There is much overhead, including aircraft and satellites, that is busy mapping land, your home, business and vehicle for a variety of purposes, such as monitoring your home for improvements, your insurance claim for fraud, your roof for a solar panel installation, the area around your home for fire risk—and in the case of high altitude balloons like the one shot down by U.S. fighter jets off the coast of South Carolina … who knows?
For a less nefarious but still unpopular purpose is the work of the county assessor. Homeowners who have never pulled a building permit for home improvements now face a better-armed assessor who can not only spot your secret swimming pool but also measure it to the inch—all from the safety of their office, from an eye in the sky provided by EagleView.
EagleView uses its own proprietary cameras, which are fastened to aircraft that take multiple images, from a single pass and are able to get overhead and oblique images that EagleView stitches together to get 3D models. Not only are X and Y measurements within 1 inch but so are measurements in the Z-direction. This is accomplished by rotating the angle of view from orthogonal to oblique—a fascinating mechanism that we call up EagleView’s CEO Chris Jurasek to explain.
Can EagleView measure a building’s vertical dimensions to the inch?
Yes, we can. In fact, we have a Wall application. Painters, siding applicators and other contractors can place bids without so much as stepping out of their offices.
What was EagleView’s first claim to fame?
Tax assessors were the primary government users. Then we branched out to neighboring departments like E911 or public safety applications, GIS applications. But it was tax assessors in the old days. They used to drive around and snoop into people’s property to see what changed. Did someone build a garage? A pool? Add a second story? It wasn’t a safe job. People didn’t love strangers sneaking around their property. And it was not very efficient. A lot of human resources were being deployed for that task with assessors in the field. EagleView came in with 9-inch accuracy, then 6-inch, then 3-inch. Now we have sub-1-inch accuracy. That’s sub-1-inch not only in the orthogonal view but also in the oblique view. That’s the only way to tell if there’s a new second story on a house. You can’t tell that from an orthogonal view. And a lot of times there are obstructions. Having the oblique images and being able to stitch all of the images together in 3D allows assessors to do their jobs remotely. They can digitally transform their workflow. They don’t actually have to go in the field.
With computer vision and machine learning, we can take a look at an entire county and compare it to last year in 3D. The application can highlight changes. Our county customers use what we call a change finder or change detection. They are able to zoom in on changes and recover tax dollars that they otherwise would have missed. That can be tens of millions of dollars in some counties. This has transformed the workflow for tax assessors.
What about public safety and law enforcement?
With our applications, when a dispatcher gets an emergency call and has to send personnel to the field, they can go in with some situational awareness. For example, if there is a fire, what side of the building is the propane tank? When a SWAT team goes in, they would know where people could hide, what are ingress points for the dwelling, etc. They are able to zoom in and out, look all around, and plan their mission.
How much detail can your application detect?
Details smaller than 1 inch. Let me give you an example. Take electric utilities. They need to manage their infrastructure, like telephone poles, wires, attachments on those poles.… They used to not have a way to do that without going out into the field. With our technology, they can detect wires even less than 1 inch in diameter.
How can you detect objects less than 1 inch in any dimension with cameras that have 1-inch resolution?
Let’s say I have a half-inch diameter white ball in my hand and you take an aerial image at 1-inch revolution. You can see that there’s something in my hand, though you might not see it is a ball. But you’ll definitely detect it because there are pixels with different coloration.
An electric utility wire can be a half-inch diameter. You can easily see it at 1-inch resolution. Not only that, but because you can see it in 3D, you can see how it hangs, measure the slack, the low point, its height from the ground, the clearance over a driveway. You can see the poles, see if they are leaning or bending. You can see what is attached to the poles, like a cable box, a transformer or a data system.
What kind of aircraft are used for your aerial imaging?
We use airplanes and sometimes drones. Drones have to be flown within line of sight—at least right now. They’re not that efficient at capturing a massive area. So, we mostly fly at altitude with airplanes with very sophisticated systems that capture hundreds of square miles per flight.
Tell me more about the camera systems. Good optics?
Yes. The optics are not rocket science but definitely are aerospace science. The tolerances that they are built to are incredible. The system that moves the lens moves it by microns—half the thickness of a human hair.
What can you tell me about the camera?
It looks like a normal camera, only larger, with a body and a 300mm lens. It’s an SLR. The mirrors have to be flat within a twentieth of a wavelength. The tolerances we are dealing with are substantial.
Does the cameral point down and swivel?
Actually, the camera is pointing horizontally and the mirrors change the view to straight down.
How do you get the oblique views?
It depends on that particular system. We have cylindrical tubes that let the cameras sweep the ground. The cylindrical tubes have cameras loaded in them with windows and mirrors and they rotate as the plane flies.
What is the frequency of rotation and is it smooth?
The tube rotation stops to take a picture at different angles. It’s a little bit jerky. It rotates to a position, stops, takes a picture, rotates, stops, takes a picture and so on. The sweep speed and frequency are a function of the airplane speed and the format of the sensor. Imagine a sensor that is a thousand pixels across. I’ll just use a thousand because it’s a round number. Each pixel represents one square inch of ground. Therefore, the plane has to move a thousand inches before the next frame. That’s roughly the idea. Of course, there is some overlap.
How many passes does the plane make?
One pass. It’s all done with one pass. We get everything—orthogonal and oblique photos—with a single pass. But how many times we cover the area depends on the customer, on their subscription.
All your customers are on a subscription?
We’re moving everyone to subscription. There are two components to our subscription. One is the actual software itself. The second is a data package. The subscriber can choose the frequency of the flights, whether it is every six months or a year, for example. Most of our subscribers choose one or two years.
To be continued….