Guides, industry commentary and technical articles from the Angell Surveys team — covering UAV survey, LiDAR, inspection, BIM and the regulations that govern them.
A surveyor's view of terrain-following flight control after the UgCS 6.3 release: why holding a constant height above ground on sloping sites decides whether a drone LiDAR point cloud meets the RICS accuracy band specified, what it does for point density and flight-line count, and the three things it leaves exactly where they were: vegetation penetration, ground control and georeferencing.
A surveyor's view of drone-in-a-box monitoring after the 14 October 2026 launch of DJI Dock 4 and the Matrice 5TD: what automation genuinely changes for repeat capture on a fixed site, why survey control and check points still decide whether the output meets a RICS accuracy band, where a mobilised crew is still the right answer, and who carries the regulatory, data-ownership and QA burden.
A large ground-mounted solar and battery storage site is surveyed in one fixed-wing UAV sortie carrying LiDAR and a metric camera, controlled by a GNSS ground-control network tied to OSGB36 and Ordnance Datum Newlyn, and verified against independent check points. This guide sets out the method we used on a 250 ha Lincolnshire DCO site, the flight and control parameters, the deliverable set each consenting workstream needs, and the accuracy achieved.
Angell Surveys flies two Wingtra vertical take-off fixed-wing aircraft for large-area and corridor photogrammetry — the WingtraRAY with the 61 MP oblique MAP61 camera and the WingtraOne GEN II with the 61 MP RGB61 — and the DJI Zenmuse L3 LiDAR on a Matrice 400 for bare-earth capture under vegetation and for overhead lines, with a Wingtra LiDAR payload hired in for the largest envelopes, the DJI Matrice 4E for small sites, and Flyability Elios collision-tolerant aircraft for confined-space inspection. This guide sets out what each platform is for, the resolution and coverage it gives, and how every aerial survey is controlled and verified to RICS Band F or better.
Photogrammetry models the top of the canopy. Multi-return LiDAR records ground returns through gaps in it, so a bare-earth model under hedgerow, woodland and scrub is possible, but only as good as the canopy, the season, the point density and the classification allow.
LiDAR and photogrammetry reach the same RICS bands on hard detail. The choice is decided by the ground: vegetation, texture, light, structures and corridor geometry. A ground-by-ground guide to specifying the right capture method, or both.
Orthomosaic, point cloud, DTM and DSM, contours, CAD, the accuracy report and the datum statement: what each item in a UAV survey deliverable pack is for, what a client should look for in it, and the RICS band language it should be written in.
A drone LiDAR topographical survey is normally specified to RICS Band D or Band E and its accuracy is proven by independent check points, not by the sensor brochure. This guide explains the bands, what governs the achieved accuracy, and what the accuracy report must show.
A good UAV survey brief states the extent, the purpose, the datum, the RICS accuracy band, the deliverables and formats, the resolution, existing control, access and dates, site constraints and the reporting cycle. It does not specify the aircraft. Here is the ten-point list with example wording.
A drone measures position in a global GNSS frame. UK engineering wants OSGB36 National Grid and Ordnance Datum Newlyn. OSTN15 and OSGM15 are the Ordnance Survey models that make the conversion correctly, and a site grid is a further step on many infrastructure schemes. This guide explains each, with the OS accuracy figures.
What a UAV LiDAR survey of an overhead line corridor or a live substation actually delivers: a classified point cloud with the conductors in their own class, sag and clearance geometry, vegetation heights against the line, and a measurable 3D model of the compound, drawn from work we have delivered.
How a weekly UAV earthworks monitoring programme is built so that every epoch is comparable: permanent control, check points re-observed each week, identical flight design, surface differencing against the design TIN, zone-by-zone cut and fill, stockpile volumes and a 24-hour report that carries its own accuracy evidence.