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Ruby script to calculate Greenwich times.
#! /usr/local/bin/ruby
# coding: utf-8
#---------------------------------------------------------------------------------
#= グリニジ視恒星時 GAST(= Greenwich Apparent Sidereal Time)等の計算
# : IAU2006 による計算
#
# * IAU SOFA(International Astronomical Union, Standards of Fundamental Astronomy)
# の提供する C ソースコード "gst06.c" 等で実装されているアルゴリズムを使用する。
# * 参考サイト
# - [SOFA Library Issue 2016-05-03 for ANSI C: Complete List](http://www.iausofa.org/2016_0503_C/CompleteList.html)
# - [USNO Circular 179](http://aa.usno.navy.mil/publications/docs/Circular_179.php)
# - [IERS Conventions Center](http://62.161.69.131/iers/conv2003/conv2003_c5.html)
#
# Date Author Version
# 2016.09.06 mk-mode.com 1.00 新規作成
#
# Copyright(C) 2016 mk-mode.com All Rights Reserved.
#---------------------------------------------------------------------------------
# 引数 : 日時(UTC(協定世界時))
# 書式:YYYYMMDD or YYYYMMDDHHMMSS
# 無指定なら現在(システム日時)を UTC とみなす。
#---------------------------------------------------------------------------------
#++
require 'mk_greenwich'
class CalcGreenwichTime
def initialize
@utc = get_arg
end
def calc
begin
g = MkGreenwich.new(@utc.strftime("%Y%m%d%H%M%S"))
puts g.utc.strftime(" UTC = %Y-%m-%d %H:%M:%S.%L")
puts g.tt.strftime(" TT = %Y-%m-%d %H:%M:%S.%L")
puts g.ut1.strftime(" UT1 = %Y-%m-%d %H:%M:%S.%L")
puts g.tdb.strftime(" TDB = %Y-%m-%d %H:%M:%S.%L")
puts " ERA = #{g.era}"
puts " EO = #{g.eo}"
puts "GAST: #{g.gast} rad"
puts " = #{g.gast_deg} °"
puts " = #{g.gast_hms}"
puts "GMST: #{g.gmst} rad"
puts " = #{g.gmst_deg} °"
puts " = #{g.gmst_hms}"
puts " EE: #{g.ee} rad"
puts " = #{g.ee_deg} °"
puts " = #{g.ee_hms}"
rescue => e
msg = "[#{e.class}] #{e.message}\n"
msg << e.backtrace.map { |tr| "\t#{tr}"}.join("\n")
$stderr.puts msg
exit 1
end
end
private
# コマンドライン引数の取得
def get_arg
unless arg = ARGV.shift
t = Time.now
return Time.new(t.year, t.month, t.day, t.hour, t.min, t.sec)
end
exit 0 unless arg =~ /^\d{8}$|^\d{14}$/
year, month, day = arg[ 0, 4].to_i, arg[ 4, 2].to_i, arg[ 6, 2].to_i
exit 0 unless Date.valid_date?(year, month, day)
hour, min, sec = arg[ 8, 2].to_i, arg[10, 2].to_i, arg[12, 2].to_i
exit 0 if hour > 23 || min > 59 || sec > 59
return Time.new(year, month, day, hour, min, sec)
rescue => e
raise
end
end
CalcGreenwichTime.new.calc if __FILE__ == $0
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