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Author Topic: Problems with receiving GPS signals  (Read 38945 times)

TWG_TECH8

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Re: Problems with receiving GPS signals
« Reply #45 on: May 23, 2010, 10:05:02 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

Hi Hubert,

Thanks for your finding! Do you both enable WAAS/ENGOS? It will improve performance.
Beside GPS receiving verification, the other features still need to evaluate.
I am not sure it is first sample or antenna problem, but I will keep check.
Anyway, there is someting difference between two devices. Or we can say, GH-625 is too perfect to overtake! :D But I think Globalsat products always be superior in the worldwide. :D


Have a nice day,

Geoffrey

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Longjog @ GS-Sport-Servicecenter

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Re: Test getting 3D-Fix
« Reply #46 on: May 24, 2010, 03:27:36 am »

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
Hello Geoffrey,

I have made a interesting conclusing.
Starting GH625 and 505 together, first time the 625 needed around 50 seconds, the 505 around 100 seconds. Than switch both off and start again.
625 only needed some (<5) seconds to fix. 505 needed 45 seconds. Off and on again: GH625 and 505 needed both only some seconds to get 3 Dfix.
40 minutes later (both watches off for this time) switching on: 625 a few seconds, 505 100 seconds. Switch off / on, GH 625 fix at once, GH 505 45 seconds. Third time: Both watches only a few seconds.

10 minutes later, both watches off while this time. 625 fixes in less than 5 seconds after switchign on. GH 505: After 100 seconds 03/4 sattelites, 180 sec. 3D-fix.

Both watsces laying on a chair under free sky for these tests.

Yesterday I also watched GH505 with problems getting the fourth satellite for fixing.

Is it possible its something wrong with storing the almanach-data in GH 505?

Regards

Longjog
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GH-625M, GH-625XT, GH-505, GH-561, GB-580P, BT-338
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TWG_TECH8

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Re: Test getting 3D-Fix
« Reply #47 on: May 24, 2010, 10:05:22 am »

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
Hello Geoffrey,

I have made a interesting conclusing.
Starting GH625 and 505 together, first time the 625 needed around 50 seconds, the 505 around 100 seconds. Than switch both off and start again.
625 only needed some (<5) seconds to fix. 505 needed 45 seconds. Off and on again: GH625 and 505 needed both only some seconds to get 3 Dfix.
40 minutes later (both watches off for this time) switching on: 625 a few seconds, 505 100 seconds. Switch off / on, GH 625 fix at once, GH 505 45 seconds. Third time: Both watches only a few seconds.

10 minutes later, both watches off while this time. 625 fixes in less than 5 seconds after switchign on. GH 505: After 100 seconds 03/4 sattelites, 180 sec. 3D-fix.

Both watsces laying on a chair under free sky for these tests.

Yesterday I also watched GH505 with problems getting the fourth satellite for fixing.

Is it possible its something wrong with storing the almanach-data in GH 505?

Regards

Longjog

Hi Longjog,

The result is interesting and surprising!
Maybe we can start checking from GPS firmware, and then to double to check power management.
Today, we took GH-505 from factory for free running and compare with GH-625.
The accuracy and total is better and closer to real case than GH-625. ???
Tomorrow I will post.

Sincerely,

Geoffrey

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Hubert

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Re: Test getting 3D-Fix
« Reply #48 on: May 24, 2010, 12:41:59 pm »

Hi Longjog,

very good idea !  ;)
Is it possible its something wrong with storing the almanach-data in GH 505?

However - not really new:  ;)
Maybe the alamanac data isn't stored correctly ?
Does the storage need battery power ?

Okay - finally we came to the same conclusion. Maybe GlobalSat should also think about
this idea. I think, Geoffrey gave already an answer. I'm afraid, I didn't understood him completely...

