It would look almost as good as your bucket hat!

Here's the difference between the Xperia on my arm and the GW52 on my head.
Red is GW52, blue Xperia Logit.


Fangy's sent me his tracks of the xperia on the top of his camel pack. I'll be back after I've looked at them.

Well Fangy if your Canmore tracks are worse than this I'd hate to see them, your logit file looks worse than mine.
Here's a gybe that goes down to 1 satellite only.




The bottom green line is number of satellites, the upper limit is 10.
You can see what happens to the tracks when they drop down to 1.

Next time I go out I'll wear the xperia on my head and see what those tracks look like.
For people who want to only use the phone, this sort of track is far from ideal.

Sorry peeps. I just went and looked at all my tracks again from both the Canmore and Xperia. I think I might have got them confused when I was posting on GPSTC. The Canmore gybes look nice and smooth as they should whilst the Xperia ones look like I feel today - a bit ragged.

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fangman said..
Sorry peeps. I just went and looked at all my tracks again from both the Canmore and Xperia. I think I might have got them confused when I was posting on GPSTC. The Canmore gybes look nice and smooth as they should whilst the Xperia ones look like I feel today - a bit ragged.

So the Canmore was on your head?

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decrepit said..

fangman said..
Sorry peeps. I just went and looked at all my tracks again from both the Canmore and Xperia. I think I might have got them confused when I was posting on GPSTC. The Canmore gybes look nice and smooth as they should whilst the Xperia ones look like I feel today - a bit ragged.

So the Canmore was on your head?

On my Camelpak too, mounted below the Xperia.

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John340 said..

Mike,
I had a problem with the wind whistling in my ear when using the water proof ear buds on the blue tooth earphones. Have you had the same problem?

Have you tried it without the earphones? I have only used it that way and with the Sony Xperia on my arm I can hear it quite clearly both when sailing or skiing and I wear a helmet for both.

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decrepit said..
Here's the difference between the Xperia on my arm and the GW52 on my head.
Red is GW52, blue Xperia Logit.


Fangy's sent me his tracks of the xperia on the top of his camel pack. I'll be back after I've looked at them.

Well Fangy if your Canmore tracks are worse than this I'd hate to see them, your logit file looks worse than mine.
Here's a gybe that goes down to 1 satellite only.




The bottom green line is number of satellites, the upper limit is 10.
You can see what happens to the tracks when they drop down to 1.

Next time I go out I'll wear the xperia on my head and see what those tracks look like.
For people who want to only use the phone, this sort of track is far from ideal.

I agree it is not too flash. I wonder if it was a lot to do with where and how it was worn though?

There is strong evidence of 'grid effect' in that graph. I have not seem that with my Sony Xperia in any of my skiing tracks recently. (The snow is too good to be sailing! )

I found the Xperia definitely has quite average accuracy but I wonder if you say tighten up the filters on GPSResults (maybe acceleration and Sats) perhaps you can smooth it out a bit.

When you say 'average accuracy', what parameters/divisions are you looking at?

I am finding the Doppler speed results agree very well with the GT-31 and GW-52 in most circumstances.

Yep me as well, the numbers I'm getting are very close, it's just the strange tracks in gybes that worry me.

Anyone else struck the issue with the tracks display where it asks you to update some Google thing and then proceeds to ask you for your life history and identity to allow it, and force you to have a G-mail account so they can read you emails and spy on your life some more?

Bugger that crap!

The strange thing is that I saw the map view in a earlier version. Now it's gone.

Yesterday was the first day I've used the GPS-Logit App with Speedchat. Like Decrepit I've coupled the Xperia phone with the Pyle waterproof bluetooth earplugs. The earplugs work really well - no messy cable. I use the side flaps on my nylon sailing bucket hat to hold the earplugs in position. I had a couple of minor stacks and the earplugs felt secure. Only a full blown over the handle bars moment will be the real test. I set the frequency of update to 2s on the App and the threshold speed at 25kts. This seems to be a good compromise and provides sufficient feedback without being annoying. The realtime feedback is a game changer. I was able to modify my tracks to optimize speed and was able to achieve a PB for the board and sail size at that location. Only one problem, there was a 0.7kt discrepancy between the 2sec max on the phone compared to my GT-31. I wore the phone on my upper arm and the GT-31 on the shoulder strap of my impact vest, so location of the devices shouldn't be a factor. The number of satelites used by the devices when the 2sec max was recorded were 14 for the phone and 9 for the GT-31.

A .7kt difference isn't huge, and sat numbers are fairly typical, go with the GT31.
Yoyo phoned me from a bus doing 100km/hr he said his xperia was varying by .9kt up and down constantly although the bus appeared to be doing a steady speed. He thinks it's some sort of grid effect.

