http://citycyclingedinburgh.info/bbpress/ CityCyclingEdinburgh Forum » Topic: Why is GPS accuracy on my Garmin so rubbish in the mornings. en Wed, 13 May 2026 05:48:06 +0000 http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-172527 Mon, 17 Nov 2014 19:06:30 +0000 Kenny 172527@http://citycyclingedinburgh.info/bbpress/ <p>No difference, tbh. Accuracy pretty much the same, as is the plotted line on GC/Endo/Strava. However, once again it didn't lose connectivity, and it mainly struggles when on the NEPN where you'd expect it to be a bit pants anyway. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-172398 Sun, 16 Nov 2014 15:16:11 +0000 Kenny 172398@http://citycyclingedinburgh.info/bbpress/ <p>Ok, done that, let's see what happens tomorrow... </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-172298 Fri, 14 Nov 2014 15:04:24 +0000 richardlmpearson 172298@http://citycyclingedinburgh.info/bbpress/ <p><a href="https://support.garmin.com/support/searchSupport/case.faces?caseId=%7B84774820-e4ef-11de-d785-000000000000%7D" rel="nofollow">https://support.garmin.com/support/searchSupport/case.faces?caseId=%7B84774820-e4ef-11de-d785-000000000000%7D</a> </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-172297 Fri, 14 Nov 2014 15:02:31 +0000 richardlmpearson 172297@http://citycyclingedinburgh.info/bbpress/ <p>It may help. Try this:</p> <p>Hold Lap and Start, Turn on device, release lap and start and then leave for 20 mins (in sight of satelites). </p> <p>This apparently resets all the satellite data on the device and may correct your inaccuracy. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-172163 Thu, 13 Nov 2014 22:33:52 +0000 Kenny 172163@http://citycyclingedinburgh.info/bbpress/ <p><em> Have you tried all the reset options for the device</em></p> <p>No, I have not done anything aside from changing it to record every 1 second, rather than the default setting. I only did that so that it wasn't so jumpy when watching Strava flybys. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-172157 Thu, 13 Nov 2014 22:08:47 +0000 richardlmpearson 172157@http://citycyclingedinburgh.info/bbpress/ <p>Mine has been far better too. Have you tried all the reset options for the device. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-172136 Thu, 13 Nov 2014 19:30:51 +0000 Kenny 172136@http://citycyclingedinburgh.info/bbpress/ <p>Ok, so I'm now starting to realise that the issues I was having for a few weeks were merely a minor escalation of what was happening before. The only reason I was aware that the GPS was having issues in the morning was because it was completely losing connection to the satellites, and thus no plotting was possible. The past few days, it has not done this, and I've been focusing instead on the accuracy reading on the device. But just now, I've had a look back at my traces in the mornings before the issues started, and I can see that they were similarly "off" at around the same points as they are now. It was just that I wasn't seeing this lack of accuracy, because it's still pretty accurate.</p> <p>Therefore, the important thing is that I have not lost connection to the satellites for a few days now, so things have indeed returned "to normal". I have, of course, jinxed it by saying this. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-172064 Thu, 13 Nov 2014 11:59:43 +0000 gowgowuk 172064@http://citycyclingedinburgh.info/bbpress/ <p>I see. Thanks! </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-172036 Thu, 13 Nov 2014 10:56:12 +0000 Snowy 172036@http://citycyclingedinburgh.info/bbpress/ <p>Aerial size basically, and the fact that car GPS is effectively 'always on'.</p> <p>As I understand it, the GPS unit in your car usually shares the same antenna as the radio, which may be built in unobtrusively or it may be a roof mounted model. Either way it's an enormous aerial for picking up the GPS signal, compared with anything portable.</p> <p>Also, the car maintains power to the GPS electronics even when the ignition is off, so it doesn't have to re-acquire when you get in and drive off. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-172028 Thu, 13 Nov 2014 10:44:43 +0000 gowgowuk 172028@http://citycyclingedinburgh.info/bbpress/ <p>The day before yesterday, I left without having my Edge500 locked. It was far too long and really I don't want to get up earlier in order to factor the time my edge take to lock on satellites! On my way back it never happens, but arguably the situation is more open with less tall buildings around. I have a (naive) question: why don't car's GPS have the same problem? I understand that as opposed to my Garmin edge 500 the track is "forced" to fit on existing roads, which, I guess, helps a lot, but I never heard of drivers having to wait 5-10 minutes in the morning for their GPS to lock on satellites... Or the track suddenly jumping to the road one block further (which is sometimes the level of inaccuracy I have). It's not as if they are especially a lot more expensive than the bike ones.... </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-172020 Thu, 13 Nov 2014 01:54:40 +0000 Snowy 172020@http://citycyclingedinburgh.info/bbpress/ <p>Ofcom notifies about jamming of GPS, <a href="http://stakeholders.ofcom.org.uk/spectrum/gps-jamming-exercises/">here</a>. Nothing for central belt, not surprisingly.