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 #49 on: May 24, 2010, 10:43:32 pm »

Hi

Here is yesterday field test, GH-505 vs GH-625:
Weather is sunny, no cloud. GH-625: 5 fix satellites, GH-505: 6 fix satellites.
Walk Test,  four times for 400m sport field.



GH505 is 1.598KM and GH625M is 1.607 KM.
Here is accuracy comparison:

No big different.

RunningTest,  five times for 400m sport field.

GH505 is 2.132KM and GH625M is 2.071KM.
And the trace is better than GH-625 for short run test.  ???
That is why I think there might have hidden problem in long distance.
Can you help to verify that?

Sincerely,

Geoffrey

« Last Edit: May 24, 2010, 10:56:14 pm by TWG_TECH4 »
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abdominizer

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Re: Problems with receiving GPS signals
« Reply #50 on: May 25, 2010, 03:49:38 am »

Hello,
I have been thinking about this problem. Since not all have problems with GH-505 GPS-fix and it is also not consistent, sometimes it is fine and sometimes it is no good at all, I think the problem might be caused by a bad antenna or a loose antenna contact. 

Any thoughts about this?

Sincerely,
Jonas
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GH-625M, Firmware: F-GGH-2A-1001073 (Version XII)
GH-505 #00006, Firmware: F-0TH-0C-1005061 (Version 2.0)
Sporttracks Version 2.1.3465
GS-Sport Gym Version 2.1, GS-Sport Gym Pro V.1.2

Rookie

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Re: Problems with receiving GPS signals
« Reply #51 on: May 25, 2010, 05:21:54 am »

Hi,

Walk tests looks very good result but running test was not as good as GS (and Garmin) users be inured to.

For 625 more than 3% and for 505 more than 6% error is much bigger what I have had experiences ever with my 615. :o Usually error is less than 1% (many case less than 0,5%) and it is what I exept from device.
Hopefully you found reason what causing this huge error.

I'm especially very surpriced that you get so big error with 625 in sport track where wasn't any buildings near by. How data recording was setup, how many seconds was used as record frequency?

Good luck with solving this problem.

Rookie
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Hubert

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Re: Problems with receiving GPS signals
« Reply #52 on: May 25, 2010, 05:48:09 am »

Hi all,

For 625 more than 3% and for 505 more than 6% error is much bigger what I have had experiences ever with my 615. :o Usually error is less than 1% (many case less than 0,5%) and it is what I exept from device.
...
How data recording was setup, how many seconds was used as record frequency?

I agree to what Rookie said. I also cannot believe, that GH-625 should be as inaccurate as shown !
I never made this experience !  There has to be something different...

* Did you use the same FW for GH-625 as we all have or something new ("improved") ?
* As Rookie already asked: Wow many seconds were used for record frequency?

And one more question: Did you also find results for the time used to get the GPS fix (625/505) ?

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

ultrapetita

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Re: Problems with receiving GPS signals
« Reply #53 on: May 26, 2010, 01:10:56 am »

Hi all,
I agree to what Rookie said. I also cannot believe, that GH-625 should be as inaccurate as shown !
I never made this experience !  There has to be something different...

* Did you use the same FW for GH-625 as we all have or something new ("improved") ?
* As Rookie already asked: Wow many seconds were used for record frequency?


Just to remind you of my last experience on running track testing: 64km and the total error was <400m.

(When running on 400m track, I have noticed that it is important to keep the watch on innermost wrist. This will minimize the effect of the tall objects (trees, buildings etc.) next to the track)

http://www.usglobalsat.com/forum/index.php?topic=1185.msg3823#msg3823

One item that I have recently tested: the accuracy on 400m track is not that different if varying with 1-4s recording interval. (The result above was recorded with 4s interval) This will affect only a little bit to distance shown by ST and I think 4s interval the ST's and GH-615's results match very well.
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TWG_TECH8

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Re: Problems with receiving GPS signals
« Reply #54 on: May 27, 2010, 10:33:07 am »

Hi,

Walk tests looks very good result but running test was not as good as GS (and Garmin) users be inured to.

