Garmin GPS - Downloading Garmin eTrex stored tracks

Author

Downloading Garmin eTrex stored tracks

Arne Schmitz

2007-10-15, 10:33 am

I am using a Garmin eTrex (the simple, yellow one). I am using gpsbabel and
gpsman for downloading my stored tracks and I am visualising them with
Google Earth. I noticed that the stored tracks have a quite coarse
resolution which does not compare to the resolution I see on my device when
tracking "live".

Is this a bug or a feature? I.e. is this some sort of "compression" that is
applied when storing away one track?

Arne

--
[--- PGP key FD05BED7 --- http://www.root42.de/ ---]

dold@82.usenet.us.com

2007-10-15, 10:33 pm

Arne Schmitz <arne.schmitz@gmx.net> wrote:
> I am using a Garmin eTrex (the simple, yellow one). I am using gpsbabel and
> gpsman for downloading my stored tracks and I am visualising them with
> Google Earth. I noticed that the stored tracks have a quite coarse
> resolution which does not compare to the resolution I see on my device when
> tracking "live".

> Is this a bug or a feature? I.e. is this some sort of "compression" that is
> applied when storing away one track?

Yes. Compare the number of steps in the active log to the number of steps
in the saved log. I have an active log with 134 points, and the saved log
of that same track is 113 points. There are also no time stamps in the
saved logs. There is a maximum number of steps in a saved log that might
be less than the maximum in the active log.

I rarely save, unless I am in danger of wrapping around and overwriting the
start of my tracklog. I copy the active file to my PC instead.

--
Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5

Arne Schmitz

2007-10-16, 4:33 am

dold@82.usenet.us.com schrieb:

> I rarely save, unless I am in danger of wrapping around and overwriting
> the start of my tracklog. Â_I copy the active file to my PC instead.

Ok, thanks. I had to save, because I was on a long trip. :-)

Arne

--
[--- PGP key FD05BED7 --- http://www.root42.de/ ---]

Otavio Exel

2008-01-16, 3:33 pm

dold@82.usenet.us.com <dold@82.usenet.us.com> wrote:

> I have an active log with 134 points, and the saved log of that same
> track is 113 points. There are also no time stamps in the saved logs.
> There is a maximum number of steps in a saved log that might be less
> than the maximum in the active log.

a nasty "feature" indeed! is it present in all garmin models?

[]s,

--
Otavio Exel /<\oo/>\ oexel@economatica.com.br

dold@82.usenet.us.com

2008-01-16, 10:33 pm

Otavio Exel <oexel@economatica.com.br> wrote:
> dold@82.usenet.us.com <dold@82.usenet.us.com> wrote:

[color=darkred]
> a nasty "feature" indeed! is it present in all garmin models?

As far as I know, it applies to all saved tracks on all Garmin models.
It has been discussed here so many times I'm surprised that I replied to
this thread in October.

--
Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5

Jack Erbes

2008-01-16, 10:33 pm

dold@82.usenet.us.com wrote:
> Otavio Exel <oexel@economatica.com.br> wrote:
>
>
>
> As far as I know, it applies to all saved tracks on all Garmin models.
> It has been discussed here so many times I'm surprised that I replied to
> this thread in October.

I've heard that regardless of how many points are in the track (max
would be 2,000 or 10,000 depending on model and settings) a saved track
never has more than 400 and never has the date and time.

If we're talking about an "x" series model with a microSD card, I think
all of those have the "Log Track to Data Card" option and those will
save every track point collected, with the lat/long, date/time, and
elevation (GPS or barometer, depending on the model and setting) as long
as there is some free space on the card.

Jack

--
Jack Erbes in Ellsworth, Maine, USA (jackerbes at roadrunner dot com)
(also receiving email at jacker at midmaine dot com)

Dan Anderson

2008-01-16, 10:33 pm

Jack Erbes wrote:
& #91;snip]
> I've heard that regardless of how many points are in the track (max
> would be 2,000 or 10,000 depending on model and settings) a saved track
> never has more than 400 and never has the date and time.
[snip]

The maximum number of points in the "saved track" (actually points
for a tracback route) ran from 125 in the first eTrex to 750 in
the b&w 76 series. How many points are actually stored depends
on how many "significant" points are in the active track.

