GPS Recommendations

"Jason Settles" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Does anyone use a GPS while cycling?

I'm looking for recommendations/suggestions for usage.
I would like something small that will upload/download to a computer.
Something that will also track altitude and/or grade changes will riding.

I have experience with a Garmin III Plus as well as considerable software
background so I am open to high tech suggestions.

Thanks in advance for any assistance.
*Jason. in Indy

Just started to use one which I borrowed off a friend. It's a Magellan GPS
315, I also use the shareware GPSU software.

Firstly, I created my own mount using a bit of fabric and a couple of zip
ties. Pretty sturdy on the stem.

Next, I joined the Google maps API and started building my own software to
view my routes and create new waypoints. Then I discovered that someone else
had got a little further than me, here's my copy of his software ...

GPS Map, shows actual routes downloaded from the unit and saved as .gpx
files.
http://fishpluschips.com/GPS/gpsmap.php

GPS Route allows the waypoints to be created.
http://fishpluschips.com/GPS/gpsroute.php

I've found the GPS fantastic around London. I just set a few waypoints and
then hack about closing in on each area. As I haven't registered gpsu, I am
limited to the number of waypoints, but you could get pretty complicated if
you wanted to...

Here's an example of one ride I setup ...
http://fishpluschips.com/GPS/gpsviewroute.php

You can then see the actual route I took on GPS Map (choose the Windsor
ride).

I just bought a Garmin Forerunner 301. Combines GPS and heartrate
monitor. Can upload data to PC.

Anyone know if I can get the data in Excel format so that I can play
with it?

Anyone have trouble with motionbased.com? I can't upload my data to
them. Their tech support says my firewall is in the way. I turned my
firewall off (brielfy) and still can't connect to them.

On Mon, 08 Aug 2005 17:05:28 GMT, "Jason Settles" <[email hidden]>

Quoted message said:

Does anyone use a GPS while cycling?

I'm looking for recommendations/suggestions for usage.
I would like something small that will upload/download to a computer.
Something that will also track altitude and/or grade changes will riding.

I have experience with a Garmin III Plus as well as considerable software
background so I am open to high tech suggestions.

Thanks in advance for any assistance.
*Jason. in Indy

Don said:

One thing about using GPS altitude: it will be subject to the same
uncertainty as your lat/lon, so if your GPS shows an accuracy of, say,
30 feet, that will apply to the altitude reading as well. Even if you
are riding on a dead-flat road, the GPS altitude will vary over time
just due to accuracy issues. (Where I was riding, the GPS uncertainty
accounted for more observed elevation gain than I actually rode, and
I've recorded instances where my altitude varied by over 100 feet while
boating on a large lake :-)

It's worse than that. The elevational error range is roughly 3 times
the variance in the horizontal. If you have a newer WAAS capable GPS
unit, you may be able to get 1 to 3 meter accuracy in an open area in
the U.S. Otherwise, recreational GPS units are up to 10 meters off
without differential correction (WAAS turned on and available).

While testing some GPS units a few weeks ago, I found location errors
in the 1 to 3 meter range horizontally and errors of over 30 meters
vertically. This was with $5,000 mapping-grade GPS units from Trimble.

Don was right - if you want better elevation information, you need a
GPS unit with a built-in barometer.

-Buck

Jason Settles said:

Does anyone use a GPS while cycling?

I'm looking for recommendations/suggestions for usage.
I would like something small that will upload/download to a computer.
Something that will also track altitude and/or grade changes will riding.

I've got the cheapest etrex ($99) and it pretty much does what you want
so I'm guessing they all will. The cable was an extra $25 or so. The
software for uploading/downloading was free.

Quoted message said:

Anyone know if I can get the data in Excel format so that I can play
with it?

Excel can import just about any kind of file. So you will have no problem
getting the data in.

Don <www.donwiss.com> (e-mail link at home page bottom).

Quoted message said:

Anyone know if I can get the data in Excel format so that I can play
with it?