For 625 more than 3% and for 505 more than 6% error is much bigger what I have had experiences ever with my 615. :o Usually error is less than 1% (many case less than 0,5%) and it is what I exept from device.
Hopefully you found reason what causing this huge error.

I'm especially very surpriced that you get so big error with 625 in sport track where wasn't any buildings near by. How data recording was setup, how many seconds was used as record frequency?

Good luck with solving this problem.

Rookie

We both 1s for recording. Maybe wear to right hand to get larger error.

Sincerely,

Geoffrey
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TWG_TECH8

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Re: Problems with receiving GPS signals
« Reply #55 on: May 27, 2010, 10:39:04 am »

Hi all,
I agree to what Rookie said. I also cannot believe, that GH-625 should be as inaccurate as shown !
I never made this experience !  There has to be something different...

* Did you use the same FW for GH-625 as we all have or something new ("improved") ?
* As Rookie already asked: Wow many seconds were used for record frequency?


Just to remind you of my last experience on running track testing: 64km and the total error was <400m.

(When running on 400m track, I have noticed that it is important to keep the watch on innermost wrist. This will minimize the effect of the tall objects (trees, buildings etc.) next to the track)

http://www.usglobalsat.com/forum/index.php?topic=1185.msg3823#msg3823

One item that I have recently tested: the accuracy on 400m track is not that different if varying with 1-4s recording interval. (The result above was recorded with 4s interval) This will affect only a little bit to distance shown by ST and I think 4s interval the ST's and GH-615's results match very well.

Hi Ultrapetita,

Because watch calculates distance in memory inside, so it won't affect reult with different recording.
About ST, it calculates regarding to total accumulative distance by every point.


Sincerely,

Geoffrey
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ultrapetita

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Re: Problems with receiving GPS signals
« Reply #56 on: May 29, 2010, 01:27:02 am »


Hi Ultrapetita,

Because watch calculates distance in memory inside, so it won't affect reult with different recording.
About ST, it calculates regarding to total accumulative distance by every point.

Yes, this is well known and as you remember our discussion on this topic earlier, 4s recording interval yielded the best match between ST and GH-615/625 distance calculations.
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TWG_TECH8

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Re: Problems with receiving GPS signals
« Reply #57 on: May 29, 2010, 03:42:15 am »


Hi Ultrapetita,

Because watch calculates distance in memory inside, so it won't affect reult with different recording.
About ST, it calculates regarding to total accumulative distance by every point.

Yes, this is well known and as you remember our discussion on this topic earlier, 4s recording interval yielded the best match between ST and GH-615/625 distance calculations.

We also implement this concept into GH-505 firmware. So it will as similar as ST.


Sincerely,

Geoffrey
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Hubert

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Re: Problems with receiving GPS signals
« Reply #58 on: June 12, 2010, 12:45:39 pm »

Hi Geoffrey and all,

I didn't really expect a change in GPS behaviour with new FW version (F-GGH-2C-1006102),
but there was still a little hope...

However - GPS is still very inaccurate !  Please look at the recorded track.
It should be right on the street...


And it's not only the track, what is looking bad...
Of course all GPS dependent data, like auto-lap, pace, distance are not okay.   :'(

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 #59 on: June 12, 2010, 08:49:47 pm »

Hi Geoffrey and all,

I didn't really expect a change in GPS behaviour with new FW version (F-GGH-2C-1006102),
but there was still a little hope...

However - GPS is still very inaccurate !  Please look at the recorded track.
It should be right on the street...


And it's not only the track, what is looking bad...
Of course all GPS dependent data, like auto-lap, pace, distance are not okay.   :'(

Regards, Hubert


Hi Hubert,

It seems pity, perhaps likes I said, operator damaged antenna. :'(
Do you try to enable WAAS/EGNOS?
How poor of result for this run?

Sincerely,

Geoffrey
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