We don’t live in a flat world, yet we insist on portraying our environment in flat, two-dimensional form. Things are changing . . . slowly.
New technologies always create some buzz, but getting from a whisper to a full-on shout isn’t easy. When global positioning systems debuted, they were interesting – a curiosity. As long as the higher capabilities and accuracies were reserved for government [military] use, GPS languished on the commercial side and didn’t even show a blip with consumers. We’ll skip ahead in the story, and now GPS is not only a common tool for land surveyors and geospatial professionals, it’s in nearly every imaginable consumer device where data on relative position can be useful.
Laser scanning and 3D imaging exhibit a different evolution. There is the slow slog of applying lasers to metrology and data collection (eg. bar code scanning), but the limitations were imposed more by the technology and cost than by some artificial constraint. From the beginning, lasers had a reputation for pinpoint accuracy and, in the common vernacular, the term laser became synonymous with accuracy. Single-beam lasers quickly became commonplace for anything from presentation pointers to rifle sights to land surveying.
Using the “time of flight” to calculate the distance the laser beam traveled to a target and back proved to be extremely accurate for measurement, but when that single beam could be pulsed rapidly and sweep a targeted area to offer accurate measurements to multiple points, things really got interesting. Assembling those points into an image meant taking a “cloud” of points and registering them so they provided a reasonable picture of what the laser saw. This offered a new view of the world.
Point clouds aren’t the handsomest versions of reality, but with a little animator talent and good design software, they could start to look more realistic. Adding a camera to gather panoramic images along with the laser scanning measurements enabled a better workflow where the actual image could be stitched to or laid over the point cloud. Now, the scene looked realistic and the designer could get accurate measurements just by touching the various points. Hollywood was ecstatic, but surveyors were still skeptical.
While animated films got a lot more exciting, there was work to be done to tie down the accuracy of the points in the point cloud to actual points in the real world. A higher level of accuracy can be achieved with targets to help align the overlapping point cloud images. But for the highest level of accuracy and precision, survey control is needed – often relying on the laser cousin total station to augment the scan.
Point clouds aren’t needed in every instance, nor is survey-level control needed in every point cloud, but it is getting easier (and cheaper) to get both. The technology is continuing to improve and it is increasingly being paired with other technologies, as it was with the panoramic camera, to provide new potential and new options.
Winston Churchill famously declared after a decisive British victory in World War II, “Now this is not the end. It is not even the beginning of the end. But it is, perhaps, the end of the beginning.” Laser scanning has made some strategic gains over the years and the technology’s evolution has certainly passed its beginning stage. It is difficult to say where it is on the continuum, but it is nowhere near the end of its potential.