Aardvark Posted at 2018-10-23 16:33
I'm not sure if this has been covered already, but you do have 'Show flight route' enabled in 'General Settings' menu ?
Also 'Cache Map in the Background' might help.

Checking the setup for Go4... Show Flight Route is on (switch is to the right and green).

The only cache option below that item is 'cache locally when recording' under video cache. I can't find any map cache option.

The interesting thing is, when I power up the CS by itself and launch Go4, I get a map and a home point within SECONDS. Baffling.

Mark Weiss Posted at 2018-10-24 06:47
Checking the setup for Go4... Show Flight Route is on (switch is to the right and green).

The only cache option below that item is 'cache locally when recording' under video cache. I can't find any map cache option.

You could try updating to latest firmware for P4P V2, there might be some fixes there that would help when CS connected to RC.

https://dl.djicdn.com/downloads/ ... elease_Notes_EN.pdf

Aardvark Posted at 2018-10-24 06:55
You could try updating to latest firmware for P4P V2, there might be some fixes there that would help when CS connected to RC.

https://dl.djicdn.com/downloads/phantom_4_pro/20181024/Phantom_4_Pro_V2.0_Release_Notes_EN.pdf

I saw that there was an update available, but read that it caused problems with the video transmission quality so I decided if it ain't broke, don't fix it.
The other concern is I don't know if the new FW further decreases the aircraft's areas where it's able to fly (geofencing).
These update notes make no mention of the home point problem.

Mark Weiss Posted at 2018-10-24 11:10
I saw that there was an update available, but read that it caused problems with the video transmission quality so I decided if it ain't broke, don't fix it.
The other concern is I don't know if the new FW further decreases the aircraft's areas where it's able to fly (geofencing).
These update notes make no mention of the home point problem.

"so I decided if it ain't broke, don't fix it."

But I thought it was broken, hence problems with maps etc ?

The update would be the first thing to try, as it was only released yesterday/today there can't be too many reliable reports on it yet. And the geofencing is likely to be more accurate with each release. As the home point problem only seems to affect the setup you have then it would be worth trying.

Aardvark Posted at 2018-10-24 11:54
"so I decided if it ain't broke, don't fix it."

But I thought it was broken, hence problems with maps etc ?

I tried downloading the map section where I fly for offline use. Will see if that makes a difference next flight.

Since the update says it is not reversable, I am hesitant to risk having something change that might cause me to lose the ability to fly where I live.

Mark Weiss Posted at 10-24 16:45
I tried downloading the map section where I fly for offline use. Will see if that makes a difference next flight.

Since the update says it is not reversable, I am hesitant to risk having something change that might cause me to lose the ability to fly where I live.

I did some experimenting in the past week. I noticed that when the Go4 app has internet access, I get a home point on the screen and a flight path. When it doesn't, I get nothing and can only tell where the AC is by VLOS.
When I flew up at S. Kent last Sunday, I brought my cell phone and turned on the wireless tethering so that Go4 on the controller would have internet access. Lo and behold, I got a "home point recorded" and saw a flight path and blue dot with a H in the center.
It seems that this feature only works when internet is available. No internet, no flight path.

I don't fly with Go4, but I suspect your mobile device didn't have a GPS fix.  My Go app on my tablet without a GSM card for my P3P works wonderfully showing the flight path in the middle of hillbilly Deliverance country without a wifi signal for miles.  

Mark The Droner Posted at 11-8 18:14
I don't fly with Go4, but I suspect your mobile device didn't have a GPS fix.  My Go app on my tablet without a GSM card for my P3P works wonderfully showing the flight path in the middle of hillbilly Deliverance country without a wifi signal for miles.

Goddamit, now theres that tune in my head and a squealing pig......

Makes me wonder if the Tablet has GPS capability switched off or even available ?

If an APP only gets location when Internet / phone is linked to the tablet - this often means Tablet has GPS capability disabled .. the phone then supplies GPSa data ... based on GSM triangulation augmented by GPS input ..

Nigel

solentlife Posted at 11-9 05:36
Makes me wonder if the Tablet has GPS capability switched off or even available ?

If an APP only gets location when Internet / phone is linked to the tablet - this often means Tablet has GPS capability disabled .. the phone then supplies GPSa data ... based on GSM triangulation augmented by GPS input ..

