Select to expand quotesailquik said..
I am now the humble owner of one of these Alcatel Pixi's. Unbelievable value at $29.50!
It makes a GPS-Logit folder in the phones memory and saved a file from a short test today. >>>.
That's good, I have a feeling that Cory didn't say yes at the right time during the installation
Select to expand quotesailquik said..
Just waiting for the Spring storms now! 
Actually, the speed resolution is not an issue at all for me as I will be posting with GT-31/GW-52 anyhow, as all the competitive sailors should. I will be using the App for on water feedback and in that role it will be very valuable!
I will probably continue to mostly use the Sony Xperia just because it connects to my Macbook Pro directly with Sony Bridge.
And it is important to stress using a really good waterproof bag! The Paqua is really good, but I think the one Roo found (H2O Audio) is fantastic. I have given it heaps of abuse in the snowfields this season and it has been faultless. Comfortable, waterproof, easy to use, good fit for the phone and has provision for waterproof earphones.
Only thing we need now is for Manfred to set the app up to link to a bluetooth 10hz UBlox gps so we have high res data. We already have the Wintec units so now we just need the app.
Been using the H2O Audio for years now without any leaks, same goes for their earphones.
Picked up my Alcatel Pixie yesterday ($29.50 at Officeworks) and loaded GPS-Logit last night. Ready for a sail this afternoon if the forecast holds.
Select to expand quoteJohn340 said..
Picked up my Alcatel Pixie yesterday ($29.50 at Officeworks) and loaded GPS-Logit last night. Ready for a sail this afternoon if the forecast holds.
Snap again. I'll see if I can figure out how to do a sensitivity comparison.
I was very conscious of ticking the right boxes during installation, but I also had Corey's problem. Couldn't see a logit folder on the phone from the computer, and at the bottom of the main logit page, the file address is on the sd card.
However I took Roo's advice and checked with file manager, and low and behold the logit folder is in the phone storage. So had to copy it's contents into the "Downloads folder" then the files were accessible from the computer.
Select to expand quotedecrepit said..
John340 said..
Picked up my Alcatel Pixie yesterday ($29.50 at Officeworks) and loaded GPS-Logit last night. Ready for a sail this afternoon if the forecast holds.
Snap again. I'll see if I can figure out how to do a sensitivity comparison.
I was very conscious of ticking the right boxes during installation, but I also had Corey's problem. Couldn't see a logit folder on the phone from the computer, and at the bottom of the main logit page, the file address is on the sd card.
However I took Roo's advice and checked with file manager, and low and behold the logit folder is in the phone storage. So had to copy it's contents into the "Downloads folder" then the files were accessible from the computer.
I often see the same issue with the files not 'appearing' on the computer but they are in the file manager. I 'Dropbox' them from the Alcatel as it does not connect to my Mac like the Sony will.
I did notice that the Alcatel seems to have just GPS connectivity and perhaps not the other systems as I am only seeing 8 sats connected with it. That might lead to more errors in poor satellite coverage situations.
I also did some exporting of files in CSV format from RealSpeed to open in EXCEL. Easy to sort them and see what the precision steps are that way.
I also checked the GT-31 and GW-52 files. Both of these appear to have a speed resolution of -0.019438/-0.019439. (Realspeed obviously exports the data to six decimal places!)
The Alcatel also shows up as -0.019438/-0.019439.
The Sony as -0.485961/-0.485962. It is the same from both .GPX and .SBP files.
It is important to emphasise that this resolution IS NOT the same thing as accuracy!
Interestingly, the calculated average speeds from RealSpeed end up being very similar between the Alcatel and Sony Phone in GPS-Logit, and within the same spread as the 3 GT-31's and one GX-52 I was using.
It is also important to repeat that the data from the GT-31's and the GW-52 is able to have it's accuracy verified, whereas the data from the GPS-Logit app (and Canmore/Garmin/ whatever else) cannot be verified for accuracy. I have already seen an instance of erroneous speeds from other devices that were luckily obviously wrong enough to know they were errors. This will not always be the case.
Select to expand quotesailquik said..
Interestingly, the calculated average speeds from RealSpeed end up being very similar between the Alcatel and Sony Phone in GPS-Logit, and within the same spread as the 3 GT-31's and one GX-52 I was using.
Andrew, you must be lit up like a christmas tree!
Select to expand quoteJohn340 said..sailquik said..
Interestingly, the calculated average speeds from RealSpeed end up being very similar between the Alcatel and Sony Phone in GPS-Logit, and within the same spread as the 3 GT-31's and one GX-52 I was using.
Andrew, you must be lit up like a christmas tree!
Two GT-31 in helmet, left arm bag with GT-31 and GW-51, Phone on right arm. At least I got plenty of data!!
Select to expand quotesailquik said..John340 said..sailquik said..
Interestingly, the calculated average speeds from RealSpeed end up being very similar between the Alcatel and Sony Phone in GPS-Logit, and within the same spread as the 3 GT-31's and one GX-52 I was using.
Andrew, you must be lit up like a christmas tree!
Two GT-31 in helmet, left arm bag with GT-31 and GW-51, Phone on right arm. At least I got plenty of data!!
