76
General / Re: Agisoft DEMs - comparing in-flight and flight to flight DEMs
« on: July 11, 2014, 07:53:59 PM »
I'll include RGB mosaics of the June 9 and June 17 flights if that helps.
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77
General / Agisoft DEMs - comparing in-flight and flight to flight DEMs
« on: July 10, 2014, 08:14:32 PM »
I'd like to explore how useful Agisoft's DEM is and how it can be used for analysis, particularly different flights in time.
Our UAV has two cameras on board - RGB and NIR. Both are flown at the same time in the same UAV. They sit 3 inches apart from each other. They do not have the same exact frame footprint, and also have slightly different camera XYZ positions when taken from the air.
I used the same six aerial GPS targets to generate my mosaics for Flight 1 RGB and NIR and then Flight 1 RGB and Flight 2 RGB. Flights 1 and 2 are 8 days apart. I exported the DEM in 0.6m mosaic, then I snapped one to the other to ensure the same pixel footprint for raster calculations. The flight went over two center-pivot agricultural fields. The lines that look like "clock hands" are the irrigation arm in different locations so ignore those areas.
There is a lot of +/- in the data. What kind of error would you expect with Agisoft's DEM? This was a 600 m altitude flight.
I'll display some results below. The map displays everything except, -0.10m to 0.10m and -1.0m to 1.0m. Are these the kind of difference results you would expect, or have you seen better? What do you think in general? The ground outside of the crops should be the exact same terrain.
In the northern most center pivot field, there is some red/orange indicating an increase of 0.4-0.88m. Pretty sure alfalfa doesn't grow that quickly in 8 days. The southern field shows some negative numbers which matches as the field was harvested before Flight 2. However, there are still a few positive values as well.
What kind of error margin does Agisoft have?
Our UAV has two cameras on board - RGB and NIR. Both are flown at the same time in the same UAV. They sit 3 inches apart from each other. They do not have the same exact frame footprint, and also have slightly different camera XYZ positions when taken from the air.
I used the same six aerial GPS targets to generate my mosaics for Flight 1 RGB and NIR and then Flight 1 RGB and Flight 2 RGB. Flights 1 and 2 are 8 days apart. I exported the DEM in 0.6m mosaic, then I snapped one to the other to ensure the same pixel footprint for raster calculations. The flight went over two center-pivot agricultural fields. The lines that look like "clock hands" are the irrigation arm in different locations so ignore those areas.
There is a lot of +/- in the data. What kind of error would you expect with Agisoft's DEM? This was a 600 m altitude flight.
I'll display some results below. The map displays everything except, -0.10m to 0.10m and -1.0m to 1.0m. Are these the kind of difference results you would expect, or have you seen better? What do you think in general? The ground outside of the crops should be the exact same terrain.
In the northern most center pivot field, there is some red/orange indicating an increase of 0.4-0.88m. Pretty sure alfalfa doesn't grow that quickly in 8 days. The southern field shows some negative numbers which matches as the field was harvested before Flight 2. However, there are still a few positive values as well.
What kind of error margin does Agisoft have?
78
General / Re: Why aren't my GCP points working? Off 5-30m in Mosaic
« on: June 19, 2014, 12:21:40 AM »
THank you for your tips, Andy!
I paid more attention to the error of each point, sorted them, revisited them, removed/edited points until my overall error seemed good, and then reran the optimization followed by the point cloud.
It worked! Thanks!
I paid more attention to the error of each point, sorted them, revisited them, removed/edited points until my overall error seemed good, and then reran the optimization followed by the point cloud.
It worked! Thanks!
79
General / Why aren't my GCP points working? Off 5-30m in Mosaic
« on: June 12, 2014, 09:10:31 PM »
Hello all,
I have a PhotoScan Pro project where I've added about 20 GCP on a 5 mile stretch of river. The GCP are just rocks and log features, not official air photo targets. I have XYZ coordinates (picked from a basemap, not in the field).
NORMALLY, after I've add GCP to an existing project, I redo the optimization (thus clearing the previous non-GCP solution), realign photos, then redo the point cloud, then the mesh and finally texture - this usually updates the mosaic with the GCP an everything is good. New rectified mosaic done.
The project I am on right now is not dong that. The observed GCP locations are about 5-30 meters off from the actual GCP locations when comparing GCP to the Agisoft Mosaic. I have check and rechecked that I am picking the right points in my mosaic - even the model shows them all in the right place. But the exported mosaic is not correct. I even used a couple of those points on mosaics upstream and downstream with success.
