NASA develops new type sextant

[acem]

I've been busy working and it's been cloudy most the time so I haven't done any more yet.

Here is a link to the course.

https://my.vanderbilt.edu/astronav/

I plan to use pdf almanac for now. When I'm ready to go offshore I'll get a real set.

I'm a nubie so it'll take a while.

Thx-Ace

[SeanPatrick]

Originally Posted by Aethelwulffe

Re: an astrolabe reference by another poster, that is nearly useless, as it is a calculator mostly used for predicting times and events and is generally a set of graphs printed or engraved ON a quadrant. Mostly it is used in astrology for generating B.S.

There are, generally, two types of astrolabes. The one you describe and the "mariner's astrolabe". The latter being a device designed solely for measuring altitudes of celestial bodies. They are not as accurate as sextants/octants/etc., of course. But they are certainly not B.S.

Originally Posted by Adelie

You don’t need $100s for sight reduction tables. $34 will get you Pub-249 for 0-40deg Lat. Another $34 gets you 39-89deg Lat.

Hardback 2021 Nautical Almanac is $70. Privately produced almanacs are considerably less.

Kolbe Long term almanac hood thru 2050 is $26 and includes Davies/NASR sight reduction tables. Davies is a pain to use but is compact and come with the almanac.

Pub 229 and 249 are available for download for FREE at the Maritime Safety Information website.


Kolbe's almanac is excellent.

Originally Posted by MicHughV

I seem to recall that back in the day, you could buy a computer or program of sorts, that had the almanac, sight reduction tables, etc, you basically just plugged in your sextant readings...I seem to recall it was a HP model......a handheld....but my memory is fuzzy...

I think these might still be available, but I don't know for sure...I've never seen nor used one......but I'm intrigued....in my retirement years, I may have found a new hobby here..

Rodger Farley's Teacup Navigation is a great free celestial program which includes an almanac, sight planner, fix calculator and more. There's also Navigational Algorithms by Andres Ruiz Gonzáles. That one is excellent, too and has loads of features. Or you could download this free almanac I made for Excel. I'm still working on it and I plan to add more, but it's a fully functional almanac as is.

[Adelie]

Originally Posted by SeanPatrick

.....
Pub 229 and 249 are available for download for FREE at the Maritime Safety Information website.


Kolbe's almanac is excellent.

I am of 2 minds about 229&249 in PDF.
Free is a wonderful price.
Not requiring any space to store is great.

Having to page around a lot in a PDF gets old real fast.
Ease of use can be very device dependent.

If CelNav is going to be considered a backup the everything needs to be paper. If failure of electronics is an issue that leads you to consider CelNav a backup system then it shouldn’t be reliant on electronics in any way you can help.

I like Kolbe’s system generally, except for the part about having to do multiplication. At home no problem. In the field it’s a source of increased error.
That said I do use it.

[SeanPatrick]

Originally Posted by Adelie

I am of 2 minds about 229&249 in PDF.
Free is a wonderful price.
Not requiring any space to store is great.

Having to page around a lot in a PDF gets old real fast.
Ease of use can be very device dependent.

If CelNav is going to be considered a backup the everything needs to be paper. If failure of electronics is an issue that leads you to consider CelNav a backup system then it shouldn’t be reliant on electronics in any way you can help.

I like Kolbe’s system generally, except for the part about having to do multiplication. At home no problem. In the field it’s a source of increased error.
That said I do use it.

I agree with all of that. But if money is tight, it's an option.

[barnakiel]

Imho going the pdf way or using any other digital crutches kills the whole point of doing it the sextant way.


The point is to have an alt way of doing something.


Go sextant, use printed aids. Memorise the triangle solutions and resolve on paper, with a pencil.


!



b.

[SeanPatrick]

Well, in my opinion the main benefit is that the data is from an independent source. That's why it's a valid cross-check. Having the necessary tools in a different format is just hardening the system against certain types of possible failures. Which is a good thing.

[acem]

I agree that when using it on a voyage hard copies should be carried. However I live about 500 miles from the coast and normally sail on lakes so it's merely a learning exercise at this point.

