my sympathies !!

Dear friends and even those here who dislike me: Do we really have to go back to the fundamental basics each time again? Isn't it clear to everyone here that our drones work on two satellite systems right now (GPS and Glonass) with a third one probably joining soon (Galileo)? And is there anyone here who can credibly claim not to know that a stable satellite link requires at least 6 satellites of one of these systems as an absolute minimum and that only if DJI GO 4 shows at least 11 links you can be sure to have six of either system? And it is not a secret either that the satellite links can go up or down any time during the flight. Green or red colour in DJI GO 4 naturally can only show a snapshot of any given moment that can change the next second with a low number of satellite links.

hallmark007 Posted at 2018-7-2 13:15
Then your spark is broke, because you cannot turn of VPS with spark so on weak gps it should be limited to 16ft.
If you say had 6/8 sats this does not mean weak gps, if you have 6 gps locked or 6 glonass locked your good to fly, but we have no way of knowing which we are locked on to , your graph bar is one indicator if it shows white bars you are good to fly, when it shows 2/3 only white bars you are not normally locked on.
Was your telemetry top left showing red weak gps, if not then you didn’t have weak gps ?

I was trying to simulate ATTI so i had my spark cover covered with alu foil.
So bad GPS and fly in OPTI, no problem to go higher than 5 meter.

The reason for trying  this: What will happen in ATTI mode if the OP press RTH on the RC??

In OPTI mode the result was beeping as RTH was activated, but ofcourse nothing happend to Spark because in OPTI. When i got higher GPS sats reception (grrr) so i could not do the same test in ATTI. Next time better.

If the results are the same...when users press in panic RTH in ATTI mode (we know they do) and they hear that familiar sound of RTH.....do nothing and wait to see it fly back.....not!

cheers
JJB

JJBspark Posted at 2018-7-2 13:05
Thank you, must have missed this but i had a flight today (Spark) in that second setting and was able to fly higher than 5 meters...So i have to read the Spark manual again.

There are two GPS values in the logs, number of sats and gps reception. So what does DJI mean by GPS signals....number of reception?

So what does DJI mean by GPS signals....number of reception?

That question has been asked / brought up before.  DJI never weighed in.

Get your hands on a GPS reciever that shows satellites being received and tracked, and you will see that DJI's GPS signal strength as used is misnomer or misleading.
Every satellite being received and tracked has its own GPS signal strength shown.  Garmin handheld I use has Bar graph page.  Each bar represents a GPS satellite, and height of bar the signal strength of GPS signal being received.

If I was just looking at the logs and ignoring anything that was said, my guess would be that the aircraft ran into the boat it took off from at the 26.6s point of the flight after being launched without a locked in GPS signal and causing it to be difficult to control.  

Wachtberger Posted at 2018-7-2 13:30
Dear friends and even those here who dislike me: Do we really have to go back to the fundamental basics each time again? Isn't it clear to everyone here that our drones work on two satellite systems right now (GPS and Glonass) with a third one probably joining soon (Galileo)? And is there anyone here who can credibly claim not to know that a stable satellite link requires at least 6 satellites of one of these systems as an absolute minimum and that only if DJI GO 4 shows at least 11 links you can be sure to have six of either system? And it is not a secret either that the satellite links can go up or down any time during the flight. Green or red colour in DJI GO 4 naturally can only show a snapshot of any given moment that can change the next second with a low number of satellite links.

What is needed is for DJI Corp / Engineers to specifically state:
1) Minimum  number of Satellites required
2) Whether number of Satellites shown is All GPS Sats being received regardless of whether Sats can be used -OR- only number GPS Sats being used for GPS position data.
3) Minimum number of GPS Bars required.  Accorinding to manual, More Than one bar means adequate for GPS flight.
4) What GPS Bars actually represent, because it can't be Signal Strength that is value reserved for single GPS satellite frequency being received.
Amended:
GO-4 should show accuracy of GPS fix in feet / meters, and provide maximum accuracy distance for safe GPS flight.

