Hi Yaw, thanks for your answer, the differential correction its important to get more precision; for example two poles with less than 2m of separation, with a normal GPS you get about 3m, so it is difficult to know which pole is the one we capture.
I'm reading and get information about tools like RTKLib ( http://www.rtklib.com/ ), and get raw data from the Phone GPS with tools like ´Geo++ RINEX Logger´, but I would like the integration of ODK to this kind of tools.