Esri shops, the same data is exportable as Shapefile / GeoPackage / DXF / IFC for any standards-compliant utility GIS.
Sectors
The methodology is sector-agnostic for any new-build utility:
- Water and sewerage — pipe networks, manholes, chamber details before backfill.
- Gas distribution — service connections, valves, anode tap points.
- Telecom and fibre — duct banks, hand-holes, splice locations.
- Power and electric — duct banks, substations, transformer pads.
- District cooling and heating — large-bore mains and lateral connections.
- Irrigation — drip-line networks and control valves.
- Petrochemical and industrial — buried tanks, vents, in-plant utility tunnels.
- Transport and rail — culverts, signalling cable runs, bored crossings.
SLA, URA and where it goes from here
The Singapore Land Authority is using the methodology in production. The Urban Redevelopment Authority brought Easepect on-stage at an industry panel on geospatial infrastructure for the next generation of Singapore's built environment. The case studies are linked at the bottom of this post.
For utility-authority programmes elsewhere in the region, the playbook is the same: PIX4Dcatch + Emlid RTK in the trench, surveyor partnership for sign-off, ArcGIS / utility GIS for publication. Easepect runs the supply, the training and the rollout.
Brief us on a utility programme. Easepect ships the kit, runs a two-day training, and configures SiReNT corrections — typically inside a fortnight. Get a quote.