Add an action to update the home point for GPS Rescue from the remote control

[wshadw]

Is your feature request related to a problem? Please describe

The function to set the return home point at the time of the flight from the remote control is very necessary.
Please add this feature as it should be very simple, but at the same time it will simplify use and greatly increase the likelihood of saving the drone in places with difficult terrain.

Describe the solution you'd like

Examples of using:

1. The flight starts from an area where it is impossible to get GPS and fix the return home point. For example, a cave, or a narrow gorge, etc. At the same time, the flight itself takes place in the open air and there is a risk of going beyond the bend and losing the signal, and I want the drone to return to the same point of visible open space that I recorded earlier, so that the signal appears and I can land it myself.
2. There is no time to wait for GPS fixation and I am forced to start flying immediately. During the flight, satellites will be caught and you need to be able to set the return point to where it is now, so that the drone returns at least there, since there is a connection with it.
3. You are going to fly around a very high obstacle from the side. You can fly up to the bend, set the return point, then flying beyond the bend the connection will be lost, the drone will return in a straight line to the return point and establish contact. And if this is not done, then now he will simply fly straight home and crash into an obstacle.
4. The pilot is in a moving vehicle, and I would like to periodically update the return home point when driving over an obstacle, so that if communication is lost, the drone does not fly straight into the obstacle.

Describe alternatives you've considered

Now there is no way to rely on returning home if the satellites cannot be fixed, and you have to fly very, very, very carefully.

Other information

The only problem that can be caused by setting the home point during the flight is that the height of the landing point will be higher than the ground, and when the drone reaches it and travels another 5 meters (according to the documentation), it will disarm while in the air.

I see three solutions:

1. Make the ground level equal to the take-off point in the presence of baro.
2. Disable auto disarmament after passing the bar 5 meters below the landing point, if the home point was updated in the air.
3. Leave everything as it is, the easiest way, because when updating the home point in flight, the main goal is for the drone to return to communication, and then you can take over control by landing yourself.

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs within a week.

[wshadw]

pull request #13648