Ruby - 太陽・月視位置計算 gem の作成（海保略算式版）！
Updated:
以前、Ruby で、海上保安庁・海洋情報部の「コンピュータによる天体の位置計算式」を利用して、太陽や月の視黄経や視赤経等を計算しました。
今回、そこで使用したロジックを gem ライブラリにしました。
0. 前提条件
- Ruby 2.3.1-p112 での作業を想定。
- 自作した gem ライブラリの名称は “eph_jcg” で、計算対象年は 2008 年〜 2016 年。
（2017 年以降も係数データが公開される度に対応する予定） - 当ライブラリの計算可能項目
- Sun
- 視赤経, R.A.(= Right Ascension, Alpha)
- 視黄緯, Dec.(= Declination, Delta)
- 地心距離, Dist.(= Distance)
- グリニッジ時角, hG.(= Greenwich hour angle)
- 視半径, S.D.(= Apparent Semidiameter)
- 視黄経, Lambda(= Ecliptic longitude)
- 視黄緯, Beta(= Ecliptic latitude)
- Moon
- 視赤経, R.A.(= Right Ascension, Alpha)
- 視黄緯, Dec.(= Declination, Delta)
- 地平視差, H.P.(= Horizontal Parallax)
- グリニッジ時角, hG.(= Greenwich hour angle)
- 視半径, S.D.(= Apparent Semidiameter)
- 視黄経, Lambda(= Ecliptic longitude)
- 視黄緯, Beta(= Ecliptic latitude)
- R (グリニッジ時角の計算に必要な値)
- 平均黄道傾斜角, Epsilon(= Mean obliquity of the ecliptic)
- 視黄経差, Lambda difference between Sun and Moon
- Sun
1. インストール
$ sudo gem install eph_jcg
2. Ruby スクリプトの作成例
File: ex_ephemeris_jcg.rb
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#! /usr/local/bin/ruby
# coding: utf-8
require 'eph_jcg'
obj = EphJcg.new("20160609")
# 一括計算、一括出力
obj.calc_all
obj.display_all
puts
# 個別計算、個別出力
obj.calc_sun_ra; puts " SUN R.A. = #{obj.sun_ra}"
obj.calc_sun_dec; puts " SUN DEC. = #{obj.sun_dec}"
obj.calc_sun_dist; puts " SUN DIST. = #{obj.sun_dist}"
obj.calc_sun_h; puts " SUN hG. = #{obj.sun_h}"
obj.calc_sun_sd; puts " SUN S.D. = #{obj.sun_sd}"
obj.calc_moon_ra; puts " MOON R.A. = #{obj.moon_ra}"
obj.calc_moon_dec; puts " MOON DEC. = #{obj.moon_dec}"
obj.calc_moon_hp; puts " MOON H.P. = #{obj.moon_hp}"
obj.calc_moon_h; puts " MOON hG. = #{obj.moon_h}"
obj.calc_moon_sd; puts " MOON S.D. = #{obj.moon_sd}"
obj.calc_r; puts " R = #{obj.r}"
obj.calc_eps; puts " EPS. = #{obj.eps}"
obj.calc_sun_lambda; puts " SUN LAMBDA = #{obj.sun_lambda}"
obj.calc_sun_beta; puts " SUN BETA = #{obj.sun_beta}"
obj.calc_moon_lambda; puts " MOON LAMBDA = #{obj.moon_lambda}"
obj.calc_moon_beta; puts " MOON BETA = #{obj.moon_beta}"
obj.calc_lambda_s_m; puts "LABMDA SUN-MOON = #{obj.lambda_s_m}"
puts
puts " SUN R.A. = #{obj.hour2hms(obj.sun_ra )}"
puts " SUN DEC. = #{obj.deg2dms( obj.sun_dec )}"
puts " SUN DIST. = #{obj.deg2dms( obj.sun_dist )}"
puts " SUN hG. = #{obj.hour2hms(obj.sun_h )}"
puts " SUN S.D. = #{obj.deg2dms( obj.sun_sd )}"
puts " MOON R.A. = #{obj.hour2hms(obj.moon_ra )}"
puts " MOON DEC. = #{obj.deg2dms( obj.moon_dec )}"
puts " MOON H.P. = #{obj.deg2dms( obj.moon_hp )}"
