After adding GCPs to my maps?

I been doing mapping with mavic 2 pro and Autel EVO 1 for lets say 4 months without GCPs. My orthos and models were looking pretty good! Ill post examples.
Then I bought two emlid reach RS+ , I learned how to set them up and connect to NTRIP for base corrections in Las Vegas. Be for adding GCPs on some maps I would lay out points at a certain distance like 10’, 20’, 28’ and so on. and when measuring it out on DD it was dead on or 1/2" out at most.

After four flights using GCPs and check points using reach RS+ base connected to NTRIP for 30 min and reach RS+ rover all in FIX and 999.9 AR. My orthos and models look choppy and last map I did, I laded out a point of measure and it was 4" off . This is with mavic 2 pro
Be for GCPs the maps were beautiful and x and y seemed spot on.
Any Ideas on what I could be doing wrong? Thanks, Im lost at this point


After GCPs;jwt_token=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzUxMiJ9.eyJleHAiOjI1MzQwMjMwMDc5OSwiaWQiOiI1ZTljN2E4MTkyYTRmOTIxODJlN2FlN2MiLCJzY29wZSI6WyIxYTVjNDk2NjVmX0M2QjJEMzdCRTBJTlNQSVJFIl0sInR5cGUiOiJSZWFkT25seVBsYW4iLCJvdmVybGF5X2ZvbGRlcl9pZCI6IjVlOWM2YTBmOTJhNGY5MjE4MmU3YWU3MiJ9.NrIjhmLLBS1W5NDOD1GUmmw0gooiEU9caYix7nGdkhPgViWl8gsKRjs979rOI01wj7-YzaQrPwO90eLDxri5EQ

The map report looks great with the GCPs add the the maps RMSE of 0.1, I can share a report if someone would like to view it. But again the maps look choppy to me and my points of measure are out as of 4". Nothing has changed from the way I was doing them be for.
Again my emlid set up is connected to local NTRIP with full fix, RTK, RS+ base and rover, 2 meter pole and brass adt. accounted for, WGS84.
Any input will be much appreciated! Thanks

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Also I would like to add I was 7 kilometers away from local NTRIP station.

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I’m not sure what you are referring to as choppy, but the 4-in bust is definitely a concern unless one of the GCP measurements went awry. Are you comparing the measurement between two GCP’s by coordinate vs on the screen?

If the choppiness you are referring to is the buildings and wall then that looks normal for a standard map flight. Did you use any oblique images? It can be a catch-22 because obliques would be needed to get vertical elements better, but they are not good for GCP’s and terrain.

yes I did do oblique shoots in the GCPs map.
Im not sure how to compare measurements between GCPs ?
Ill try a map with no obliques and see how it turns out.
To my eye the maps with GCPs do not look as good as the ones without.
And how do you use check points or GCPs as measurements or to check the accuracy of a map? Thanks for your response, I am doing my best to learn!


So the best way seems to be, do your GCPs and just fly your mission with no obliques. save that. then do your obliques say on another SD card.
Then do two different uploads. one with GCPs and mission photos only.
Then another upload with no GCPs inserted add mission photos and your obliques to make the model. Sound somewhat correct? to get the best of both.
Maybe my obliques are throwing stuff off with the GCPs.

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In my experience I have gotten worse ground accuracies when including oblique images on maps using GCP’s. The problem is that the oblique angle can sometimes see the targets much further away so it ends up giving you poor quality views in comparison that can also get very skewed. I don’t think GCP’s can hurt a model meant for structures only, but I do normally use the two-process method when I want one map with really tight terrain and another with a nice model of a structure. Nadir-only processed in Terrain mode vs with obliques in Structure Mode.

I’d be willing to bet that nadir-only images with the GCP’s would tighten up the measurements, but the choppiness may just be continuing to learn the get the right oblique images.

The model of the condos above looks really good, but it would take a ton of close-proximity shots to make it much better. Scaffolding and walls are tough to get with any amount of shots. You just have to keep in mind that any detail less than 4-6 inches is going to be really tough to consistently model. Walls usually work best when shot from above to capture the top cap and then with obliques looking square at it.

Thank you, Ill try a GCP map in terrain mode nadir photos. and lay out some measuring points.
And do a separate flight for 3D model.
As always thank you, I am grateful for your imput

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Check out this 3D model, I think it turned out pretty good, Mavic pro 2;jwt_token=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzUxMiJ9.eyJleHAiOjI1MzQwMjMwMDc5OSwiaWQiOiI1ZTE0ZWJlYTJlYzBmYmZmODNjOWZjNWUiLCJzY29wZSI6WyIxZjAzNzRjNjc1X0M2QjJEMzdCRTBJTlNQSVJFIl0sInR5cGUiOiJSZWFkT25seVBsYW4iLCJvdmVybGF5X2ZvbGRlcl9pZCI6IjVlMTRkNTk2MTZiMjk1MzM5ZDI3YjRjMyJ9.YD9ON-g3m0WvgyywPUNogNor7D8CrrMY_ie5u8Isx0unC_kxpkTTMn5YH9FiuI2IZPnfOdtxjQiusY1RtdZoWQ


Very nice! You should post it on the Beautiful Maps section!


You know a 3D Model is going to look pretty good when the edges are crisp like this!

THANK YOU SIR! I will post it on there

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