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sailquik said..
Anyone else struck the issue with the tracks display where it asks you to update some Google thing and then proceeds to ask you for your life history and identity to allow it, and force you to have a G-mail account so they can read you emails and spy on your life some more?

Bugger that crap!

The strange thing is that I saw the map view in a earlier version. Now it's gone.

Elmo has shown me how to go into "developer mode". That allows you to stop all background process, I don't think the google thing was anything to do with tracks display, unless you were doing a google overlay?

I already have a gmail account so that may be why I haven't noticed it.

Yes it was interesting as though the speed display was in hundredth of a km/h (up to 100 then in tenths) the speed went 99.0 99.9 100.8 101.7 up and down with no speed readings in-between. So basically it read in 0.9km/h steps which just happens to be 1/2 a knot steps. I wonder if this is caused by lack of decimal places outputted by the phone gps or whether it is software related and perhaps Manfred needs to add some more decimal places and it might take some of the jaggedness out of the alphas.
I use Navigator as well but it only reads whole numbers in speed. I will try to find an app that has better (tenths) speed resolution.

Andrew, Google is just like the NSA but with better computers and no oversight. In WA the transport department was unable to investigate Uber because it's investigators were barred from the site. The WA government has no idea how Google found out who it's investigators were but it should be obvious ...Google tracks everyone/everything. You can not use the gps on your Xperia unless you allow Google to track you.

Do you remember the stink when Google street view cars were logging wi-fi..... Well they promised not to do it again... Haha...they don't need to do it anymore as everyone with an android phone does it for them!! Yet this does not seem to bother the public....

Google is profiling the world so it can sell your secrets to advertisers... whilst paying only 0.6% tax on its Australian generated profits by funnelling them through Singapore (for a 2% commission) to Ireland that does not tax foreign generated profits.

If you tried to do this as an individual the ATO would come down on you like a ton of bricks but multinationals......

Just had an email from Manfred.

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...
taking a closer look to the Xperia data shows, that the speeds have a 'grid-effect' i.e. a limited resolution of 0.25m/s = 0.9km/h = 0.486knots
...
You can easily see that in the speed-column of GPSResults, all speeds from the Xperia are multiples of the resolution...
No other smartphone I tested up to now shows this effect, normally the resolution is 0.01m/s=0.036km/h=0.02knots.
The Xperia is not very well suited for our purposes! A slightly more expensive Samsung Galaxy J1 is way better.

So it's not the software it's the phone!

Oh well, the Xperia still has sufficient accuracy to be used for real time session feedback, but I'll continue to use the GT-31 for my results. I've adjusted my results on GPSTC for Wednesday to the GT-31 results.

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decrepit said..
Just had an email from Manfred.

...
taking a closer look to the Xperia data shows, that the speeds have a 'grid-effect' i.e. a limited resolution of 0.25m/s = 0.9km/h = 0.486knots
...
You can easily see that in the speed-column of GPSResults, all speeds from the Xperia are multiples of the resolution...
No other smartphone I tested up to now shows this effect, normally the resolution is 0.01m/s=0.036km/h=0.02knots.
The Xperia is not very well suited for our purposes! A slightly more expensive Samsung Galaxy J1 is way better.

So it's not the software it's the phone!

Yes. This is what Yo Yo is seeing. I had a closer look at the data from mine and confirmed it is doing the same. Lack of fine resolution.

This phone is definitely not suitable for posting top team or individual results to GPS Team Challenge.

But as John says it is still great for instant on water feedback. Just use you GT-11/31 or GW-52 for the posted results.

It is also probably a good cross reference for using the low cost Canmore GPS. (If the results from both agree closely).

Manfred reports he has tested ten other Phones and says none have not exhibited this lack of resolution that the Sony Xperia has. If you are not sure of your phone, it is not hard to check the file results for a grid effect if you know what you are looking for.

Again I stress, it is still very useful on water feedback and well worth having. Just be sure to post results from the approved devices.

Just had a closer look at my Ace 3 files and they also appear to have a slightly less than .5kt resolution .
Gavin has sent me some files from his LG and I've see numbers around .02kts apart, (it's an older LG, before he upgraded it it was using Android 4.1.2)

I think we need a list of which phones make higher resolution files.

GPS-Logit in action in the snow. A recent powder day on my Monoski (This is the short interlude season for snow not water! )

Turn the volume up and you can hear the speed talking. Note that I don't hear the wind noise in the camera mic as I ski so the speed talk is quite clear. This is worn on my upper arm in the H2O Audio waterproof arm bag without the earphones. I can hear it quite clearly sailing as well this way.

Sweeeeet Powder Must get back to the snow soon! Now Logit gives me a new reason

Andrew, I first tried mine without headphones, but I could only hear it up to about 15kts, then it got drowned out by board and wind noise.

