Forum

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Topics - George

Pages: [1] 2 3
1
General / Computational power
« on: September 02, 2013, 09:36:25 AM »
Hello guys!
I know that this issue has been well discussed so far. However, time runs and there could be some changes.
I still wonder what could be the best solution for Pscan hardware? Say no limitations with resourses (at reasonable level indeed).
In simple terms what is the best computer to use Pscan?
What is the main feature that influences its performance? RAM, graphic card, CPU, hard drive type etc.?
Has anyone implemented a cluster solution?
Appreciate all ideas.
Cheers

2
General / Terrain model out of DSM
« on: August 14, 2013, 09:19:52 AM »
Hello guys,
did any one tried and succeded in creating DTM from DSM (DEM generated from Pscan)?
What were your ingridients?
George

3
General / Ground signals for Aerial Photography
« on: June 14, 2013, 09:19:44 AM »
Hello all,
guys what type of signals do you use (the ones to put on the ground at a site) at your projects?
From what altitude do you find them working effectively?
Could you share an image and sizes, please?
Cheers, George

4
General / Detect markers
« on: June 03, 2013, 09:43:06 AM »
Hi all,
what is "Detect markers" function (under Tools) and how does it work?
Could that be somehow applied at aeriaphotography applications?
In the manual not really much of explanation to that.
Cheers

5
General / Lens correction (aerial photography)
« on: May 23, 2013, 10:41:45 AM »
What do you think about using this for correction of a lens distortions?

http://www.epaperpress.com/ptlens/index.html

Worth using?

6
General / Georegistration based on coarse DEM/DTM
« on: May 03, 2013, 02:50:12 PM »
Hi
over and over again about the geo-registration issues at aerial photography and modeling applications.
Typical process of a project is quite simple: GCPs arrangement and their measurements, flight, post-processing. No need to bother about terrain model etc. since GCPs measured with GNSS equipment should be just true. At post-processing Pscan does its job perfectly based on correctly measured GCPs.

However, have you ever considered the following application?
You have a terrain model which is not really a DTM but more or less DEM. Say it is Aster GDEM or SRTM - the satellite products.
And the goal is to georeference your fine model to that coarse something (GDEM or SRTM ... whatever).
As far as I know Pscan produces linear distortions simply scaling a model according to the GCP assigned at referencing process. The real fuss to a large extent is just about Z value because in the end only that value could introduce the problems over entire model.

I have prepared a very simple drawing (attached) of my thoughts around this.
Do you think it is true that the DSM produced with Pscan will get the distortions desired/required according to the Z values taken from the coarse DTM? Or Pscan will tend to compensate that distortion somewhere between such GCPs?
Any ideas or experience, guys?
The application is forestry, where existance of a DTM is crucial for further analysis. However, the only DTM available is GDEM or SRTM.

7
General / GCPs in the middle of nowhere
« on: April 23, 2013, 01:19:52 PM »
Hi all concerned with aerial photography,
just need your lovely advice ...
Imagine that you are in the middle of nowhere or say in the middle of no-no-no ... fcking nowhere ...
That may have much in common with Amazon river basin case ...
So fact is that it is literally impossible to collect any kind of GCPs.
You capture images of approx. 20-35 km2.
However, the problem still persists - you need fairly nice geo-registration; at least at the level of meters (definitely not dm or cm). Your on-board GPS reciever is a classic GPS which is far not of the high accuracy required for geo-registration (definitely not for Z coordinate).
What would be your method for GCPs collection and/or geo-registration?
Thanks in advance.

8
General / Auto stabilization of the images
« on: April 23, 2013, 10:27:45 AM »
Hi all,
how tolerant is Pscan to the auto stabilization function enabled at a camera?
Does it influence performance of Pscan at any point when it comes to aerial photography?
GR

9
General / Rolling lens camera (mosaic issues)
« on: March 01, 2013, 10:27:49 AM »
Hi
is anyone familiar with the issue of rolling lens or long shutter travel?
Why that could be an issue for postprocessing (mosaicing) at Pscan?
Thanks.
George

10
General / Images enhancement (prior applying Pscan)
« on: February 27, 2013, 03:58:16 PM »
Hi all,
what are the standart pre-postprocessing operations do you do to enhance your imagery prior mosaicing?
Could that affect (in negative way) e.g. geometry reconstruction?
George

... and what software do you, guys, use for that?

11
General / Masking
« on: February 23, 2013, 07:55:02 PM »
Hi all,
Could you please explanr what does exactly masking mean?
How that affects exported DEM, mosaic, point cloud, 3d model?
In what cases do you normally use masking?
Thanks.
George

12
General / DEM for forest inventory
« on: February 12, 2013, 09:57:20 AM »
Hi all, hi 'foresters' (if any ;))
did any one make forest measurements (in the filed) in order to compare DEM by Pscan and manual measurements by e.g. ultra sonic Vertex or classic clinometer/heightmeter); or even laser?
Thanks.
George

13
General / Point cloud for large/huge area
« on: January 31, 2013, 02:46:59 PM »
I have an area of say 2600 ha. The result should be delivered as a point cloud.
Massive task to generate and export in one chuck or project file indeed, isn't it?
However, it is possible to divide it in blocks.
What would you recommend as a tool to cut the blocks in a way that they fit one to another geographically absolutelly correctly.
Is it possible to do with Pscan? Bound box? No?
External software? Which?
Appreciate any ideas guys. Thank you.

14
General / Unexpected application of Pscan
« on: January 25, 2013, 06:00:10 PM »
I have an area for which I need to accomplish a modified 3D model at SketchUp and export it to PDF.
The problem is that I don't have an aerial imagery and 3D model produced but I do have a LIDAR point cloud and good enough ortho.
Seems like its the solution ... but NO!
Having ArcScene I easily produced triangulated model and exported it to .WRL format. At that stage Blender software could have been of a help but it failed - the area turned to be that big that the file exported to .3ds did not appear correctly at SketchUP and Collada file just crashed SketchUp each time I imported one.
The solution turned to be very intelligent.
Blender can export to .ply or .obj, which can be imported to Pscan.
I simply opened a ready project and Imported mesh in .ply then immediately exported 3D model to .3ds and got a perfect display at SketchUp.
That's it.
Now I wish Pscan could enable the function of Mesh Importing at any stage of post-processing - even at the very first (prior to Alignment).

15
General / Refined camera calibration parameters
« on: January 09, 2013, 10:33:42 AM »
Alexey hello,
could you explain please the meaning of camera calibration parameters under "Tools, Camera Calibration"?
In particular Initial and Refined. This is not totally a clear aspect.
At one discussion I found that you recommend to apply Refined for better results - you offered to substitute Initial with Refined.
However, the scale of the problem matters ... I mean that there are projects with 10 images and projects with 1000 images, which is a pain in terms of changing paramentes manualy for the pile.
What can the substitution give? Is it possible to substitute Initial with Refined for all the images with one click?
George

Pages: [1] 2 3