What is ionospheric activity and how do I mitigate against the impact on GNSS? How can I fault find Veripos NTRIP? How does GNSS work? What geodetic reference frame do Veripos services use? What is GNSS? What is NMEA? What is RTCM? What is the difference between terms dual beam, dual constellation and dual frequency? Wiring diagram for the DG14/16 DB-25 serial connector