Almanac and Celestial Navigation Calculator

[GrowleyMonster]

Originally Posted by StoneCrab

Is it even possible anymore to purchase a current Nautical Almanac?.

Celestaire, inc.
https://www.celestaire.com/product/2...rcial-edition/
Air and ocean navigation products, sold at very un-marine prices, from an unlikely location in the heart of the North American continent, Wichita, Kansas. I bought my second sextant from them many many years ago, an Astra IIIb, shortly after it came out.They even have the old Rude star finder. Fascinating tool if you have never seen one.Books, videos, useless but compelling doodads, full and concise sight reduction tables in software or hard copy, everything. Some day I will make a pilgrimage to their shop and spend the day looking around at all the old 1930's aircraft sextants and stuff.

They got their start there after WW2 selling surplus air navigation stuff, because Wichita was a major hub for aircraft contstruction. Then they branched off into marine navigation and the world of the navigator was forever changed. Great people to do business with.
.

[SeanPatrick]

Originally Posted by Midnight Son

If a program, please post the source on Github.
Thank you

That's a little bit of a sore spot for me. I made the spreadsheet as a sort of "proof of concept". In doing so, I had to type well over 8,000 formulas and hundreds of coefficients from Meeus' book. Needless to say it was a lot of work and it took me a long time.


So, I wanted to password protect the workbook so that no one could just copy and paste all of my hard work into their own project. Shortly after I published the spreadsheet, I was informed that programs like Numbers and OpenOffice would simply bypass the password and show all of the sheets.


Now granted: Meeus' book is available to anyone - his formulas are not secret and I don't own them. Most of the other formulas in my spreadsheet are also in the public domain. I even have a spreadsheet on my hard drive made by someone else that uses the same formulas. I could have easily copied and pasted his work into my spreadsheet. But it's the principle of the matter.


Anyway ... I guess the 'damage' is done. So when I do finish the app/program, I suppose there is no reason not to post the source. I don't know. We'll see.


But I would like to thank everyone again for all of the support and kind words. It really means the world to me that my work might inspire someone to learn celestial navigation. Thank you!

[SeanPatrick]

Originally Posted by GrowleyMonster

Celestaire, inc.

The CEO (Ken Gebhart) is a member of NavList. His posts are few and far between, but he's a really nice guy. I bought a small navigation library from him a while back - and I get most of my celestial gear from his company.


I highly recommend them.

[GrowleyMonster]

Originally Posted by SeanPatrick

That's a little bit of a sore spot for me. I made the spreadsheet as a sort of "proof of concept". In doing so, I had to type well over 8,000 formulas and hundreds of coefficients from Meeus' book. Needless to say it was a lot of work and it took me a long time.


So, I wanted to password protect the workbook so that no one could just copy and paste all of my hard work into their own project. Shortly after I published the spreadsheet, I was informed that programs like Numbers and OpenOffice would simply bypass the password and show all of the sheets.


Now granted: Meeus' book is available to anyone - his formulas are not secret and I don't own them. Most of the other formulas in my spreadsheet are also in the public domain. I even have a spreadsheet on my hard drive made by someone else that uses the same formulas. I could have easily copied and pasted his work into my spreadsheet. But it's the principle of the matter.


Anyway ... I guess the 'damage' is done. So when I do finish the app/program, I suppose there is no reason not to post the source. I don't know. We'll see.


But I would like to thank everyone again for all of the support and kind words. It really means the world to me that my work might inspire someone to learn celestial navigation. Thank you!

Any incentive for noobs to learn how to navigate is a good thing. There are way too many boats out there without a navigator, and navigation is a science that needs and deserves to be preserved. And the more you understand of it, the more fascinating it gets. When you realize it is all nothing but math, and that you can massage the formulae to yield a lot of facts and figures besides the obvious, then things really get deep. Once the triangle and sphere become fixed in the mind, it is incredible what you can do with pencil, paper, and precomputed solutions.

