GPS-Logit

Had the xperia E on my head today, pixie on my right arm and GT31 on left arm.

Wind was light so only reached 21kts, don't know if that's why all 3 2s are the same run this time, and the GT31 is the fastest.





red is GT31 yellow is the Pixie and blue is the Xperia E

So looks like being on my head hasn't helped the xperia very much, the pixie looks to have a smoother speed graph.
So next time it's the pixie that'll be on my head.

I'm of a different opinion to Andrew, I think I prefer the Pixie, it gets a satellite fix quicker than the xperia, and so far is a little bit more accurate.
Although on Sunday it was running out of battery sooner than the xperia, but this could be down to Sunday only being it's 2nd full charge.

And here's another interesting view of the xperia.
The 3 speed graphs from GPSARPRO on top, with the GPSRESULTS Xperia speed and satellite graph below.




Blue is the xperia, red GT31, yellow pixie3.
It's fairly evident that where the xperia deviates from the other 2 there's a change in satellite numbers, so trying to get a better signal is the way to go, but mounting on my head obviously isn't the whole answer.
The other interesting thing is the GT31 has 7 sats 90%of the time and a singal drop to 6sats near the beginning of the alpha.
The pixie3 has 9 sats most of the time with the odd drop down to 8
. while the xperia does 12, 11 and 10

I think I see the problem, the galaxy 3 mini I googled is only Android 4.1. Manfred has specified Android 4.2 Minimum, that's why it says it's not compatible.
Some where here, somebody else has used an older phone, and updated the software to successfully load logit, it may be the one in the list.

Just did some more googling, and there were some models with 4.2

en.wikipedia.org/wiki/Samsung_Galaxy_S_III_Mini

So this is a bit of a trap for the unwary, you have to make sure what operating system you're getting!!!!!
Unless you know how to upgrade it.

Tried a geostationary comparison between the xperia E1, Pixie 3/4 and GT31, with very strange results. As expected the GT31 sat at around 0.1kts with the very odd excursion to 0.5kts. the Xperia sat a at a rock steady 1.9 knots for over 3 hrs with one tiny glitch to 2.2kts (thought these were supposed to be 0.5kt steps?)
But the Pixie is the strangest, that records a rock steady 0.0 for 4minutes, then stops recording, only starts recording again when I pick it up and take it inside.
I also wanted to do an attitude test, started with the phones about 20deg off vertical then after about 1/2hr tilted them a bit more to about 5deg off vertical then layed them horizontal for the last hr. Can't tell with the Pixie of course it wasn't recording, but as far as I can see there's no difference with the xperia.

Does logit stop recording automatically when speed is 0.0?????? I haven't seen a log turn off when sailing.
So a very inconclusive experiment.
I did notice some differences though.
At the end of the test the xperia battery said 59% the Pixie said 49%
The Pixies got a satellite fix long before the xperia, and here's the strange one, while inside with very poor satellite view. the xperia said it had 9sats but was only using 5, whereas the Pixie said it had 5 and used 5.
The reported distance accuracy and altitude was much better on the Pixie




This is the worst case, in the middle of the room, 3 sats used on the pixie, 2 sats used on the xperia, but it still says 9.

And I guess the "bearing" only works when you're moving, because they are quite different as well.
And we are above sealevel, I'd guess at 10m

Yoyo has discovered this app.
sourceforge.net/projects/bluegps4droid/
Looks like you can replace the gps chip in the phone with a blue tooth gps logger.
I think it should work with a BGT31, anybody out there got one, as well as a phone to try it out?

If it works well, the next trick is to source a good inexpensive 10hz blue tooth dongle.

Did a run with Xperia (running GpsLogit) and GT11 side by side on seat next to me. The weird thing was that although the Xperia had 9-10 sats the speed was all over the place whilst the GT11 had a pretty smooth track although the location was testing its not very sensitive chip with mostly only 4-5 sats and sometimes much less !

Those Pixie results look good Mike

Some very strange results yesterday, tried the xperia in the new H20 armband, and after about half an hour it started working it's way through my playlist, all by itself. I'd left the music off to conserve battery, but couldn't be bothered turning it off.