What is going on? I have not started over completely (which sometimes is one of my methods). I'm trying to avoid doing that. So far I've always been realigning photos within the same existing project.
I have a PhotoScan Pro project where I've added about 20 GCP on a 5 mile stretch of river. The GCP are just rocks and log features, not official air photo targets. I have XYZ coordinates (picked from a basemap, not in the field).
NORMALLY, after I've add GCP to an existing project, I redo the optimization (thus clearing the previous non-GCP solution), realign photos, then redo the point cloud, then the mesh and finally texture - this usually updates the mosaic with the GCP an everything is good. New rectified mosaic done.
The project I am on right now is not dong that. The observed GCP locations are about 5-30 meters off from the actual GCP locations when comparing GCP to the Agisoft Mosaic. I have check and rechecked that I am picking the right points in my mosaic - even the model shows them all in the right place. But the exported mosaic is not correct. I even used a couple of those points on mosaics upstream and downstream with success.
What is going on? I have not started over completely (which sometimes is one of my methods). I'm trying to avoid doing that. So far I've always been realigning photos within the same existing project.
80
General / Re: Is my .psz salvable after a blue screen of death?
« on: May 31, 2014, 12:37:35 AM »Hello aggieair,
Any unsaved data could not be recovered.
If the project file could not be opened you can apply Zip-fix utility to it to recover all the possible data.
Could you please also specify the hardware configuration of your computer and dense cloud generation parameters?
Alexey - any ideas? I just lost ANOTHER day of work because of the blue screen of death crash. I had one Agisoft running while I was trying to build dense point cloud on another. It totally killed the other program I was running, and despite saving the file, the project file is corrupt due to the crash. Graphics card is up to date too.
81
General / Re: What causes "Can't build dense cloud"?
« on: May 31, 2014, 12:35:33 AM »
I've also had this error too even after updating the projection system, re-optimizing (like when I add control points), save and then it doesn't build then either. Sometimes if I close out and then open the project back up it will build suddenly (not sure why?). Other times the computer will crash on me!
82
General / Re: What causes "Can't build dense cloud"?
« on: May 31, 2014, 12:33:52 AM »
Have you tried zooming way out to see if there are any random points floating in space? Highlight them with the square, circle or draw tool, and delete them with the delete key. That was one known reason for not building the point cloud.
83
General / Re: Adding GCP after mosaic is created
« on: May 23, 2014, 08:48:33 PM »
Thank you for the reply! So start right after the Align photos (only do once) and also do not do the Optimize option after adding new points.
84
General / Re: Is my .psz salvable after a blue screen of death?
« on: May 23, 2014, 08:47:22 PM »
Hi Alexey,
I was wondering about the other 40 points that had been saved many times (not the last 3 points in particular). I will try to apply a Zip-fix utility.
I have Windows 7, Intel Core i7 CPU, 2.80 GHz, 4GB RAM, 64-bit.
I also have a graphics card NIVIDIA Quadro FX 3800 [http://www.nvidia.com/object/product_quadro_fx_3800_us.html] that is used for EnsoMosaic (Mosaic Mill).
For my Build Dense Cloud parameters, I use Medium for Quality and Aggressive for Depth Filtering. This is a ~16 mile long section of river corridor flown at 400 m AGL and 13cm pixel resolution.
Thank you! The blue screen has happened a few times.
I was wondering about the other 40 points that had been saved many times (not the last 3 points in particular). I will try to apply a Zip-fix utility.
I have Windows 7, Intel Core i7 CPU, 2.80 GHz, 4GB RAM, 64-bit.
I also have a graphics card NIVIDIA Quadro FX 3800 [http://www.nvidia.com/object/product_quadro_fx_3800_us.html] that is used for EnsoMosaic (Mosaic Mill).
For my Build Dense Cloud parameters, I use Medium for Quality and Aggressive for Depth Filtering. This is a ~16 mile long section of river corridor flown at 400 m AGL and 13cm pixel resolution.
Thank you! The blue screen has happened a few times.
85
General / Re: Adding GCP after mosaic is created
« on: May 22, 2014, 10:57:25 PM »
Anyone? So far when i add any additional GCP, I go through all these steps again to create my Mosaic_version2: Optimization / Point Cloud / Mesh / Texture .
If that does not work out, then I start all the way from Align Photos on occasion.
Normally should I go through all the steps again minus the Align Photos part? What is the best order when you already have a mosaic, but you just add one more GCP, etc?
Any advice would be appreciated.
If I do not need to do all those steps above, this would save me time in the long run.
