OsmAnd / phone GPS sensor in pocket / Garmin GLO

[Ben T]

Just discovered the android app OsmAnd, and have had a go with it and it seems good, some quite clever stuff.
It can calculate routes and speak, with voice output going to headphones, and you can seemingly give it what routeable files you like, so I could tweak the maps I give it to see what effect it has on routing.
But annoyingly, my phone seemingly consistently loses its GPS signal when i put it in my back pocket.
Weirdly it seemed to work ok when I was on the coast, but then I went up a hill and found myself on a sort of ex-military area, which was basically a barren moor, and quite high - about 250m, and that's where it didn't seem to get any reception from my pocket. If anything I would have expected it to be the other way round?
 I don't want to have it mounted on the handlebars as I don't think it's safe enough, or possibly even waterproof enough.
So I was thinking of trying an external gps sensor - Garmin make one called "GLO" but it's about 60 quid, which I think is a bit expensive when I'm not even sure it would be that good anyway.

Just curious really if anyone else has any experience of using OsmAnd, or even more interestingly, tinkering with it?
What's its routing like?
Or any ideas on how to improve a phone's ability to see satellites in a pocket?
Or had any experience with a Garmin GLO, or have one for sale secondhand they don't want?

[Kim]

Are you certain about the exness of the military area?  They get up to all sorts of radio shenanigans...

Try the phone facing the other way in your pocket, maybe.

How about in your luggage rather than against your body?  That might improve its view of the sky...

[andyoxon]

Just discovered the android app OsmAnd, and have had a go with it and it seems good, some quite clever stuff.
It can calculate routes and speak, with voice output going to headphones, and you can seemingly give it what routeable files you like, so I could tweak the maps I give it to see what effect it has on routing.
But annoyingly, my phone seemingly consistently loses its GPS signal when i put it in my back pocket.
Weirdly it seemed to work ok when I was on the coast, but then I went up a hill and found myself on a sort of ex-military area, which was basically a barren moor, and quite high - about 250m, and that's where it didn't seem to get any reception from my pocket. If anything I would have expected it to be the other way round?
 I don't want to have it mounted on the handlebars as I don't think it's safe enough, or possibly even waterproof enough.
So I was thinking of trying an external gps sensor - Garmin make one called "GLO" but it's about 60 quid, which I think is a bit expensive when I'm not even sure it would be that good anyway.

Just curious really if anyone else has any experience of using OsmAnd, or even more interestingly, tinkering with it?
What's its routing like?
Or any ideas on how to improve a phone's ability to see satellites in a pocket?
Or had any experience with a Garmin GLO, or have one for sale secondhand they don't want?

Limited experience of OsmAnd on bike, when my Etrex needed to be replaced.  Not tried in rain - though I have a stem mounting waterproof phone holder from decathlon.   I had tried gps logging with MyTracks (which I found robust) while navigating a downloaded gpx.  Osmand crashed an took Mytracks with it - so ended up with ~30% of the ride.  This year, actually used the osmand (car) navigation, as a back-up to an out of date mapping on TomTom, not too bad.  I know, however, I for one wouldn't be able to put up with that electronic (default) voice in my ear on a ride.     Back with an old s/h Etrex...

[Ben T]

Are you certain about the exness of the military area?  They get up to all sorts of radio shenanigans...

Try the phone facing the other way in your pocket, maybe.

How about in your luggage rather than against your body?  That might improve its view of the sky...

That's what it said on the sign. There was a massive wall stood in the middle of a moor, and a large stone arrow in the ground pointing at it..... Dread to think!

[Plug1n]

Or maybe try a different app and see if that has GPS signal problems?

I use the free Google My Tracks app on a phone in my back pocket without problems when my Garmin 705 is forgotten or flat.

[Kim]

Or maybe try a different app and see if that has GPS signal problems?

Don't see how that would make a difference, they just read the stream of data from the chipset.

[fuaran]

There does seem to be a lot of variation between phones, some have excellent GPS reception, others are rather poor.
You could try a GPS status app, so you can check how strong a signal it is getting from what satellites etc.

Yes, the back pocket should usually be pretty good for signal. Probably better than on the handlebars, if leaning forwards.

[Ben T]

hmm, cheers, might try that. so it's supposed to be able to see  through, say, jersey material then.

Is it not just electromagnetic waves... am I wrong to assume since I can't visually see through my jersey, that a gps sensor won't also be able to see a satellite through it? Does it make a difference whether it's black  or white?

[Kim]

hmm, cheers, might try that. so it's supposed to be able to see  through, say, jersey material then.

Is it not just electromagnetic waves... am I wrong to assume since I can't visually see through my jersey, that a gps sensor won't also be able to see a satellite through it? Does it make a difference whether it's black  or white?

It's radio at about 1.5GHz, at an insanely low level (the really impressive thing about GPS is that the receivers can pick the signal out of the noise with a little omni patch antenna rather than the directional dish you'd normally expect to use for such things).  Strictly line-of-sight stuff.  Most materials will attenuate it to some extent, but a dry cycling jersey isn't going to have a significant effect (the receiver's plastic case is denser).  An ugly bag of mostly water, on the other hand, will cut it right down.

GPS chipsets vary:  Early eTrexs would struggle to maintain a lock under tree cover (the water in the leaves absorbs the signal).  The modern ones will get a usable signal indoors.  My general experience is that the chipsets built into lower-end smartphones aren't as robust as those used by the likes of Garmin, but that trees and urban canyons aren't the problem they once were.

While the antennas used in handheld gadgets aren't directional, they tend to have a 180degree field of view, oriented so they're pointing at the sky in normal handheld operation.  As such, you can expect a phone's GPS to work better with its screen facing outwards, rather than towards your body.  I'd generally carry such things in my pocket with the screen facing inwards in order to protect it from damage, which is exactly the wrong way round.

I don't spend a lot of time with my phone (MotoG) in my pocket, but it certainly maintains an adequate GPS signal outdoors from the pocket of a pannier, wedged between some shopping and the contents of my wallet.

[Ben T]

Hmm. Thanks Kim. I'll have to try it a bit more. Might have been some military cloaking or something going on. 

[Kim]

The other thing that's really good at jamming GPS signals is the BR Class 220/221 (Super) Voyager.  For non-trainspotters, that's the CrossCountry/Virgin diesel trains with the stupid dangly bike spaces.  For reasons that can only be explained as poor electrical engineering, they emit enough RF interference to almost completely obliterate GPS signals, even on a sensitive receiver like the modern eTrex.  Quite annoying when you're trying to use GPS to work out if you're near your destination yet.

Rower40 once pointed out that they obliterate the radio time signal to the York signal box when they're parked on the adjacent platform, too.

And yet the cellular signals are strong enough to still get through.  So you still get to listen to annoying ringtones and "I'M ON A TRAIN!"

At least they don't smell of poo.  Usually.

[Ben T]

I had been on a ferry, but I'd got at least several miles inland from it, and it had potentially turned round and gone back as well.. However I have seen how big one of them's diesel engines is, it fills a room, and a fairly large room at that. Although I imagine it needs it's own GPS so that would have to not be interfered with.

[yoav]

The other thing that's really good at jamming GPS signals is the BR Class 220/221 (Super) Voyager.

No idea what class of train it was but I once cycled to Appleby, then caught a train home to Carlisle and forgot to switch off the Garmin. It had me doing 60 mph for the journey home. 

[frankly frankie]

An ugly bag of mostly water, on the other hand, will cut it right down.

That's no way to talk about my midriff.