I would say that this thread is intended to help in finding a solution to the particular problem with weak GPS signal if it really exists.

  

I already tried to make a thread pointing out these hardware/software issues. Although it is found making some good points to debate, the thread failed because of my probably wrong approach and also because most of the active forum members own ‘healthy’ units and easily transfer the blame to human errors, which in fact has nothing to do in these particular cases.

  

I think the forum is designed both to share pleasant experiences and to point out problems and solutions.

  

I propose to follow these steps:

  

First, find out whether weak GPS signal is really an existing hardware/software issue.

  

If yes, try to determine what is causing the issue and then look for a possible solution.

  

So far we can see units, which are fast in obtaining GPS signal on ground and constantly keep strong signal during flight. However, others get signal on the ground very slowly and have trouble keeping it in flight. My experience is with a problematic one and I can say that the problem is not particularly affected by the surrounding environment or location.

  

Other similar ones are recently shared here:

  

https://forum.dji.com/thread-114785-1-1.html

  

https://forum.dji.com/thread-115609-1-1.html

  

https://forum.dji.com/forum.php?mod=redirect&goto=findpost&ptid=115948&pid=991626&fromuid=1059957

  

https://forum.dji.com/forum.php?mod=redirect&goto=findpost&ptid=115948&pid=991662&fromuid=1059957

So have you sent your flight data to DJI for analysis? This would be the first thing for me to do if I had your not so satisfactory experiences. And if your Spark has a deficiency, it will be a clear case for warranty.

If you are having trouble receiving gps, It would not be the first time a dodgy receiver or an ill fitted receiver was the cause of weak signal. But before you ship it back I think it would be worth your while testing , so first if you could get another drone similar I think I seen a thread with you demonstrating a P3 , if you still have it then maybe try making comparisons, if not then try maybe 3 locations to see if this makes any difference.

I do think that because GPS receiver in all sparks are the same then the should work the same but however environment can make a big difference.

The most common factor that interferes with a GPS signal is what is termed "Urban Canyon." The term refers to the high rise concrete buildings and skyscrapers that do not allow the signals to pass through them. These urban structures either totally block the radio signals sent by the satellites or alter their path so that they never reach the GPS servers or GPS device. Even if the signals are able to get through the buildings, they become so weak that it becomes weak for the GPS device's receiver to interpret the signal.

Several factors interfere with a GPS signal: dense clouds, dust particles, natural elements such as mountains, and even man-made flying objects, such as airplanes.

All of above must also be taken into consideration when testing along with other stuff I just can’t think of, if after all of this you should be able to conclude if you have a faulty GPS receiver in your spark.

https://forum.dji.com/forum.php? ... amp;fromuid=1089861

hallmark007 Posted at 2017-10-11 12:48
If you are having trouble receiving gps, It would not be the first time a dodgy receiver or an ill fitted receiver was the cause of weak signal. But before you ship it back I think it would be worth your while testing , so first if you could get another drone similar I think I seen a thread with you demonstrating a P3 , if you still have it then maybe try making comparisons, if not then try maybe 3 locations to see if this makes any difference.

I do think that because GPS receiver in all sparks are the same then the should work the same but however environment can make a big difference.

Here are my observations in comparison to Phantom 3:
Being at one place – flat terrain with some trees and small buildings around – P3 records the Home point about 30 seconds after turning on, while Spark is not able to record Home point at all. Sometimes it happens after a few minutes of hovering in the place at some height.
In the air P3 keeps constant 15-20 satellites lock as usual, while Spark - inconsistently 10-12 satellites and sometimes loses strong GPS signal and GPS related functions do not work. It has happened even in wide open areas:

I have observed similar performance of Spark in different locations and the number of satellites it sees is less than predicted by UAV Forecast
I also do think that GPS receiver in all sparks are the same then they should work the same but however not only by me different work is observed.
You know, my Spark has been crashed and lost (because of other reasons) and I have no opportunity to explore the problem further but I follow the topics about this issue with interest.

Whether it is possible to look for a solution other than repetitive warranty cases?

djiuser_gjLUHKA Posted at 2017-10-11 13:35
Here are my observations in comparison to Phantom 3:
Being at one place – flat terrain with some trees and small buildings around – P3 records the Home point about 30 seconds after turning on, while Spark is not able to record Home point at all. Sometimes it happens after a few minutes of hovering in the place at some height.
In the air P3 keeps constant 15-20 satellites lock as usual, while Spark - inconsistently 10-12 satellites and sometimes loses strong GPS signal and GPS related functions do not work. It has happened even in wide open areas:[view_image]