If an APP only gets location when Internet / phone is linked to the tablet ...
You are forgetting that the app gets GPS data from the Phantom.

The 'tablet' is a DJI Crystal Sky Ultrabright. It has GPS built in. But the GPS locations comes from the Phantom, not the tablet.

Hunch: if no map is available (no internet), Go4 doesn't display a home point or flight path.

Labroides Posted at 11-9 06:33
If an APP only gets location when Internet / phone is linked to the tablet ...
You are forgetting that the app gets GPS data from the Phantom.

No not actually forgotten ...

The Tablet also gets its own GPS data for various functions that needs both AC and Tablet to have location details.

The reason I mentioned the fact of GPS capability of tablet - is his post saying only Home Point etc. is recorded / made when network is connected ... which is of course a confusing item ... as I agree Home Point should be recorded based on AC GPS data ... not internet or GSM ...

Nigel

solentlife Posted at 11-9 07:43
No not actually forgotten ...

The Tablet also gets its own GPS data for various functions that needs both AC and Tablet to have location details.

'The Tablet also gets its own GPS data for various functions that needs both AC and Tablet to have location details.'

Certain models of iPads do not have any GPS receiver, but still function perfectly well with any of the Phantom models.

I think its 5

Geebax Posted at 11-9 14:59
'The Tablet also gets its own GPS data for various functions that needs both AC and Tablet to have location details.'

Certain models of iPads do not have any GPS receiver, but still function perfectly well with any of the Phantom models.

True and not in contention ...

If you want to do follow-me etc. - then GPS capability is needed on the tablet.

As we read more posts - its getting clearer that the GPS data is not being picked up from AC to RC - and so for GO.
Why would GO then show Home Point etc. when internet / network actioned ? Doesn't make sense as the Adv and Pro are cable connected.

BUT now we read Crystalsky ..... so many posts around the internet complaining about the Crystalsky ..

Nigel

Christine96 Posted at 11-9 15:05
I think its 5

It's not 5 and the answer isn't as simple as a single number.
To find out, read post #4

solentlife Posted at 11-10 02:35
True and not in contention ...

If you want to do follow-me etc. - then GPS capability is needed on the tablet.

its getting clearer that the GPS data is not being picked up from AC to RC - and so for GO.
Why would GO then show Home Point etc. when internet / network actioned ? Doesn't make sense as the Adv and Pro are cable connected.
Nothing is clear.
The OP is convinced that his Phantom's GPS doesn't work in overcast weather.
He's not a great source for accurate information.

Labroides Posted at 11-10 03:18
It's not 5 and the answer isn't as simple as a single number.
To find out, read post #4

I'm still not convinced post #4 is correct - it seems to be more of an assumption which could be valid or invalid.  I'd be happier to see some sort of evidence.  For example, a log that shows 10 or 11 satellites and no fix.  

I kind of like msinger's assessment - forget about the number and worry about the 4 bars showing "strength."  In other words, the number of satellites not something we need to dwell on.  

Mark The Droner Posted at 11-10 04:07
I'm still not convinced post #4 is correct - it seems to be more of an assumption which could be valid or invalid.  I'd be happier to see some sort of evidence.  For example, a log that shows 10 or 11 satellites and no fix.  

I kind of like msinger's assessment - forget about the number and worry about the 4 bars showing "strength."  In other words, the number of satellites not something we need to dwell on.

It's not an assumption.
The Phantom's GPS doesn't mix and match GPS + Glonass
It needs 6 of one type or the other to have a good GPS position fix.

Labroides Posted at 11-10 08:07
It's not an assumption.
The Phantom's GPS doesn't mix and match GPS + Glonass
It needs 6 of one type or the other to have a good GPS position fix.

Yeah - the problem is there is no evidence to support this other than the last generation's satellite fix strategy.  

Labroides Posted at 10-2 13:57
Your P4 pro receives signals from US GPS satellites and Russian Glonass satellites.
To get a good GPS location fix, it needs to have 6 satellites of one kind.
The display in the app does not show the split between US and Russian satellites.

Very interesting.  Would never have thought that different satellite source would matter.  We live and learn.

