Surveys · Local authorities

Ortho-graphy: city base layers from an aerial photo

Machine recognition on the authority's own aerial photo, manual completion and full QC: buildings, pavements, drainage, poles, signs, trees and more, with heights, in GIS, DWG and PDF.

Aerial photo becoming layers: crossings, pavements, plants

Client: Local authorities
Field: Surveys
Source: Client aerial photo · 3D model

The same neighbourhood with digitised GIS layers: buildings, trees and road markings — Digitised layers: buildings, trees, road markings

The challenge

Base layers are usually built slowly: buildings in one project, pavements in another, trees perhaps a few years later. Meanwhile a recent aerial photo is already sitting with the authority, and what it shows does not yet exist as a layer anyone can filter, measure or maintain.

A 3D street built from aerial-photo layers

The solution

We ran machine recognition (AI) over the authority's existing aerial photo to flag features. Interpreters then completed by hand whatever the machine missed and checked every feature, with heights taken from the 3D model. Depending on the brief, the layers cover buildings, drainage inlets, manholes, culverts, fire hydrants, pavements and kerb colour, poles, signs, traffic lights, bus stops, bike lanes, roundabouts, parking, roads, traffic islands, lane lines, trees, shrubs and fences.

Aerial photo of a neighbourhood and junction, before digitising — Aerial photo of a neighbourhood before digitising

The outcome

The authority gets a full set of base layers for a whole area in a single project and works with it in its own system: counting, measuring, planning maintenance and using the layers as the starting point for future surveys.