Just came across another strange anomaly, I tried using GPSarPRO to look at speed resolution, because it does a sort on the speed column. That was showing a 0.18kt resolution for the xperia, so I've compared the same part of the file in gpsresults, gpsarpro and realspeed, and something very funny is going on with GPSarPRO!
I don't think it's any good for determining speed resolution.

track, gps res, gpsar, realspeed
#4139 25.756 26.58 25.756
#4140 25.756 24.69 25.756
#4141 25.270 25.71 25.27
#4142 25.270 25.32 25.27
#4143 25.270 25.50 25.27
#4144 24.298 21.26 24.298
#4145 22.840 18.39 22.84
#4146 21.382 21.55 21.382
#4147 19.924 19.55 19.924

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decrepit said..
Andrew, I first tried mine without headphones, but I could only hear it up to about 15kts, then it got drowned out by board and wind noise.

Just came across another strange anomaly, I tried using GPSarPRO to look at speed resolution, because it does a sort on the speed column. That was showing a 0.18kt resolution for the xperia, so I've compared the same part of the file in gpsresults, gpsarpro and realspeed, and something very funny is going on with GPSarPRO!
I don't think it's any good for determining speed resolution.

track, gps res, gpsar, realspeed
#4139 25.756 26.58 25.756
#4140 25.756 24.69 25.756
#4141 25.270 25.71 25.27
#4142 25.270 25.32 25.27
#4143 25.270 25.50 25.27
#4144 24.298 21.26 24.298
#4145 22.840 18.39 22.84
#4146 21.382 21.55 21.382
#4147 19.924 19.55 19.924

I suspect the speed column in gpsar is track-points not doppler. I've just had more of a play with real speed, that also does a column sort. and gives both doppler and track-point columns. If I sort on the doppler speed I get a steady increase at the unit's resolution, but the track-point data is much the same as the above gpsar column, all over the place!

I heard that the Samsung S2 has a SirfStar IV chip. This one might eventually be quite good with GpsLogIt.

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decrepit said..

decrepit said..
Andrew, I first tried mine without headphones, but I could only hear it up to about 15kts, then it got drowned out by board and wind noise.

Just came across another strange anomaly, I tried using GPSarPRO to look at speed resolution, because it does a sort on the speed column. That was showing a 0.18kt resolution for the xperia, so I've compared the same part of the file in gpsresults, gpsarpro and realspeed, and something very funny is going on with GPSarPRO!
I don't think it's any good for determining speed resolution.

track, gps res, gpsar, realspeed
#4139 25.756 26.58 25.756
#4140 25.756 24.69 25.756
#4141 25.270 25.71 25.27
#4142 25.270 25.32 25.27
#4143 25.270 25.50 25.27
#4144 24.298 21.26 24.298
#4145 22.840 18.39 22.84
#4146 21.382 21.55 21.382
#4147 19.924 19.55 19.924

I suspect the speed column in gpsar is track-points not doppler. I've just had more of a play with real speed, that also does a column sort. and gives both doppler and track-point columns. If I sort on the doppler speed I get a steady increase at the unit's resolution, but the track-point data is much the same as the above gpsar column, all over the place!

Great science Mike!

You could well be correct. That would make sense because the trackpoints (location data) does tend to see-saw a lot with some devices. Part of this could be due to the original phenomenon that came to our notice with the old Garmin units and which we called the 'grid effect'. It is caused by a lack of resolution in the locational data. Part of it is caused by the position error factor inherent in Trackpoint data.

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decrepit said..
Andrew, I first tried mine without headphones, but I could only hear it up to about 15kts, then it got drowned out by board and wind noise......

Yeah, I found the wind noise also became a problem on skis on icy snow over about 80k's.

Bugger! looks my Pyle blue tooth headphones are dead.
The battery ran out after only 3hrs, last time I used them, so I tried charging from the car's usb charger. After that it didn't want to turn off, but still worked ok.

Now it charges up from the computer OK, and turns off as soon as unplugged, but won't turn on.

So this really makes the pyle unsuitable unless you only ever do less than 3 hrs at the beach. I guess you could charge them up from a laptop, but that's something I don't like leaving in the car anywhere around here!

Decrep,

On your GPS setting on the Sony do you have the unit set up as "GPS only" or using WIFI and tower info as well as GPS.

Some forums claim the GPS only is more accurate for GPS proper readings.

From what I gather the other stuff is for "location services" (big brother)

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elmo said..
Decrep,

On your GPS setting on the Sony do you have the unit set up as "GPS only" or using WIFI and tower info as well as GPS.

Some forums claim the GPS only is more accurate for GPS proper readings.

From what I gather the other stuff is for "location services" (big brother)

Good question Alby, Just checked and it's set to "gps only"