Choosing the right drone survey

Interviewer:

[00:00:02] This will be from a client's point of view. How do you approach when they kind of get on to you with their spec? How do you approach then selecting the right drone or survey method and especially when factors like terrain, accuracy and access come into play?

Bob Foley: Engineers With Drones

[00:00:16] Yeah, absolutely. So let's start at the end. The drone doesn't care about access except for things like airports and whatnot. The drone doesn't see the ground underneath it. doesn't really care about it. So long as you have a takeoff and landing point and you can access a sufficient amount of points to put down some ground control, then the drone will go wherever it likes, wherever it's legally allowed to go. So that's not a factor.

An interesting thing to consider is, you never want to be thinking about the drone. You always want to be thinking about the technology to use. So there are two broad technologies in land surveying, LiDAR and photogrammetry.

Okay, LiDAR, a bunch of laser beams shoot out, take measurements, and it generates what's called a point cloud. Photogrammetry, you take a load of photographs, you technically stitch them all together in a very precise way. and you generate also a point cloud with other deliverables from that as well.

>Depending on what you're trying to achieve, it's very important to choose the correct technology.

LiDAR, when my clients ask, the first thing I ask is what sort of land you want to map. If they say it's highly vegetated and I really want to know what's underneath, then LiDAR is the only technology for that.

If you have a lot of hardscape land, like in the middle of a city or a built up area where it's lots of roads, footpaths, houses and so on and so forth, small gardens, light grass, that sort of thing, then photogrammetry is a much better solution for that. So the first question I'm usually asking is what is on the land and what are they trying to get out of it?

If they tell me there's lots of trees, forestries, trees, forestry, vegetation, LiDAR, if they tell me it's mostly open light grass and there's lots of hardscape, things like that, then it's photogrammetry.