【オンデマンドブック】Nautical Almanac 2026

Celestial Navigation Almanac 2026 — The Definitive Edition of Japanese Astronomical Navigation, Now More Precise Than Ever

The Celestial Navigation Almanac 2026 is a highly accurate ephemeris based on Japanese-style astronomical navigation. It serves as a reliable reference for maritime navigation and astronomical observation. This edition follows the structure of the former celestial almanac once published by the Japan Coast Guard, with an intuitive format that experienced navigators will find familiar and easy to use.

[Major Updates in the 2026 Edition]

Revised Atmospheric Refraction Calculations
→ Incorporates the latest meteorological data, including the global average temperature of 2024, to provide real-world correction values and reduce observational errors.

Improved Altitude Correction Tables
→ The included correction tables now account for year-to-year variations, allowing for highly accurate altitude adjustments.

New: Daily Moon Phase Diagrams and Lunar Libration Angles
Visual moon phase diagrams are now included for each day, offering intuitive insight into the Moon’s appearance.
Additionally, lunar libration angle data has been newly added, supporting precise lunar observations and advanced positional calculations.