The answer is that there are entire journals devoted to the science. Have you looked at any of them? Their evidence is presented in the exact place you would expect to find it. Are you trying to imply that geodesy has no evidence? Or that the field itself is a scam? I am not sure what you are getting at.
I've looked at them. They say stuff like "if we take these magnetic field readings from the US, Europa and Asia, we can conclude x about the globe's magnetic field". None of it is actually about demonstrating that the earth is a globe.
https://www.staff.ncl.ac.uk/peter.clarke/offprints/Spatar_etal-2015-pp.pdf
https://blogs.ncl.ac.uk/geodesy/2015/08/14/two-papers-on-ocean-tide-loading/
http://www2.unb.ca/gge/Pubs/TechnicalReports.html
http://gpi.savba.sk/GPIweb/ogg/ikohut/WEBCD/Slovak-National-Report-to-IUGG_2011-2014.pdf
http://geodesy.unr.edu/publications.php
http://science.sciencemag.org/content/346/6205/65
https://scripps.ucsd.edu/research-topics/geodesy-and-lithospheric-deformation
http://www.mred.tuc.gr/home/mertikas/geodesy.html
Just a sample of published papers some do involve the magnetic field and a lot do not.
Most by themselves do not prove a round Earth but collectively they put the puzzle together.
There is plenty of observations spanning over 2,000 years that do not involve the magnetic field.
Then there is this, which is also is part of the geodesy field:
https://forum.tfes.org/index.php?action=post;quote=91680;topic=4717.60;last_msg=91681
This seems like something you could do to me. The equipment is not too cost prohibitive and it will allow you to make accurate measurements. If you can prove the methodology flawed or conduct a survey with the methodology clearly and precisely given not measuring a curve then you got something.
Edit: Just wanted to add since I did not think about satellites you will need to look for research conducted pre-satellite era. Since in most cases the latest tech will be utilized to collect data. As I pointed out there is plenty to find before the 1950's and NASA.
None of those links are really about showing that the earth is a globe. It's mostly "we have this data and here is how we can piece it together and tell us something interesting about the magnetic field/gravity/whatever on a globe earth".
The problem you are going to have looking at current research is no one is looking to try to find out the shape of the Earth. The closest you are going to get is just more precise measurements of the Earth. If you are expecting someone to say,"We just proved the Earth is spherical again!", I think you maybe waiting a long time. My guess some cataclysm would need to take place that destroys all the knowledge gained by humanity about the shape of the Earth.
Current science is building upon the foundation already built and proven by consistently making accurate predictions.
FE proponents are the ones that are going to need to step up and start making accurate and reliable predictions based on a FE model. Since currently I do not think anyone involved in mainstream science is out to prove the shape of the Earth.
I will repeat myself. If you start collectively looking at the information in the links I provided it starts to make a picture of the world we live in. None by themselves will prove the shape of the Earth.
If none of the research is about showing that the earth is curved, or that the earth is a globe, then what good is it to us?
I could take some data of the most abundant minerals on each continent and make a visualization with a Flat Earth map, but that would do nothing to show that the earth is flat.
Here is an example:
https://scripps.ucsd.edu/news/new-map-exposes-previously-unseen-details-seafloor"Developed using a
scientific model that captures gravity measurements of the ocean seafloor, the new map extracts data from the European Space Agency’s (ESA) CryoSat-2 satellite, which primarily captures polar ice data but also operates continuously over the oceans, and Jason-1, NASA’s satellite that was redirected to map the gravity field during the last year of its 12-year mission."
"Combined with existing data and drastically improved remote sensing instruments, the new map, described in the journal Science, has revealed details of thousands of undersea mountains, or seamounts, extending a kilometer or more from the ocean bottom. The new map also gives geophysicists
new tools to investigate ocean spreading centers and little-studied remote ocean basins."
"The authors of the study say the map provides a new window into the
tectonics of the deep oceans."
https://blogs.ncl.ac.uk/geodesy/2015/08/14/two-papers-on-ocean-tide-loading/The above is research into the accuracy of using GPS and other satellites used for taking measurements and the stuff that needs to be taken into account.
Here is research involving satellite errors, Earth body tide, tide loading, gravity, moon, seismological observations and tectonics. The second paper was the result of noticing discrepancies of 2-3 mm in a certain area of the world.
Even without doing an in depth analysis I think we can assume currently accepted calculations and models were used to make predictions. That is why the discrepancies were mentioned in the paper. Here we have researchers making predictions based on models for satellite errors, tide loading, Earth body tide, gravity and tectonics. Somehow the pieces fit together in a satisfactory manner with discrepancies of under 3 mm. I think it is important to note that a group of scientist who are indoctrinated into a false world view took the time to find out why predictions for a certain area were 3 mm or less off.
Do you really think that over many, many experiments, studies, observations, calculations used, predictions being made no one saw a discrepancy as big as being wrong about the general shape of the Earth? An error like that would resonate through many fields and make predictions and calculations, measurements, etc wrong and noticeable.
As I stated before no one except a small group is out to prove the shape of the Earth, to the best of my knowledge. Current science is making accurate and reliable predictions based on a heliocentric and spheroid models. If you expect to read a paper from someone in main stream science focusing on the shape of the Earth it will likely not happen unless they are making refinements to the currently accepted measurements.
As for the above tectonics, tides, satellites, Earth body tide IMHO you should take note of and research further. Maybe look into how they were able to make predictions based on the currently accepted knowledge and models.