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Celestial Navigation Tools:  Free Book and Software

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A free celestial navigation book unlike any other, including lunar distance equations. This book is dedicated to removing the cloak of mystery; to teach the concepts, some interesting history, the techniques, and computational methods using the simple pocket scientific calculator. And yes, also how to build your own navigational tools. It also has condensed S-tables and work sheets for when you have no calculators available.

Book: Celestial Navigation in a Teacup             new revision 11/27/2022  (cleaned up a little)

Why I wrote this book...

Growing up, I had always been fascinated by the thought of navigating by the stars. However, it instinctively seemed to me an art beyond my total understanding. Why, I don't know other than celestial navigation has always had a shroud of mystery surrounding it (no doubt to keep the hands from mutiny). Anyway, I love to know the how & why of things, so this book is the result. What I discovered was that it was based on concepts and geometry that was so simple, you have to slap yourself on the forehead and say "Why didn't I think of that myself?"! This book will show you why.  Click on the link below to download the pdf book.

  Book Cover Art  Download book here 

If you wish to acquire a hard copy of this book, you can purchase it at Lulu.com. It is published as a paperback. Click this link to get the book at Lulu

Farley Octant

Views of my sextants 
My collection so far...
Click here to download the booklet "Building the Farley Octant"

Click here to download the pdf and cad drawing plans for the Farley Octant

TeacupNAV (TeacupCelestial) CN full suite software

Comprehensive FREE Celestial Navigation Software for Windows OS. This will run in Ubuntu (Linux) when "Wine" software is also installed. The same for a Mac when the Mac version of Wine is used. Just do the normal set up as you would in Windows. An icon is inserted in the installed software list.

TeacupCelestial, also called TeacupNav, from Teacup Navigation. Sight planning, built-in perpetual almanac, sight reduction with plotted LOPs and global COPs. Rise/set times, and Lunars are also part of this program along with many utility calculators.

Showcase of TeacupNav Forms

Click here to download software  Version 3.3
Click here to download instruction manual
Click here to download a simple Excel file Celestial Worksheet  It will allow 6 simultaneous observations to be recorded and reduced, but you still need the hourly GHA and declination from the nautical almanac.

A note of confusion concerning the Settings: the General Settings form has a note on it saying you have to go to the Sight Planner form to make changes to the Time Zone.  After which you fill out your Lat, Lon, and then press the bar that says “Remember these settings as my default”.  That should save a settings file (TeacupNav.nv1) in the same location as the folder where the executable is (TeacupCelestial32.exe).  If you are in Europe then the data files will not be written correctly; see notes below.

Time zone form

I have gotten responses that upon initial installation and first usage some people get the error note "Problem reading settings file".  This is usually an indication that you are using European formatting of decimals as a comma (,) instead of the USA typical of a period (.).  For those of you in Europe, a Swedish user discovered the trick of making the software work correctly in Europe:
Quote: "In the control panels national localization, I changed the the decimal sign to a period from the comma and changed the thousands delimiter to a comma from a period.  This is all that that needs to be done to get the program to work perfectly and Windows is still in Swedish with the correct keyboard."

Or follow these diagrams for Windows 7:


If you have suggestions for improvements, some functionality you would like to see incorporated, then please email me using the address on the 1st page or in my software help menu!

Version History
Version 3.2h, Nov 28, 2014 (works well on netbooks too).  Even though I originally called this Teacup Celestial, people call it TeacupNav when they contact me, so I now call it that as well!
This freeware program I authored in VisualBasic 5 for Windows is the result of years of effort. Simple, intuitive, easy to use, flexible, and very accurate ephemerides. This is a complete and seamless celestial navigation package. You must try out this program, especially with the new changes!!!  (version 2.0 was a major change)

ver 1.0 original, no lunars or rise/set
ver 1.1 rise/set included
ver 1.2 lunars included
ver 1.3 rise/set corrected for "clock math" errors
ver 1.4 got rid of the clock math all together!
ver 1.5 lunars have files that can be saved
ver 1.6 fixed bug in lunars, and I have made it "push-button"
ver 1.7 added arc distance function to Sight Planner
ver 1.8 added ecliptic plane on Sight Planner
ver 2.0 simpler interface with almanac facsimile removed, and a tide and leeway calculator added
ver 2.1 added a utility calculator for plane sailing, calculated altitude, and calculated longitude for the Sumner Line method.
ver 2.2 added in the calculator utility distance to the horizon, and dip when using a land reference horizon.
ver 2.3 added function in dip calculator to give the additional correction (above&beyond normal horizon dip)for using land as the horizon. 2.3a corrected a small inconvenience in the Tide set/ True course calculator.
ver 2.4 added separate rise/set time form, and fixed some minor tabbing problems.
ver 2.5 fixed a bug in the ephemeris generator that affected long term accuracy 0.1' per 200 years
ver 2.6 added a default file for the sight planner tool to remember your personal settings
ver 2.7 added some helpful error messages
ver 2.7 netbook: reformatted some forms so that all will show in a netbook setting
ver 2.8 allows Venus to be tracked on the sight planner during the day
ver 2.9 has a simplified sight reduction form for single shots, found under Calculators. This is good for training where there is more of a manual feel to what you are doing. Also included a date and time loading button to load other forms with the date and time on the main form.
ver 3.0c includes the 3-point resection calculations for coastal navigation, to be found under the Calculators.  Made some format changes.  The fix graph and Sight Planner graphs can now be resized by grabbing lower right corner and refreshing .
ver 3.2a  Made improvements to the 3-point protractor (resection), and added a global circles of position visualizer!  Rise/set times improved for upper limb of sun on visual horizon.
ver 3.2d made resizing of Sight Planner and LOP plot smoother.  Fixed viewing problem in Plane Sailing Calculator.
ver 3.2e LOPs are now identified with labels in both the LOP plot and the global COP view.
ver 3.2f Minor improvements.
ver 3.2g Superficial changes
ver 3.2h Fixed a problem I created in 3.2g

A friend of mine from the USPS Offshore Navigation Committee has created celestial navigation tools too.  It should be a valuable addition to any navigator's tool box!
Click here to visit the Celestial Tools web site


Home | Celestial Navigation | Radio Control Aircraft | Interesting Stuff <<< Click on these links to the left to navigate to the different pages!