He managed to find a few good deals on electronics components online, including and Arduino Uno, a GPS module ... this data and displays the correct map onto the 320×240 TFT display.

Source: GPS for Land Surveyors This data can be provided over the Internet or via a LoRa radio link, and allows the module to deliver a fix accurate down to the centimeter in ideal conditions.

Google is working on an update that will leverage Google Maps' 3D building data to calculate how buildings interfere with GPS, and it says Android's new "3D mapping aided corrections module" can ...