noglider 

The last few days, I've had a weak GPS signal, as ridewithgps reports. Using google maps for navigation, the app falls behind in knowing where I am and which direction I'm moving in. Last night was bad, and I couldn't see how dense the cloud cover was. We are having snowfall this morning, so maybe the clouds were dense last night. The path the ridewithgps says I've taken is much more zig-zaggy than reality.

Is the problem likely to be attributable to clouds? Do other things cause this? Is it possible that the GPS receiver in my iPhone might be starting to fail?

Tourist in MSN

GPS satellite power is not very strong and the satellites are something like 12,000 miles up which is a pretty long way for the signal to travel. And a GPS receiver needs a pretty good antennae to pick up the signals. With GPS units that do not have a really good antennae I have often had poor reception under heavy tree cover and if there was a lot of rain clouds above. I would give it a few weeks of use before deciding if your phone has a problem.

If it reoccurs, you might want to see if there is a correlation to battery strength vs reception.

JasonD67

In addition to cycling, I use GPS in my car, sailboat, and aircraft. I've never had a GPS signal failure due to cloud cover/heavy precip. As a pilot and mariner, I'd be damned scared if there was a possibility that I'd lose GPS when the weather is bad -- that's just when I need it. I've only lost signal due to overhead trees or buildings (like in the downtown area of a major city).

Now, my little Element Bolt is by far the smallest GPS I've ever used (and the least critical), but I only lose signal under trees, and that rarely.

sdmc530

I don't know if I have ever lost a gps signal....even when riding in the Black Hills on the Mickelson Trail that is very covered I have not lost gps.

I would think its a hardware issues and maybe not a location/gps signal issue. Just my opinion though....

canklecat

I always blame Russian hackers when GPS dropouts mess up my Strava logs.

But, yeah, it's usually atmospheric conditions, terrain, man made obstacles, etc. In my area usually when anyone experiences GPS glitches, several folks report the same problems.

A couple of years ago Strava wasn't very good at recovering ride logs when glitches occurred, while Cyclemeter did very well when I ran both apps at the same time. Since then it appears Strava is better at guesstimating our likely routes and recreates routes and related data pretty accurately despite GPS glitches.

Iride01 

GPS Satellites are not geostationary or geosynchronous. Throughout a 24 hour period, some drop lower on the horizon or even go entirely below the horizon affecting the numbers of satellites pool your device has to choose where to get position data from. As well, throughout the year the number visible to your location may vary significantly. I've always heard the further north you are the less gps satellites you will have available to you particularly during the winter. I suppose since this was told to me, perhaps they may have closed some coverage gaps.

You can always go to satellite tracking websites and filter out for just GPS, GLONASS or what ever you desire and see what should be in the sky over you for any particular time, date and position. This is one I used recently..... https://in-the-sky.org/satmap_radar.php
Be sure to select your satellite types and check your location.

But yes, precip of any sort, foliage--especially wet foliage, shadowing by terrain and buildings, even your body and rf interference can affect your signal.

jadocs

Tourist in MSN

I have never heard that, and I had no difficulty in keeping a good GPS signal when I was bike touring in Iceland which was just a hair south of the Arctic Circle.

I am not sure but I think that you could loose WAAS if you are farther north, that could impair your accuracy and precision.

The Op mentioned iphone, which of course uses different apps than android devices, but on my android phones I found this app was very good at telling me which satellites are up there.
https://play.google.com/store/apps/d...tcross.gpstest

On my Garmin recreational grade GPS I usually put it in battery save mode, turn off WAAS and Glasnost to save battery, that impairs my precision somewhat and makes getting a GPS location slower on start up, but otherwise it is pretty good. But I use a recreational GPS that has a very good antennae, Garmin 64, see photo.