How important is a ground range finder at height of around 35m?

As we know GPS has a rather inaccurate altitude. Normally gps altitude could range betwen 10-20m inaccuracies, in RTK that could mean around 10cm or more.

For instance in flying in urban scenario with altitude of below 35 metres. With altihold and poshold we can control the altitude but in auto mode Do you think it is necessarily important that a ground range finder is fitted?

?Yes, GPS is inaccurate (non RTK) but it’s relative altitude should be reasonably consistent over the duration of your flight. At 35m I don’t think it’s a big deal. None of mine have range finders and I fly missions at and below 35m without issue. If you’re flying below 10m, or the terrain is variable then that might be a different story.

Yes, I flew like between 15 and 3 metres height on a some waypoint across about 700-1000 metres in an open field on auto mode and it crashed. As urban can have a variety of obstacles, if flying over 1km in auto mode, if the inaccuracy is like 10-15metres can be disaster.

That’s why I am contemplating fitting a downward rangefinder. I suspect a rangefinder is important if the auto mode mission is stretch over long distance.

The barometer should be giving you better altitude performance than that. Sounds like you might have a tuning or setup issue. Even the GPS, once it has an altitude it’s relative altitude from one moment to the next should be consistent and not jump around by 10m. It may not be accurate relative to sea level, but it should be accurate relative to your home point.

Maybe I should start tuning my drone again and see how it goes.

1 Like