| Author |
Message |
Phil Wheeler
Guest
|
 Posted:
Sat Nov 26, 2005 5:08 pm Post subject:
Re: HELP ! UTM errors ? (Distance between two UTM's) |
|
|
Dave wrote:
| Quote: |
Sounds to me that you really have no "truth points" in your experiments
.. and are using multiple measurements to check one another. Poor
experimental process.
Phil
You're properly right ! If that a ham callsign I see mines G6ZKC (all lived
in US for a while!)
Dave....
|
It is. But the email address is a "spam box" (which typically gets
50-60 emails a day) and uses an old call of mine. My real call is W7OX
... and my real working email address is at a different ISP.
73, Phil |
|
| Back to top |
|
 |
David Lee
Guest
|
| Posted:
Sun Nov 27, 2005 12:59 am Post subject:
Re: HELP ! UTM errors ? (Distance between two UTM's) |
|
|
Phil Wheeler wrote
| Quote: | Dave,
I would not be too quick to agree with the Garmin-bashing troll.
|
B##T#RD!
I resent that comment. I regularly use a couple of Garmin receivers - etrex
and Vista and the Vista and Mapsource/Metroguide Europe DO have annoying
bugs and issues that Garmin refuse to fix and they ARE due to poor software
design and implementation - pointing that out is merely fact NOT pointless
"Garmin Bashing"! One nasty one of these bugs even required me to hack
Metroguide img files in order to make the product at all usable in a Vista
whilst in National Park areas. Software/Firmware design that obliterates
all detail on the screen of a GPS receiver with a pointless background
shading in my opinion can justifiably be described as "crap" or worse -
particularly since other Garmin monochrome receivers have the facility to
turn this nonesense off when it gets in the way, Garmin are fully aware of
the problem in the Vista and they flatly refuse to fix it with a firmware
upgrade release even though this model is still in production. I also fail
to understand how a reasoned attempt to analyse the source of Dave's anomaly
by reproducing his problem in my own Vista and copy of Mapsource could be
described as a Troll! If anyone is a troll then it is you yourself for
completely ignoring the facts that Dave posted and to which I was replying.
He clearly stated that the discrepancy was in the Vista and Mapsource
themselves and at no time did he assume any external measurement of the
separation of his two waypoints. He said "... in a straight line (as the
crow fly's) both using Mapsource's measure and Vista's 'Navigation' window
both say 2 km, try it!". I did try it with the UTM coordinates he posted
and reproduced his incorrect resultsin Mapsource proving the effect to be
due to Garmin bugs.
David |
|
| Back to top |
|
|
peter
Guest
|
| Posted:
Sun Nov 27, 2005 1:08 am Post subject:
Re: HELP ! UTM errors ? (Distance between two UTM's) |
|
|
Dave wrote:
| Quote: | I can report that the Navigation window and the route window 'correctly'
reports 1.95km so the 'error' is in the measure distance tool on the Vista,
guess I'm 'dividing rabbits' or is it splitting hairs ;-) I would have
thought Garmin would have these sort of bugs sorted !!
|
It's still not clear to me that there is in fact a real bug or if the
distance is just reported to fewer significant figures. On my eMap,
the 'Measure Distance' tool only gives distances in km to one decimal
place and the distance between those points is given as 2.0 km. Given
the inherent limits to accuracy of the map screen that seems like a
reasonable level of precision. (Ok, since the distance is really 1.948
km it should be rounded to 1.9 km, but that's not an error I'm going to
get very concerned about, especially when measuring distances on street
maps that probably have inaccuracies of much more than 10 meters.)
OTOH, when navigating from one point to the other the distance is given
to one more significant figure and shows as 1.95 km. The extra
precision here can be useful in showing how the remaining distance is
changing as you approach a destination. |
|
| Back to top |
|
|
|
|
|
|
FAQ
Memberlist
Register
Profile
Log in to check your private messages
Log in