Gps?

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DougPaul said:
(You will need to remember to wind the chronometer.)
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sardog1 said:
IS THAT A NANSEN CRACK????!!! Be careful boy, or I'm gonna come over and put you in a 6 x 10 hole for the winter -- with giggy for a roommate, instead of Hjalmar Johansen.
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Not at all. Such luminaries such as Lewis and Clark also used a sextant and chronometer to figure out where they were. Many used sextants and chronometers for navigation on land, sea, and air before modern electronic methods became available.

The modern sextant user has to remember the spare batteries for his WWV (time signal) radio or electronic chronometer.

Doug
 
DougPaul said:
Not at all. Such luminaries such as Lewis and Clark also used a sextant and chronometer to figure out where they were. Many used sextants and chronometers for navigation on land, sea, and air before modern electronic methods became available.

The modern sextant user has to remember the spare batteries for his WWV (time signal) radio or electronic chronometer.

Doug
Click to expand...

Fridtjof and Hjalmar each forgot to wind theirs, leaving them you-know-what for several months. It was really the sheerest luck that enabled them to find their way back from 85 north. Going south was of course not the problem, but the Siberian coast is awful long . . .
 
DougPaul said:
Many used sextants and chronometers for navigation on land, sea, and air before modern electronic methods became available.

The modern sextant user has to remember the spare batteries for his WWV (time signal) radio or electronic chronometer.
Click to expand...
Not so long ago I was employed as a flight navigator on USAF SAC aircraft. I did use a sextant, we had to train with one on every flight during an extended "nav leg". The sextant does not require electric power. For this training, all radio electronic navigation aids were turned off (to the navigator, not necessarily to the pilot) so that I and my crew remained proficient with "old fashioned" air navigation techniques, the idea being that anything electronic would be fried and useless during a real SAC mission.

My chronometer was an AF issue non-electric spring wound pocket watch set to WWV at preflight, cross checked with other analog clocks on board. Calculations for celestial navigation were required to be done totally manually long-hand for at least one position, though an electronic handheld calculator (if you had one) was usually allowed otherwise. GPS did not exist, but would not have been allowed anyway. On long overwater deployments we sometimes had a foot-locker sized INS (inertial navigation system) installed onboard, but it often drifted off into the weeds and at times was more work and frustration than it was worth. Celestial navigation and dead reckoning were the prime and only methods for long flights over water and over the pole. Navigation for joining up to refuel inflight had to be accurate enough by both aircraft to find each other in radio-out conditions - at a preplanned time at a specified location you had better be there.

So the point is it can be done without batteries or electronics, even in "modern" times.
 
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Nessmuk said:
So the point is it can be done without batteries or electronics, even in "modern" times.
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As long as you remember to wind your chronometer...

And it is a good idea to carry at least 3 and use a majority vote to get the time. That way, if one fails or is inaccurate, you still have a good chance of getting an accurate time.

The old methods still work as well as they ever did. (Same with old gear.)


GPS is increasingly being used for (nanosecond accuracy) time distribution and position measurement/navigation--both economically important infrastructure functions for a number of industries (eg surveying, travel, and cellphone systems). LORAN and the proposed eLORAN could provide backups for these functions. Despite proposals that eLORAN be installed and maintained as a backup, the US has decided to terminate LORAN on Jan 4, 2010. Any disruption of GPS could cause serious disruption of these industries. http://www.gpsworld.com/gnss-system/news/administration-ax-falls-pnt-backup-loran-c-9087

Doug
 
Columbus was way ahead of his time.. he had a solar powered sextant and a wind powered boat. The chronometer was the chalenge though.
 
While we're adrift, has anyone read or seen "Longitude," the story of John Harrison, who developed the first chronometers durable and accurate enough to be used at sea? I got exposed to that through my father, who was a clock collector. Very interesting stuff (if you're so inclined...).
 
TCD said:
While we're adrift, has anyone read or seen "Longitude," the story of John Harrison, who developed the first chronometers durable and accurate enough to be used at sea? I got exposed to that through my father, who was a clock collector. Very interesting stuff (if you're so inclined...).
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Yup, saw it. A good documentary. Read the book too. Finding latitude is easy, but finding longitude requires a very accurate clock. Difficult to keep the required accuracy after months at sea. My rule of thumb was that, even with everything else perfect, an error of only 4 seconds in the time of a sextant celestial observation could result in a location error of as much as a mile (do the math). Other error factors could be many miles large as well - coriolis effect due to aircraft speed and atmospheric refraction as a function of observed elevation angle were both always accounted for.
 
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TCD said:
While we're adrift, has anyone read or seen "Longitude," the story of John Harrison, who developed the first chronometers durable and accurate enough to be used at sea? I got exposed to that through my father, who was a clock collector. Very interesting stuff (if you're so inclined...).
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There was a nice PBS program on this. Perhaps NOVA?

Doug
 
sardog1 said:
IS THAT A NANSEN CRACK????!!! Be careful boy, or I'm gonna come over and put you in a 6 x 10 hole for the winter -- with giggy for a roommate, instead of Hjalmar Johansen.
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If the hole is a crevass, then Giggy's the guy you want on top! :)

dougpaul said:
The old methods still work as well as they ever did. (Same with old gear.)
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Well, except for cotton, which went postal sometime in the 1980's
 
"You might try calling TVNAV http://www.tvnav.com/ (a small authorized Garmin GPS dealer). Darrel (the owner) is quite knowledgeable."

DougPaul, thanks for the tip. Darrel checked with Garmin for me and they said: "The newer units still have the SiRF StarIII chipset."

Getting one from Darrel.

Alan
 
Peakbagr said:
"You might try calling TVNAV http://www.tvnav.com/ (a small authorized Garmin GPS dealer). Darrel (the owner) is quite knowledgeable."

DougPaul, thanks for the tip. Darrel checked with Garmin for me and they said: "The newer units still have the SiRF StarIII chipset."

Getting one from Darrel.
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He has a pretty good reputation from Usenet news postings. (Or at least did when there was still significant activity on the GPS newsgroups... :) for him, :( for Usenet.)

Garmin has been deemphasizing the individual GPS chipsets of late by simply calling the modern ones "high sensitivity". I believe they actually use/have used 3 different high sensitivity chipsets.

Doug
 
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sardog1 said:
[Warning: Thread drift in progress]No, but I'm pretty sure it wouldn't be a particularly restful wintering-over. [And now, back to your usual programming.]
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I will take the high road - but I prefer if people want to bust my balls, they know me first or have at least a clue how I might act in a given situation...

Shared a tent and shelter with many on this board..pretty sure all would say it was a rather decent/positive experience....

IMO - this sends the wrong message to those that don't know me personally.
 
back to GPS?

Um...not to tick anyone off with more GPS stuff...(from the "inexperienced:eek:)

But...(and yes, I have searched for this specific question and am still not really clear on it)...

The Garmin 60SCx looks like what we are heading for...

It sounds good as a hiking GPS...once you purchase the appropriate topo maps (we are looking at the one that covers the Eastern US)

Can it be used as a TURN BY TURN driving GPS too? From what I've read, this is a flaw...BUT...it seems I also read where you can purchase a "city navigator" software that will fix this issue?

We really want one that will be both a good hiking AND driving GPS (tried a Nuvie and it was AWESOME for the whole turn by turn thing!!)

Thanks...
 
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