L&M Survey Services has complete a full inspection survey of a 1,000m long tunnel using a new technique that did not call for additional lighting within the tunnel.
The survey was carried out using L&M’s new 32-bit high dynamic range (HDR) Scenecam camera and Scanlight lighting system.
The survey was carried out over three nights by a two-person team to minimise disruption to rail traffic.
The Scenecam solution was chosen for the work as a result of the HDR camera and battery powered Scanlight, which enabled the survey to capture all the detail in complete darkness.
L&M has said that its HDR technology is able to manipulate and store all colours and brightness levels visible to the human eye and beyond, resulting in a greater level of detail and clarity.
The company said: “One of the main issues with traditional digital photography imaging in rail surveys is that there is usually a need for an extra light source, which limits colour range, constrains luminance and narrows contrast banding, all of which can result in losses of information.”
Once complete, the survey report allows allows the viewer to navigate through the tunnel in a similar way to Street-view. The viewer can increase the brightness, zoom in, open reports and also measure dimensions directly from the images (possible due to the capture of stereo-pairs on the same location).
According to L&M, being able to take dimensions from anyone’s desktop means more efficient use of time and reduced schedule on site, improving productivity by around 20%.