Failsafe Location Accuracy (Home Point)?

[bergenfelter]

I have a P2V+ with the latest firmware rev. I have done a few tests with the failsafe - return home mode. I have always done a compass cali and allowed the P2V+ to get a good GPS lock before take off. When I go to failsafe mode it always seems to land in a +/- 10' radius of the home point. Is this normal accuracy for the GPS in these birds?

Thanks!

John.

 

[D_Tshudy]

10' sounds a little sloppy but it really depends on how many sats you had a the time the home point was recorded. As you know, more sats = higher accuracy. I've read that some people put it in the air for a little while until they acquire more sats (12 or so) and then re-set the home point.

 

[Birdman]

It also depends on how many sats you have on return and at landing. Phantom User Manual states hovering accuracy is 2.5 m (8.2 ft). So you're not doing too bad.

 

[bergenfelter]

10' sounds a little sloppy but it really depends on how many sats you had a the time the home point was recorded. As you know, more sats = higher accuracy. I've read that some people put it in the air for a little while until they acquire more sats (12 or so) and then re-set the home point.

How do you reset the home point after GPS acquisition?

 

[Mako79]

Do a controlled test.
With NAZA on, take off and try and acquire 9/10 sats in the air.
Set a new home pos by flicking the left toggle (S2) until you see rapid green flashing lights. Read below on proper HOME POS and COURSE LOCK.
Mark your new home point right below it.
fly to new locations and activate the failsafe.

Another thing is to watch your GPS as it descends automatically. If you are in confined spaces, chances your gps may drop to less than 6 and ATTI landing occurs where it may drift based on wind conditions.

I cant find the link right now, but you can always do the drone expert GPS Foil mod to increase GPS accuracy.

Home and Course Lock
***LEFT TOGGLE SWITCH***
1 = IOC Off
2 = CL
3 = HL

New Course Lock. this will lock the direction based on the phantom is facing. Flick between position 1 and 2 x 5.
New Home Lock. this will lock the new home position. Flick between position 2 and 3 x 5.
Wait for rapid green flashes for both the above.

 

[samd012]

The accuracy rating of hand held GPS units is within 10'. I would expect the Phantom to be the same. I really wish you could set the height it will climb before returning yourself though, that would be awesome.
I have had issues with the Phantom thinking it is at 3-8ft high when it is on the ground. No matter how many satellites I have this issue is persistent with me.

 

[TeeJayN]

10' sounds a little sloppy but it really depends on how many sats you had a the time the home point was recorded. As you know, more sats = higher accuracy. I've read that some people put it in the air for a little while until they acquire more sats (12 or so) and then re-set the home point.

How do you reset the home point after GPS acquisition?

In the User Manual 4.2 Failsafe Procedure :
"Quickly flipping the S2 switch of the Remote Controller from top to bottom 5 times or more will reset the current aircraft position as a new home point. Rear LED flight indicators will blink green rapidly when successful."
This assumes you are in the Phantom Mode. I don't know if this works/changes in the NAZA Mode.