PIX4D model. No UAV, just iphone and survey rod

Very Cool! I hope to see the results of your testing with survey points.

Very cool.

So, if you set "targets" with coordinates and use them to orient the photos, will your accuracy improve?

This is really interesting. How much time was spent processing the 75 photos you took to generate that model?

What kind of range could the right camera setup give you?

JA, PLS SoCal

I don't think relative accuracy will improve much, but targets will improve orientation to NAD83. I did read though that GCPs can help individual orientation of photos that maybe couldn't self register.
Higher Megapixel camera would improve range and quality I'd think.
Total processing time on a bare bones 64-bit 4gig ram computer was about 1.5 hours.
Total Tim time was only a few minutes.

I've done some testing with this and you will see improved relative accuracy in the model as a result of ground control points.

For example, if were to take photos of a sidewalk, relatively linear and flat.. I've often seen a bowing or bowl effect as the software builds the model. Ground control points will flatten it out. The software ties the images together and it has just enough slop that you get an arch over a relatively short distance.

PIX4D is a good pick. interesting how you can integrate CRTP, motion, and vertical aerial into the same 3D or 4D model. my pix4d animated walk through is not a smooth a motion as yours, takes some getting used to

CRTP is beginning to get mind blowing with accuracy and capture capabilities. i can see this application surpassing 3D stationary LIDAR scanning soon

Moe, the latest version released late last week has much better 3D mouse control.
Left button + drag = pan
Shift+Left button + drag = orbit
Makes it way easier to lay out a trajectory for video.

Hardline, thanks for the GCP tip.

Flew the capital building early sunday morning with my buddy and his DJI2+ guerilla style. Very short flight with limited coverage but a pretty neat model overall.

It would not be illegal for you to map your own house with a drone for personal use.

True, and that's what I intend to do in the next couple of weeks. Have to GPS a few more targets and run some reflectorless on the house.

CRTP. No UAV, just iphone and survey rod

What is CRTP? Link please?

CRTP. No UAV, just iphone and survey rod

> What is CRTP?

Close-range terrestrial photogrammetry.

CRTP. No UAV, just iphone and survey rod

Ah, gotcha... I always refer to this technique as structure from motion (SfM). While it could be considered photogrammetry I've always thought of that as where the measurements are made directly from the image.

When I was in college, in one of my photogrammetry classes we actually did a project using CRTP principles.

We had a 35mm camera with B&W film. We took 3 pictures of a wall that had some relief to it (it was in the Art department) on which we had marked some control points (felt pen X). We used a total station to establish the positions of the control points and then, once the photos were developed and printed, we were able to "map" the wall, with all of the relief, to a fairly high degree of accuracy. It was pretty cool.

So it makes sense that now, with much better resolution in photography (and no need for developing and printing of images), that one could get a high degree of accuracy using some solid control and a dense network of high resolution images.