Rally Point Absolute Altitude

weliwarmer · September 17, 2018, 7:17pm

Can rally point altitude be absolute?

I have a complicated flight plan and would like to use rally points for emergencies. My missions use absolute altitudes because, although the missions are set and repeatable, the take-off points can change depending on public access, animals, wind direction.

If the rally points are always relative altitude to home, it means I’ll need to setup multiple rally point save files and load the right one for the days take-off area, that’s added risk.

Lots of hills and narrow valleys mean terrain following is not an option.

Thanks.

weliwarmer · September 18, 2018, 2:29pm

Looks like a “no, not yet”:

github.com

ArduPilot/ardupilot/blob/master/libraries/AP_Rally/AP_Rally.cpp#L100


}


// helper function to translate a RallyLocation to a Location
Location AP_Rally::rally_location_to_location(const RallyLocation &rally_loc) const
{
Location ret = {};


// we return an absolute altitude, as we add homeloc.alt below
ret.flags.relative_alt = false;


//Currently can't do true AGL on the APM.  Relative altitudes are
//relative to HOME point's altitude.  Terrain on the board is inbound
//for the PX4, though.  This line will need to be updated when that happens:
ret.alt = (rally_loc.alt*100UL) + _ahrs.get_home().alt;


ret.lat = rally_loc.lat;
ret.lng = rally_loc.lng;


return ret;
}