A useful comparison framework
| Criterion | Question to ask | Why it matters |
|---|---|---|
| Heading technology | Dual GNSS antennas and inertial fusion? | Controls standstill and dynamic behaviour |
| Bands and constellations | Which frequencies and systems? | Affects availability and positioning robustness |
| RTK | Which correction paths are supported? | Important when centimetre-level position is required |
| Attitude | Are roll, pitch and heave available? | Needed for sonar, stabilisation and bathymetry |
| Rates | Internal calculation or real output? | Prevents comparing unrelated numbers |
| Interfaces | N2K, NMEA 0183, serial, CAN, BLE? | Determines integration options |
| Software | Configuration, logs and OTA? | Affects installation and maintenance |
Do not confuse calculation and output rates
A specification may describe the GNSS receiver rate, IMU sampling, estimator update or message output. Ask which quantity is actually delivered to the consumer and at what rate.
Compare for the actual use case
Autopilot
Prioritise stable heading, coherent rate of turn and proven network integration.
Radar
Check heading stability and source compatibility with the display.
Sonar
Look for attitude and heave with suitable timing.
Bathymetry
Add RTK, measured lever arms, logs and controllable rates.
Where Hannon GeoX fits
GeoX combines multi-band GNSS, RTK, attitude calculated up to 400 Hz, selectable output rates, several marine interfaces, configuration applications and an embedded Blackbox. The final choice should still be validated against the target vessel and consumers.