</p> <p>Surprisingly few satellites are ever out of action. Performance data <a href="http://adn.agi.com/SatelliteOutageCalendar/SOFCalendar.aspx">here</a>. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-171841 Wed, 12 Nov 2014 09:54:54 +0000 fimm 171841@http://citycyclingedinburgh.info/bbpress/ <p>Clubmate of mine went to Italy yesterday, according to Strava... (he wishes...) </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-171838 Wed, 12 Nov 2014 09:43:42 +0000 Kenny 171838@http://citycyclingedinburgh.info/bbpress/ <p>Ran both the Garmin and the Strava app on my phone this morning.</p> <p>Garmin Edge 800 was locked on really well at home, 19ft accuracy. Up to 77ft accuracy by the zoo, then over 100ft once on the NEPN. That all said, the trace on Strava looks pretty good except when I got to the Hawthornvale, but even then it wasn't too far away.</p> <p>The phone was actually worse. It went a bit crazy near Craigleith, but performed slightly better when I got to Hawthornvale.</p> <p>I'm so confused. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-171835 Wed, 12 Nov 2014 00:04:23 +0000 Cyclingmollie 171835@http://citycyclingedinburgh.info/bbpress/ <p>I don't think they circle the Arctic Dave. Don't they sit on the sea bed? </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-171691 Mon, 10 Nov 2014 19:57:29 +0000 Kenny 171691@http://citycyclingedinburgh.info/bbpress/ <p>Not for me :( back to the same duffness as last week. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-171672 Mon, 10 Nov 2014 17:20:50 +0000 richardlmpearson 171672@http://citycyclingedinburgh.info/bbpress/ <p>GPS 100% Accurate this morning. The aliens must have gone home. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-171619 Mon, 10 Nov 2014 11:58:44 +0000 cb 171619@http://citycyclingedinburgh.info/bbpress/ <p>Yes, the radio piece I heard the other day on the eLORAN service was focussed on South Korea who have a hard time of using GPS due to blocking signals sent by the Noth Koreans.</p> <p>So maybe it's all North Korea's fault? </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-171618 Mon, 10 Nov 2014 11:52:01 +0000 kaputnik 171618@http://citycyclingedinburgh.info/bbpress/ <p>Wingpig - there's Galileo (EU) and GLONASS (Russia).</p> <p>There was an article recently I read that the ground-based LORAN service has been updated by the General Lighthouse Authorities (i.e. Trinity House, Commissioners of Northern Lights and Commissioners of Irish Lights) and rebranded as eLORAN as a backup for GPS failure for inshore maritime navigation. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-171616 Mon, 10 Nov 2014 11:47:08 +0000 wingpig 171616@http://citycyclingedinburgh.info/bbpress/ <p>Shouldn't think the satellites are bothered by the number of devices on the ground listening for their signals.</p> <p>What was that other thing some people were launching new satellites for which was supposed to eventually augment GPS? </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-171614 Mon, 10 Nov 2014 11:37:56 +0000 kaputnik 171614@http://citycyclingedinburgh.info/bbpress/ <p>Is it possible that bicycle-mounted GPS are now so ubiquitous that we have reached peak-Garmin, and there is network capacity issues? </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-171613 Mon, 10 Nov 2014 11:37:17 +0000 Dave 171613@http://citycyclingedinburgh.info/bbpress/ <p>Ah, OK. I was thinking about when they're circling around in the artic etc. ready to pop their missiles out! </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-171611 Mon, 10 Nov 2014 11:30:27 +0000 ARobComp 171611@http://citycyclingedinburgh.info/bbpress/ <p>certainly used to be true on the solent.