You might think that conducting an aerial survey of the London underground lines would be a non-starter as they are underground, but surprisingly a large percentage are in fact above ground. Above All Images have been asked to provide overlapping vertical images of the lines at very high resolution so that engineers can analyse the lines, plan cable routing and perform stock checks of materials by the side of the lines.
Doing this type of survey from the air saves an enormous amount of man hours and is significantly safer as we don’t need to walk the lines, also trains are not affected and so service is maintained.
The survey is conducted from a helicopter using a camera set in a vertical rig and connected to a GPS to record (real time) the position of every image. Once the images have been taken, they are processed and assembled into runs specified by the customer, usually from station to station, but also supplied with an excel spread sheet of each image, its position, time and date taken and the altitude of the helicopter.
We also undertake this type of survey flying for both the electric companies (FLI – Pylons/Insulators) and for the Gas delivery companies doing annual TD/1 studies.