Mark The Droner Posted at 11-13 15:32
Yeah - the problem is there is no evidence to support this other than the last generation's satellite fix strategy.

Can you think of a better explanation for Phantoms having 8 or 9 sats before they get GPS-Ready to Go?

Labroides Posted at 11-15 01:58
Can you think of a better explanation for Phantoms having 8 or 9 sats before they get GPS-Ready to Go?

Of course.  4+4.  See post #8.  For example, my Trackimo only requires 4 GPS satellites.  

Mark The Droner Posted at 11-15 04:13
Of course.  4+4.  See post #8.  For example, my Trackimo only requires 4 GPS satellites.

Sorry ... it doesn't work that way.
Go back and check post #4

I've just got back home after a grueling trek nursing my vehicle actoss Europe ! It decided to split a hose or something and 2 ltrs water every hour is not funny !!

Anyway - reading the posts above ... mmmmm USA GPS + Glonass .... do they compliment each other or are they separate for GPS use on the AC ? Having wanted to know answer to this before ... I can say that I could find no actual statement clearly defining this from DJI or any other source that can be taken as Definitive proof. All you find is claims by non DJI people with no actual data to prove the case.

Personally - I cannot see why DJI would separate the two systems ... near all other dual Sat systems i use ... Lowrance .. Raytheon / Garmin .. Trimble ... etc. all amalgamate the systems to obtain best results.
One avenue I find interesting - is that the Indian and Chinese systems are not used and that includes many other Sat systems outside of Drone use. I agree that they are still being deployed to create the coverage required - but they are active.

Its actually a relatively mute point anyway - as Glonass is limited in its overall coverage and always likely to be re-directed depending on Russian 'activity' at that time.
Its also not always correct that having both GPS and Glonass gives higher accuracy of fix ... because the systems do not use ALL sats seen ... the systems reject a number based on data errors, position error etc. Just because you see a 12 ... 15 sat number ... does not automatically mean all are used for calculation.

So far I have been over significant time trying to find out what is the actual channel capability of the P3P ... and so far I have only found mention of 8 ch's but nothing stated by DJI themselves. If the number is 8 ... then it is certainly rejecting many sats it see's ... (8 ch does not mean it only locks to 8 ... depending on the module - it can be that it uses 8 to calculate position ... ).

Nigel

All you'd have to do is take a 4 satellite fix from glonass, take a 4 satellite fix from GPS, and then take the median location.  Shazaam, you have a fix from both systems.  It ain't that complicated.  If DJI is smart enough to invent Lightbridge and Occusync, they're probably smart enough to calculate a median location from two systems.  So there you would have a fix, and it would be a "weak" fix, so they'd show only three bars or whatever.  But it would work.  

Mark The Droner Posted at 11-16 03:56
All you'd have to do is take a 4 satellite fix from glonass, take a 4 satellite fix from GPS, and then take the median location.  Shazaam, you have a fix from both systems.  It ain't that complicated.  If DJI is smart enough to invent Lightbridge and Occusync, they're probably smart enough to calculate a median location from two systems.  So there you would have a fix, and it would be a "weak" fix, so they'd show only three bars or whatever.  But it would work.

Hi Mark ...

Yes ... but trouble is DJI do not publish what they actually do with the Sat locks ... they happily say GPS + Glonass ... and nothing else.

At least Lowrance / garmin and so on actually tell you how many sats and channels used.

Its interesting that my old Magellan machine from the very early days of GPS - had 8 ch's ... my later gear I use now is 21+ ... but it also says that it will iterate 21 but reject those outside of range ... so actually positions are given based on 4 up to 12+ sat data ... (when you get into the high end GPS plotters - this is what they do....)

DJI choose not to give out the info. As far as my searching shows anyway

Nigel

Yes.  But some are insisting it's absolutely no less than 6 of one or the other or both - and they are stating it as fact without any evidence.  That's what we call an assumption or a theory.  It's not a fact unless we have evidence for support.  

Anyway, it's not a big deal in the great scheme of things.  DJI's current satellite fix system, however it's designed, works very nicely regardless.  

Mark The Droner Posted at 11-16 06:26
Yes.  But some are insisting it's absolutely no less than 6 of one or the other or both - and they are stating it as fact without any evidence.  That's what we call an assumption or a theory.  It's not a fact unless we have evidence for support.  

