AMOD GPS logger. Advice appreciated
Mike Lane
I recently bought one of the above gps trackers to help me to geotag photos
with the minimum of fuss. I was very pleased with its features and specs and
it seemed (and still seems) just what I wanted. BUT after trying it for a few
days I'm *very* disappointed with unit's sensitivity and accuracy.
It is supposed to have a sensitive chipset (SiRF Star III) and yet it
performs no better (if not actually worse) than my aged Garmin GPS 72 (bought
six years ago). It takes ages - several minutes sometimes - to get a fix
after it's been switched off for a few hours, and if the sky is at all
obscured by buildings or trees it often won't get a fix at all.
Unless conditions are ideal, (i.e. a good unobscured view of the sky) the
tracks produced resemble the path of a drunken sailor on a Saturday night. To
illustrate this there's a screenshot of a 'track' produced by the unit when
quite stationary for about 5 minutes - here:
files.me.com/mike_lane/j1ccze
Admittedly it was indoors, but resting against a window pane where my gps 72
can often get a fix without too much trouble. Surely one should expect better
from SiRF III?
I've already decided I'll have to send it back, but the question is whether
this is a one-off faulty unit or whether I should abandon AMOD and go for
something different. I would really appreciate hearing of anyone else's
experience with this, or any other make of gps logger. Any recommendations?
If anyone's tried the same unit I'd really love to hear about your experience
with it.
--
Mike Lane
UK North Yorkshire
email: mike_lane at mac dot com
Mike Coon
I hven't tried a logger but my Loox PDA has SiRF III embedded. It can also
be idiosyncratic about how long it takes to get a first fix. The existence
of a service through which satellite data can be downloaded over the web to
assist 1st fix rather confirms that this is a common problem. My two elderly
(ca. 10 years) Garmins are much more reliable (though their screens are on
their way out). Also one of them has a bifilar antenna - with possible
connection of an external antenna - whereas the other has (I think) a patch
antenna.
But the quality of the continuing fix hasn't seemed to be so different. But
"looking out" of a window will make the satellite geometry rather variable
and this may impact the accuracy.
BTW a number of tracks from my older Garmin are visible with Google Earth
via http://www.mjcoon.plus.com/page38.htm
Mike.
--
If reply address is invalid, remove spurious "@" and substitute "plus"
where needed.
Mike Lane
> I hven't tried a logger but my Loox PDA has SiRF III embedded. It can also
> be idiosyncratic about how long it takes to get a first fix. The existence
> of a service through which satellite data can be downloaded over the web to
> assist 1st fix rather confirms that this is a common problem. My two elderly
> (ca. 10 years) Garmins are much more reliable (though their screens are on
> their way out). Also one of them has a bifilar antenna - with possible
> connection of an external antenna - whereas the other has (I think) a patch
> antenna.
>
> But the quality of the continuing fix hasn't seemed to be so different. But
> "looking out" of a window will make the satellite geometry rather variable
> and this may impact the accuracy.
Yes, well partly the problem is that haven't tried any track logging before,
so I'm not really sure what to expect by way of sensitivity and accuracy. I
definitely expected more than I've got though with modern "high sensitivity"
chipsets.
One review of the AMOD I read on Amazon says that after two hours of recorded
logs, "I only found one spot that strayed off my actual path by more than
about six feet". My logs seem to stray by hundreds of feet - in poor
conditions admittedly.
Another nasty habit my unit seems to have is that in poor conditions it will
get stuck with a particular pair of coordinates, and repeat the same
coordinates many times, even though you are continuously moving. Other times
it staggers about, as I said, like a drunken sailor.
I'd welcome any other experiences
Peter
model before it burnt out. Both of them could take up to 5 minutes to
get a fix in less than perfect conditions. When fixed, location is as
good as I can plot on Google earth. Elevation data can be a bit variable.
abettermap
> Another nasty habit my unit seems to have is that in poor conditions it will
> get stuck with a particular pair of coordinates, and repeat the same
> coordinates many times, even though you are continuously moving. Other times
> it staggers about, as I said, like a drunken sailor.
>
> I'd welcome any other experiences
>
> --
> Mike Lane
> UK North Yorkshire
> email: mike_lane at mac dot com
It really sounds like "send it back" time. I have 2 SiRF Star III
units and one SiRF Star II EP unit, and none of them exhibit this
behavior.
Followups set to alt.satellite.gps. No need for all the cross-posting.
Frank