I use "EasyGPS" (free) to upload data and it saves it in XML format,
which excel 2003 will import, I believe.

"Don" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

If you select a unit like the eTrex Vista that incorporates a barometer,
you can collect barometric altitude which will probably be more accurate
over the course of a ride.

I wouldn't count on it. I have a Polar watch that incorporates a barometer.
I usually have it shut off unless I am riding outdoors or cross-country
skiing. I left it on and rode my AirDyne and recorded some pretty gnarly
little climbs.

"Jason Settles" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Does anyone use a GPS while cycling?

I'm looking for recommendations/suggestions for usage.
I would like something small that will upload/download to a computer.
Something that will also track altitude and/or grade changes will riding.

I have experience with a Garmin III Plus as well as considerable software
background so I am open to high tech suggestions.

Thanks in advance for any assistance.
*Jason. in Indy

As a few others have pointed out, your Z or elevation value is by far the
least reliable of the three coordinates. Also, just about every single
commercially available GPS hand held unit has an actual accuracy of about
50-60% of that listed by the manufacturer (the manufacturers list their
accuracy in "ideal" or "optimal" conditions).

I make maps and do GIS for a living - I have yet to see an affordable,
compact hand held unit that can give useful, accurate elevation data. The
handheld that I play around with is an $200 Atlas II, it has removable
memory and tons of features. However, to get an accurate Z value I'd have
to remain stationary for about an hour or more - hardly conducive to
cycling.

Now then, if X and Y are your only concerns then there's lots of units out
there that will do the trick. What I find most helpful is a unit that has a
proximity alarm. That way I can prep my unit before a ride with a route and
all my waypoints and then set the proximity distance so that unit sounds an
alarm when I get within x ft/miles of the next waypoint.

I also find that having desktop or laptop mapping software to be a better
aide than the GPS unit. Unfortunately those software platforms are not
cheap. Anyway, if you have the PC software you can lay out your loops ahead
of time and overlay aerials or topo raster data and get extremely accurate
measurements of distances to climbs, etc. That combined with an average GPS
unit can get you totaly locked in.

42N83W said:

"Jason Settles" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Does anyone use a GPS while cycling?

I'm looking for recommendations/suggestions for usage.
I would like something small that will upload/download to a computer.
Something that will also track altitude and/or grade changes will riding.

I have experience with a Garmin III Plus as well as considerable software
background so I am open to high tech suggestions.

Thanks in advance for any assistance.
*Jason. in Indy

As a few others have pointed out, your Z or elevation value is by far the
least reliable of the three coordinates. Also, just about every single
commercially available GPS hand held unit has an actual accuracy of about
50-60% of that listed by the manufacturer (the manufacturers list their
accuracy in "ideal" or "optimal" conditions).

I make maps and do GIS for a living - I have yet to see an affordable,
compact hand held unit that can give useful, accurate elevation data. The
handheld that I play around with is an $200 Atlas II, it has removable
memory and tons of features. However, to get an accurate Z value I'd have
to remain stationary for about an hour or more - hardly conducive to
cycling.

There is accuracy and there is precision. Most of the units are
accurate enough for the average rider, esp. if one has a unit that
combines a barometric altimeter with the GPS data. As for precision,
I find that I can get repeatable measurements on the same road within
1-2% most of the time. I am not so concerned with the actual true
elevation, just the delta from top to bottom. If the unit has enough
precision that I can get a repeatable measurement ride after ride after
ride then that if good by my standards.

Quoted message said:

I also find that having desktop or laptop mapping software to be a better
aide than the GPS unit. Unfortunately those software platforms are not
cheap. Anyway, if you have the PC software you can lay out your loops ahead
of time and overlay aerials or topo raster data and get extremely accurate
measurements of distances to climbs, etc. That combined with an average GPS
unit can get you totaly locked in.

Try getting the data for northern Italy; southern France; the Czech
Republic; etc. The data is more or less available for the US, but
getting reliable topo data for much of the rest of the world is
problematic at best, next to impossible at times.

- rick