A determined position at a known time. Without satellite positioning, a survey boat takes fixes at set intervals by sextant angles or ranges, numbering each on the record so soundings between fixes can be plotted. Crews use the word for check fixes against known marks, the fixed versus float status of RTK, and log entries such as fix lost or fix regained.
Take a check fix on the beacon before you start, the nav looked off yesterday.
Also heard as
- position fix
- RTK fix
- check fix
Related terms
GNSS
Global navigation satellite systems: satellite positioning such as GPS, GLONASS, Galileo and BeiDou, used together.
RTK
Real-time kinematic: GNSS positioning that uses carrier-phase corrections from a base station to reach centimetres live.
Nav
Shorthand for the vessel's positioning data stream, or for the positioning system as a whole.
Float
Describes an RTK solution whose carrier-phase ambiguities are not yet fixed, giving only decimetre-level accuracy.