recently tried the Timex body link, but I returned it

when you buy a first generation product, that's called being on the "bleeding edge". you spend the
money out your pocket, you're the real world beta site for manufacturer and suffer discovering all
the shortcomings, bugs, and flaws. basically you get the priviledge of getting a half-baked product.

with new technology....you gotta let them work out the bugs on someone else's
dime. be patient...sit on the sidelines until it's tweaked.

In article said:

I recently tried the Timex body link, but I returned it at the store. I thought that if you go out
and your only picking up the signal part of the time that means that if you are trying to measure
a certain route, this device won't even work and give you the total distance elapsed. What are
your thoughts on this? I would have to surmise probably nobody is getting a 100% feedback, which
means that nobody is getting a complete measurement from beginning to end that would be accurate.
I appreciate any input that you might have.

This is one of the reasons I prefer a real GPS unit over the Timex thing. You can view a plot of
your route offline afterwards, and even if there are dropouts, you can deal with it (and you will
know if there are dropouts).

There's also the Fitsense watch that uses an accelerometer.

Cheers,
--
Donovan Rebbechi pegasus.rutgers.edu~elflordOpen ↗

steve waco said:

I recently tried the Timex body link, but I returned it at the store. I thought that if you go out
and your only picking up the signal part of the time that means that if you are trying to measure
a certain route, this device won't even work and give you the total distance elapsed. What are
your thoughts on this?

Not sure about the body link system, but with many GPS's they have an algorithm to fill in the
blanks - which may or may not be accurate. Or as Donovan indicated, you can fill in the holes
yourself on a regular GPS. As mentioned in many previous threads here, GPS reception depends on good
satellite alignment and minimizing sky obstructions - clouds, precip, trees, buildings, etc. Some
places get better reception than others. Where I am in Alaska, our coverage is substantially less
than in other places - as confirmed by GPS/GIS person on faculty for about 1 yr now, not just my
personal experience with consumer-grade gear.

The fit sense (accelerometer) folks indicated that their system works very well on "normal" terrain,
but are less accurate on trails and mountains. There's just too many variables. (summarized a
response from Fit Sense posted on another list, July 2002 - maybe things have changed in mean time)
Many people here seem to be getting decent results with that since many people run on road. But
iirc, it does require calibration with different shoes (which I do tend to change).

FWIW, I've got most of my normal trails mapped now using a GPS (mostly in winter when skies are
clearer and leaves are gone), and I just use an electronic topo map (All Topo Maps: Alaska, NFI) to
estimate distance for the route I just ran or plan my next run(s). This works for me since precise
distances aren't a big deal. And I've timed many of the larger or steeper hills (or some relatively
flat, straight areas with good footing) so I know which ones I can use for, say 2-min or 4-min
repeats (or 1 hr straight up), etc - at least for now. Most workouts I use are based on time since
that's the way a lot of physiological processes work. Race distances are usually approximate also. I
just enjoy the run.

Just my $.02.

Dot

--
"Success is different things to different people" -Bernd Heinrich in Racing the Antelope

Donovan Rebbechi said:

In article said:

I recently tried the Timex body link, but I returned it at the store. I thought that if you go
out and your only picking up the signal part of the time that means that if you are trying to
measure a certain route, this device won't even work and give you the total distance elapsed.
What are your thoughts on this? I would have to surmise probably nobody is getting a 100%
feedback, which means that nobody is getting a complete measurement from beginning to end that
would be accurate. I appreciate any input that you might have.

This is one of the reasons I prefer a real GPS unit over the Timex thing. You can view a plot of
your route offline afterwards, and even if there are dropouts, you can deal with it (and you will
know if there are dropouts).

I also use the GPS. I have the Garmin eTrex Vista (Got one of the first 300 first European units).
It is great, huge tracklog, maps, barometric altimeter (for altitude profiles).

Most of my routes I just measure on the electronic maps the county has put on the net (together with
aerial photos). The software they use allows you to measure in the browser. But yet, I find it to
give slightly short measuring.

steve waco' steve@spokanediscount(nospam).com said:

I recently tried the Timex body link, but I returned it at the store.

...snip

Quoted message said:

I would have to surmise probably nobody is getting ...a 100% feedback, which means that nobody is
getting a complete measurement from beginning to end that would be accurate. I appreciate any input
that you might have.

I have only very rare dropout of the signal. This occurs when under relatively heavy foliage or in
tunnels, narrow streets with high buildings. I can be extremely annoying when it happens
unexpectedly but usually you can work out when it will happen.

Even when the signal drops out for a few (10s of) seconds, the box will still interpolate and,
unless you were zig-zagging or varying speed significantly at the time, the approximate value
provided by the unit will still be better than that of a mechanical podometer or a "guess" based on
perceived pace and time.

I imagine the system is next to useless however if you're in woods most of your time.

On one of my home circuit runs, I go under two tunnels. As I run straight along the tunnel, the
systems gets a near zero error by interpolating (it knows the time taken, it knows the linear
distance between the point where it lost signal and the point where it regained signal. So..

Any help?

My intuition would tell me that signal quality/drop-out frequency is not only dependent on local
geography (tunnels, heavy tree cover), but perhaps also the continent, country, and province/state.
Do any of GPS units actually tell you how many satellites are in the area, or how far away they are?

The more satellites there are, and the closer they are to the GPS, the less the drop-outs, no?

I'm interested in this too - I'm thinking of getting the Timex speed/distance.

Richard Rogers

R. Rogers said:

My intuition would tell me that signal quality/drop-out frequency is not only dependent on local
geography (tunnels, heavy tree cover), but perhaps also the continent, country, and
province/state.

The location as well as time do make a difference. Trimble, I think, has (had?) a webpage or pgm
that would give you an idea on satellite reception in your area for a given time, but I'm not sure
that that took satellite outages into consideration, esp. if it's an offline pgm. Some people I was
working with had to wait 1/2 hr to train me on a different GPS since they couldn't get a signal
under a clear, open sky - it was a known black spot around noon for a week or two time period until
things got more Alaska-friendly. They had just forgotten about it when scheduling. But my
understanding is that coverage in Alaska is suboptimal.

It also depends on equipment. I was with some people that couldn't get any reception at all on their
GPS for most of the day, whereas I could at least get an approximate location on mine - it gives
estimated error. Some antennas work better than others; some are fussier about their orientation
(horizontal, vertical) than others.

I've gotten really good tracking on mine (Garmin 12XL, Etrex Vista) some days (within 15-20ft,
iirc), and really bad on other days (couldn't maintain a lock) for same location. The quad helix
antennas are suppposed to be better than the patch antennas on 12XL, Etrex, and the timex units.

Do any of GPS units

Quoted message said:

actually tell you how many satellites are in the area, or how far away they are?

Most GPS units show you the number of satellites, a bar with the strength of signal, and spatial
position in sky. Having them spread at various angles so they can do a better job of triangulation
is more important than distance, I'm guessing. Units generally won't give you any navigation
information unless you have a lock on at least 3 satellites. The more the merrier, obviously.

You might want to visit the following ng sci.geo.satellite-nav or these web pages for detailed info.
gpsinformation.orgdaleOpen ↗ edu-observatory.orggps.htmlOpen ↗

I'm just a user that hasn't tried to work out details.

Dot

--
"Success is different things to different people" -Bernd Heinrich in Racing the Antelope