SPA... the Starpath Perpetual Almanac
SPA is the same almanac program we use in our StarPilot software programs and in our home-study and online Celestial Navigation Courses. It is just 200kb when installed. It will run on essentially PC computer running Windows 95 or newer, including Win XP and all NT systems. It is quick, accurate, easy to use, and inexpensive. Shown below is the main CD browser window, although the program can be very efficiently obtained via direct internet download, in which case no CD browser will be needed, nor present.
The read me link on the CD explains the installation and registration process. The utilities link contains updates for older Windows systems. The product demos is a link to other Starpath Product demos.
Needless to say, we recommend a hardcopy of the Nautical Almanac if you are relying upon celestial navigation underway, but if you have a computer onboard, this simple program will provide a wonderful backup to a lost or outdated almanac.
It might also be of interest to those who do only periodic cel nav on land. Paper versions cost some $23 to $40 per year, so this perpetual data could be an economical alternative.
It is extremely simple to use and provides all ephemeris data available in the paper editions, namely: GHA, Dec, SHA, SD, HP, magnitudes, sunrise, sunset, LAN, twilight times, moonrise, moonset, moon age and phase. We include sun, moon, 5 planets, and 173 stars, i.e. one more planet (Mercury) and more stars than are in the printed version of the Nautical Almanac. In addition, we include Hc at LAN, bearing of sunrise and sunset, and the GHA of Aries midway between civil and nautical twilight for star planning. See Main Input Window.
Just enter a time and date from the convenient calendar selector, select your body via the convenient Body Selector window, and get the data. You can get individual data, or ask for a print out of sequential data for the time interval and number of points you wish. The results have the same accuracy and precision as quoted in the print version of the Nautical Almanac.
Ideal for historians as even the moon data is accurate back to 1620. We have checked numerous historic sights including many from Lewis and Clark, etc. See Accuracy and References.
Output data can be read from the screen for an individual computation or sequential computations can be printed out according to your selection of starting point and number of data points. See Calendar and Print options.
Note that this is not a celestial navigation program. It's task is to provide Nautical Almanac data alone. It does not do sight reductions or other features of celestial navigation. If you wish a general program on celestial navigation please refer to the Starpath StarPilot programs.