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Author Topic: Best practices and advice for processing P4RTK  (Read 3530 times)

cronair

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Best practices and advice for processing P4RTK
« on: March 11, 2020, 07:59:59 AM »
Hey everyone, I have been using the trial version of the software for two weeks now and have run a few jobs through it but I either dont know if I'm doing it right or if there is an easier way to do it. I am going to just ask a bunch of questions and if anyone can answer any of them or point me to the answer I would very much appreciate it.

First of all, I have been using ContextCapture through work but I want to buy something of my own for side work. I work in land surveying and have an Epoch 50 base and rover that I use for tying control and PPK post-processing. I am using REDcatch PPK processing software that exports directly to a Metashape file and thats what I start with. On to the questions...

What is the correct workflow? What settings are people using?
When do I optimize? And do I only optimize control or both control and cameras?
What exactly does the update button do?
Should I use estimate image quality and learn to use masking?
Is there an easier way to set markers in photos? Is there a way to just accept a position without right-clicking on it and clicking the place marker?
Is there a way to move the markers with arrow keys or something besides the mouse? The entire marker placement process is not exactly easy, there has to be an easier way.
Can you assign checkpoints as vertical checks only?
How can you tell if error is horizontal or vertical?
Can I process oblique and nadir at the same time or is it better to do nadir first? or something else?

My biggest frustration right now is with marker placement. It's so much better in ContextCapture but maybe there is a trick I don't know about. I hope so. I have a new computer coming and Metashape seems to be one of the best for photogrammetry and one of the least expensive. I really want to like it but I am struggling right now and my trial is running out.

Thank you!


JMR

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Re: Best practices and advice for processing P4RTK
« Reply #1 on: March 12, 2020, 03:24:35 PM »
I'd gladly give you some hints if you like. Also I can show you how gcp marking in MS can be really damn fast. Do not hesitate to contact me.
regards,
GEOBIT

cronair

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Re: Best practices and advice for processing P4RTK
« Reply #2 on: March 19, 2020, 01:50:08 AM »
JMR, thank you for the response. I sent you a PM. Can't wait to see how you do GCPs and anything else you can show me. Thanks!

peterwatson

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Re: Best practices and advice for processing P4RTK
« Reply #3 on: March 21, 2020, 09:40:23 AM »
I too have been fumbling my way with a P4RTK after using P3P / P4P and Agisoft for many years. I tried to use ContextCapture at one stage (work has an agreement with Bentley) but I found the opposite- marker placement was much easier and quicker in Agisoft! Have also tried Capturing Reality and Pix4D but always come back to Agisoft- I love it!

I would also be very keen to get my hands on anyone elses workflows for processing P4RTK just to see if I can do things better. Maybe I will sit down and write out my workflow and share here to get some feedback from others.

cronair- I found the tutorials on the Agisoft website to be invaluable in the early days to get the basics sorted (prior to using RTK). It seems to be pretty similar workflow with P4RTK- there's just a few other things to be aware of.

For aligning markers with P4RTK- if you have all your settings right- the process of fine tuning should be really quick- in theory they say you should only need to align one GCP when using P4RTK data. Coming from years of using P3P and P4P photos with only GCPs I find myself still aligning quite a few GCPs for my own piece of mind. Having said that i am currently testing data to see what differences I get if I only use 1 or 2 GCPs vs many more.

Even if you do have to align markers/GCPs- the process gets quicker the more you do- ie. the markers get closer and closer to the GCP positions in photos so you only need to move slightly to align, use Page Up/ Page Down buttons to quickly skip through photos, and also "Filter photos by Marker" to only display photos with a particular marker/GCP in them.



cronair

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Re: Best practices and advice for processing P4RTK
« Reply #4 on: March 23, 2020, 12:55:47 AM »
In CC, I like how there is a button to just accept the location if it looks good. In MS, I have to either left-click the marker, which moves it slightly, or right-click and accept the marker location. Which, inevitably, I would accidentally select the wrong menu item from the right-click menu and it would place another marker right on top of the one already there or something else. I also don't think you have to select such a tiny little circle in CC. But hey, if you think MS is better, I believe you. I must not be doing it wrong.

Gareth

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Re: Best practices and advice for processing P4RTK
« Reply #5 on: February 11, 2022, 03:13:30 PM »
Hi Cronair, did you manage to refine your workflow and achieve better results?