EDITED in Red Italic

Re GPS reception - even with 12 sats showing you can still not have the best reception ... its all to do with where they are distributed across the dome of the sky. You could for example, have one one at the zenith and the rest over to one side of the hemisphere and close to the horizon - signals strong, but lousy triangulation.... I use UAV Forecast always in preparation for a flight precisely for this reason.

JJBspark Posted at 2018-7-2 13:31
I was trying to simulate ATTI so i had my spark cover covered with alu foil.
So bad GPS and fly in OPTI, no problem to go higher than 5 meter.

So you can go as high if you start in Atti mode, so the failsafe doesn’t apply to you, only applies when you start with weak gps.

https://www.facebook.com/ABC10tv/videos/2158934771056952/

Found the video

hallmark007 Posted at 2018-7-2 14:02
So you can go as high if you start in Atti mode, so the failsafe doesn’t apply to you, only applies when you start with weak gps.

I think the manual is very clear regarding gps, strong gps blinking green on aircraft, no where in the manual does it mention 1 bar needed, this is totally incorrect and no heed must be taken from it. In the manual it clearly says white ( BAR’S) indicate adequate gps, I don’t think this can be taken to mean 1 bar, in fact I would take this to mean all bars.
So reading the manual you will see there are many different ways to check sufficient GPS

1/ white BAR’S
2/ blinking green lights
3/ numbers above lit white BARS
Not safe
1/ blinking yellow
2/ half lit bars or no lit bars
3/ no reported or low numbers above bars

I don’t think it’s a good idea for anyone to give the minimum number of satellites as this could be conflicted as Lamplighters says above, to be safe always use the maximum number and all lights lit.
We know that our GPS receiver can’t tell us which sats we have locked on to, so how are dji going to tell us this figure, if we can’t work it out ourselves, so better to be safe, take your advice from the manual, and you should be ok.

You will clearly see below your manual correctly says white BAR’S.

Streetmagus Posted at 2018-7-2 14:30
https://www.facebook.com/ABC10tv/videos/2158934771056952/

Found the video

From someone that saved all the money he could for months to be able to buy an expensive drone this is not funny at all.
$1000usd for me is a lot, glad you're rich.

Wachtberger Posted at 2018-7-2 13:02
Excellent advice, thank you JBB!

i guess you don't know very much, you just pretend.

6. GPS Signal Strength: Shows the current GPS signal strength. White bars indicate adequate GPS strength.

More than one white bar - adequate GPS strength.

Leaving one white bar as bordline?  And no bars as inadequate.

If 3 of the bar’s are grey they’re not white, I think school children would understand, I also think spreading rubbish like dji said 1 white bar is adequate is detrimental. And he changes his post again.

Post Updated to reflect - Bars with an "s".  Bars being plural, meaning more than one.   Which does not mean three bars, four bars, five bars, six bars, seven bars, eight bars, or nine bars.

What you wrote before you realized you were again giving out bad information was.

“According to the manual 1 bar is adequate to fly gps”

While that might have suited your argument, it was totally incorrect.

Fact is 99% of people can read the manual and there are many warnings as to to having strong gps when flying or take off, and they don’t seem to have any problems understanding, and if you think that those who crash are not aware of this, then you offer them very little credit for having any savvy, most people understand and have no problem understanding and for those who don’t or are not sure, maybe offering help to them might go a lot further, than trying to blame everything on the false information your putting out, but rather than help you persist on trying to blame dji on everything that goes wrong here. Because your not helping with all the whinging.

hallmark007 Posted at 2018-7-2 16:45
If 3 of the bar’s are grey they’re not white, I think school children would understand, I also think spreading rubbish like dji said 1 white bar is adequate is detrimental. And he changes his post again.

It blinks green with one white gps bar. That’s also exactly what the manual states, white bars meaning one or more. Poor gps signal the gps indicator becomes grey.

Jeff7577 Posted at 2018-7-2 17:39
It blinks green with one white gps bar. That’s also exactly what the manual states, white bars meaning one or more. Poor gps signal the gps indicator becomes grey.

