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Author Topic: Problems with receiving GPS signals  (Read 38260 times)

Longjog @ GS-Sport-Servicecenter

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Re: Problems with receiving GPS signals
« Reply #30 on: May 21, 2010, 03:51:07 am »

Hi Longjog,
....
We have implement the special alogrithm to compensate when at weak signal. You may see the training file with no problem.
Do you mean Firmware 2.0 or do you have improved it? Please mail the improved firmware to me, if you have it.
Very problematic is loosing GPS-fix while training or worse while competition.

Comparing to Sunnto and Casio GPS watch, it is much better. And users never complain them.
In Germany Garmin is most popular. Many people didnīt know there are alternatives. And itīs not easy to assert against Garmin. They have many fans.
Globalsat has to compare with Garmin and not with the others. And itīs not good to say "The others have problems there and we too, but less".

Thanks for your advice again, we will keep progessing and providing the best services to you.
I love it and I say thank you for your support! ;)

Happy weekend

Longjog
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Germany

Hubert

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Re: Problems with receiving GPS signals
« Reply #31 on: May 21, 2010, 04:10:50 am »

Hello all,

once again the GH-505 failed  >:(

Dear Hubert,

do you think the reason is only the very bad weather at the moment in Germany? ::)
I see, you are making the same experiences as I.
Hi all,

No - I'm sure the weather isn't the problem !
I'm sure, because I had my GH-625 with me also. And 625 didn't have those problems.
And weather was the same for both  ;)

Regards, Hubert
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GH-625XT, Firmware: F-GGH-2P-1112231 (Beta)
GH-505 M, Firmware: F-GGH-2C-1007161 (Beta)
GH-625 M, Firmware: F-GGH-2A-1001073 (Version XII)
with GS-Sport Gym Pro v1.6.8 and Sporttracks 2.1.3326

TWG_TECH8

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Re: Problems with receiving GPS signals
« Reply #32 on: May 21, 2010, 05:53:46 am »

Hello,
Can bad weather or Galileo really be the reason? I haven't had any problems getting satellite fix in Sweden with my GH-505, it is even faster then the GH-625!

Sincerely,
Jonas
Hi Jonas, you are a happy man ;)
Weather could have bad influence of GPS-quality. Galileo was only a joke  :o. I think it has to do with the new (smaller) antenna for GPS in GH505 (Geoffrey explained to me).
But it is really not fine that problems somtimes come and go. It was not nice to run marathon competition with GH505 which lost its function after a while and next day everything was okay again. The watch needs to be reliable, if itīs not, who would buy this? Iīm hopeing this problem can be solved.

Regards

Longjog

Hi Longjog,

I have tested at stationary under clear sky, it needs under 1 minute to get fix. But needs ten minutes while in running to get first fix.
We have implement the special alogrithm to compensate when at weak signal. You may see the training file with no problem.
Comparing to Sunnto and Casio GPS watch, it is much better. And users never complain them.
Thanks for your advice again, we will keep progessing and providing the best services to you.

Sincerely,

Geoffrey
As current GH-615 user I don't like compare Suunto or Casio (at least Suunto is very well known about problems with GPS accurancy) because my GH-615 is so good especially with GPS features. I don't like purchace device which would be worse than current one or for example Garmin.
If user compare GH-505 to some other whatch, I'm pretty sure that it would be current GS models or Garmin

Rookie

Hi Rooki,

Thank you for advice. GH-505 built-in FIFA antenna, even small but has superior receiving performance.
Since it has wide receiving direction (omni-direction), wear on hand will have good performance and put on bike mount the performance will be much better.

Sincerely,

Geoffrey


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TWG_TECH8

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Re: Problems with receiving GPS signals
« Reply #33 on: May 21, 2010, 06:00:58 am »

Hi Longjog,
....
We have implement the special alogrithm to compensate when at weak signal. You may see the training file with no problem.
Do you mean Firmware 2.0 or do you have improved it? Please mail the improved firmware to me, if you have it.
Very problematic is loosing GPS-fix while training or worse while competition.

