Greetings: I am using a 3DR X8, Pixhawk with a NEX5 for standard mapping/photogrammetry. I want to map a cliff face. Is it possible to create an autonomous flight in Mission Planner that will photograph the face in a grid-style pattern up-down and left to right (or vice versa) with the same kind of image overlap that you can do on a vertical mapping project? Think photogrammetry turned sideways to map in a vertical plane as opposed to the normal horizontal plane.
I can use a gimbal set at 90 degrees and create the waypoints fairly parallel to the face but can't figure out the up/down part at a specific waypoint. I have seen this done with oblique images that are manipulated in specialized software (EG PIX4D) but not with images taken parallel to an object in an 'up-down' format.
All help gratefully appreciated and accepted.
Marshall
Replies
Steve: That's exactly how I was thinking about it at first and, in fact, that's essentially what I'd be doing.
For me the trick will be to have multiple 'vertical' images taken at the same waypoint (ie as the UAV climbs vertically).
Any ideas how to do that in Mission Planner? Also camera trigger... a vertical climb would show no distance traveled if triggering the camera by distance. So I'm thinking a trigger by time and trying to control the rate of climb? Not sure yet...
Will be using PhotoModeler (http://www.photomodeler.com/) software as it handle near field images very well.
Will keep everyone in the loop as I work it out.
M
Marshall,
You will need to travel back and forth along the wall as you climb up in altitude. This way it will be a new waypoint so you can trigger a picture. You will need to add a false point at the end of every other flight line so you actually travel to a new point, instead of just straight vertical.
Triggering by time and setting the climb rate might work too...
I'm also interested in what flight times you are getting with the 3DR X8 and the NEX5. With which gimbal too?
Thanks and best,
Steve
Sreve: Temporarily I will use a GoPro 3 Black because that's the only gimbal/camera combo I can use. The NEX won't be on a gimbal because I want to make sure the idea works before I drop that amount of cash for a gimbal to hold the NEX.
If you have any suggestions for an NEX gimbal... It doesn't need to be massively fancy. I am concerned about weight and flight times when I get to that stage. I have heard that the X8 is a tad weak in that department.
Appreciate the replies. I will be on the road for the next few weeks for work so 'developments' will be slow but will do and post what I can.
Best,
Marshall
Marshall,
I would set it up like a typical mapping mission but, as you said, "turned sideways".
So your distance to the vertical cliff face would be your height above ground. This way you can calculate your image footprint and make sure you have good overlap.
Your altitude difference between a set a images would equate to distance from image center to image center (this would be the up-down you were asking about).
In essence you would have a bunch of photographs in a straight line, parallel to the cliff face, all taken at different altitudes and stacked on top of each other (if viewed from the top down in mission planner).
You may need to fake the software you use for stitching by putting in a "local" coordinate system and it will stitch together the images as if viewed from above. Only it would really be viewed from the side.
Does that make sense?
I'm also interested in what flight time you are getting with the X8 and the NEX5. With which gimbal too?
Interesting project, please keep us updated on how it progresses.
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