It might flash green but it won’t say good to fly that’s for sure, and it says nothing in the manual about one or more bars, if someone asked you to pick up your book’s from the floor and there was five would you think that they meant one or more, or all five, there are many checks both on your telemetry and in your manual, if you can’t figure this out then maybe flying drones is not for you.

hallmark007 Posted at 2018-7-2 17:47
It might flash green but it won’t say good to fly that’s for sure, and it says nothing in the manual about one or more bars, if someone asked you to pick up your book’s from the floor and there was five would you think that they meant one or more, or all five, there are many checks both on your telemetry and in your manual, if you can’t figure this out then maybe flying drones is not for you.

They would have made it go-no-go the way you describe it. That’s not how it works.

Jeff7577 Posted at 2018-7-2 17:49
They would have made it go-no-go the way you describe it. That’s not how it works.

Maybe you might show us where it says in your manual you need one or more bars to fly gps.

hallmark007 Posted at 2018-7-2 17:28
What you wrote before you realized you were again giving out bad information was.

“According to the manual 1 bar is adequate to fly gps”

At least I acknowledged my typo / mistake.  


Unlike Drunken Troll who continues to Blow Smoke, Insult people, derail Threads, while acting like a territory marking yapping Chihuahua, insisting he is right even when his own non-sense proves him wrong, and proclaiming his expertise with - I own six drones, I am on four drone forums, and I admin one.

Admin a forum - ROFL!  Big Freak'n deal.  To technical people, especially those in field of computers, that is pathetic claim of expertise.  When you have successfully installed Web Server for Websites on multiple platforms, each with different processors, different OSs, different compilers, different library routines; then you might be able to claim some level of exertise as being a Admin of forum.  Baring in mind, most technical people do that, as an aside to their normal duties.

Streetmagus Posted at 2018-7-2 14:30
https://www.facebook.com/ABC10tv/videos/2158934771056952/

Found the video

Good research!
If this is the video from the flightlog than the motor blockage error has something to do with loosing control.Curious what DJI would make of this short flight.

cheers
JB

hallmark007 Posted at 2018-7-2 14:02
So you can go as high if you start in Atti mode, so the failsafe doesn’t apply to you, only applies when you start with weak gps.

Hi Hallmark,

See this video, weak GPS flying in OPTI higher than 5 meters, weak GPS signals.
Guess my Spark is out of tolerance.



cheers
JJB

J.G Posted at 2018-7-2 08:34
This was not the first flight, I used the 3 batteries, charged them all again, and the 4th flight this happened. I'm not a new pilot, I had the Spark for over 10 months and after saving some money upgraded to the Mavic Air.

You did take off before waiting for more satellites to lock on, looking at the flight records you were in the air between 6/7. I previous DJI drones you were able to select ATTI mode as the flight mode and this did help build up the skill level when not in GPS mode, If you have not flown before in this mode and as was the case for you the drone switched itself into this mode, the drone will just drift on its own, can be confusing did you see the waring on the screen

J.G Posted at 2018-7-2 14:35
From someone that saved all the money he could for months to be able to buy an expensive drone this is not funny at all.
$1000usd for me is a lot, glad you're rich.

From check up your flight record does not find anything abnormal.  GPS is 9 not perfect not definitely won’t cause MA drop out of sky.  Just one thing are you take off from a beach or ground with amount of dirt and sand?  That might be another reason of "Motor Obstructed” as the OTHER object jam the motor(S) when you take off.  Otherwise hardware failure like motor stop might also be another reason cause MA fall out from the sky.

JJBspark Posted at 2018-7-2 22:49
Hi Hallmark,

See this video, weak GPS flying in OPTI higher than 5 meters, weak GPS signals.

Again you are flying opti mode, opti mode is not weak gps it’s no gps, you have used something to block out gps, so if you think about it , it’s the same as me switching my P4Pro to Atti mode no gps and I can fly higher.
My understanding is simply this that in all dji drones IE P4Pro Mavic Pro Mavic Air and Spark, if you take off with weak gps there is a failsafe to keep you from going above 16ft, so if you have 2/3 satellites this will kick in and it does, you have looked at many logs and have seen , max height reached , and alt will be around 16ft.
Your test shows you always being in opti mode, now try with 2/3 satellites, so turn of your vision sensors, and you will see that your aircraft with weak gps won’t fly above as your manual says approx 30 ft.
The misconception here is . Opti mode and Atti mode are not weak gps modes , they are no gps modes. You can clearly see this on your signal bar none lit up.