Anyway, it's not a big deal in the great scheme of things.  DJI's current satellite fix system, however it's designed, works very nicely regardless.

I agree with you.

I hate when those who do not agree with an explanation - require one to prove a theory or statement - it usually means they are lost to disprove it ... so they throw the ball over the fence ..

Trouble is here - we have no evidence I can find to support either way ... DJI themselves as seen with so much - do not publish data. If you ask them - they just refer to written specs which still does not answer it ..

As you say - the system works and that's the crucial part.

If someone can actually link to DJi information to clear this up - great .... but until then its opinion only.

Cheers
Nigel

This might help explain the mystery of gps.

hallmark007 Posted at 11-16 15:55
This might help explain the mystery of gps.

https://youtu.be/i-CnCM0iEpk

That explanation has some misleading or confusing parts.
He says you can get a sat array like this illustration in a perfectly open area

That's not going to happen at all.
Some sats may be close and that's the reason DJi wouldn't accept a fix from 4 sats with the old GPS sats only drones.
They wanted an extra two to ensure that there was a spread and the resulting fix would be of good quality.
But because the sats are deployed to provide global coverage you'll never see that many in the same part of the sky.

He also says twice that a sudden loss of GPS could cause the aircraft to start moving by itself uncontrollably.
That's quite wrong.
On sudden loss of GPS, the drone would find itself in atti mode and still quite controllable and it's not going to do any moving by itself.
The only movement would be caused by wind blowing it.

Guys, sorry to say but, this cloudy day lark is real, not speaking for my Phantom perse but i suppose on a whole, as you know, i have mentioned about  my phone gps in my car being weak and thats due to the tint in my windscreen. There are days when i do not get a signal and days  when i do and days when its after i get away from the forest,  i have never put any thought to it as to why until this past week. Tuesday i had to go pick sommat up and it was a clear sky and my note 5 gps worked great, yesterday and wednesday morning it didnt work at all and both drives were in overcast conditions, theres no other variable that i am aware of, just thick overcast. i have to go out again later today and its meant to be clear, if it works ok then overcast weather does have a bearing on gps signal to a certain extent, that extent being if you already have a poor signal due to what ever reason in the 1st place. Ridicule me all you like, I am going by real events, i would record them but erm, its also my only camera now as i sold my note three yesterday morning hence one of the journ..... wait a minute, i have my S2's as well and  K1 lol i will use them is evidence is required mmm, might be a tad hard seen as i will be driving lol, i will think of sommat

Bashy Posted at 11-16 19:53
Guys, sorry to say but, this cloudy day lark is real, not speaking for my Phantom perse but i suppose on a whole, as you know, i have mentioned about  my phone gps in my car being weak and thats due to the tint in my windscreen. There are days when i do not get a signal and days  when i do and days when its after i get away from the forest,  i have never put any thought to it as to why until this past week. Tuesday i had to go pick sommat up and it was a clear sky and my note 5 gps worked great, yesterday and wednesday morning it didnt work at all and both drives were in overcast conditions, theres no other variable that i am aware of, just thick overcast. i have to go out again later today and its meant to be clear, if it works ok then overcast weather does have a bearing on gps signal to a certain extent, that extent being if you already have a poor signal due to what ever reason in the 1st place. Ridicule me all you like, I am going by real events, i would record them but erm, its also my only camera now as i sold my note three yesterday morning hence one of the journ..... wait a minute, i have my S2's as well and  K1 lol i will use them is evidence is required  mmm, might be a tad hard seen as i will be driving lol, i will think of sommat

Despite your interpretation of observations, GPS is an all-weather navigation system.
It works in torrential downpours, it works at night and it works on cloudy days.
It really does,
If you are having issues, you need to look further to find the cause because it's not the colouds.

hallmark007 Posted at 11-16 15:55
This might help explain the mystery of gps.

What a load of 'crock' !!

He goes from a perfectly reasonable and correct foundation of HDOP to a mixed up bag of b******t !!

Lets put one point to bed ... ONLY when it was Transit did you have bunching or loss of differential position of sats ... with the later GPS system - that does NOT happen .. as each has a definite path that creates a 'framework' of evenly spaced sats that circle the earth. You would have to be in extremely high latitude to even get close to any low HDOP factor.

