Questions about GPS.

[Jenko1989]

Hi guys firstly merrsy Christmas to everybody!

I was trying to fly my phantom today and i struggled to get a GPS lock, but when i did i kept losing it. I just want to know, will the return to home function work if the phantom saves the home point at the beginning of the flight (rapid flashing green LED'S) but then loses GPS lock during flight? Will it remember the home point and be able to go to it even f it no longer has GPS? Or do you need a full GPS lock for that to work.
Also, can having an uncalibrated compass affect the GPS?

Thanks guys, have a good one!

 

[richiewrt]

Hi guys firstly merrsy Christmas to everybody!

I was trying to fly my phantom today and i struggled to get a GPS lock, but when i did i kept losing it. I just want to know, will the return to home function work if the phantom saves the home point at the beginning of the flight (rapid flashing green LED'S) but then loses GPS lock during flight? Will it remember the home point and be able to go to it even f it no longer has GPS? Or do you need a full GPS lock for that to work.
Also, can having an uncalibrated compass affect the GPS?

Thanks guys, have a good one!

No, if it looses GPS lock it won't know where it is and will have no frame of reference on how to get back to the home point. If you are loosing sats enough that you are unable to fly in GPS mode I suspect that something is wrong.

 

[MapMaker53]

RTH will not work below 6 satellites, even if you recorded a home point. Without GPS, the phantom does not know where it is and therefore does not know how to get back to the home point. And since GPS relies on the Earth's lat./long. grid, an uncalibrated compass will certainly result in incorrect heading information.

 

[Jenko1989]

RTH will not work below 6 satellites, even if you recorded a home point. Without GPS, the phantom does not know where it is and therefore does not know how to get back to the home point. And since GPS relies on the Earth's lat./long. grid, an uncalibrated compass will certainly result in incorrect heading information.

Thanks for the reply. So basically if i record a home point, then lose GPS, I could possibly risk losing my Phantom unless i am very careful and bring it back in ATTI mode?

 

[IrishSights]

Correct

 

[Jenko1989]

Correct

Ok thanks.

 

[auen1]

Side question.
Why are 6 satellites needed?
Why not 5 or 4 or even 1?
Seems like something is better than nothing in a pinch?
Thanks!

 

[erikgraham]

RTH will not work below 6 satellites, even if you recorded a home point. Without GPS, the phantom does not know where it is and therefore does not know how to get back to the home point. And since GPS relies on the Earth's lat./long. grid, an uncalibrated compass will certainly result in incorrect heading information.

Thanks for the reply. So basically if i record a home point, then lose GPS, I could possibly risk losing my Phantom unless i am very careful and bring it back in ATTI mode?

Correct... but it's also likely that the drone will reacquire GPS lock on its own and find its way home.

 

[erikgraham]

Side question.
Why are 6 satellites needed?
Why not 5 or 4 or even 1?
Seems like something is better than nothing in a pinch?
Thanks!

My understanding is that it needs 6 for accurate 3D GPS, as in latitude, longitude, AND altitude.

 

[flyNfrank]

Ok thanks.

Where are you located?
And how high are you you going the you are still not getting 6+ satellites?

 

[MacCool]

My understanding is that it needs 6 for accurate 3D GPS, as in latitude, longitude, AND altitude.

The Phantom 2 uses barometric pressure sensors for altitude, doesn't it?

 

[justin00]

Search the forums for the gps fix using aluminium or copper tape.
Here is a link to one of the threads.. there are heaps of threads discussing it, but nothing lately.I think because DJI fixed the problem in the v3's. Is yours v3 ? If so, you don't need to do the mod.
viewtopic.php?f=27&t=19402

At the front of my house in the street I could 6-7 satts, but at the park 5 min down the road where I fly I get 10+... Could just be you don't get any in that area... ?
So your location could also be a factor, especially if you have a v3.

 

[Jenko1989]

Ok thanks.

Where are you located?
And how high are you you going the you are still not getting 6+ satellites?

I live in Worcestershire in the UK, and I was only less than 400ft high when I lost GPS. I couldn't t go higher as it told me flight limit reached. I later found Out that there is an airfield nearby (as ive never flown in this location before.)

 

[Jenko1989]

Search the forums for the gps fix using aluminium or copper tape.
Here is a link to one of the threads.. there are heaps of threads discussing it, but nothing lately.I think because DJI fixed the problem in the v3's. Is yours v3 ? If so, you don't need to do the mod.
viewtopic.php?f=27&t=19402

At the front of my house in the street I could 6-7 satts, but at the park 5 min down the road where I fly I get 10+... Could just be you don't get any in that area... ?
So your location could also be a factor, especially if you have a v3.

How do I know if I have a V3??? Sorry if that sounds silly but I really don't know.

 

[aartsf]

The most easy way to recognise a v3 is looking at the Rx that came with it. When that Rx had gimbal tilting weal on the top left hand corner its a v3; if not you don't have a v3.
An other question related to your problem though.... as you were flying in a different area than you usual fly, did yoy callebrate the compas before flying?

 

[justin00]

^^ Yip
Plus I think on your motors it will say somthing like "dji.com" and "960kv"
Whereas on previous versions the motors say nothing on them.

 

[Mako79]

^^ Yip
Plus I think on your motors it will say somthing like "dji.com" and "960kv"
Whereas on previous versions the motors say nothing on them.

+1
Get a prop out and measure the pitch. If its a 50 pitch, then its v3. if its 43 pitch then its the old.

Kidding....

Best way is to look at the motors. 2 of motor tips are black to help identify prop direction. If the the threaded part is painted entirely black then you have the v3. If you see a little black dot, then its the old version

 

[Jenko1989]

The most easy way to recognise a v3 is looking at the Rx that came with it. When that Rx had gimbal tilting weal on the top left hand corner its a v3; if not you don't have a v3.
An other question related to your problem though.... as you were flying in a different area than you usual fly, did yoy callebrate the compas before flying?

No i didn't....

 

[Jenko1989]

^^ Yip
Plus I think on your motors it will say somthing like "dji.com" and "960kv"
Whereas on previous versions the motors say nothing on them.

+1
Get a prop out and measure the pitch. If its a 50 pitch, then its v3. if its 43 pitch then its the old.

Kidding....

Best way is to look at the motors. 2 of motor tips are black to help identify prop direction. If the the threaded part is painted entirely black then you have the v3. If you see a little black dot, then its the old version

Thanks, i have the old version then.

 

[Shuether]

Another way to ID v3, on th serial number sticker on bottom mine says "V 3.0"