Ah as the Irish would say,
"To be sure, to be sure"
Select to expand quotesailquik said..
I often see the same issue with the files not 'appearing' on the computer but they are in the file manager. I 'Dropbox' them from the Alcatel as it does not connect to my Mac like the Sony will.
Strange the logit folder in the pixie has now appeared on the computer, but today's test run in the xperia failed to appear.Select to expand quote
I did notice that the Alcatel seems to have just GPS connectivity and perhaps not the other systems as I am only seeing 8 sats connected with it. That might lead to more errors in poor satellite coverage situations.
Agreed, I was going to try and do a test in varying depths of water to see how it affected number of sats, but not much point when the xperia has more to choose from!Select to expand quote
>>>> I have already seen an instance of erroneous speeds from other devices that were luckily obviously wrong enough to know they were errors. This will not always be the case.
My last sail the xperia gave me a false 31.5 when the GW52 said I was only doing 29s, without the GW52 it would have been hard to prove the 31 wasn't valid.
There was also a difference in alpha separations, my best gybe was within the 50m on the xperia but not the GW52.
I took the Xperia, Pixie3, GW52 and GT31 for a cycle ride this morning. started off with the gt31 and gw52 on the back carrier and the phones on each upper arm, then half way through the ride swapped then over, phones in back carrier and the Gs on my arm.
Trouble is, when I did the swap, the pixie display was off, and I don't know when that happened.
Loaded the phones and GT31's tracks into GPS visualizer to see how they went.
Above is the Gearies lookout where I did the swap, red is pixie, green xperia and blue GT31
below is the first turn at the Avalon lookout, I suspect the display on the pixie was off here.
I think, where the pixie's screen was off, the xperia's tracks look better, but once the pixie's screen was back on, it's tracks look marginally better.
As for numbers.
2s 5x10 alpha NM dist
GT31 19.409 16.331 12.173 7.145 2.798
pixie 19.691 16.153 14.560 3.54 2.718 but there was a false 2s of 29.67
xperia 20.410 17.804 12.809 0 2.155 but this also has a false 2s of 23.083 in a very similar spot.
So pixie numbers look closer than the xperia, but I'll do some more tests, with the pixie and xperia screen on and off.
Select to expand quoteThought I'd better add the pixie3
Best
0.019 knots resolution
Samsung Galaxy S5
Samsung Galaxy S3
Samsung Galaxy SIII mini
Samsung Galaxy J1
Sony Xperia Z3
Alcatel One Touch Evolve 2
Alcatel One Touch Pixie3(4)
Huawei Ascend Y330
LG L7 2
Seans Mpie Mini 809T, but so far it's only been tested on a car dashboard, and the file has plenty of gaps in it, so sensitivity is suspect. We'll know more when Sean takes it out under open skys.
Worst
0.486 knots resloution
Sony Xperia Z1 compact
Sony Xperia E1
Motorola Moto X
Motorola Moto E
Galaxy Ace 3 (GT-S727ST)
Checked what happens with the Pixie3 when "display on" is unticked, in other words the display is allowed to turn itself off.
Both GT31 and Pixie3 in the rear bike carrier, facing the sky.
Did two identical runs along the foreshore, one with display on unticked, then with it ticked.
The difference isn't the same as the xperia, here the pixie seems a bit laxy getting it's position, rather than having holes in the data.
Blue track GT31 Red Pixie3
All the running around on top of the houses are in the first 2 minutes while the phone finds itself. But even when it seems to have settled, it's out several metres in a north south direction.
After I come back home, turn display on, and go for the 2nd run, the tracks follow the GT31 much better.
In that first few minutes there are 3 false highs of 29, 26 and 23knots, but after that the speeds aren't too bad, but they're much better once display is on.
here's the GPSarPro view of the GT31 and Pixie3 speed graphs.
Yellow is Pixie3 Red is GT31. There's a marked difference once the display is on in the 2nd half.
I attribute the big spike in the middle to my body blocking satellites while I turned the display on.
Like the Xperia the Pixie needs a good view of the sky.
Alby, you may be on to something here. The survey version has up to 10Hz , 1m accuracy (post-processing 10-50cm). All in a more ergonomic yellow box than the 5Hz locosys GW52.
bad-elf.com/pages/be-gps-3300-detail
but I still await a reply from the company. It looks like the Surveyor one has the same chipset.
Select to expand quotedecrepit said..
Thought I'd better add the pixie3
Best
0.019 knots resolution
Samsung Galaxy S5
Samsung Galaxy S3
Samsung Galaxy SIII mini
Samsung Galaxy J1
Sony Xperia Z3
Alcatel One Touch Evolve 2
Alcatel One Touch Pixie3(4)
Huawei Ascend Y330
LG L7 2
Seans Mpie Mini 809T, but so far it's only been tested on a car dashboard, and the file has plenty of gaps in it, so sensitivity is suspect. We'll know more when Sean takes it out under open skys.