Comparing to Sunnto and Casio GPS watch, it is much better. And users never complain them.
In Germany Garmin is most popular. Many people didnīt know there are alternatives. And itīs not easy to assert against Garmin. They have many fans.
Globalsat has to compare with Garmin and not with the others. And itīs not good to say "The others have problems there and we too, but less".

Thanks for your advice again, we will keep progessing and providing the best services to you.
I love it and I say thank you for your support! ;)

Happy weekend

Longjog

Hi Longjog,

Thanks for advice. Maybe my instant is not well.
The current firmware has implement, but we will keep improving that.
I am not sure small antenna is the major reason, but we found Garmin also use small antenna.
Or can you show me more detail data which get lost signal in competition? I would like check the effect and discuss with engineering team.

Sincerely,

Geoffrey
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Longjog @ GS-Sport-Servicecenter

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Re: Problems with receiving GPS signals
« Reply #34 on: May 21, 2010, 07:21:34 am »

Hi Geoffrey,

mail with act-file sent on 9th of Mai and again just now.

Best regards

Longjog
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TWG_TECH8

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Re: Test getting 3D-Fix
« Reply #35 on: May 21, 2010, 10:45:24 am »

Hello,

I made a test with my GH615 and GH505

Switch on
GH615 0:58 to 3D-fix, with 6 satelites
GH505 1:40 to 3D-fix, with 4 satelites, 5 after a while

then switch of, turn on again:

GH615 0:01 (at once) to 3D-fix
GH505 0:40 to 3D-fix

Why???

Regards

Longjog


Hi Longjog,

According to PIFA antenna character and our design, the performance will be better when lay on ground or bike mount. It also works even reverse place. Can you please help to check it with GH-625?
My last test in sport field, the fix time is as same as GH-625.

Sincerely,

Geoffrey
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TWG_TECH8

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Re: Problems with receiving GPS signals
« Reply #36 on: May 21, 2010, 10:55:07 am »

Hi Hubert,

Quote
Yes - I'm rather sure now.  In the meantime I have learned, when you move the watch over a longer
distance (I forgot what "long" means, I think it was something like 100 miles or km ?) the internal data
of so called "Alamanac" is lost or invalid and has to be re-loaded. This can take about 15 min. time.
This normally is defined as "Cold Start".  So I do not understand, why GlobalSat gives a value of
average 42 sec. for a cold start. I think there is some misunderstanding or different definitions ?

The average 42sec is provided by GPS vendor upon clear sky, in still and no noise interference. But it also needs to consider antenna type, casing design.

Quote
Second thing is, that I don't understand why the watch seems to need a coldstart, even when it is
not moved over a long distance    Maybe the alamanac data isn't stored correctly ?
Does the storage need battery power ? Normaly it shouldn't. It should be stored in non volatile memory.
Like other configuration data. This isn't lost during battery empty. ...you never know...
Eventually, GPS will aquire the last satellite according to last fix. If your location to last time is far or time is over 4hours, GPS will spend more time to locate. Meanwhile, you start running, GPS might won't get fix! At this situation, we need Cold Start to reset old ephemeris in memory.

Hope it is clear for you.


Geoffrey
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TWG_TECH8

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Re: Problems with receiving GPS signals
« Reply #37 on: May 21, 2010, 11:05:06 am »

I want the be able to get GPS data later when available, there are many usecases like you gona run with your friend and they start the nice mounten run and you dont want to wait a few minutes to get a signal. The reace start and you dont have a GPS signal, like the start is in a tunnel or you missed to start the watch in time, or you start in a city with high buildings. But I also think the indoor question is great, what about
Code: [Select]
+-----------------------------------+
|            No GPS signal          |
|+---------+ +---------+ +--------+ |
||  Start  | | Indoor  | | Abort  | |
|| anyway  | |  Mode   | |        | |
|+---------+ +---------+ +--------+ |
+-----------------------------------+
  • start anyway - GPS data will be recorded when available and distance will be wrong as discussed
  • indoor mode - No GPS data ever GPS is off to save battery HR & other sensors are still recorded
  • Abort - back out
Timer should be started in the background in "start anyway" mode as the user might just press start and run for a while until she/he look at the watch. If GPS gets available before user has selected anything the "No GPS signal" might change to something like "No startup GPS signal". This will simplify the indoor selection alot also.

