Taking off & setting RTH altitude

[Sn4pper]

Evening guys,

Just a quick question about taking off an the RTH altitude.

When taking off should I enter a brief hover to set the RTH altitude? or should I be using the take off function within the app?

 

[old man mavic]

Evening guys,

Just a quick question about taking off an the RTH altitude.

When taking off should I enter a brief hover to set the RTH altitude? or should I be using the take off function within the app?

set you RTH height before you get air born after you have done your pre flight checks for your surroundings but there is nothing wrong in hovering for a few seconds, to make sure the drone is flying correctly ,and you have a good GPS lock, and the drone responds to stick input as it should

 

[Deleted member 103366]

Plus you can change your RTH height during the flight PROVIDING you are NOT IN AN RTH at the time. I can vouch for the fact the trying to change it whilst in RTH does not work

 

[Peterson]

This is a hot topic
question here but since I have been flying I take off and hover at about 50 feet and do a slow 360 degree turn in place so that the drone has a good mapping of the RTH location and away I go. For the past year or so after having done this my MP2 will land within inches of take off point most of the time exact spot. This works for me and other experiences for other folks may very.

 

[Deleted member 103366]

Precision landing is applicable only to those drones that feature this the M2P/Z being one, I think you will find the necessary pure vertical climb from take off is 7m and no 360 is needed.

 

[Rich QR]

Precision landing is applicable only to those drones that feature this the M2P/Z being one, I think you will find the necessary pure vertical climb from take off is 7m and no 360 is needed.

I don't have a drone with precision landing capability, but I think you're right.

However, a climb and a 360 can be useful for a different reason, related to the title of this thread. To verify you have selected an appropriate RTH altitude, keep your gimbal level at 0 degrees, climb to approximately where you think RTH should be, do a 360 and verify that no obstacles are above the center of the view screen. Adjust altitude as needed to be safely above obstacles, but not too far above. Set RTH height to that altitude.

Do this process right after launching at a new location, before you go flying off to a distant spot where signal might be lost and RTH might be initiated.

 

[Deleted member 103366]

Good points Rich QR but I get the impression that Peterson was implying that the 50ft and 360 look around do something for the drone and enhance its 'knowledge' of the homepoint, as far as I am aware they do not. Assuming I am correct my post is intended to highlight that for those purposes the 50ft and 360 look around are of no benefit. Your reasons bear weight.

 

[Meta4]

This is a hot topic
question here but since I have been flying I take off and hover at about 50 feet and do a slow 360 degree turn in place so that the drone has a good mapping of the RTH location and away I go. For the past year or so after having done this my MP2 will land within inches of take off point most of the time exact spot. This works for me and other experiences for other folks may very.

Rotating the drone at 50 feet doesn't do anything to provide "good mapping of the RTH location".
Try not doing it and RTH autoland will still put the drone within an inch or two of the launch point.

 

[Peterson]

Rotating the drone at 50 feet doesn't do anything to provide "good mapping of the RTH location".
Try not doing it and RTH autoland will still put the drone within an inch or two of the launch point.

Have tried it and it works better for me when I do it. Takes all of 15 seconds so the effect on battery life is minimal in my opinion. Without the 360 turn my drone was landing anywhere from a foot to two feet from take off point and yes I am using a landing pad which BTW I have found makes a difference as well. In my experience it works for me and my MP2. If yours will get the same results without the 360 turn great! One less step in the take off process.

 

[old man mavic]

for me its not about the 360 turn its the fact that the drone is hovering at a fixed point for the few seconds it takes to do the 360 ,just for fun go up and try it just hover count to 10 then fly off with out the rotation and see how close it gets to the home point

 

[Peterson]

for me its not about the 360 turn its the fact that the drone is hovering at a fixed point for the few seconds it takes to do the 360 ,just for fun go up and try it just hover count to 10 then fly off with out the rotation and see how close it gets to the home point

Tried it and do not get the same results. It still comes close but not as close as the rotation does for me. Why is this? I cannot tell you but bottom line for me is that it gets almost spot on exact spot with the rotation rather than within a foot or two without the rotation. Tomatoes tomato type of thing I guess. Take it for what it's worth.

 

[Meta4]

Tomatoes tomato type of thing I guess. Take it for what it's worth.

It's more like coincidence and a superstitious ritual kind of thing.
There are things that help RTH autoland put your drone exactly where you launched (Precision Landing).
And there are things that don't do anything to help (every thing else).
If you do what Precision Landing needs, the autolanding will be within an inch or two.
With all the rest you are just fooling yourself, because it makes no difference at all.

Your drone records a homepoint with GPS as soon as it gets good GPS reception.
If your launch point is in a clear spot with a good sky view, that isn't improved by spinning in space.
GPS alone will put the drone within approx six feet of the launch point.
Precision landing works by recording a still image of the launch point while the drone is hovering above it to give the drone a record of exactly where the launch point is and how it relates to its surroundings..
Spinning around can't possibly make any difference.
If you don't hover for a few seconds at the appropriate height, the drone uses GPS alone.

Your manual has more details about the limitations that can also affect the Precision Landing system.

 

[Peterson]

It's more like coincidence and a superstitious ritual kind of thing.
There are things that help RTH autoland put your drone exactly where you launched (Precision Landing).
And there are things that don't do anything to help (every thing else).
If you do what Precision Landing needs, the autolanding will be within an inch or two.
With all the rest you are just fooling yourself, because it makes no difference at all.

Your drone records a homepoint with GPS as soon as it gets good GPS reception.
If your launch point is in a clear spot with a good sky view, that isn't improved by spinning in space.
GPS alone will put the drone within approx six feet of the launch point.
Precision landing works by recording a still image of the launch point while the drone is hovering above it to give the drone a record of exactly where the launch point is and how it relates to its surroundings..
Spinning around can't possibly make any difference.
If you don't hover for a few seconds at the appropriate height, the drone uses GPS alone.

Your manual has more details about the limitations that can also affect the Precision Landing system.

Ok, here is the thing and this is not something that should come as a surprise to anyone that has been around for awhile. Yes, I have read the manual from start to finish, I'm retired and do not have a life. If you go back and read my posts I said IMO. I have tried not turning 360 and it does not get the same results for me. Does it make sense, not to the manual or to others but at the end of the day it works for me. There are a lot of things in the manual that I have seen published here that get different results for different folks. My max distance is considerably further then what the manual says it should be under proper VLOS conditions. So, yes it does not make sense to you or what the manual says should be the ability of the RTH function. I was offering it up as a solution to try and see if it received the same results as me. If not discard the advice and look for other solutions to the issue.

 

[Meta4]

I have tried not turning 360 and it does not get the same results for me. Does it make sense

No, it makes no sense at all.
If your drone is auto-landing within an inch or two of the launch spot, that means you paused at the right height for the downward sensors to record the launch point and the location was suitable for Precision Landing.
Your spinning around has absolutely no effect because there's nothing it could do that would have any effect

If autolanding doesn't put the drone within an inch or two, that means either you did not pause at the right height or that the surface was unsuitable (no identifiable features or texture etc).