[OSM-talk] Choice of GPS for bicycle use in London

Andy Robinson Andy_J_Robinson at blueyonder.co.uk
Mon May 22 11:05:28 BST 2006


Yes, my Garmin eTrex Legend (B&W) produces poor track data (ie very poor
accuracy) in the urban canyon and below tree cover (leaves really do confuse
the poor thing). The resultant track is clearly a Garmin fudge and mostly it
would be better if it did not record it at all. I hadn't thought of
transferring the NMEA data rather than the Garmin format from the GPS but
will do some testing on this and see if at least the poor data can or cannot
be weeded out effectively.

There is no doubt that the older eTrex range is poorer than the more recent
60's. In fact we used the two in parallel in Manchester the weekend before
last and the 60's definitely performed better although all were a long way
from ideal in the inner city with track definition average or poor at best.

What is really needed is a like for like comparison between the various
units in these difficult areas of coverage. At the moment it's pretty
pointless heading into the city centre with these traditional handheld
units. For Manchester I have found the historic maps and local observation
and pictures is more accurate than the gpx for laying down the compact
street layout.

See here Manchester city centre, northern quarter:

http://www.openstreetmap.org/index.html?lat=53.4805950801913&lon=-2.232932&z
oom=14   

However, when away from the city centre, that includes normal residential
areas, industrial estates and rural settings I find you can't beat the
simplicity and general ruggedness of the Legend when mounted on the bike as
this:

http://wiki.openstreetmap.org/index.php/Image:ETrexLegend_onbike.png


Cheers,

Andy

Andy Robinson
Andy_J_Robinson at blueyonder.co.uk 

>-----Original Message-----
>From: talk-bounces at openstreetmap.org [mailto:talk-
>bounces at openstreetmap.org] On Behalf Of Barnett, Phillip
>Sent: 22 May 2006 10:10
>To: talk at openstreetmap.org
>Subject: RE: [OSM-talk] Choice of GPS for bicycle use in London
>
>That's annoying. I've just bought a Garmin Legend CX, partly to take
>part in OSM, and it's a bit galling if that unit generates bogus data.
>Can anyone confirm this happens on Legend CX?
>
>(It's also annoying that I can't get track logs directly out using my
>Powerbook, but have to turn on my ancient PC in the basement. I was
>hoping to do some logging in North Wales this summer, but editing will
>be a pain - and may have to wait indefinitely. Anyone have an update on
>Garmin's 'Mac support in 2006' statement?)
>
>Phil
>
>-----Original Message-----
>From: talk-bounces at openstreetmap.org
>[mailto:talk-bounces at openstreetmap.org] On Behalf Of Christian van den
>Bosch
>Sent: 21 May 2006 16:59
>To: Emil Vaughan
>Cc: talk at openstreetmap.org
>Subject: Re: [OSM-talk] Choice of GPS for bicycle use in London
>
>Emil Vaughan wrote:
>
>> I'm not clear on what would be the best for osm, as this will probably
>
>> be the only thing I use it for.
>
>I've been using an eTrex Vista with handlebar mount here in Cork,
>Ireland; mostly it works quite well, but is pretty useless on narrow
>streets, especially given Garmin's stupid, stupid, stupid "oh. I've lost
>signal. let's extrapolate track log points according to the course and
>velocity at the moment I lost signal".
>
>This might not sound like a big deal, but in the city I most often lose
>signal when turning a corner into a narrow street, so the Garmin
>extrapolates according to some course being followed mid-turn, resulting
>in a nice plausible-looking straight line of completely bogus points.
>
>The Garmin's NMEA output at least tells the truth, but still gives very
>little useful data on narrow streets, so I've just picked up a Sirf Star
>III-based Holux 213 for $35 on eBay. This should by all accounts work
>happily in the depths of my backpack, where I can hook it up to some
>small device like a PDA, subnote or perhaps a Linksys NSLU2. You
>mentioned a Zaurus - you wouldn't have a good (cheap, reliable) source?
>
>Cheers,
>
>Christian / cjb
>
>http://www.cjb.ie/
>
>_______________________________________________
>talk mailing list
>talk at openstreetmap.org
>http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
>Please Note:
>
>
>
>Any views or opinions are solely those of the author and do not necessarily
>represent
>those of Independent Television News Limited unless specifically stated.
>This email and any files attached are confidential and intended solely for
>the use of the individual
>or entity to which they are addressed.
>If you have received this email in error, please notify
>postmaster at itn.co.uk
>
>Please note that to ensure regulatory compliance and for the protection of
>our clients and business,
>we may monitor and read messages sent to and from our systems.
>
>Thank You.
>
>
>_______________________________________________
>talk mailing list
>talk at openstreetmap.org
>http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk







More information about the talk mailing list