First I want to say, that I also like Zingo's suggestion !  It provides all possibilities and (as he already
mentioned) simplifies the indoor mode selection.
However - let's not forget the main purpose of all this ideas:  When GPS is not available at start:
* It should be enabled automatically when available and
* The timer should never be resetted !

Btw.: I made another test this morning. I made one more run with both GH watches on to compare
some results. The first test was the GPS fix when switching both on:
First the GH-625 seemed to be faster, because after a short time it showed 3/4 fixed,
while GH-505 still showed 0/4 fixed. But then after a short moment, GPS fix appeared exactly at the
same time on both watches (about 15 sec. after switching on).
So far - so good. As it remains like this: No problem...

Regards, Hubert

Dear all

Today we come out a solution for combintion of in-door training and lost singal situation:

Start Training --> Yes
GPS no fix --> No signal, start anyway? --> [YES]
Record (lat/log): (0,0000 0,0000) , Software will recoganize as invalid potint and won't show on Map, but others information is valid

GPS fix --> Keep training and recording;
Lost Signal --> Copy (lat/log) as last point, HR, cadence still be saved.
:
Stop training

Please advise what you think


Have a nice weekend,

Geoffrey

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Longjog @ GS-Sport-Servicecenter

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Re: Problems with receiving GPS signals
« Reply #38 on: May 21, 2010, 02:02:23 pm »

Dear all

Today we come out a solution for combintion of in-door training and lost singal situation:

Start Training --> Yes
GPS no fix --> No signal, start anyway? --> [YES]
Record (lat/log): (0,0000 0,0000) , Software will recoganize as invalid potint and won't show on Map, but others information is valid

GPS fix --> Keep training and recording;
Lost Signal --> Copy (lat/log) as last point, HR, cadence still be saved.
:
Stop training

Please advise what you think


Have a nice weekend,

Geoffrey
Hi Geoffrey,

for me itīs okay, but what is, when GPS is fixed again, before training or competition ends? I hope GPS data is also recorded again then.
And it would be fine, if the track could be modified in GS-Training Gym Pro after downloading from watch in order to have the correct distance.

Happy weekend also

Longjog
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zingo

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Re: Problems with receiving GPS signals
« Reply #39 on: May 21, 2010, 03:15:53 pm »

I like it but wont to modify it a little se the bold additions:

Start Training --> Yes
GPS no fix --> No signal, use anyway? --> [YES]
Record (lat/log): (0,0000 0,0000) , Software will recognize as invalid point and won't show on Map, but others information is valid
In background before user select YES it has been recording from the start.

GPS fix --> Keep training and recording;
Lost Signal --> Record (lat/log): (0,0000 0,0000) , Software will recognize as invalid point and use last valid point, but others information is valid.
:
Stop training

By using the long/lat=0 trick on lost GPS the you can later in SW decide to handle this differently, like mark in in some way, or even better interpolate a straight line.

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Longjog @ GS-Sport-Servicecenter

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Re: Problems with receiving GPS signals
« Reply #40 on: May 22, 2010, 09:53:40 am »

Hello,

today I lost GPS-fix again although weather was very fine with blue sky. It was at a point, where GPS-fix some days ago was lost already. But the GH-625 didnīt have had problems there.  ??? :-\

Regards

Longjog
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TWG_TECH8

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Re: Problems with receiving GPS signals
« Reply #41 on: May 22, 2010, 09:56:34 am »

I like it but wont to modify it a little se the bold additions:

Start Training --> Yes
GPS no fix --> No signal, use anyway? --> [YES]
Record (lat/log): (0,0000 0,0000) , Software will recognize as invalid point and won't show on Map, but others information is valid
In background before user select YES it has been recording from the start.