Shame .. the video started good and then fell apart ...

Nigel

solentlife Posted at 11-17 01:00
What a load of 'crock' !!

He goes from a perfectly reasonable and correct foundation of HDOP to a mixed up bag of b******t !!

I think calling something that is basically a good piece of work a crock is fine, but from what I read here it’s not alone and your not completely devoid of that yourself, there are many contradictions on this thread. Not everyone here is right all the time and don’t discount yourself from that.

Labroides Posted at 11-16 19:34
That explanation has some misleading or confusing parts.
He says you can get a sat array like this illustration in a perfectly open area
[view_image]

While I agree yes it’s not out of control, I think he was referring to bad conditions and inexperienced pilots. And maybe should have said not controllable for some, but the message is not the worse message to put out, he did mention could.
While you say dji drones need 6 sats to be safe to fly, then if that’s the case with a mix of glonass and gps this would only guarantee 5 of one type, which would leave controller needing a total of 11 to guarantee he has 6 sattlites and not 10 .

Labroides Posted at 11-16 21:40
Despite your interpretation of observations, GPS is an all-weather navigation system.
It works in torrential downpours, it works at night and it works on cloudy days.
It really does,

I have already explained that i have a weak signal due to the windscreen, when its cloudy i have no GPS reception for my phone, when its clear skies, i have a signal, you cannot dispute this, you are not here to see the effects, just because it works flawlessly for yourself does not mean it does for everyone, other people have an opinion and based on FACTS, you have to respect this.
PS, we all know for a fact that water molecules can effect the signal, not by a lot granted, but in my case and by the looks of it, it is the same as Marks, our windscreen reduces the signal considerably, enough so that when it is overcast, be it higher cloud or low cloud (aka fog) it is obviously enough to add to the winscreen effect and totaly stop the signal.

I think it helps to remember that the number of visible satellites in the sky vary hour by hour.  So you can't make any conclusions based on clouds, rain, sunshine, etc., without also knowing what the actual number of visible satellites is at a given time.  

Fact is, this conversation about the weather and GPS has been going on in dozens of threads for half a decade or more.  I used to think clouds and rain interfered too.  I was wrong.  Research it.  Clouds/rain don't block the GPS signal.  That's a hard fact.  

Bashy Posted at 11-17 03:40
I have already explained that i have a weak signal due to the windscreen, when its cloudy i have no GPS reception for my phone, when its clear skies, i have a signal, you cannot dispute this, you are not here to see the effects, just because it works flawlessly for yourself does not mean it does for everyone, other people have an opinion and based on FACTS, you have to respect this.
PS, we all know for a fact that water molecules can effect the signal, not by a lot granted, but in my case and by the looks of it, it is the same as Marks, our windscreen reduces the signal considerably, enough so that when it is overcast, be it higher cloud or low cloud (aka fog) it is obviously enough to add to the winscreen effect and totaly stop the signal.

I don't have to respect the  fact that you are thick as a brick.
If you have your GPS in a place where it's signal is blocked by whatever it is in your car or windscreen, don't blame the weather.
It's where you have the GPS that's your problem.
GPS really, really is an all-weather navigation system and it works perfectly for anyone that doesn't try to use it in your car.

How pointless would it be to spend billions of dollars on a global navigation system for planes and ships if it didn't work on cloudy days?
Really?
I can't think of anything that would be more stupid.

To give an idea of how resilient GPS signal is :

My seagoing yacht has both Lowrance and Magellan GPS units. The Lowrance is a modern day multi channel plotting unit - the Magellan is the old handheld unit with swivel antenna ... some may remenber both Magellan and Garmin sold such units many years ago.

My yacht has solid GRP cabin sides and top (deckhead) ... average 20mm thick ... not a foam or balsa cored construction as many newbuilds are.

BOTH GPS work fine with antenna's INSIDE the cabin ... in fact my Lowrance - my primary system only has the antenna propped up on the 'curtain rail' !!

I've sailed her in storms, heavy rain, basically all except hurricane force and NEVER had any loss of GPS performance.

I have TOMTOM and iGO in my vehicles with old and new sat tablets ... (I believe in belt and braces when driving across Europe !) .... never seen any difference regardless of weather.

Nigel