I knew a guy who kept his old Loran C long after the stations were shut down. Why? Because he could use the Great Circle computation ability of the obsolete Loran to calculate his Zn and Hc by entering declination and GHA as a waypoint and his AP as another, and subtracting the resulting miles as minutes of arc from 90, All because he understood the celestial triangle and how it fits in to the world and universe around him. And this depth of understanding came from a dedicated study of Navigation. Cool? I think so. Some navi-phobes I am sure will disagree.

[A.Sailor]

Amazing work! I wish I could use it!
...it would be rather hard while far from the sea.

[SeanPatrick]

Originally Posted by A.Sailor

Amazing work! I wish I could use it!
...it would be rather hard while far from the sea.

Not hard at all! Just get yourself an artificial horizon:

[Cpt Mark]

Originally Posted by A.Sailor

Amazing work! I wish I could use it!
...it would be rather hard while far from the sea.

An artificial horizon is a pan of water in the backyard on a calm day. If there's any wind then an acrylic wind screen is needed.

[SeanPatrick]

New version posted at my website.


Changes:


v 0.2.6

• Added printable bodies list
• Reformatted notes on "Precession and Stars" tab

[SeanPatrick]

New version at my website.


beta v 0.2.7 Bug fixes/changes:

• Fixed a bug causing the intercept "away/toward" cell for sight #10 to remain empty
• Updated the cities database from ~15,500 cities to Pareto's current [free] offering: 26,570 cities (+ the two suggested cities)

And here's an animation I made showing "Xerxes' Eclipse" on Oct. 2nd, 480 BC:

[SeanPatrick]

I have added my PostScript plotting sheets to my website.


PostScript Plotting Sheets v4

• Generates precise plotting sheets for any latitude/longitude
• Customizable … turn the following features on or off:
  • Compass
  • Center latitude/longitude lines
  • Upper/lower latitude lines
  • Meridians
  • Latitude scale
  • Longitude scale
• Can be used for plotting LOPs, radar contacts, solving maneuvering problems, etc.
• Designed for use with U.S. Letter sized paper
• Can be edited with any text editor, including Notepad
• Recommended programs for editing/printing:
  • Notepad++
  • Rampant Logic PostScript Viewer
    • With PostScript Viewer, you can view and even save the plotting sheet as a .pdf
• * Updated February 8th to fix a minor formatting issue and a typo in the notes *

[GrowleyMonster]

Originally Posted by SeanPatrick

I have added my PostScript plotting sheets to my website.


PostScript Plotting Sheets v4

• Generates precise plotting sheets for any latitude/longitude
• Customizable … turn the following features on or off:
  • Compass
  • Center latitude/longitude lines
  • Upper/lower latitude lines
  • Meridians
  • Latitude scale
  • Longitude scale
• Can be used for plotting LOPs, radar contacts, solving maneuvering problems, etc.
• Designed for use with U.S. Letter sized paper
• Can be edited with any text editor, including Notepad
• Recommended programs for editing/printing:
  • Notepad++
  • Rampant Logic PostScript Viewer
    • With PostScript Viewer, you can view and even save the plotting sheet as a .pdf
• * Updated February 8th to fix a minor formatting issue and a typo in the notes *

Excellent. I simply construct mine manually but someone will for sure find this useful.

[SeanPatrick]

Originally Posted by GrowleyMonster

Excellent. I simply construct mine manually but someone will for sure find this useful.

Try it out. I used to make mine by hand, too.

[SeanPatrick]

Just added a well-cared-for Tamaya MS-633 to my collection.

[SeanPatrick]

New version available at my website.


v 0.2.8 - 2021, Feb 28

• Increased the number of decimals of azimuth included in the data series to a ridiculous precision.
• Fixed a bug causing the spreadsheet to display wildly inaccurate values for the equation of time under certain circumstances.

[SeanPatrick]

Originally Posted by SeanPatrick

The CEO (Ken Gebhart) is a member of NavList. His posts are few and far between, but he's a really nice guy. I bought a small navigation library from him a while back - and I get most of my celestial gear from his company.


I highly recommend them.

It is my sad duty to report that Ken Gebhart has passed away.


Rest in peace, Ken.