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Old 25-02-2010, 12:26   #121
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I don't know. I have never been able to get a good sight on any of those man made satalites. They move too fast. The error between sight and time seems too big. I guess if I got a new sextant with a stopwatch type feture things might work better. I also think any of the systems would be greatly improved if they used colored lights or something for better identification. Perhaps the Russians will think of that. No matter what, I haven't got one of those gps things to give me their possition. Does anyone know where to get the tables for those manmade satelites? The natural ones have been figured out and published for centuries...
This is a spoof, right?

Or, just maybe, you've been hittin' the maple syrup too much :-)

B.
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Old 25-02-2010, 13:52   #122
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This is a spoof, right?

Or, just maybe, you've been hittin' the maple syrup too much :-)

B.
Ya, my leg was getting longer before I half read it. Pretty good, really.
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Old 25-02-2010, 13:57   #123
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Oh yeah I'd rely on a Russian based GPS system! the point of this thread is to develop multidimensional navigational capability but I myself will never rely on what I'd describe as flaky Russian technology. I think they'd definitely degrade their signal that's available publicly.
This thread has discussed GPS and sextants. I guess 2-dimensional is multidimensional.

Why do you say GLONASS is "flaky Russian technology"? Do you have something to back up that statement, or do you just have something against Russians? The Russians put the first satellite in orbit. In just a few months, they will be the space-race leader again. Russians are more than capable of building and maintaining a satellite network. You can't get to the space station without them.
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Old 25-02-2010, 14:18   #124
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Alternatives ... yes, sure BUT not with our existing hardware ...
Very true. GLONASS receivers are available, but the cheapest I've seen cost thousands of dollars ($8K+). That said, electronics prices typically fall quickly. Ten years ago, GPS units cost thousands of dollars too, now millions of people drive around with units costing around $100 on their dashboards.

There is a company called NemeriX that has patented a single-chip RF receiver that will receive GPS, Galileo, and GLONASS signals. In a few years, we might be getting a fix from all three satellite systems simultaneously.

So, while not really viable today, it may be something worth considering when replacing existing hardware in a few years.
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Old 25-02-2010, 14:18   #125
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(The syrup is good this year!)
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Old 25-02-2010, 14:24   #126
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If the Russians get behind something and really support it the system will work fine. The technology itself won't be flaky it will be the way it's implemented. It will be setup to support their military solely there is no reason for them to support it's use for civilians. Speaking of military how about the Kursk as an example of them being willing to support their state of the art technolgy.
There will be a period when human transport to the space station will be solely by the Russians, but not at present.

I think you should feel free to use GLONASS, I'm saying it'll be undependable.
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Old 25-02-2010, 18:41   #127
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Oh yeah I'd rely on a Russian based GPS system! the point of this thread is to develop multidimensional navigational capability but I myself will never rely on what I'd describe as flaky Russian technology. I think they'd definitely degrade their signal that's available publicly.
If Russian technology is as bad as you claim, why then have Magellan incorporated it into their newest state of the art geodetic sat-nav?

Maybe you should call Magellan and tell them they do not know.

Hahaha.

b.
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Old 29-03-2010, 15:54   #128
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Why do people get so hostile about GPS and sextants?
Probably because some posters are prone to adopting (or implying) rather uncompromising positions, e.g.:
  • "celestial navigation is obsolete, and any mariner who relies upon it is unsafe", or
  • "GPS is unreliable, and any mariner who relies upon it is unsafe".
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Anybody an idea of "good" (read "easy to understand") literature about learning the sextant ?
For sextant lore (history, use, adjustment, etc.), try Bruce Bauer, The Sextant Handbook, or Dag Pike, Reed's Sextant Simplified.

There are plenty of good books providing an introduction to celestial navigation. You might try Susan P. Howell, Practical Celestial Navigation (using HO-229) or Otis S. Brown, One-day Celestial Navigation (using HO- 249).
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Old 29-03-2010, 16:52   #129
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I like 'Self Taught Navigation' by Robert Kittredge.
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Old 31-03-2010, 17:57   #130
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If Russian technology is as bad as you claim, why then have Magellan incorporated it into their newest state of the art geodetic sat-nav?

Maybe you should call Magellan and tell them they do not know.
the following is not directed at barnakiel specifically:

I am a surveyor who earns a living using GPS as well as other conventional methods and instruments to fix position and/or solve problems. The GPS equipment I am currently using has the ability to receive GPS (american), GLONASS (russian) and Galileo (EU) even though Galileo is not fully populated with satellites and its system is not fully functional. The Chinese system (COMPASS) is in the planning stages. GPS and GNSS are both excellent for navigation. Most surveyors that can will collect GNSS data just because they can but will exclude it from their calculations unless it helps the final precision.

The problem with these systems is they are competing with each other in more ways than one. In the event that there is some sort of global conflict or emergency they can and will be scrambled. There could also be a stategic shift in the satellite constellations coupled with a "tightening" of the proper corrections whereby the data you received can not be relied upon until next week, next month or possibly never.

This would put me, as a surveyor, in a position in which I would have to rely totally on "the old way" of getting things done. No big deal, I learned to do what I do that way. But for someone that is mid-ocean plowing towards atolls, islands, shallow oceanic plateaus, etc...

Do you want to be caught off guard and need to learn how to use a sextant in the middle of the ocean? Will you even have one to learn with? Sextants are sexy and having one could save you a lot of grief and heartache. Besides, arent you the one that was complaining about being bored on the long trip?

Jim the newb
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Old 31-03-2010, 18:28   #131
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Our sextant is right next to the collision mat and trysail. Hopefully none of them have to get used that much. But if you need one and don't have it you're going to feel mighty silly.
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Old 31-03-2010, 19:39   #132
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Small detail: There are ways to emulate a sextant with common boat junk, while the almanac and chronometer cannot be substituted by any self-sufficient means. Where are those?
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Old 31-03-2010, 20:18   #133
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At this very moment there are people I know crossing oceans with very little knowledge of celestial navigation.They have sextant, but prefer to rely on the 3 to 4 GPS method.If GPS shutdown, society would come to a standstill,it's not gonna happen.
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Old 31-03-2010, 20:49   #134
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At this very moment there are people I know crossing oceans with very little knowledge of [...] navigation
Corrected your text :-)

Many cruisers ask any other random cruiser for "the waypoint". Punch it into their chart plotter and go make lunch...

"We just punch in the waypoint and hit GOTO." I heard this firsthand from a cruiser of the seas....wow. I suppose the EPIRB is the backup.
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Old 31-03-2010, 21:32   #135
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Makes you wonder,relying on other peoples possibly questionable waypoints,sends shivers down my spine.I carry 2 sextants,tables,3 GPS's,AIS(good for hailing ships for position checks)which has picked up targets up to 130 miles.Taking and calculating noon sights is all you need to know.
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