No offence to NBC News anchor Lester Holt, but when we hear the mainstream media talking about geospatial technologies, it piques our interest.
The case in point was a nightly news broadcast where Holt described how “light detection and ranging” technology had helped to uncover ancient Mayan ruins. LiDAR, he explained, provided images of a much larger network of structures than had been previously known to archaeologists.
It’s great that the technology is getting some positive press. But, there are some gaps for purists among the geospatial community. One media outlet describing the Mayan discoveries commented that, “While we mostly talk about LiDAR as a tool that helps self-driving cars and robots see their environments, scientists have also been using it to survey the environment without disturbing it.”
Where do we start? Perhaps a good place is with the surveying reference. Even Wikipedia acknowledges LiDAR as a surveying technology. That would imply that surveying came first – or at least ahead of the type of imaging used for the Mayan discoveries. Having said that, surveying and related geospatial operations have been critical to the evolution of LiDAR technologies.
Sending out repeated laser pulses and measuring their return time to get an accurate measurement is nothing new. Adding the ability to spread those pulses over a wider area and gather many more measurements of a larger surface area got us rolling from simple measurement into imaging. It’s not likely Lester Holt et al will be diving into point clouds any time soon or issues of how vegetation affects the point cloud. For now, the public will simply believe you point a laser and get an image.
While the Mayan project is certainly LiDAR imagery, is it really surveying? That term gets thrown around a lot without much effort to clarify what constitutes a valid survey. We’ll just leave the question of “control” hanging out there for the moment.
The point-cloud imagery being presented with the Mayan story is great for capturing the hearts and minds of the general public. When they see how the LiDAR units detect objects and produce an accurate image, it is comforting to know that is what your future autonomous vehicle will be using to guide you safely to your destination. They won’t see the anomalies that result from some of the technical limitations of LiDAR. Surveyors and geospatial professionals account for these in their work. And, to be clear, it’s not a fault of the technology, it’s a fact of the technology – reflective surfaces and vegetation are among the factors that must be considered. Manufacturers are developing better and more robust solutions every day, so the results improve with each enhancement.
While we’re at it, why not mention the survey application of LiDAR and the imaging are also fundamental tools for autonomous vehicles to know where they are in space before relying on the onboard scanners to look around and “see” what is present. The collected data may provide important cues for the vehicle when the survey-generated image says there is a wall and the onboard scanner doesn’t see a wall.
All of these discussions are great fun and good exercises in demystifying (and demythologizing) the technology. One of the biggest benefits of this mainstream discussion of LiDAR may be that it opens the door to talking about the professions employing, experimenting, and developing the technology. Imagine when someone comments about the Mayan discovery and you can say, “I work with LiDAR every day.” Or, when schools and parents are trying to interest young students in STEM programs and you can help show some practical use for the knowledge while highlighting some of the exciting parts of careers in surveying, photogrammetry, and other geospatial professions.
So, thanks, Lester (and others) for starting the conversation. Let’s not leave it at an ancient, extinct civilization. Let’s capitalize on the opening and put some 21st century spin on it.