You shouldn’t need a solution if your GPS receiver is not working properly then you would need it replaced.
However if other users think that environment doesn’t play a part in weak gps then you will just have more hysteria about faulty GPS receivers.
My thinking about this is dji should educate users on why gps signal might be weak what is likely to cause it and although most of this is in the manual it needs to be presented in a much better way and similar should be done with how compass problems can arrive and correct procedures to try to prevent problems.

djiuser_gjLUHKA Posted at 2017-10-11 13:35
Here are my observations in comparison to Phantom 3:
Being at one place – flat terrain with some trees and small buildings around – P3 records the Home point about 30 seconds after turning on, while Spark is not able to record Home point at all. Sometimes it happens after a few minutes of hovering in the place at some height.
In the air P3 keeps constant 15-20 satellites lock as usual, while Spark - inconsistently 10-12 satellites and sometimes loses strong GPS signal and GPS related functions do not work. It has happened even in wide open areas:[view_image]

If you think that weak gps signal is not caused by environment, please provide more information.
To locate the problem, I would recommend you export your flight data and the black box data for us to analyze.

hallmark007 Posted at 2017-10-11 14:07
You shouldn’t need a solution if your GPS receiver is not working properly then you would need it replaced.
However if other users think that environment doesn’t play a part in weak gps then you will just have more hysteria about faulty GPS receivers.
My thinking about this is dji should educate users on why gps signal might be weak what is likely to cause it and although most of this is in the manual it needs to be presented in a much better way and similar should be done with how compass problems can arrive and correct procedures to try to prevent problems.

I think the problem with weak GPS signal is somewhat underestimated. I would not call it an exception because of the number of similar problems recently shared. We can assume that there are other users who have no idea that something is wrong due to lack of education.
All of the above gives the basis for some “hysteria” in terms of favorite hobby. :-)
I totally agree that DJI should educate users, but if they do DJI support will lose the opportunity easy to mislead customers in warranty cases. example
Fortunately, the guy was smart enough to do the right thing.

DJI Elektra Posted at 2017-10-11 18:52
If you think that weak gps signal is not caused by environment, please provide more information.
To locate the problem, I would recommend you export your flight data and the black box data for us to analyze.

Thanks for the response. My Spark is lost (it was another case, you can see here) so on board data is not available, but my app logs are synced and you can find them either by user name or by request (#721138)

  

I'm curious to hear your comments and conclusions about both of my problems i.e. the misleading, in my opinion, explanation received by DJI support, described here and the other problem with weak GPS signal.

djiuser_gjLUHKA Posted at 2017-10-12 02:02
Thanks for the response. My Spark is lost (it was another case, you can see here) so on board data is not available, but my app logs are synced and you can find them either by user name or by request (#721138)  I'm curious to hear your comments and conclusions about both of my problems i.e. the misleading, in my opinion, explanation received by DJI support, described here and the other problem with weak GPS signal.

Sorry for your lost. We will help you follow your case.

DJI Elektra Posted at 2017-10-12 02:27
Sorry for your lost. Did you contact our support and start a case? If not, please contact them first: http://www.dji.com/support. Or you can provide me the ticket number, I can help you follow the case.

I appreciate your willingness to help me.

Maybe I should be clearer. The “lost” case is completed. If you follow the links from my above post you will see that I have a request for clarification which is still unanswered. In regard to this case I only use the occasion to remind.

Regarding your request for more information about the weak GPS signal, which is actually a separate problem, the only data available is my log files from DJI GO4 app, synced with DJI servers. I have not started a case about this problem.

I got a couple of times a "no location, switch on phone GPS?" message from Go 4.
I am not sure, if that is a "trick" from DJI, to find out if I maybe block the drones GPS and wanna fly somewhere in a NFZ, but:
After switching the Phone GPS on, it seems to help the drone, to decide where it is and to find Satellites!

My guess is that DJI wanna have both systems, GPS and Glonass, strong enough for a position.
And that both of them, of course,  deliver almost the same information.
Which needs a lot of CPU power.
Anyway, you cant see more as 10 of the GPS Sats in one time, 6 is a good average, 4 is usually needed and everywhere available .
(Maybe not aside hills or in forests, cities)
So showing 17 or more, that must mean both systems are engaged.
And if then GPS changed to "No-GPS", that must be a navigation device problem!
Just my2cent, but I think it is a DJI problem!
Hardware or Software, they should know and change!

S-e-ven Posted at 2017-10-12 06:22
I got a couple of times a "no location, switch on phone GPS?" message from Go 4.
I am not sure, if that is a "trick" from DJI, to find out if I maybe block the drones GPS and wanna fly somewhere in a NFZ, but:
After switching the Phone GPS on, it seems to help the drone, to decide where it is and to find Satellites!

For gps lock you need 6 sats, so to be sure of having at least 6 you would need 11, 6 of one and 5 of another minimum.
4 is not enough to get good gps lock.

