Your opinion on USGS Agisoft Processing Workflow

[stihl]

Funny, seeing how I followed this workflow and got worse results than following our own developed workflow.

I suppose it all depends on your data set.

Could you outline your workflow and describe your type of data, out of interest?

Unfortunately I prefer not to go into depths of our workflow. I can say that it's quite different than what USGS following for their gradual selection filtering.
The results that the USGS workflow yielded were slightly worse absolute errors compared to independent check points than our own workflow and showed a decrease in the amount of detail for the dense cloud. Most likely due to larger misaligment errors compared to our own workflow.

[mks_gis]

I understand commercial implications, it's a shame though as sharing our settings and experiences helps the community overall. We'll slog on, cheers.

[TXPE]

How, if at all, would the use of higher precision geotags (5-20 cm) affect step 1 (pg 4) of the instructions that state, "keep the accuracy settings to the default values...".

[2bForgotten]

Hi there,

So I don't know about y'all, but I still am eager to hear someting from our Agisoft pro's on this forum regarding the questions raised in OP.

Regards,

[wizprod]

The link in OP is now broken. Did anyone save the full workflow PDF and can post it here?

[PROBERT1968]

Is that what you are looking for ?


https://uas.usgs.gov/nupo/otherresources.shtml

apparently they may have move it or  change..

[wizprod]

Yep! Thanks!

[bgroff]

Hi. I've tried the USGS workflow for a few weeks now on several projects and these are my observations:

• Number of projections per photo seems better at a minimum of 150, rather than 100 as USGS suggests
• The mean error in each photo of 0.3 pixels seems fine, though 0.4 is my usual result
• The whole gradual selection workflow appears okay. No major hangups with it
• Tie point tolerance has the greatest effect on increasing SEUW to 1, but I find that my GCP and check point errors are much higher as I lower tie point tolerance toward 0.1. My preference is to set tie point tolerance to around 0.3 and this appears to result in my desired 5cm accuracy for GCP and check points.

All of my mapping operations are using a P4P with 20MP camera, no RTK/PPK yet, but GCP set with diff. GNSS receivers. We're looking at higher quality mapping drones.

[working_guy]

bgroff

Where you define the set tie point tolerance? I Can't find that.

Thanks

HRS

Hi. I've tried the USGS workflow for a few weeks now on several projects and these are my observations:

• Number of projections per photo seems better at a minimum of 150, rather than 100 as USGS suggests
• The mean error in each photo of 0.3 pixels seems fine, though 0.4 is my usual result
• The whole gradual selection workflow appears okay. No major hangups with it
• Tie point tolerance has the greatest effect on increasing SEUW to 1, but I find that my GCP and check point errors are much higher as I lower tie point tolerance toward 0.1. My preference is to set tie point tolerance to around 0.3 and this appears to result in my desired 5cm accuracy for GCP and check points.

All of my mapping operations are using a P4P with 20MP camera, no RTK/PPK yet, but GCP set with diff. GNSS receivers. We're looking at higher quality mapping drones.

[bgroff]

Hi HRS. It's in the Settings dialogue on the reference panel.

[working_guy]

Thanks I go see that.

[MaciekK]

Hello everyone,

I'm new to the forum and also at work on Metashape. I have some experience with photogrammetry - a few years of work on Z / I Imaging. Now I start with Agisoft .... But back to the topic, I practiced the USGS workflow on several data sets - 1.5 ha (75%, 75%) 100 photos, 12 ha (80%, 80%) 530 photos and 12 ha (60%, 40%) 370 photos grid- the same area, GCP measured with accuracy xyz 1cm, pixel 2cm, drone P4RTK. Alignment carried out to obtain errors assumed by USGS, camera parameters - all marked without additional. I recommend this workflow, very good results obtained. At 33 checkpoints, errors no larger than 2cm. The dense cloud finally generates quickly, about 40 minutes on high setting. Dense cloud height accuracy at +/- 2 cm checkpoints. I really recommend.
PS. I want to introduce some modifications of the workflow in order to obtain more accurate image matching from about 0.2 pix

Regards
Maciek

[working_guy]

Hello everyone,

I'm new to the forum and also at work on Metashape. I have some experience with photogrammetry - a few years of work on Z / I Imaging. Now I start with Agisoft .... But back to the topic, I practiced the USGS workflow on several data sets - 1.5 ha (75%, 75%) 100 photos, 12 ha (80%, 80%) 530 photos and 12 ha (60%, 40%) 370 photos grid- the same area, GCP measured with accuracy xyz 1cm, pixel 2cm, drone P4RTK. Alignment carried out to obtain errors assumed by USGS, camera parameters - all marked without additional. I recommend this workflow, very good results obtained. At 33 checkpoints, errors no larger than 2cm. The dense cloud finally generates quickly, about 40 minutes on high setting. Dense cloud height accuracy at +/- 2 cm checkpoints. I really recommend.
PS. I want to introduce some modifications of the workflow in order to obtain more accurate image matching from about 0.2 pix

Regards
Maciek

Dont forget tell us what you change and your results, great work. 

[cronair]

Thank you for bumping this thread back to the top. This is exactly what I have been looking for. Its a couple years old but sounds like its a still a valid workflow. I am trying it now.

And echoing what working_guy said, don't forget to tell us your modifications MaciekK.

[2bForgotten]

Hello everyone,

I'm new to the forum and also at work on Metashape. I have some experience with photogrammetry - a few years of work on Z / I Imaging. Now I start with Agisoft .... But back to the topic, I practiced the USGS workflow on several data sets - 1.5 ha (75%, 75%) 100 photos, 12 ha (80%, 80%) 530 photos and 12 ha (60%, 40%) 370 photos grid- the same area, GCP measured with accuracy xyz 1cm, pixel 2cm, drone P4RTK. Alignment carried out to obtain errors assumed by USGS, camera parameters - all marked without additional. I recommend this workflow, very good results obtained. At 33 checkpoints, errors no larger than 2cm. The dense cloud finally generates quickly, about 40 minutes on high setting. Dense cloud height accuracy at +/- 2 cm checkpoints. I really recommend.
PS. I want to introduce some modifications of the workflow in order to obtain more accurate image matching from about 0.2 pix

Regards
Maciek

Hi there,

Thanks for sharing!

Some year ago I gave it a try myself. Did get some mixed results on a project with sandy dunes and low vegetation.

But the questions raised in OP regarding the workflow with the gradual selection tool are still open to debate. Have you experimented with that too?

Regards,