Autolanding with Rangefinder - Parameter Setup Question

When using a rangefinder the documentation says you can set LAND_FLARE_SEC to zero if you only want to use altitude.

Similarly, can I also set LAND_PF_SEC to zero if I only want to use altitude?



Yes. And if you set LAND_PF_ALT to zero, you just won’t have a pre-flare.

What exactly does this “Rangefinder engaged at 4.12m” message mean?

I have the pre-flare stage set at 3 meters and the flare set to 1.5 meters, both worked wiht this TFMini unit.


Note that the TFMini rangefinder comes alive at about 6 meters over grass.



May be related to this :

During the approach, the glide slope is actually calculated to pass through a point in front of the LAND waypoint. The distance in front is calculated as groundspeed * flare_alt / TECS_LAND_SINK, where flare_alt is LAND_FLARE_ALT, or LAND_FLARE_SEC times glide slope sink rate.