HedgeTrimmer Posted at 2018-7-2 18:25
At least I acknowledged my typo / mistake.  

First I never tried to derail any thread, I simply gave my opinion and facts that were correct. I then pointed out before you edited any post. That nowhere in your manual did it say it’s ok to fly gps with one single bar showing.

What you have asked dji to do regarding the manual is this.

They need to specify, what an open area is , they need to give measurements for both rural and urban.
My opinion most people with any modicum of sense when flying a drone knows what an open area is.

You then asked that manual be given the minimum distance that you could take off from concrete structures, metal structures and any other likely interferences, in the world.
Again most people with any savvy can work this out for themselves and if that wasn’t so then we would see many more crashes.

Your now telling us dji should tell us exactly the minimum number of satellites and what type before we can take off, yes this would be great but not possible with these drones now, so not relative to OP’s case.

You bring it on pretty thick about the tech we should have in these drones, while I prefer to talk about the tech we have now in these drones.

Most people here are hobbyists, we all take up hobbies for the challenges they offer, if tech was able to allow you fly these drones from your armchair without moving your butt , then we would see a real demise from the hobbyists using these now.

Most hobbies will have elements of human error, after all we are humans and to error is part of our DNA, and so what.
We like machines because they are challenging sports because they are challenging, and drone flying because it is challenging, if you remove the challenge, then you won’t have the interest.
Case in point JB Spark above loves the challenge of how he can try to change the boundaries of his spark. If he couldn’t, I’m certain he would do something else.

We are continually being told by more experienced people vloggers, not to place our trust in this technology completely, and this is sound advice.
Learn the mechanics, learn how your aircraft works for you, learn how to fly correctly, become better at what you do, not what technology does for you.

This is a hobby for humans, human error is bound to happen, learn from it and move on to better things, if you remove the human aspect from it, you won’t have a hobby.

So maybe try to teach others what you know about the technology that they have,  not the technology you would like them to have.

To err is to be human.

Good Luck.

hallmark007 Posted at 2018-7-3 02:31
Again you are flying opti mode, opti mode is not weak gps it’s no gps, you have used something to block out gps, so if you think about it , it’s the same as me switching my P4Pro to Atti mode no gps and I can fly higher.
My understanding is simply this that in all dji drones IE P4Pro Mavic Pro Mavic Air and Spark, if you take off with weak gps there is a failsafe to keep you from going above 16ft, so if you have 2/3 satellites this will kick in and it does, you have looked at many logs and have seen , max height reached , and alt will be around 16ft.
Your test shows you always being in opti mode, now try with 2/3 satellites, so turn of your vision sensors, and you will see that your aircraft with weak gps won’t fly above as your manual says approx 30 ft.

Hi Hallmark,

How does my Spark knows that i try to block its GPS. No, it doesn`t know that ofcourse.
So when i start my Spark and have weak GPS (as i had) it will use its VPS sensors thus OPTI mode.

So OPTI mode is not weak gps and its not a gps ( i agree with your) but OPTI mode is automatically ON when GPS signals are weak. Try to fly inside your house  ; no or weak GPS and stable flying cause in OPTI.
So i cannot understand you logic and arguments.

Manual say i cannot fly higher than 5 meters (als VPS is always active on Spark).

cheers
JJB

JJBspark Posted at 2018-7-3 03:10
Hi Hallmark,

How does my Spark knows that i try to block its GPS. No, it doesn`t know that ofcourse.

First forget about opti mode, opti mode only works when there is no gps. How does your spark know you blocked gps, this you can see clearly in your video, No signal bars lit up, it means only that you have no gps signal, why because you blocked it.
Your right the spark can’t know that you went to the store to buy tape to blindfold it’s gps, I mean how could it :+) .

Try flying indoors with no gps covered, you will see your spark opt out of opti to gps as your drone picks up gps and this is normal and fine.