Worst
0.486 knots resloution
Sony Xperia Z1 compact
Sony Xperia E1
Motorola Moto X
Motorola Moto E
Galaxy Ace 3 (GT-S727ST)
You can't rate the performance on GPS-Logit phones on speed resolution alone. For example the Alcatel Pixie might have a resolution of 0.02kts but the sensitivity of its GPS reception is rubbish. Last weekend, speed chat informed me of speeds in excess of 40kts while I was standing on the beach. Later in the session the speed varied wildly between 15kts and 35kts while sailing on a reach in marginal planing conditions on my raceboard. I think the problem with the Pixie is related to the poor perfomance of its GPS antena.
On the other hand the Xperia Z1 has poor speed resolution of 0.5kts but has reliable GPS reception. The results from the Xperia reflect the results from my GT-31 within the speed resolution error of 0.5kts.
I will continue to use my Xperia, because the instant feedback while sailing is fantastic. However I will only use my GT-31 and the GW-52 (when it arrives) for uploading results into the GPS Team Challenge.
Select to expand quoteJohn340 said..
...
You can't rate the performance on GPS-Logit phones on speed resolution alone. For example the Alcatel Pixie might have a resolution of 0.02kts but the sensitivity of its GPS reception is rubbish. Last weekend, speed chat informed me of speeds in excess of 40kts while I was standing on the beach. Later in the session the speed varied wildly between 15kts and 35kts while sailing on a reach in marginal planing conditions on my raceboard. I think the problem with the Pixie is related to the poor perfomance of its GPS antena.
On the other hand the Xperia Z1 has poor speed resolution of 0.5kts but has reliable GPS reception. The results from the Xperia reflect the results from my GT-31 within the speed resolution error of 0.5kts.
I will continue to use my Xperia, because the instant feedback while sailing is fantastic. However I will only use my GT-31 and the GW-52 (when it arrives) for uploading results into the GPS Team Challenge.
Totally agree John, we need a reliable way to measure sensitivity, to make this list more meaningful. The number of satellites is an indication, but by no means the whole story, there's also how clean the signal is. I've had errors with both the xperia E and pixie3 whilst showing 12 satellites, I think the errors are due to a weak and noisy signal, rather than a lack of satellites.
I was thinking of submersing the phones in water, and comparing how the number of satellites dropped out with depth, may still do it. But the comparison is only valid at that time and place. It's not going to be an absolute measurement capable of comparing different phones in different places.
Seems like there's a big difference between the xperia Z1 and the E, because I think the pixie has marginally better reception than the xperia E.
Both of them need to be horizontal with a clear view of the sky
I'm going to try having the Xperia E or the Pixie3 on my head and see if that improves the signal enough to eliminate the errors.
Ditto to that.
The Xperia sensitivity in my Paqua is rubbish whereas the Canmore had no problems at all. Though maybe it was not recording every sec and I need to look at the settings more closely.
The Canmore tracked the walk on the path almost perfectly
Select to expand quoteseanhogan said..
Hi Yoyo,
what software do you use to come up with those nice colours ?
GPSvisualizer.com
And you can put multiple files in and colour by tracks instead of speed.
Select to expand quoteyoyo said..
Ditto to that.
The Xperia sensitivity in my Paqua is rubbish whereas the Canmore had no problems at all. Though maybe it was not recording every sec and I need to look at the settings more closely.
>>>>>
David that is indeed rubbish, but I've only seen tracks that bad if the phone is vertical with the display off. With the display on and phone on my upper arm, the results I'm getting only vary a small amount from the GT31, enough to be a worry, but no where near as bad as yours.
So could the display have turned off, phone been vertical or obscured??
Select to expand quoteJohn340 said..
>>> For example the Alcatel Pixie might have a resolution of 0.02kts but the sensitivity of its GPS reception is rubbish. Last weekend, speed chat informed me of speeds in excess of 40kts while I was standing on the beach. Later in the session the speed varied wildly between 15kts and 35kts while sailing on a reach in marginal planing conditions on my raceboard. I think the problem with the Pixie is related to the poor perfomance of its GPS antena.
>>>>.
John, I'm not getting results anywhere near as bad as that, in fact today in light winds the pixie was very close to the GT31, better than the Xperia E.
I've only had bad results when the screen turned off, and/or the phone was vertical instead of horizontal.
There's a big difference when wearing it on my upper arm, between sailing and bike riding. When on my bike my upper arms are vertical and when sailing they're horizontal. I suppose when riding they're a bit more obscured from the sky, that may be a factor as well.
Mike, I'll persevere with the Pixie and see if I can get some more consistent results.
Select to expand quotedecrepit said..yoyo said..
Ditto to that.
The Xperia sensitivity in my Paqua is rubbish whereas the Canmore had no problems at all. Though maybe it was not recording every sec and I need to look at the settings more closely.
>>>>>
David that is indeed rubbish, but I've only seen tracks that bad if the phone is vertical with the display off. With the display on and phone on my upper arm, the results I'm getting only vary a small amount from the GT31, enough to be a worry, but no where near as bad as yours.
So could the display have turned off, phone been vertical or obscured??
All three perhaps. I thought I had ticked "screen on" but it kept going off. Mike what "min speed" setting do you use?