I'm picking up a few used books to learn from on the cheap. The current almanacs are not cheap and old ones are not useful, I understand.

I did get a nice sextant at a nice price. It is in excellent condition but it has the whole horizon mirror, I would prefer the traditional mirror. I was planning on a plastic sextant and this just kinda fell into my lap.

Thx-Ace

[Dulls]

Originally Posted by Breaking Waves

look up Marvin Creamer - he went round the world (successfully, around 1984) with NO navigation instruments - no clock, no compass, nothing but his eyes and brain.

Some have even done it with out a brain.

[flightlead404]

Originally Posted by Singularity

If really bored, consider reading into ancient astronomy, back to the Babylonian era. Certainly they created devices to measure things down to a degree or so, and otherwise mapped out lunar cycles and certain planetary cycles to a high degree (some of it maybe encrypted in the Old Testament).
https://www.scientificamerican.com/a...ablet-reveals/
And a book printed on unobtanium:
https://www.amazon.com/Mathematical-.../dp/354006995X

Read "Hamlet's Mill" fascinating stuff. Some of the features of the Giza necropolis are aligned with stars, where they would have been 10,000 years ago (including the sphinx which would have been aligned with the heliacal rising) in the age of Leo then. Ancient people knew about the Precession of the Equinoxes, which we only "re-discovered" in relatively recent times. It takes just less than 26,000 years for the whole circle and a little over 2,100 years to complete each "house".

This is why we had pre-mosaic dwellers in the middle east worshiping bulls (taurus), why the Jews use the symbol of the ram/sheep (aries), why in the christian era the fish is symbolic (pices) and why you have Luke 22:10 (NIV) "He replied, "As you enter the city, a man carrying a jar of water will meet you. Follow him to the house that he enters," this is a reference to entering the age or "house" of aquarius.

There was a tribal dance (forget the details) discovered to match the details of astronomical data for a binary star system, and I think you're talking about the number of pillars in the hall that Samson pulled down on the Philistines maybe?

Lots of stuff encoded in many tales that have come down from the ages.

Or it all could be coinkidink and us seeing what we want to see

[StoneCrab]

Originally Posted by flightlead404

Read "Hamlet's Mill" fascinating stuff. Some of the features of the Giza necropolis are aligned with stars, where they would have been 10,000 years ago (including the sphinx which would have been aligned with the heliacal rising) in the age of Leo then. Ancient people knew about the Precession of the Equinoxes, which we only "re-discovered" in relatively recent times. It takes just less than 26,000 years for the whole circle and a little over 2,100 years to complete each "house".

This is why we had pre-mosaic dwellers in the middle east worshiping bulls (taurus), why the Jews use the symbol of the ram/sheep (aries), why in the christian era the fish is symbolic (pices) and why you have Luke 22:10 (NIV) "He replied, "As you enter the city, a man carrying a jar of water will meet you. Follow him to the house that he enters," this is a reference to entering the age or "house" of aquarius.

There was a tribal dance (forget the details) discovered to match the details of astronomical data for a binary star system, and I think you're talking about the number of pillars in the hall that Samson pulled down on the Philistines maybe?

Lots of stuff encoded in many tales that have come down from the ages.

Or it all could be coinkidink and us seeing what we want to see

Interesting stuff. I clicked on the link to the book. The price is a bit too stiff for me:

Hardcover
from $3,205.99
Other Sellers
from $3,205.99
More Buying Choices
1 used from $3,205.99

[flightlead404]

Originally Posted by StoneCrab

Interesting stuff. I clicked on the link to the book. The price is a bit too stiff for me:

Hardcover
from $3,205.99
Other Sellers
from $3,205.99
More Buying Choices
1 used from $3,205.99

Wow! I got my paperback decades ago for the price of a typical text book. I'm in the wrong business

[GordMay]

Download (Free) "Hamlet's Mill: An Essay on Myth & the Frame of Time"
➥ https://archive.org/details/HamletsMill