Many people have the 60 and 76 color series with a 500 point
maximum "saved track". The algorithm doesn't reduce to the
best 500 points but simply reduces to whatever is considered
significant points. It's possible that no one has "saved"
enough to find an active track with 401-499 significant
points and it's also possible that the firmware has a
bug that cuts it off at 400 even though it could go to 499.

The 76Cx saves more points (more detail) in the "saved"
log than the 76S even though the 76S has more storage space.

--
Dan
(Email: dan at domain below )
(www.gpsmap.net)

Dan Anderson

2008-01-16, 10:33 pm

Dan Anderson wrote:
> Jack Erbes wrote:
> [snip]
> [snip]
>
> The maximum number of points in the "saved track" (actually points
> for a tracback route) ran from 125 in the first eTrex to 750 in
> the b&w 76 series. How many points are actually stored depends
> on how many "significant" points are in the active track.
>
> Many people have the 60 and 76 color series with a 500 point
> maximum "saved track". The algorithm doesn't reduce to the
> best 500 points but simply reduces to whatever is considered
> significant points. It's possible that no one has "saved"
> enough to find an active track with 401-499 significant
> points and it's also possible that the firmware has a
> bug that cuts it off at 400 even though it could go to 499.
>
> The 76Cx saves more points (more detail) in the "saved"
> log than the 76S even though the 76S has more storage space.
>
I just "saved" the active logs that were in my receivers
from my last walk.

The eTrex Vista HCx was full at 9,999 and saved to 500 points.
The 76Cx was full and saved to 412 points.
The 76S had 4,886 points in the active log and saved to 314
points.

--
Dan
(Email: dan at domain below )
(www.gpsmap.net)

Ricky Raccoon

2008-01-17, 4:34 am

Jack Erbes <jacker@midmaine.com> wrote:
> If we're talking about an "x" series model with a microSD card, I think
> all of those have the "Log Track to Data Card" option and those will
> save every track point collected, with the lat/long, date/time, and
> elevation (GPS or barometer, depending on the model and setting) as long
> as there is some free space on the card.

Further clarification. If all x models are like my 60 CSx and Vista HCx:

Main memory contains
Base map
Active track log
Saved tracks
Routes
Waypoints

microSD card contains
Maps loaded via MapSource (or other)
Daily track logs (track log points only, .gpx file)

Track data is logged in two places: active track log (main memory) and
daily track logs (microSD card) and is started and stopped by one switch
on the Tracks page. Note: you do have to turn on data card logging in
the Data Card Setup page first. Nothing else is recorded on the microSD
card; no waypoints, no routes, no saved tracks. Just daily track log
points (and the maps, of course).

The daily track logs are in gpx format and named yyyymmdd.gpx
The only way I know how to download the gpx files to my iMac is to put
the receiver in USB Mass Storage mode and connect it to my iMac with a
USB cable. After power on, the receiver appears on the desktop and I
drag copy the gpx files to my iMac. I usually use the receiver to erase
the gpx files at a later time. I have accumulated around 10 gpx files
at a time before erasing. I'm using 2GB microSD cards and the map I'm
using only takes up about 306MB, so there's lots of room.

Other - I use an iMac running Mac OS X 10.4.10 and NG TOPO! and MacGPS
Pro to manage data transfer between my iMac and my GPS receivers. These
Mac applications use 1 : 24,000 topo maps of Colorado onto which the
data is displayed. I also use Google Earth a lot. GPSBabel+ is a handy
tool to convert between various file formats.

On my GPS receivers, I use a 1 : 24,000 topo map of Colorado made by
Above the Timber. The map is in Garmin format and I copy it to the
microSD card in USB Mass Storage mode using drag copy. I do not use
MapSource. I'm more of a logger than a route follower...

As ever - HTH ;-)

Jack Erbes

2008-01-17, 10:33 am

Dan Anderson wrote:
<snip>
> I just "saved" the active logs that were in my receivers
> from my last walk.
>
> The eTrex Vista HCx was full at 9,999 and saved to 500 points.
> The 76Cx was full and saved to 412 points.
> The 76S had 4,886 points in the active log and saved to 314
> points.

Thanks Dan, this is obviously something other than a predictable behavior.

It is nice to have folks here that have both multiple receivers and
insatiable curiosities. :> )

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)

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