Hi Guys,
Recently purchased a GT 31 gps. I have set the unit up following the settings suggested by the GPS Team Challenge website -(http://www.gpsteamchallenge.com.au/guides/setupgt11_2008.php).
The problem I'm having is that the GPS still logs speeds under 3 knots; ie when i'm walking to and from the beach to my car. I have tried setting the minimum speeds to 6 knots but it doesn't make any difference. Any suggestions???

That sounds very strange, how are you looking at the stored data?

Because real speed or googleearth can still show a presumed track, they just join the dots, of actual recorded points.

And of course the display will show less than the store minimum set.

I'm using gps action replay version - 3.3.3bis - April 07 to view the data.

Just checked my last file on gpsarpro, and to my surprise I'm in the same boat, memory card is set to 2kts and data logger 3kts, but there's loads of stuff under that.
But there's also long periods of time with no data recorded, (when I've been stationary) so maybe it doesn't start and stop instantly?

What program do you usually use Decrepit? Is there one that you can recommend?

For my important posts on the challenge site I use realspeed, I think it's what most people use, it seems to have a better alpha algorithm, and some argue a more accurate 2sec. (although it gives lower values, because it uses 3 readings for the average not 2).
Because I hate using windows, ( I'm a linux fan) I use gpsarpro for any non critical purposes.
But I have a feeling realspeed will also have the lower speeds as well, I'll look next time I'm in windows.

Thanks Decrepit

An interesting observation guys. I will have to do some testing to see if my GPS's are doing the same.

Just checked in real speed and of course those low numbers are still there, but it's a bit easier to see how they're placed, and there aren't too many low numbers together with 1sec intervals, there's usually a multi-second interval (where it's stopped recording) before or after them.

i didnt think the basic gps action replay could read gt 11 (gt31) files....is this true? and would it have any effect such as smithers has described?

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snides8 said...

i didnt think the basic gps action replay could read gt 11 (gt31) files....is this true? and would it have any effect such as smithers has described?

As far as I know you're right the basic version won't open .sbin files, sorry should have asked that question.

So Mr Smithers, can you enlighten us, are you using the basic gpsar version, if so what sort of files are you putting in it?

I'm using version 3.3.3bis April 07. The procedure I use is to open Navilink II and convert the sbn file on the SD card to NMEA, save it to a folder and then open gpsar. Very new to the gps thing so any advice is appreciated.

Don't worry you're doing well, I'd forgotten about the latest navilink having file conversion.
I think most of us who where around when the file first went .sbn, before navilink could handle it, use realspeed or gpsarpro. and load the .sbn file direct from the card.
Less messing around, but you have to pay for the program.

So if I purchase realspeed will it do the same thing, or will my problem be solved???

Now there's a good question, somehow I doubt it.
Unfortunately I'm going to be away for a while otherwise you could have posted me the .sbn and nmea files, and I'd check them with realspeed.

But is it a problem?? Just means a slightly bigger file size, (if it's like mine and there's only a few low numbers either side of a gap where it hasn't recorded)

I guess it's no big deal but it would be nice not to have that data there, especially since the gps unit has settings to prevent it logging below a certain set speed. (that's if my understanding of the way the gt 31 works is correct)

Just checked Smithers's files and they look OK to me, there's only two 1 sec recordings under 6kts on the .sbn file, and a handful below 3kts on the .sbp file.
The .sbn file has only one section that falls under 6kts, but the .sbp file drops below 3kts several times. the data shows low speeds but the time frame is several seconds, the individual 1sec points aren't recorded.

While we're on the subject of GT-31's, I remember reading somewhere that I can't download straight from the SD card via USB to my computer. Can someone confirm this? Also, I've found it quite hard to get the card out. Is there some special eject button I can't find or is it just fat finger syndrome? Thanks

Jethrow

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Jethrow said...

. . . can't download straight from the SD card via USB to my computer . .

&
. . . hard to get the card out . .

Downloading directly should be OK; you need an SD card reader, which will cost about $20 (JB Hi Fi, Dick Smith, Harvey Norman etc). Plug it in to any USB port. The PC will see the SD card as another storage device, and you can drag the GPS files from it and drop them onto your Local Disk. (or copy / paste, if you prefer) You can also directly delete files from the card, typically once you've stored them on your PC.

To eject the SD card, hold the GPS with the card slot downwards. Push the card upwards with your fingernail against the internal spring, then "snap" your finger away. Gravity and the spring will eject it. Works for me every time!

Sorry, I meant can I download files straight from the GT-31 onto my computer without removing the card or using a reader. Thanks

Jethrow

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Jethrow said...

Sorry, I meant can I download files straight from the GT-31 onto my computer without removing the card or using a reader. Thanks

Jethrow

Yep you can useing this.

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smithers said...

The procedure I use is to open Navilink II and convert the sbn file on the SD card to NMEA, save it to a folder and then open gpsar. Very new to the gps thing so any advice is appreciated.