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 Posted: Fri Oct 03, 2008 1:58 pm Post subject: Lines and boundaries |
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For those of you who have ever marked or flagged lines or boundaries
with GPS in whatever cover (light to heavy). I would be interested to
know what your procedure was, what your results were, what brand and
type of receiver used and whether or not an external antenna was used? |
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John Tyson
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| Posted: Fri Oct 03, 2008 9:02 pm Post subject: Re: Lines and boundaries |
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<rvalcourt@persona.ca> wrote in message
news:0de984de-8c21-4af8-9793-98c79471eb5f@l64g2000hse.googlegroups.com...
[quote]For those of you who have ever marked or flagged lines or boundaries
with GPS in whatever cover (light to heavy). I would be interested to
know what your procedure was, what your results were, what brand and
type of receiver used and whether or not an external antenna was used?
[/quote]
You may find this recent thread on the Groundspeak forum interesting:
http://forums.groundspeak.com/GC/index.php?s=984e6c3bda9db99be63b6ab185bedf30&showtopic=204773
John |
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Dan Anderson
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| Posted: Fri Oct 03, 2008 9:05 pm Post subject: Re: Lines and boundaries |
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rvalcourt@persona.ca wrote:
[quote]For those of you who have ever marked or flagged lines or boundaries
with GPS in whatever cover (light to heavy). I would be interested to
know what your procedure was, what your results were, what brand and
type of receiver used and whether or not an external antenna was used?
[/quote]
I map trails (a form of lines). The best sky view has been on top of
narrow mountain peaks over 14,000 feet. The worst in narrow, wooded
canyons where a position lock is not made when there is a lack of
overhead satellites (I>ve yet to be in a slot canyon in Utah with
a receiver.).
Currently I use three receivers - Garmin 76Cx, 76CSx, and 76S.
Those give me two sets of elevation data from barometric altimeters and
one set from GPS. Also I get two sets of horizontal data from sensitive
receivers and one set from a less sensitive receiver. The less sensitive
receiver (76S) isn>t affected as much by multipath so does better in
some environments. The 76S is connected to an external antenna mounted
on a hat or helmet.
There>s some more information at www.gpsmap.net
particularly under tests. "Results" are hard to answer because it
depends on the environment. Also, the 76CSx, which was bought a year
after the 76Cx, seems to track more consistently than the 76Cx. They
both have the same SiRF III firmware.
The "x" models are set to record a point every second. The 76S is
set to record every two seconds in most cases.
I hand hold the 76Cx and the 76CSx is mounted on a post connected
to my pack. I do what I can to keep my body from blocking the sky
view and I pay attention to the satellite constellation especially
when gathering data in narrow canyons.
Wind effects the altitude data from the barometric altimeters -
effectively reduces fine resolution.
--
Dan
Personal: www.gpsmap.net
Business:
Western Maps LLC
www.westernmaps.us |
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