Module: Sekki24::DeltaT

Defined in:
lib/sekki24/delta_t.rb

Class Method Summary collapse

Class Method Details

.seconds(decimal_year) ⇒ Object

Espenak & Meeus polynomials. The return value is TT - UT in seconds.



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# File 'lib/sekki24/delta_t.rb', line 8

def seconds(decimal_year)
  year = Float(decimal_year)

  case year
  when 1860...1900 then between_1860_and_1900(year - 1860.0)
  when 1900...1920 then between_1900_and_1920(year - 1900.0)
  when 1920...1941 then between_1920_and_1941(year - 1920.0)
  when 1941...1961 then between_1941_and_1961(year - 1950.0)
  when 1961...1986 then between_1961_and_1986(year - 1975.0)
  when 1986...2005 then between_1986_and_2005(year - 2000.0)
  when 2005...2050 then between_2005_and_2050(year - 2000.0)
  when 2050..2150 then between_2050_and_2150(year)
  else
    raise RangeError, "delta T is supported for years 1860..2150"
  end
end