If your on the ground and gps is not covered, as soon as any gps is picked up your telemetry will change from opti to gps, this does not mean vision sensors are not working it just means your aircraft has picked up gps and now replaces opti mode with gps, and this will be seen both in your bar graph and numbers above.

If at this point you take off with low numbers let’s say 4 , then failsafe will kick in and limit altitude of your flight until you receive enough satellites, we have seen this many times particularly with spark, so we know it works.

Your challenge is to try take off with low satellites signal and then see if your aircraft can go above failsafe height.
So if your up for it, I’d suggest you go to location IE under the cover of trees where it is likely you will receive low sat count then try and see what happens. If your really brave enough then I suggest using your Mavic Air , you can also test with vision sensors off.

“The person who follows the crowd will usually go no further than the crowd. The person who walks alone is likely to find himself in places no one has ever seen before.”

hallmark007 Posted at 2018-7-3 03:30
First forget about opti mode, opti mode only works when there is no gps. How does your spark know you blocked gps, this you can see clearly in your video, No signal bars lit up, it means only that you have no gps signal, why because you blocked it.
Your right the spark can’t know that you went to the store to buy tape to blindfold it’s gps, I mean how could it :+) .

Your explanation of indoor flying is correct, i know that. (wish my ceiling was 6 meter high..)

In my test i got into the hover and higher with few sats and reception low.
So fail safe will kick in as you write, well i did not.

I will take this challenge as you call it, no probs to do that.

BTW the reason why i try this is because i think there is a 'error' in the drone software. Ever try to press RTH in OPTI / ATTI mode? Your RC is gonna to beep like it activates the RTH action. ofcourse it does`n do that!  But what if users think, ok let`s wait and see when it return to HP. And we all know that doing nothing in ATTI mode is 'killingly' wrong.

And yes i have been to places where no one ever was before  

JJBspark Posted at 2018-7-3 03:10
Hi Hallmark,

How does my Spark knows that i try to block its GPS. No, it doesn`t know that ofcourse.

Look at it like this.

You have 3 flying modes on your spark. GPS, OPTI, ATTI.
All of these modes work independently, yes they can change, drop from gps to opti to Atti , but opti mode won’t work with or alongside gps mode, so they don’t work together.

You took off and stayed in opti mode, opti mode is not weak gps mode, it’s just opti mode, because you had gps signal blocked it was impossible for aircraft to switch between opti and gps.

If in your case you went above 30ft or outside opti range your aircraft would now enter Atti mode, bring it lower and it should enter Atti mode.

What the manual explains is , there is a failsafe for low or weak gps, nothing to do with opti as it is not a weak gps mode, so you were in opti not weak or low gps, so your aircraft will not enter failsafe.

JJBspark Posted at 2018-7-3 03:10
Hi Hallmark,

How does my Spark knows that i try to block its GPS. No, it doesn`t know that ofcourse.

Look at it like this.

You have 3 flying modes on your spark. GPS, OPTI, ATTI.
All of these modes work independently, yes they can change, drop from gps to opti to Atti , but opti mode won’t work with or alongside gps mode, so they don’t work together.

You took off and stayed in opti mode, opti mode is not weak gps mode, it’s just opti mode, because you had gps signal blocked it was impossible for aircraft to switch between opti and gps.

If in your case if you went above 30ft or outside opti range your aircraft would now enter Atti mode, bring it lower and it should enter Atti mode.

What the manual explains is , there is a failsafe for low or weak gps, nothing to do with opti as it is not a weak gps mode, so you were in opti not weak or low gps, so your aircraft will not enter failsafe.

hallmark007 Posted at 2018-7-3 03:49
Look at it like this.

You have 3 flying modes on your spark. GPS, OPTI, ATTI.

I know this. But if i start my Drone and i have a weak GPS it will go into OPTI.
So when does your weak GPS mode and fail safe height kick in ?

When i start to fly in GPS mode, keep below 5 meter and GPS signal gets weak....than the fail safe height becomes active?

My GPS sinnal was kind of blocked, when i got higher it switched to GPS mode (must be the reflections via the ground reaches the drone)
So your statement that it cannot switch is not correct.