If that does not work out, then I start all the way from Align Photos on occasion.
Normally should I go through all the steps again minus the Align Photos part? What is the best order when you already have a mosaic, but you just add one more GCP, etc?
Any advice would be appreciated.
If I do not need to do all those steps above, this would save me time in the long run.
86
General / Re: ORTHOPHOTO problems
« on: May 22, 2014, 10:53:44 PM »
Did you make sure you uncheck all the photo files so that only GCP are checked? Run Optimization (but update your coordinate system first).
Usually when my orthophoto is wonky it's because I forgot to uncheck all the photos/cameras. However, it won't indicate that I've missed that step until I go to export the mosaic to view (in GIS, etc).
Usually when my orthophoto is wonky it's because I forgot to uncheck all the photos/cameras. However, it won't indicate that I've missed that step until I go to export the mosaic to view (in GIS, etc).
87
General / Is my .psz salvable after a blue screen of death?
« on: May 22, 2014, 10:52:21 PM »
Every so often I get a blue screen error when I want to build Dense Clouds. nvlddmkm.sys is the error so I think it's something with my Nvidia card that I haven't seemed to fix yet.
Anyway, I had just added three more ground control points to my river corridor (after putting in/saved about 40!), and then I go to build Dense Cloud again (so it can incorporate the new points) and it told me "Can't Build Model". I tried it one more time and that's when the blue screen occurred! I had not saved the project file after adding the three last points.
After restarting the machine, it appears my .psz cannot be opened now. The error is "Can't Open File."
Anyway to salvage this? Or I am going to just start all over again? Anyone else deal with this error when trying to build the point model?
Anyway, I had just added three more ground control points to my river corridor (after putting in/saved about 40!), and then I go to build Dense Cloud again (so it can incorporate the new points) and it told me "Can't Build Model". I tried it one more time and that's when the blue screen occurred! I had not saved the project file after adding the three last points.
After restarting the machine, it appears my .psz cannot be opened now. The error is "Can't Open File."
Anyway to salvage this? Or I am going to just start all over again? Anyone else deal with this error when trying to build the point model?
88
General / Re: Volume/Area Calculation and QA/QC
« on: May 13, 2014, 06:54:26 PM »
Ah! Very good point! I did not think about that. Thank you!
89
General / Volume/Area Calculation and QA/QC
« on: May 09, 2014, 07:52:34 PM »
I want to calculate the volume and area for a landfill.
My outline of steps:
Add images, add flight log, Align Photos
Add Ground Control, set projection
Build Dense Cloud (high quality), Build Mesh
Add 5 scale bars, enter distances (assuming you just get the distance from ArcGIS???, I went out 1 decimal place) - My GCP are throughout the entire image, not right upon the landfill like in the training manual.
Remove secondary faces so that only my landfill feature is left
Close holes 100%
Find Volume and Area
I get an area of 906,537 m^2. (Volume is 3.2181e+06 m^3.)
However, when find the AREA in ArcGIS it's tells me 338,692 m^2. Granted I'm not drawing the EXACT same footprint, but pretty darn close. I used the ruler tool to draw an area around the landfill.
The ArcGIS project and the Agisoft project are in the same projection system (UTM, WGS84, Zone 12).
Did I do my volume steps correctly?
My outline of steps:
Add images, add flight log, Align Photos
Add Ground Control, set projection
Build Dense Cloud (high quality), Build Mesh
Add 5 scale bars, enter distances (assuming you just get the distance from ArcGIS???, I went out 1 decimal place) - My GCP are throughout the entire image, not right upon the landfill like in the training manual.
Remove secondary faces so that only my landfill feature is left
Close holes 100%
Find Volume and Area
I get an area of 906,537 m^2. (Volume is 3.2181e+06 m^3.)
However, when find the AREA in ArcGIS it's tells me 338,692 m^2. Granted I'm not drawing the EXACT same footprint, but pretty darn close. I used the ruler tool to draw an area around the landfill.
The ArcGIS project and the Agisoft project are in the same projection system (UTM, WGS84, Zone 12).
Did I do my volume steps correctly?
90
General / Re: Adding GCP after mosaic is created
« on: April 17, 2014, 01:08:01 AM »
OK, it seems I do not have to redo the dense point cloud after I add GCP.
I started right up with Build Mesh and it included all my GCP in the new mosaic.
I still would like to know if I'm going about it correctly!
I started right up with Build Mesh and it included all my GCP in the new mosaic.
I still would like to know if I'm going about it correctly!
