Non-GPS Navigation¶
These are the available options that allow a vehicle to estimate its position without a GPS. Once enabled this allows all autonomous and semi-autonomous modes just as they do would a GPS is available.
Note
Most of the above systems (except Beacons) require that the ORIGIN be set manually, except if a GPS is present. In order to do this the user must either use the GCS to set Origin, as shown below using Mission Planner, or use a lua script like this one
![../_images/setorigin.jpg](../_images/setorigin.jpg)
Note
The low cost IMUs (accelerometers, gyros, compass) used in most autopilots drift too quickly to allow position estimation without an external velocity or position source. In other words, low-cost IMUs on their own are not sufficient for estimating position.
Note
A board with more than 1MB of flash is required to run non-GPS navigation, except for Vicon as 1MB boards still support the GPS_INPUT message, although they don’t support the GLOBAL_VISION_POSITION_ESTIMATE so they have to be run using the GPS_INPUT message. See Firmware Limitations for details.