GNSS Compass for Vessels: Dual-Antenna Heading vs Gyro
A GNSS compass gives a vessel true heading from two GNSS antennas mounted a fixed distance apart — no spinning mass, no magnetic deviation, and typically a fraction of the cost of a marine gyrocompass. Heading accuracy scales with the antenna baseline: as a rule of thumb, about 0.1–0.2° per metre of separation. What actually…