Like the last few sessions speed talk and the displayed numbers were a fair bit higher than the GW52, and the results processed from the xperia's file. This morining I woke up with a light bulb moment, thinking the xperia had somehow been set to mph, so I was disappointed to find it correctly set on kts. Could it be a bit confused, and think it was in mph even though it says kts????

I then tried the pixie in the new pouch, thinking that would give more accurate speech, and it did for a while until that too started playing music, and much sooner than the xperia. But it didn't just go through the playlist, with every movement of my arm it changed track, either forward or back, so I listen to very short jumbled snippets. Then all this activity resulted in the display turning off, and speed talk went crazy, telling me I was doing 45kts at one time, that came good as soon as I restored the display.
Today I've been trying to work out what the problem is, I disabled the music player, but in the pouch it still starts playing music and a slight shake will change tracks. I checked settings, and change tracks with a shake is unticked, (why would anybody want that??)

Everything worked much better in my cheap ($12) Chinese armband, there's no way to fit any protection in the H20

This is all starting to get a bit too hard.

Think I've worked out what's causing the music to start, the non waterproof phone earphones don't do it, and the cheap chinese waterproof phones are for a music player not a phone, they only have 3 connections not 4 like the phone does.
I think this is confusing the audio software, but why it only does it through the H20 pouch and is worse for the Pixie is another mystery. So I guess I need some waterproof phone earphones.

those tracks look a lot better than my Xperia results and the value for money of the Pixie would be hard to beat

Took my Galaxy Ace 3 for a sail today. It doesn't have the "display off" syndrome, and has good satellite sensitivity, but only has the lower 0.486kt resolution.
Wore it on my upper right arm with the GW52 on my head.
It produced very acceptable results.
GW52
2s 26.500, 5x10 24.635, 1hr 10.787, @ 17.789, NM 19.103, Dist 46.639

ace3
2s 26.242, 5x10 24.629, 1hr 10.779, @ 17.810, NM 19.152, dist 47.975

I think the difference in distance is because I have min speed set to 3kts on the GW52, otherwise the numbers are well within the +/- 0.25Kt, accuracy that's the basic resolution of the Ace3.

Here's the 2s doppler speedgraphs





and here's the alphas





As you see the graphs and tracks are very close, especially at higher speeds, there is a bit of divergence at lower speeds, not sure why at the moment.

I think this is a closer result than either the PIxie or xperia when they were on my head.

OK a couple of geostationary tests resolved the issue, in the 2hrs with display on, it didn't miss a beat, continuous 1sec recordings. But 1/4 hr with display off it had typical big gaps up to almost 2 minutes long.
But like the xperia, and unlike the Pixie, it doesn't make big speed spikes while the display is off.
I'm still not sure what caused the drop outs, when I'm fairly sure the display was on, it was on top of the car in hot sun, so there may be a heat issue. I don't want to test for this, in case I damage the phone, we'll let Fin do that!
So as long as there's no heat problem, I think this is a better phone than the Pixie and the Xperia.
It has the high res of the Pixie but the absence of big spikes like the xperia

Here's a car ride with the GT31 and ZTE next to each other on the roof racks.
Red is GT31, yellow ZTE
The green centre line is where the ZTE has a drop out, that's why the yellow line takes a short cut across the bottom of the red peak. Apart from that the two lines are very close.



And this next one is a bike ride with the GT31 in the rear carrier with the ZTE on one arm and the Xperia on the other.



Blue ZTE, red GT31 yellow Xperia
Again the centre line is where the ZTE had a drop out, but you can see how much better it is than the xperia, when it's not dropping out.

Both the Pixie and Xperia, don't give good results on my arm when I'm bike riding, because my arms are more vertical than when sailing, and my body shields the satellites more, doesn't seem to worry the ZTE as much, but it's still not as close to the GT31 as it is when on top of the car with a good sky view.

Corey has solved the spikes and data gaps with the Pixie, and I'll try the Xperia soon and see if I can fix that as well.

You just have to go to "settings" "Display" "Sleep" and set that to "never"

looks like you may be right, went for another ride, hardly any data at all!
I've got no idea now what is going on!
Think I'll just forget about it for a while, it's doing my head in.