Messages

1

General / Re: GCP, check points accuracy don't match the model.

« on: November 04, 2018, 10:46:24 PM »

Hi Alexey,  thanks for the reply.  The dense point cloud was done at the medium level as any higher than that I find unnecessary for surface models. I did discover since my post something I’ve never had before with coordinate systems.  Recently I’ve been using the Nad 83 CSRS instead of just Nad 83 and I realized that it was adding a shift to my coordinates when generating the DEM without knowing and that is how my elevations got shifted.? Im not sure why this is happening but for now I will go back to using only the Nad 83.  I’m finding the CSRS is causing me some grief in some instances.  Im a bit confused how Agisoft handles these different coordinate systems as it seams to have alot of areas where you can change the coordinate system.  This concerns me as I think at times I’m shifting the data by accident.  My raw photo coordinates are lat and long and geoid HT2 height, then i convert them in Agisoft after importing them to UTM Nad 83 CSRS Z12.  My ground controls are UTM Nad 83 CSRS z12 as well with Geoid HT2.  I think I will go back to just Nad83.  What are your thoughts?

2

General / GCP, check points accuracy don't match the model.

« on: November 03, 2018, 01:01:27 AM »

I"ve  been having a few issues with my accuracy on check points not matching the ground elevations.  My check points once I have them all aligned to my GCP's they show an accuracy of 3cm or so.  However when I hover my mouse over the DTM under the check point, the difference in elevation between the model and my actual surveyed GCP is about 50cm.  I"m very confused as to why this difference.  What is the software referencing to when it returns an accuracy of 3cm?  Please advise.
I've attached some screen shots of Agisoft to show the issue.

3

Feature Requests / Volumetric Stockpiles more options

« on: June 04, 2018, 08:06:28 PM »

Best fit plane, Mean sea level and custom level are the only options available.  Best fit plane works fine where stockpiles are on a uniform plane but in some cases we need to specify the elevation of the perimeter in certain spots so the calculation can cut through the pile and NOT follow the contour of the pile perimeter.  The polygon that determines the perimeter for volume calculation follows the surface to exact which in some sections along the pile perimeter would be preferable to slice through the pile to get a better representation of the base.  Some software's have this ability but not agisoft.

4

Feature Requests / Shape Report more options

« on: June 04, 2018, 07:39:06 PM »

The shape report is a great tool,  Could we get more options like customizing the report, more Shape attributes or information available to turn on/off.  Options to customize the shape number or name.  Would be great to have the ability to show different map view also, DEM, Ortho, 3D.
Thanks

5

General / DEM does not match the CGP

« on: October 11, 2017, 09:50:07 PM »

I've been generating DEM's and Orthos for a couple years now using UAV imagery and Agisoft.  I use accurate GCP's using high end RTK equipment.  Why doesn't the final surface model more exactly match my GCP's?  In some cases they are very close, within a few cm, while other times they can be as far out as 0.5m or more.  After initial alignment, I always do a gradual selection and delete ties based on reconstruction uncertainty (using level 10), I then do the same with reprojection uncertainty (level 1.1) and again projection accuracy (level 10) and then optimize cameras.  After bringing in my GCP's, locating them on photos, I  uncheck the photos and check the GCP's then optimize again. My Reference settings are always set to marker accuracy of 0.005 and camera to 10m since I'm using a DJI Phantom 3 Pro.  This tells me that Agisoft should ignore the photos tags and shift the project to match the GCP's (correct?)  At the very least I would expect the model to be accurate at the GCP locations.  Outside of those GCP's I can understand where error will occur based on many factors.  My assumptions was that Agisoft using the parameters I've described should force the photo positions and tie points to match the xyz values at the GCP locations and therefore the final DEM should be representative at the GCP locations as well.  I would also expect that after selecting the GCP's and un-checking the photos, then updating and optimizing the the values shown in the Reference pane would drastically change and the error value would change to a few cm indicating that the project is now refereed tightly to the GCP's.  Again these values are often several cm's out 5-10cm is normal and some as high as 50 plus.  Am I doing something wrong, or perhaps my expectation of Agisoft is incorrect?  Please advise.  thanks very much!

6

General / Re: elimination of distortion

« on: January 17, 2017, 05:05:23 PM »

OK that makes sense.  It works now.  Thanks very much!!

7

General / Check Points not working

« on: January 17, 2017, 07:58:38 AM »

Hi,

I can't figure out how to get the check points to work.  I loaded all my GCP's,  uncheck the one(s) I want to use for check points before optimizing so they are not used, then after the dense cloud is built and all my DEM and ortho is complete, I check the GCP back on that was unchecked and I hit the update button.  Nothing changes for the values all blank... Then I tried also optimizing and still  blank (no values)..  What am I doing wrong?  see attached.  Point 7 is the one I want to use as a check point.

8

General / Re: Changing destination of folder with pictures

« on: March 03, 2016, 01:28:42 AM »

I have the same issue.  I looked for the option to change path as you mentioned Alexey but I can't find it anywhere in the Photo Pane.  Can you give more exact instructions?

9

General / Re: force DEM on ground control

« on: February 29, 2016, 09:55:03 PM »

make sure your cameras are unselected and your GCP's (markers are selected) before you optimize.  Set your accuracy paramaters according to your GCP accuracy.  this should bring your DEM (after you re-do your dense clould) to very tight with your GCP's.