GPS fix --> Keep training and recording;
Lost Signal --> Record (lat/log): (0,0000 0,0000) , Software will recognize as invalid point and use last valid point, but others information is valid.
:
Stop training

By using the long/lat=0 trick on lost GPS the you can later in SW decide to handle this differently, like mark in in some way, or even better interpolate a straight line.

Yes, it is. But it is difficult to manage for 3 party software likes SportTracks.



Sincerely,

Geoffrey
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TWG_TECH8

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Re: Problems with receiving GPS signals
« Reply #42 on: May 22, 2010, 10:12:20 am »

Hello,

today I lost GPS-fix again although weather was very fine with blue sky. It was at a point, where GPS-fix some days ago was lost already. But the GH-625 didnīt have had problems there.  ??? :-\

Regards

Longjog

Dear Longjog,

There might have some reson to cause the situation:
- Antenna different; If it is real, we have to use firmware to compensative the weakness.
- Because of quality of the first sample production; Production guys told the 2nd run performance is something better than first. We can check this.
- Firmware problem??? GPS info seems a little lag, it is a clue.

We made another ODM project with same antenna, but performance is not bad. ???
Anyway, we will try to find a way to keep the performance as better as GH-625. Please let me know if any finding.

Have a nice day,

Geoffrey


W
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Hubert

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Re: Problems with receiving GPS signals
« Reply #43 on: May 23, 2010, 03:04:25 am »

There might have some reson to cause the situation:
- Antenna different; If it is real, we have to use firmware to compensative the weakness.
- Because of quality of the first sample production; Production guys told the 2nd run performance is something better than first. We can check this.
- Firmware problem??? GPS info seems a little lag, it is a clue.
Hi Geoffrey,

I'm wondering, if it really makes sense to continue testing, when the beta testers have some kind
of proto-types, which are different from your normal production ?  Is it really useful, when I'm posting
problems with GPS signal recieving, when you already modified something with antenna and anything
else ?

However - I will share one more finding about GPS problems:

Yesterday I made a run with 625 and 505 together. First result:
625 needed about 1 Min. to get the GPS fix.
505 needed didn't have a fix after 3 Min.. After GPS reset the fix was there in about 2 Min. (Sum: 5 Min.).

More important (and more terrible) was the result of the track recording.
Please have a look at the two screen shots (first: 625, second: 505).

I should mention, that I run exaclty the same round track 4 times.
As you can see, also 625 has some abreviations. However it is okay.
GH-505 is far away from being okay  >:(



Just to clarify: Both pictures are taken from the same run !

I could add, that finally the GH-505 showed about 600m more for the total distance of 10km,
but I think, when you have a look at the recording, this isn't the main problem.

I'm wondering, what could be the problem. Btw.: The weather was fine, nearly clear sky, no clouds,
sun shining. The track has some trees on the right side, but is open (water) on the left side.
It is complete nature there. No buildings, no technical equipments, almost no other people.

However - both watches had the same conditions. And GH-625 worked fine.

Regards, Hubert
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GH-625XT, Firmware: F-GGH-2P-1112231 (Beta)
GH-505 M, Firmware: F-GGH-2C-1007161 (Beta)
GH-625 M, Firmware: F-GGH-2A-1001073 (Version XII)
with GS-Sport Gym Pro v1.6.8 and Sporttracks 2.1.3326

zingo

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Re: Problems with receiving GPS signals
« Reply #44 on: May 23, 2010, 03:53:44 am »

Quote
Yes, it is. But it is difficult to manage for 3 party software likes SportTracks.
Now you have a new device so there is new driver written. Now is the time to do it right....

I think that repacing 0,0 with the last "good" value in the PC SW-driver should be extreamly easy to add in the code for each SW project. And now the user will get the same experiace as you suggest. The nice thing is that "better" SW can interpolate as they know that GPS was missing here, and try to do it's best. If you in the watch use the last known coordinates the SW don't know and can't fix it. A good SW will also be able to mark in the MAP that the GPS signals was lost and the user will be able to get visual feedback and know where it had interploations.
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