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Re GPS



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 2. Is it worth buying a GPS for hiking?

Ried writes>>>>>

>> Purists would say no.  If it increases your enjoyment, go for 
it!  (I love navigation; it's been a hobby since I encountered topo 
maps at age 10.)  As with instrument flying, one should not rely 
upon a single system.

           
 
       No wing and a prayer for me either. Purists long ago 
probably said "all I need the sun and stars, don't need none of 
this compass stuff!" Some guy said "I only need my compass, don't 
need any directional gryo."  Just because you up-step, doesn't mean 
you shouldn't forget you must know the basics first. Up-steps 
should be a natural thing, like man first wrote on rocks, then 
parpus, paper,  then typewriters, then word processors. I've only 
hiked in a few whiteouts, on the trails I've been on could have 
used an ILS approach!  
         
>>Map and compass are of course adequate but GPS offers unique 
capabilities.  With GPS and a two-way radio you can in theory call 
down a medical helicopter to carry away sick or injured people.  
(Quartz crystals actually do have healing powers) 
With GPS you can be a Technobuddhist:  If you encounter spiritual
enlightenment, you can erect an environmnetally-correct virtual 
shrine simply by pushing a button to record the location.   
Ohmmm...  :-)
 
      Doubt if I'll be using for SAR stuff, except for myself, 
 but you never know..........    
  M & C is the only way, if that's all you got! 
 
 4. What's the best way for a hiker to program waypoints, ie,      
Latitude & Long, UTM, etc?
 >> UTM is easiest to measure from topo maps:  Units are decimal 
and scale is constant ("grid north" is neither true nor magnetic, 
but close enough).
 
         If they have the tic marks, I understand some don't. I got 
an interesting comment on this from Brick Robbins, off the PCT 
Mailist. He seems to be saying, don't even bother using a GPS. 
Would like your comments on his thoughts, as follows, quote:

BR>>"One other interesting complaint, was echoed by Jeff Schaffer, 
one of the authors of the PCT trail guides. The USGS topos are not 
accurate, so when you get a good GPS fix, you cant place yourself 
on the map. The topos are based on aerial photos, and some features 
may be off by as much as 1/2 mile or more. This presented problems 
to the PCT cartographers when they made the
maps for the guidebooks, because their ground surveys turned up the 
errors. They chose, for example, to show the PCT crossing a pass at 
the col on the map, even though the col was in the wrong place. The 
typical user will compare the map with what he sees, and head for 
the col, instead of using surveying tools. They did this to make 
the guidebook maps useable for the hiker -- and they did a great 
job."
 
>> I'm used to lat/lon; I use aeronautical sectional charts for 
roadmaps,especially "out west." BTW, new sectional charts cost 
about $7 but they become obsolete for air navigation every 6 
months, so used ones can be found inexpensively or free.
 
     Do you mean for just road driving, or walking to? I used to 
empty my Jepp case to, wish I kept the maps!
 
 5.What map computer program is most useful to get waypoints from,
to preprogram the GPS?
 6.Are there anymore specfic GPS 'puter programs...
 >> GPS web site:  http://www.tech.net/technotes/gps
>> The FAQ on Garmin products includes software reviews.
 
          Will look, the site is strickly Garmon? You didn't say if 
you have used the other GPS 'puter prgs I mentioned?

7.What are the best distances apart to use for waypoints, for
 hiking? (5, 10, 30, etc?)
 
>> Use personal preference.  Perhaps set significant destinations, 
or just turn the unit on occasionally to check progress and record 
present position each time.  On a well-marked north-south trail, 
latitude alone is sufficient for a fix.
 
           Not clear what you mean, marked on the map or stored in 
the GPS, or both? Like I said in my post, not going on a well 
marked tail, starting on CDT in NM, were there isn't much marked 
trail, and a lot of cross country.
 
 8.What measured unit, statue, nautical miles, or kilometers, is
 best to use? ...
 
>> I use statute miles because they're most familiar.  Meters are 
appropriate
>> when using UTM coordinates.  Nautical miles are good for lat/lon 
navigation by sea or air where there are no landmarks:  A nautical 
mile is one arc-minute of latitude, 6076 feet.  It is very nearly 
2000 yards or 2  kilometers.
 
         Like I said, don't know which would be best for me. Would 
it be simpler to use a aero plotter and maps, then program the legs 
into GPS?  Is this one way you do? Its true course, as I'm not 
going to have compinstate 
for wind drift!
 
>> GPS altitude is nearly worthless due to "selective availability" 
error which may be removed someday if the vote-getting potential of 
promising to remove it wears thin.)  GPS altitude is not referenced 
to sea level, but to the the center of mass of the earth around 
which the satellites orbit.  The earth is not perfectly spherical 
and has gravitational anomalies; maps are available showing 
variation between sea level and GPS zero altitude (about
40m max in continental US).
      
      Very interesting..............I don't need to worry about  
crashing into a mtn, ie, adjusting my altimeter for sea level 
barometric pressure,  just worry about the strain of getting up and 
over!
 
 
 A rule of thumb for estimating walking speed:  The number of paces 
walked in 36 seconds, divided by 10, is your speed in miles per 
hour.  A pace is one full cycle of the legs, i.e., two steps.  The 
original definition of a  mile was 1000 paces as marched by the 
Roman Army; he word comes from Latin "mille," meaning 1000.  One 
pace is 1/1000 mile, 36 seconds is 1/100 hour.  Calculate the 
appropriate time period if your pace is significantly
>> different from 5.28 feet.  It doesn't work on rough terrain.
 
      This is good info, I use now, the old  pace method, a 100 ft 
3 times and average it out for my pediometer set. Me with this GPS 
thing is what do I do now? Like the guy approaching a tower:
 
Tower, Tower, this is Tango Lima 112, my engine's on fire! What do 
I do?
 
Tango Lima 112, this is tower, repeat, Tower, repeat after me, Our 
father, who art in................

PS I'm posting my answers to you on the mailist, cause I got 
bounced mail when I sent to your private e-mail address, read 
below.

   ----- Transcript of session follows -----
554 Too many hops 18 (17 max): from <trailblazer@juno.com> via 
hamlet.ucs.indiana.edu, to <reid@hamlet.ucs.indiana.edu>
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