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Messages - cadm8

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General / Re: Large Error in GCPs
« on: February 13, 2018, 03:46:06 PM »
Split your data in chunks by sensor type ie all p4p photos together and dslr ones apart. You can use different camera groups within the same chunk for the aerial photos, if you want to split them. Then realign chunks and follow the procedure for marking down GCPs.

General / Re: Altitude used in Processing UAV (DJI Phantom 4 Pro)
« on: January 26, 2018, 01:51:05 PM »
Quote from: jazzyj
... If Photoscan used the barometric altitude, then it would negatively effect the accuracy

You're speculating on the software's performance by inspecting an individual sensor reading. Run a test project the correct way (GCPs georeferenced etc) and test it against survey data to verify your results

General / Re: Trouble with GCP marker error UAV survey
« on: January 17, 2018, 10:12:36 PM »
I've checked all my GCP on the CS10 unit, and they all had at least 5 recorded RTK positions and all with maximum error of 0.0025, while most of them was below this.
Surely your unit will have them logged as accurate, although this accuracy level is unrealistic and... it doesn't exist. Uncheck them all but a few with lower readings and start adding one by one. You may even have more than one outlier in your project. Also, I believe that the rolling shutter algorithm is producing over optimistic estimations in accuracy, despite the fact that is actually working correctly. We have had older projects that have been flown with a phantom 3 pro (rolling shutter) and older versions of photoscan (no rolling shutter compensation) and cross checks with total station and GNSS data have shown fabulous results.

General / Re: Trouble with GCP marker error UAV survey
« on: January 17, 2018, 03:09:37 PM »
Also some of your erroneous GCPs are on the edge of the project, so maybe too few projections for them? Try re-arranging control points and check points. Still though, is there a possibility to have errors in your coords from the GPS? Did you survey by RTK, maybe you have one or two rogue observations? Finally why not using 40k and 10k for key point and tie point limit?

Personally I'm suspecting that you have a couple or more wrong GCP coords, try selecting a minimum number of GCPs and then adding slowly the rest until you spot the problematic ones.

General / Re: Do large differences in GSD screw up processing?
« on: January 14, 2018, 12:47:36 AM »
DJI Phantom 4 Pro Drone.
Use a planning software like mission planner to get your waypoints and then use Litchi to fly them using ground awareness. That way you will get a constant GSD throughout the mission

General / Re: Do large differences in GSD screw up processing?
« on: January 13, 2018, 08:28:19 PM »
What platform are you using to get your photos?

General / Re: Network processing - questions
« on: January 12, 2018, 12:01:06 PM »
Hello again, I have unchecked "build dense cloud" on the "secondary" ie less powerful nodes of our system and now the project has completed, even though one node (the slower one) had 2 bad allocation errors. Great new feature to be able to check or uncheck specifically to build only depth maps. The increase in speed is extremely big, thank you Photoscan (and Alexey  ::) )

One question more; Does higher priority mean that the node will be assigned with more work to process?

General / Re: GCP Error as function of distance from GCP
« on: January 12, 2018, 11:53:32 AM »
Generally there is no mathematical answer to your questions.

How does error increase as a function of distance from the GCP?
Depends on the project and gcp dispersion
How should GCPs be placed to meet a certain accuracy requirement? Should GCPs be placed closer together to increase the accuracy of a site?
- Does significant elevation differences on the site require an increase in the number of GCPs?
Generally GCPs should be placed to cover the entire site, without big gaps and taking into account extreme elevation changes. Do consider that spreading out a large number of GCPs does NOT proportionally increase accuracy.
- How much elevation difference is allowed between GCPs? Is that even a criteria that needs to be considered?
No specific criteria, think of your project as a 3D object that needs to be "tied" by various points with GCPs

General / Re: Network processing - questions
« on: January 11, 2018, 01:41:22 PM »
Hello Alexey, I've checked my logs and cannot find the bad allocation line, maybe because I'm cancelling the project? I will reprocess the project by unchecking point cloud processing in fine task menu, to see if that will have an effect

General / Re: Network processing - questions
« on: January 10, 2018, 04:49:01 PM »
Hello Alexey and thank you for your time. Yes photoscan 64bit is installed on all nodes. One of them is a server type Xeon with windows server r2012 (64bit photoscan also)

General / Network processing - questions
« on: January 10, 2018, 04:03:20 PM »
Hello to all, we have recently started testing network processing and I'm facing one or two problems during the procedure. More specifically we get a lot of bad allocation errors, even with the node unit that has been by now our main processing engine (working locally). I've checked with 1.4.0, tried building the depth maps and then cancelling the process. If I choose to process the project again with the single node (i7 6800k and 32gb RAM) by reusing the depth maps, the cloud is generated!

General / Re: Vertical error in DEM and Ortho
« on: January 09, 2018, 12:59:04 PM »
I agree regarding the eastern area. Judging by the scale of the map, there are very big gaps, where you're significantly lacking overlap. For these areas there will be problems in ortho recreation (no images available) and dem  creation.

The proper solution would be to re-fly these parts of the project only, or else try to eliminate them -if possible- from the final product

General / Re: Agisoft PhotoScan 1.4.0 pre-release
« on: January 02, 2018, 08:06:47 PM »
is it possible (if yes how) to have different versions of photoscan installed on the same PC and running independed from another

General / Re: Is Photoscan the correct tool for production volumetric calcs
« on: December 27, 2017, 08:09:19 PM »
No not the right software. Try global mapper instead, a whole Lotta different things needed for that kind of processing.

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