puts " MOON hG. = #{obj.hour2hms(obj.moon_h )}"
puts " MOON S.D. = #{obj.deg2dms( obj.moon_sd )}"
puts " R = #{obj.hour2hms(obj.r )}"
puts " EPS. = #{obj.deg2dms( obj.eps )}"
puts " SUN LAMBDA = #{obj.deg2dms( obj.sun_lambda )}"
puts " SUN BETA = #{obj.deg2dms( obj.sun_beta )}"
puts " MOON LAMBDA = #{obj.deg2dms( obj.moon_lambda)}"
puts " MOON BETA = #{obj.deg2dms( obj.moon_beta )}"
puts "LABMDA SUN-MOON = #{obj.deg2dms( obj.lambda_s_m )}"
3. サンプルスクリプトの実行
$ ./ex_ephemeris_jcg.rb
[ JST: 2016-06-09 00:00:00, UTC: 2016-06-08 15:00:00 ]
SUN R.A. = 5.14759173 h (= 5 h 08 m 51.330 s)
SUN DEC. = 22.91390281 ° (= 22 ° 54 ′ 50.050 ″)
SUN DIST. = 1.01514003 AU
SUN hG. = 27.01399780 h (= 27 h 00 m 50.392 s)
SUN S.D. = 15.78107401 ′ (= 0 ° 15 ′ 46.864 ″)
MOON R.A. = 8.40863875 h (= 8 h 24 m 31.099 s)
MOON DEC. = 15.80751986 ° (= 15 ° 48 ′ 27.072 ″)
MOON H.P. = 0.96198018 ° (= 0 ° 57 ′ 43.129 ″)
MOON hG. = 23.75295078 h (= 23 h 45 m 10.623 s)
MOON S.D. = 15.72769188 ′ (= 0 ° 15 ′ 43.662 ″)
R = 17.16158953 h (= 17 h 09 m 41.722 s)
EPS. = 23.43446466 ° (= 23 ° 26 ′ 04.073 ″)
---
SUN LAMBDA = 78.23788375 ° (= 78 ° 14 ′ 16.381 ″)
SUN BETA = -0.00010341 ° (= -0 ° 00 ′ 00.372 ″)
MOON LAMBDA = 124.63246155 ° (= 124 ° 37 ′ 56.862 ″)
MOON BETA = -3.38996467 ° (= -3 ° 23 ′ 23.873 ″)
DIFF LAMBDA = -46.39457781 °
SUN R.A. = 5.147591732785325
SUN DEC. = 22.91390280958854
SUN DIST. = 1.0151400332768776
SUN hG. = 27.013997801148722
SUN S.D. = 15.781074014278948
MOON R.A. = 8.408638749052159
MOON DEC. = 15.807519861977596
MOON H.P. = 0.961980181276102
MOON hG. = 23.75295078488189
MOON S.D. = 15.727691881531724
R = 17.16158953393405
EPS. = 23.4344646577545
SUN LAMBDA = 78.23788374531598
SUN BETA = -0.0001034098752735779
MOON LAMBDA = 124.63246155278357
MOON BETA = -3.389964665474966
LABMDA SUN-MOON = -46.394577807467584
SUN R.A. = 5 h 08 m 51.330 s
SUN DEC. = 22 ° 54 ′ 50.050 ″
SUN DIST. = 1 ° 00 ′ 54.504 ″
SUN hG. = 27 h 00 m 50.392 s
SUN S.D. = 15 ° 46 ′ 51.866 ″
MOON R.A. = 8 h 24 m 31.099 s
MOON DEC. = 15 ° 48 ′ 27.072 ″
MOON H.P. = 0 ° 57 ′ 43.129 ″
MOON hG. = 23 h 45 m 10.623 s
MOON S.D. = 15 ° 43 ′ 39.691 ″
R = 17 h 09 m 41.722 s
EPS. = 23 ° 26 ′ 04.073 ″
SUN LAMBDA = 78 ° 14 ′ 16.381 ″
SUN BETA = -0 ° 00 ′ 00.372 ″
MOON LAMBDA = 124 ° 37 ′ 56.862 ″
MOON BETA = -3 ° 23 ′ 23.873 ″
LABMDA SUN-MOON = -46 ° 23 ′ 40.480 ″
4. gem ライブラリ
以前作成した Ruby スクリプトを何かと応用したかったので gem ライブラリ化した次第です。
以上。
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