Messages

1

General / Re: Rolling Shuter - How do you check the accuracy and reliability of your models?

« on: May 09, 2017, 03:19:20 PM »

Now I've finished my last try with an object that has no displacement.
Drone of flat terrain with 10 marks on the ground. It does not matter whether it is optimized with or without roller shutter. The differences are negligible.
I have a question. How do you shoot such types of objects that have large earthwork
 and large embankments, not just a mass of material concentrated in one place?

2

General / Re: Rolling Shuter - How do you check the accuracy and reliability of your models?

« on: May 09, 2017, 11:37:39 AM »

Cadm8,
I will not be able to check the laser scan every time, because the meaning of the drones is lost . In this case, I had the object scanned and just to check the dron model we decided to fly over the scanned depot.
I know that I need 6 GCP to define an object, what is visible, for depot2 we have put 11 - the idea is to use 6 and 5 to be as controlling. But it was so that the model with 6 and 11 points differed by another 5 centimeters, so we decided to release it with all the points.
I want to be sure, that the next time we fly again with the drone, we will give the right results. I also want to know, if I can not put control points inside the landfill (as in this case) how I will give the client a fair result?

PS: My tie points limit is 0 because we want have no limit and use all tie points. Then, Gradual - reprojection error 0.5; So we save time to make a dence cloud. There is no significant difference from 40000/4000( and then time for dence cloud) and 50000/0. When we see the results and decide the correct method and model we build a dence cloud

3

General / Re: Rolling Shuter - How do you check the accuracy and reliability of your models?

« on: May 09, 2017, 11:19:11 AM »

We use Dronedeploy. We work - 1 object - 1 battery if possible
For depot 1 we have a flying speed of about 4.5 m/s; 1 battery; 412 photos (2sec); Overlap 80% and sitelap 75%;  Height: 48 m (according to the report). Ortho Height GCP 723 m Baltic system
For depot 2 we have a flying speed of about 4.25 m/s; 1 battery; 452 photos; Overlap 80% and sitelap 60%; Height: 45m (report)
The next time we will fly slower, but this will be the next time  . The situation is dynamic, so I have no chance to fly again.

We have made comparisons with PIX4D. The results are Photoscan without roller shutter is close to pix4d with the roller shutter on?!?!

4

Feature Requests / Export Mesh as XML ?

« on: May 06, 2017, 04:26:06 PM »

Hi,

is there a possibility to export the mesh as an XML for AutoDesk Civil 3D?


Thanks

5

General / Rolling Shuter - How do you check the accuracy and reliability of your models?

« on: May 06, 2017, 04:18:36 PM »

Hi, I have a question about rolling shutter. We work with Phantom 3pro and you advise to use a fit rolling shutter but the results do not seem right to me. I have an object - a landfill in the embankment, scanned with ScanStationC10 and P3p.
The results are attached in the picture1.
Gray is scanned.
Blue is a version on PS1.26 and camera adaptive camera model fitting and all parameters f cx cy k1 k2 k3 k4 b1 b2 p1 p2 p3 p4 - so we have run it.
Green is processing with version PS1.31 like: Align Photos – no camera model fitting/ /50 000/0; optimize - rolling shutter-OFF; F cx cy k1 k2 k3 b1 b2 p1 p2
Purple is processing with PS1.31 like: Align Photos – no camera model fitting/50 000/0; optimize - rolling shutter-ON; F cx cy k1 k2 k3 b1 b2 p1 p2
As can be seen, the difference between ONrSh and OFFrollSh is 10 cm. But OFFrSh is closer to the scanned, which I think is true. The difference between the scanned and the OFFrollSh  is 1-3 cm.
Interestingly, the ONrollSh  is lower. I have another depot that is in the excavation and there a rolling shooter ON is 10 cm higher from rolling shutter OFF.
Help me to optimize my projects.  When object is in excavation or ditches - the results is higher, and when embankments or convex elements the model is lower.
How do you check the accuracy and reliability of your models?
The height of flying both objects is 45 m. I have an each project of 10 GCP.
Thanks