</p> <p>Assuming that it was public knowledge that the subs were going to be in that area (they would announce it on channel 16) - Blocking GPS accuracy over a few square miles making sure you can't pinpoint a bomb within 300 yards is a rather good idea </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-171596 Mon, 10 Nov 2014 10:29:31 +0000 Dave 171596@http://citycyclingedinburgh.info/bbpress/ <p>I hope that's not quite true, as it would mean to find our nuclear deterrent, you could just send out a bunch of drones and see which ones reported a loss of GPS signal :-) </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868&page=2#post-171586 Mon, 10 Nov 2014 09:51:03 +0000 ARobComp 171586@http://citycyclingedinburgh.info/bbpress/ <p>The military has a tendency to disrupt GPS at sea while submarines are operating in the area. Does your commute pass over any large bodies of water? OR larger than average puddles? </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868#post-171560 Sun, 09 Nov 2014 21:54:28 +0000 Kenny 171560@http://citycyclingedinburgh.info/bbpress/ <p>Went for another ride this morning. Signal solid as a rock again. Weird. It'll be very interesting to see what happens tomorrow morning... </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868#post-171482 Sat, 08 Nov 2014 14:41:55 +0000 Kenny 171482@http://citycyclingedinburgh.info/bbpress/ <p>Signal was solid as a rock this morning. I took the same route initially on my ride as I do when commuting in - 10ft accuracy. Unbelievable. It's like something is happening during the weekday mornings, but only for Garmin devices. I can't see any time that the GPS signal, and thus my trace, was ever even slightly off.</p> <p><a href="http://www.strava.com/activities/216803079" rel="nofollow">http://www.strava.com/activities/216803079</a> </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868#post-171455 Fri, 07 Nov 2014 23:48:09 +0000 Kenny 171455@http://citycyclingedinburgh.info/bbpress/ <p><em> I'd agree with the posts about GPS accuracy being a bit rubbish in the mornings recently. This sort of thing does happen every so often</em></p> <p>Interesting... the monitoring shall continue :) </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868#post-171453 Fri, 07 Nov 2014 23:46:21 +0000 Kenny 171453@http://citycyclingedinburgh.info/bbpress/ <p><em>Not sure that helps or is relevant...</em></p> <p>I don't know if it helps either, but it's certainly food for thought, so thanks!</p> <p>The tricky thing about Garmin devices is you can be fooled into thinking they are not recording data very often, due to Garmin Connect being a bit crap. Garmin Connect does not show you all the data / GPS points. I think Strava might be the same. If you use a different tool (I have written my own) then you can see all the data points, and thus determine how often the data is being written / stored.</p> <p>The Garmin Edge 200 uses "smart recording", and you can't change it, AFAIK. The 500 and 800 uses smart recording by default, but you can change it to record every 1 second. The issue that we're having, though, is to do with GPS accuracy, not how often it records track points. The Garmin tells you how accurate it is all the time. I have not seen a mobile device app being able to tell you this.</p> <p>That all said, I think what I will do on Monday is to record my trip using Endomondo or Strava on my phone, and use the Edge as normal, and compare the two. That said, if my mobile then records it really well, I'm not sure where that leaves us, because it doesn't appear to be that the Garmin is broken, since it is recording data at other times ok?</p> <p>I'm heading out for a ride tomorrow morning. Let's see what happens then...</p> <p>Ramblings over for the night. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868#post-171448 Fri, 07 Nov 2014 23:39:09 +0000 Snowy 171448@http://citycyclingedinburgh.info/bbpress/ <p>I'd agree with the posts about GPS accuracy being a bit rubbish in the mornings recently. This sort of thing does happen every so often. I've particularly noticed it on my phone when playing gps-based games in areas where it's normally fine.</p> <p>I can only conclude that a couple of the most relevant satellites are out of action for maintenance, or something. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=13868#post-171445 Fri, 07 Nov 2014 23:17:08 +0000 Greenroofer 171445@http://citycyclingedinburgh.info/bbpress/ <p>@Kenny - I did my weekly Strava upload today and compared the tracking precision of my Garmin 200 on the towpath with a colleague who cycles the same route using (according to Strava) an Android device. My Garmin was mostly tracking the route OK, but it's clear that it was only reporting intermittent positional fixes and something (Strava) was interpolating the track in-between. His Android device was reporting much more frequent positions, so tracked the towpath much more accurately.</p> <p>I do remember reading that the Garmin 200 has quite a coarse recording: something like only recording changes in speed and position, rather than actual speed. I think the more expensive ones record a much more precise trace of activity.</p> <p>Not sure that helps or is relevant... </p>