Let's start with the tech...
The majority of laser scanners used for measured surveys use a combination of LIDAR technology and rotating mirrors to record measurements of thousands and even millions of points a second. These measured points are collated in the form of a point cloud which can then be interrogated or converted into CAD drawings and 3D models. Inbuilt cameras match high definition colour imagery with the coordinate database in order to create a photo-realistic 3D representation of the measured environment.
Why are surveyors so excited about it all?
Our surveyors are always keen to get their hands on the latest technology available and keep up with the latest the industry has to offer. Laser scanning is only one aspect of surveying, but it's an area where some of the biggest developments have been made in recent years. Scanners have been used by surveyors for a number of years now, but it has only relatively recently become a regular tool for the average land or building surveyor.
Where once they were heavy, cumbersome and often frustratingly slow at measuring the environment around them, now many of the latest scanners are as lightweight and portable as a camera, and can record vast quantities of data at the push of a button.
When using laser scanning, the site or structure is captured so comprehensively that the key measurements required can be taken from the comfort of the survey office rather than from behind an instrument. If an architect needs one additional section through a key building truss, there’s no need for a return visit to site, as the data can be pulled from the point cloud model in minutes. Leaning walls in older buildings, sagging trusses or purlins will all be captured in far greater detail and in turn will allow for the production of far more accurate final drawings. Even some of the more complex architectural details such as cornice profiles or architraves can be extracted. The laser scanners can also provide Google earth style panoramic tours, that can be issued to the design team and often limit their need for site visits.
So are surveyors now choosing to drop the more traditional survey techniques and equipment in favour of laser scanners?
Well, no not entirely. Most surveyors still use total stations, levels and GPS equipment to establish the key control and base measurements for any survey. There are also plenty of jobs that just aren’t suitable or possible to be undertaken with a laser scanner. And of course; there’s always a time and a place for the humble tape measure.