I have suffered of the same problem (weak GPS - 6-7 sats at the open field). Spark was fully unflyable. But when I turn my spark on without SD card I saw about 19-20 sats at the same place. So I have replaced my SD card and now it works OK. I AM NOT SHURE because I have made only one flight afterwards, but you should try it.

Mhhhh:
"So I have replaced my SD card and now it works OK"

I just try to think about what a SD card could have do with GPS trouble of a drone.
That would be really a crazy finding!

djiuser_gjLUHKA Posted at 2017-10-12 02:02
Thanks for the response. My Spark is lost (it was another case, you can see here) so on board data is not available, but my app logs are synced and you can find them either by user name or by request (#721138)  I'm curious to hear your comments and conclusions about both of my problems i.e. the misleading, in my opinion, explanation received by DJI support, described here and the other problem with weak GPS signal.

Sir, I have checked your case again, and here is the data analysis result:

1.The aircraft was controlled by pilot in ATTI mode due to no GPS signal.
2.T=02:15, H=1m, aircraft drifted and crashed and flight record interrupt..Before the crash pilot was pushing throttle stick upward. Then flight record interrupted.

Conclusion: The drone could not hover or brake in ATTI mode. According to the analysis, the incident was not caused by any product malfunction factors. As such, we could not provide warranty service, please kindly understand.
Attached is the screenshot of flight record for reference.

DJI Susan Posted at 2017-10-17 02:12
Sir, I have checked your case again, and here is the data analysis result:

1.The aircraft was controlled by pilot in ATTI mode due to no GPS signal.

Dear DJI Susan,

Thank you for your response.

  

I understand that DJI could not provide warranty service in this case and I accepted this. I do not claim warranty service anymore. I do not think the crash was caused by the lack of GPS signal. I made that flight knowing that the GPS signal will be weak or no and I will fly in ATTI mode. I have some experience doing this with my Phantom 3 and the conditions were favorable – weak wind about 2 m/s. (note that I am confident in my judgment about the winds because of my 15 years of experience as a paragliding pilot).

I need some more information to complete my “lesson” regarding Spark’s GPS receiver capabilities.

  

These are pictures that give an idea of the surrounding environment on this flight:

  

Is it normal for Spark's receiver not to record GPS coordinates for more than 2 minutes (according to the flight record it is Lat:0.0000000 Lon:0.0000000) while my phone, in a worse position near the rocks, shows  46.546083 N 12.066960 E

And one more question:

  

How to make a picture like this safely?

  

This is a screenshot captured from the official video presentation of Spark and in fact this photo inspired me to get Spark. Obviously it is out of range of the VPS and also the conditions are unfavorable for strong GPS signal.

  

I have done similar shots with my P3 and I know that this situation is not easy to handle. I've never been so brave to get so close to the rock. May be this is my closest one:

  

In such a situation P3 is not able to keep strong GPS signal constantly and I switch it to ATTI mode in order to avoid some GPS glitch (not possible with Spark).

I do think that the more detailed information provided in relation to both questions above will also be useful for other users.

djiuser_gjLUHKA Posted at 2017-10-17 22:57
Dear DJI Susan,Thank you for your response.  I understand that DJI could not provide warranty service in this case and I accepted this. I do not claim warranty service anymore. I do not think the crash was caused by the lack of GPS signal. I made that flight knowing that the GPS signal will be weak or no and I will fly in ATTI mode. I have some experience doing this with my Phantom 3 and the conditions were favorable – weak wind about 2 m/s. (note that I am confident in my judgment about the winds because of my 15 years of experience as a paragliding pilot).
I need some more information to complete my “lesson” regarding Spark’s GPS receiver capabilities.  These are pictures that give an idea of the surrounding environment on this flight:[view_image][view_image]  Is it normal for Spark's receiver not to record GPS coordinates for more than 2 minutes (according to the flight record it is Lat:0.0000000 Lon:0.0000000) while my phone, in a worse position near the rocks, shows  46.546083 N 12.066960 E
And one more question:  How to make a picture like this safely?[view_image]  This is a screenshot captured from the official video presentation of Spark and in fact this photo inspired me to get Spark. Obviously it is out of range of the VPS and also the conditions are unfavorable for strong GPS signal.  I have done similar shots with my P3 and I know that this situation is not easy to handle. I've never been so brave to get so close to the rock. May be this is my closest one:[view_image]  In such a situation P3 is not able to keep strong GPS signal constantly and I switch it to ATTI mode in order to avoid some GPS glitch (not possible with Spark).

According to the picture you offered, the flying environment is not ideal and the signal is easily shielded. As we know, flying in ATTI mode requires high operational skills and precise judgement of unpredictable factors.

The official video was shot by professional pilots and they made a lot of preparations before this. Maybe I'll never try this as it needs courage and heartbeat all the time.