Good news!
Any chance you can attach the Quality Report as it will answer any questions I have such as did you only use the Control Points as Check Points and what your final RMSE was on those checks.
To answer your questions:
Another question for you - Is there anything specific that I need to do when setting up the processing using RTK correction data?
Yes you can use the Accurate Geolocation option, but I have never had to. My opinion is that having the accuracy data for the images and GCPs weights Pix4D well enough for RTK obtained images and my results are almost always very good using the normal settings. There are some other more advanced options and things you can try, but I have only lightly delved into them as I use Agisoft Metashape now and have stopped exploring them.
I have also adjusted the camera to the 'Optimized' parameters and saved it for future use.
Yes, some people will save the camera parameters from a good processed data set for future use. I have also done this, but for the most part, I still usually use the default values and will then goto a saved set if I had trouble getting tight results.
When we were testing the two UAVs in NH (NH doesn't have a CORS system so we tend to rely on ME, MA, and VT depending on which is closest to us) neither of our UAVs achieved a 'fixed' solution even after about 20 minutes. So...my plan in this type of situation is to fly non-RTK, like we would with the Mavic. When flying non-RTK, follow the same guidelines you've outlined above (minus the RTK specific instructions)?
I am only lightly familiar about VRS, a couple of our other members will surely chime in with good information about it. I do know that it uses multiple bases around where you are. In my opinion you are too far from the bases and since you would think VRS wants bases around your position, accuracy/precision will suffer. What GNSS rover do you use? I use Emlids which are good for my use cases. From my testing the GNSS chip in our drones are not as good as the ones in handheld rovers and when my Phantom 4 RTK is more than 25 km from a base, it starts to have trouble holding fix, while my handheld Emlid rover gets FIX and holds it.
There are a couple of things you could do. Fly a non-RTK workflow and just collect GCPs and Check Points and process as you said as a non-RTK drone. If you have 2 Emlid units you could use VRS to make your own known point on site, send corrections to your rover to collect GCPs and Checks and send corrections to your Evo 2. You could even try a PPK workflow.
I am a firefighter and was put through classes to run our drone program through Emergency Mangement and our cops are now using it for accident scenes. Every problem you had, they had so I am well versed in addressing them. I stress one thing, don't settle for anything other than the best output. Make your products as accurate as can be and do not skimp on your vertical datum. EGM96 will not give the best orthometric ("Above Sea Level") elevation. The geoid undulation process I showed you will allow you to use NAVD88, using Geoid 18 which is the correct vertical datum for NAD83(2011).
A problem I saw is that a member of PD took an accident scene class that was a week long. There is no possible way that this class could teach you datums, coordinate systems, geoids and ellipsoids as well as all of the other information you need to start making maps. If it was crammed in there, it would be information overload. This is the weakness of those classes, they give you enough to start making maps and models and good workflows, but as soon as you need to change a workflow you do not have enough base knowledge to proceed.
On a final note check you Private messages, I will link you a video I made when I taught Remote Sensing at our local college. It shows processing an RTK drone dataset, full explantion of how and why to choose coordinate systems for your images, control points and outputs. It also shows with visual aid how the geoid undulation works and why Pix4D mapper introduces error since it lacks a true geoid 18 grid. I also have a video on processing GCP maps and maps with no GCPs and no RTK drone.
And finally I learned my craft from our local college, members on these forums, local surveyors and just plain reading books, white papers and Dave Doyles incredible webinars on Youtube for Florida GIS.
One more thing, always use Check Points!!! You cannot make an assumption on the absolute accuracy of your data without them!
Any chance you can attach the Quality Report as it will answer any questions I have such as did you only use the Control Points as Check Points and what your final RMSE was on those checks.
To answer your questions:
Another question for you - Is there anything specific that I need to do when setting up the processing using RTK correction data?
Yes you can use the Accurate Geolocation option, but I have never had to. My opinion is that having the accuracy data for the images and GCPs weights Pix4D well enough for RTK obtained images and my results are almost always very good using the normal settings. There are some other more advanced options and things you can try, but I have only lightly delved into them as I use Agisoft Metashape now and have stopped exploring them.
I have also adjusted the camera to the 'Optimized' parameters and saved it for future use.
Yes, some people will save the camera parameters from a good processed data set for future use. I have also done this, but for the most part, I still usually use the default values and will then goto a saved set if I had trouble getting tight results.
When we were testing the two UAVs in NH (NH doesn't have a CORS system so we tend to rely on ME, MA, and VT depending on which is closest to us) neither of our UAVs achieved a 'fixed' solution even after about 20 minutes. So...my plan in this type of situation is to fly non-RTK, like we would with the Mavic. When flying non-RTK, follow the same guidelines you've outlined above (minus the RTK specific instructions)?
I am only lightly familiar about VRS, a couple of our other members will surely chime in with good information about it. I do know that it uses multiple bases around where you are. In my opinion you are too far from the bases and since you would think VRS wants bases around your position, accuracy/precision will suffer. What GNSS rover do you use? I use Emlids which are good for my use cases. From my testing the GNSS chip in our drones are not as good as the ones in handheld rovers and when my Phantom 4 RTK is more than 25 km from a base, it starts to have trouble holding fix, while my handheld Emlid rover gets FIX and holds it.
There are a couple of things you could do. Fly a non-RTK workflow and just collect GCPs and Check Points and process as you said as a non-RTK drone. If you have 2 Emlid units you could use VRS to make your own known point on site, send corrections to your rover to collect GCPs and Checks and send corrections to your Evo 2. You could even try a PPK workflow.
I am a firefighter and was put through classes to run our drone program through Emergency Mangement and our cops are now using it for accident scenes. Every problem you had, they had so I am well versed in addressing them. I stress one thing, don't settle for anything other than the best output. Make your products as accurate as can be and do not skimp on your vertical datum. EGM96 will not give the best orthometric ("Above Sea Level") elevation. The geoid undulation process I showed you will allow you to use NAVD88, using Geoid 18 which is the correct vertical datum for NAD83(2011).
A problem I saw is that a member of PD took an accident scene class that was a week long. There is no possible way that this class could teach you datums, coordinate systems, geoids and ellipsoids as well as all of the other information you need to start making maps. If it was crammed in there, it would be information overload. This is the weakness of those classes, they give you enough to start making maps and models and good workflows, but as soon as you need to change a workflow you do not have enough base knowledge to proceed.
On a final note check you Private messages, I will link you a video I made when I taught Remote Sensing at our local college. It shows processing an RTK drone dataset, full explantion of how and why to choose coordinate systems for your images, control points and outputs. It also shows with visual aid how the geoid undulation works and why Pix4D mapper introduces error since it lacks a true geoid 18 grid. I also have a video on processing GCP maps and maps with no GCPs and no RTK drone.
And finally I learned my craft from our local college, members on these forums, local surveyors and just plain reading books, white papers and Dave Doyles incredible webinars on Youtube for Florida GIS.
One more thing, always use Check Points!!! You cannot make an assumption on the absolute accuracy of your data without them!
