I am a GPS RTK engineer from Tersus GNSS. Tersus GNSS is a start-up company from Switzerland who make least expensive, reliable, centimeter-level positioning accuracy GPS RTK boards for surveying, precision agriculture, and drones, etc. Our RTK boards can be integrated to other host devices or served as an independent GNSS receiver at a very affordable price.
In the meantime, we offer bundle kit with related antennas, cables which aim to make your application easy and convenient. If you are interested and want to know details of technical specifications, drop us a line to firstname.lastname@example.org.