Better stop this discussion Hallmark, i come back when i have it tested under trees.

cheers
JJB

JJBspark Posted at 2018-7-3 03:41
Your explanation of indoor flying is correct, i know that. (wish my ceiling was 6 meter high..)

In my test i got into the hover and higher with few sats and reception low.

You need to look at your telemetry and use your manual, your telemetry clearly shows No gps and your manual also tells you if bars are not lit you have no gps signal, those 7/8 gps are only numbers not signal, if you choose to fly with only numbers showing in grey and all signal bars grey, then you are in for a rough flight, you signal bars are your barometer for having or not having gps, not your numbers, as shows on your log.

How many times have you looked at flight logs and seen 15 sats but grayed out, telling you no signal was being received, and this is the very same in your log above.

hallmark007 Posted at 2018-7-3 03:58
You need to look at your telemetry and use your manual, your telemetry clearly shows No gps and your manual also tells you if bars are not lit you have no gps signal, those 7/8 gps are only numbers not signal, if you choose to fly with only numbers showing in grey and all signal bars grey, then you are in for a rough flight, you signal bars are your barometer for having or not having gps, not your numbers, as shows on your log.

How many times have you looked at flight logs and seen 15 sats but grayed out, telling you no signal was being received, and this is the very same in your log above.

I can tell you that the gray bars in the GoApp not always tell the same as the data written in flightlogs etc.
I had a GPS reception of 2 (scale 1-  5). See my chart in the previous post.

I feel your pain. My first Air was lost to water a week after I got it, and I put my second on in a lake recently as well (thankfully the second one I could recover and send back for warranty replacement).

JJBspark Posted at 2018-7-3 03:54
I know this. But if i start my Drone and i have a weak GPS it will go into OPTI.
So when does your weak GPS mode and fail safe height kick in ?

That’s wrong if you start your drone it will first go to opti mode if there is no gps if there is weak gps it will warn you of this.
Your spark couldn’t go to weak gps because you had it blocked, so failsafe doesn’t come into the equation, as I said try taking off with weak gps not opti mode and then you will see failsafe kick in, it as it point out in the manual is for weak gps, not opti and opti is not weak gps, opti .
Yes your aircraft may drop down from weak gps to opti, but failsafe height should still have kicked off because you took off in weak gps, if you gain more gps failsafe will go away. It also has to be said that we have seen this working and it does work, whether it can be fooled, I haven’t tried, but your test also doesn’t prove it as a proper test.

hallmark007 Posted at 2018-7-3 04:12
That’s wrong if you start your drone it will first go to opti mode if there is no gps if there is weak gps it will warn you of this.
Your spark couldn’t go to weak gps because you had it blocked, so failsafe doesn’t come into the equation, as I said try taking off with weak gps not opti mode and then you will see failsafe kick in, it as it point out in the manual is for weak gps, not opti and opti is not weak gps, opti .
Yes your aircraft may drop down from weak gps to opti, but failsafe height should still have kicked off because you took off in weak gps, if you gain more gps failsafe will go away. It also has to be said that we have seen this working and it does work, whether it can be fooled, I haven’t tried, but your test also doesn’t prove it as a proper test.

nah, my GPS receiver does not know why its not getting enough signals! Because of bad or weak signals or because signals could not reach the receiver (also bad or weak signals).

So this sentence is really wrong thinking , your "Your spark couldn’t go to weak gps because you had it blocked"

Spark GPS receiver acts on getting signals or not, not on the reason why it does not get signals.

JJBspark Posted at 2018-7-3 04:05
I can tell you that the gray bars in the GoApp not always tell the same as the data written in flightlogs etc.
I had a GPS reception of 2 (scale 1-  5). See my chart in the previous post.

In order for gps to be available in your drone you need to be in gps mode, if your not then your in some other mode.

Case in point I take off with P4Pro, in Atti mode, my gps signal bar graph shows all lights out , gps is switched off, above my graph I can clearly numbers going up but I’m operating without gps signal, but it lets me know that their are 14/15 satellites available if I need to switch from Atti to gps, this was and is very similar to your test, except I imagine you blocked the signal from tracking most of available satellites, so your numbers show low count.