The EKF has fixed the point it measures positions from
What ArduPilot says:
- EKF3 IMUN origin set
- EKF2 IMUN origin set
- AHRS: using recorded origin:N.N,N.N,N.N
The EKF, ArduPilot's position and attitude estimator, measures every position in metres from one fixed point on the Earth, its origin. This copy has now set it, from the first GPS position that passed the EKF's quality checks for 10 s in a row. Outdoors that is usually 30 s to a few minutes after power-on, depending on how quickly the GPS gets its fix. It is set once and not moved. Home is set soon afterwards. Before this line, modes that need a position are refused.
Without a GPS the origin can be given by the ground station (“Set EKF origin here” on the map).
Parameters to look at
| Parameter | What it is |
|---|---|
EK3_GPS_CHECK | GPS preflight check |
EK3_SRC1_POSXY | Position Horizontal Source (Primary) |
The code that sends it
EKF3 IMUN origin set
libraries/AP_NavEKF3/AP_NavEKF3_Control.cpp NavEKF3_core::setOrigin() · Open in ArduPilot Copter-4.7.1
EKF2 IMUN origin set
libraries/AP_NavEKF2/AP_NavEKF2_Control.cpp NavEKF2_core::setOrigin() · Open in ArduPilot Copter-4.7.1
AHRS: using recorded origin:N.N,N.N,N.N
libraries/AP_AHRS/AP_AHRS.cpp AP_AHRS::use_recorded_origin_maybe() · Open in ArduPilot Copter-4.7.1