In recent years we’ve scanned a number of sites for a customer in the beautiful areas of Perthshire and Inverness-shire in Scotland. Working for Maptek does have its perks! We scan each site on a regular basis as we’re looking to measure signs of slope movement. On one occasion, the weather rapidly changed from beautiful sunshine to heavy rain. So typical of Scotland. The scanner was fine, but we got soaked and rushed back to the car as fast as we could. If you regularly use a laser scanner outdoors, you’ll know how important it is to get the job done quickly. Perhaps the weather’s terrible or blasting and excavating is about to take place in the area you’re surveying. Maybe you just want to get back indoors to process and analyse the data you’ve collected. Whatever the reason, you don’t want to hang around.
In the following blog we’re going to share some techniques you can use to save time when collecting scan data.
At Maptek and we produce our own line of 3D laser scanners and software for managing point cloud data. We have designed our scanners for speed, among other benefits, but you don’t need to own a Maptek scanner or software to take advantage of the techniques below:
Most models of laser scanner allow the user to vary point density. This makes a lot of sense as scanning with a high point density takes a lot longer than scanning with lower point density. By varying your point density, you can save yourself a lot of time.
Choose a lower point density (resolution) for a general area, and only use high-density scans for areas of interest, where you may be surveying for geotechnical analysis for example.
When surveying a large site, during end-of-month reconciliation for example, scanning from a vehicle can really speed things up. Depending on your needs, you could use a stop and go system, where quite simply you stop the vehicle to perform a scan before moving on.
An even faster method is to scan continuously from a moving vehicle. Be aware that continuous scanning is unlikely to deliver the same level of accuracy as stationary scanning, and as such it may not be the best option for certain surveying applications.
Change the rate of capture from normal to fast to rapid. Many time-of-flight scanners on the market today allow the user to specify the speed of the laser (by selecting which kHz setting the scanner uses). This gives the user in the field more control over how quickly the scanning is done. Just bear in mind that range will be reduced at certain rates of capture.
Acquiring GPS for every scan can be time consuming and sometimes GPS is unavailable. Free-scanning is one way around this problem.
Here’s how you do it: If you already have the GPS position for one or two scans, consider free scanning (i.e. scanning without GPS) for the other scans. Register those to the original scans back in the office.
This point relates to processing scan data back in the office. Many tasks associated with managing point cloud data can be sped up.
Luckily, most software packages that deal with point cloud data, including our own I-Site Studio, allow for custom workflows to be created to speed up or automate filtering, registering and other tasks. Learn how to set up custom workflows in your software so when you’re back in the office you can output results.
Next time you’re scanning, keep these tips in mind, and let us know how you go. If you have any of your own tips for speeding up scanning that you’d like to share, please leave them in the comments section below.
Joseph Sykes
Marketing Manager EMEA
August 30, 2017
For additional information about Maptek, including use of the Maptek logo, product images and reproduction of case studies, please direct inquiries to Global Marketing Communications Manager jane.ball@maptek.com.au