Celestial Nav vs Navigation Almanac

We believe celestial navigation is an amazing skill and develop Celestial Nav to offer a simple, yet powerful and all encompassing app for our users. Celestial Nav is an easy to use, all-in-one tool which offers: • Celestial navigational computations for your device • Simple toolbar menu for quick access • Internally stored perpetual Almanac • Offline ready and functional without the need for other external tools • Quick and easy capture celestial observation data • High accuracy sight reductions • Star reference tables SIGHT PLANNING • Local Hour Angle (LHA) for Aries • Star tables sorted by name, magnitude, declination, and SHA • Sunrise, sunset, twilight, and location reference • Moon phase reference SIGHT REDUCTION • High accuracy sight reduction algorithm • Perpetual Almanac offering accurate data for years 1600 - 3000 • Almanac data for Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn • Detailed Almanac data for 58 navigational stars • Assumed Position (AP) for any user defined position • Line of Position (LOP) intercept data for accurate course and speed adjustments • Computational variables displayed for accuracy and validation CELESTIAL FIX • Computations by USNO algorithm in the Nautical Almanac • Save all your LOP in an easy reference table BASIC VERSION Free daytime celestial navigation tools using the sun: • Unlimited sextant sight reduction calculations • Sight reduction to a line of position using the sun • Perpetual almanac for the sun • Advanced sight corrections for index error, eye height, temperature, and pressure • Support for upper and lower limb reference • Star Table with navigational references • Detailed Sun references • Limited Moon references PRO FEATURES (IN-APP PURCHASE) Advanced Day & Night Celestial Navigation includes all BASIC features plus: • Almanac data for 65 navigational bodies for years 1600 through 3000 • Map display for saved LOPs • View intercepts with course and speed corrections • Metric and imperial unit support with automatic conversions • Support for coordinate entries in different formats (H° M’ S” or Decimals) • Save all your LOP calculations for future reference • Save user preferences and settings • Unrestricted moon references • Almanac and algorithmic models for 65 navigational bodies: • Sun, Moon, Mercury, Venus, Mars, Jupiter, and Saturn • 58 navigational stars Supported stars: Acamar, Achernar, Acrux, Adhara, Aldebaran, Alioth, Alkaid, Alnair, Alnilam, Alphard, Alphecca, Alpheratz, Altair, Ankaa, Antares, Arcturus, Atria, Avior, Bellatrix, Betelgeuse, Canopus, Capella, Deneb, Denebola, Diphda, Dubhe, Elnath, Eltanin, Enif, Fomalhaut, Gacrux, Gienah, Hadar, Hamal, Kaus Australis, Kochab, Markab, Menkar, Menkent, Miaplacidus, Mirfak, Nunki, Peacock, Polaris, Pollux, Procyon, Rasalhague, Regulus, Rigel, Rigil Kent., Sabik, Schedar, Shaula, Sirius, Spica, Suhail, Vega, Zubengenubi REFERENCES Sight reductions and celestial calculations use various internationally accepted references for the most accurate results: • Jean Meeus - Astronomical Algorithms • US Naval Observatory (USNO) Almanac and Algorithms • Hipparcos New Astrometric Catalog, Published 2007 • ELP2000-85 SUBSCRIPTION TERMS Celestial Nav is free to download and the basic features free to use. A paid upgrade to the PRO version provides access to premium features and additional tools. We may offer trial subscriptions that give limited time access to all PRO features and premium content for the duration of the trial period. Trial subscriptions automatically expire and the app will revert back to the Basic version thereafter. No data is lost but access and use of premium features will no longer be available.

Navigation Almanac is a complete celestial-navigation toolkit for iPhone and iPad. It reduces a sight, tabulates the almanac data you would otherwise look up on paper, and works entirely offline - no signal, no subscription, no account. SIGHT REDUCTION Enter your position and the date and time in UTC or local time, then pick a body. You get azimuth and computed altitude, GHA, LHA, SHA and declination, semi-diameter and horizontal parallax, along with the magnetic variation from the WMM-2025 model and the current value of ΔT. ALMANAC The Sun, Moon, Venus, Mars, Jupiter and Saturn together with the 57 navigational stars, each with azimuth, altitude, hour angles and declination for the moment you have chosen. RISE, SET AND TWILIGHT Rise, meridian transit and set for any body, with civil and nautical twilight at the Sun's standard altitudes (-0°50′ / -6° / -12°), shown in UTC or local time. SKY VIEW The sky drawn as a chart of azimuth against altitude, or as a full-sky dome with the zenith at the centre. Background stars, constellation lines, and a predicted GNSS satellite layer computed from a bundled orbital catalogue. GPS Live position, course and speed over ground, altitude and horizontal accuracy, the magnetic variation at your position, and the ephemeris of the selected body. One tap fills the observer position for a reduction. COMPASS ERROR Solve gyro and magnetic compass error from an observed bearing, with variation and deviation kept separate, the way the correction is actually applied on the bridge. FIX CALCULATOR Cross two lines of position from your reductions, advance the first line for the vessel's run between sights, and read off the observed position. WORKS OFFLINE The ephemerides are computed on the device from the VSOP87 and ELP2000 series with IAU 1980 nutation - they are not downloaded. Everything above works with the phone in airplane mode, weeks from shore. SIXTEEN LANGUAGES English, Russian, Ukrainian, French, Spanish, Italian, Portuguese, German, Dutch, Polish, Swedish, Danish, Greek, Turkish, Latvian and Simplified Chinese. The navigation terminology in each was taken from that country's own nautical almanac and navigation textbooks rather than translated word for word. NAVIGATIONAL WARNINGS Warnings in force from the national coordinators of the worldwide navigational warning service, grouped by country and by NAVAREA, with the full text of every message and the positions read out of it. The feed is rebuilt every hour and the last copy stays on the device, so it is there when the signal is not. This is an experimental feature and the screen says so: the data is gathered automatically, it can lag behind the broadcast, and it can be incomplete. It does not relieve you of the requirement to receive Maritime Safety Information over NAVTEX and SafetyNET as provided for by SOLAS. Navigation Almanac is a computational aid. Carry the official almanac and tables required for your voyage.