Module: When::TimeStandard

Included in:: TimeStandard

Defined in:: lib/when_exe/timestandard.rb,
lib/when_exe/region/martian.rb

Overview

標準的な時刻系の定義

Defined Under Namespace

Classes: LocalApparentTime, LocalMeanTime, MartianTimeCoordinated, TemporalHourSystem, TimeStandard, UniversalTime

Constant Summary collapse

DeltaT0 = TT(Terrestrial Time) - UTC(Universal Time, Coordinated) at 1970-01-01T00:00:00Z

(40 + 377.0/2048) * When::TM::Duration::SECOND

TAI_UTC = maia.usno.navy.mil/ser7/tai-utc.dat

[[2437300.5,  1.422818, 37300.0, 0.001296 ],
[2437512.5,  1.372818, 37300.0, 0.001296 ],
[2437665.5,  1.845858, 37665.0, 0.0011232],
[2438334.5,  1.945858, 37665.0, 0.0011232],
[2438395.5,  3.24013,  38761.0, 0.001296 ],
[2438486.5,  3.34013,  38761.0, 0.001296 ],
[2438639.5,  3.44013,  38761.0, 0.001296 ],
[2438761.5,  3.54013,  38761.0, 0.001296 ],
[2438820.5,  3.64013,  38761.0, 0.001296 ],
[2438942.5,  3.74013,  38761.0, 0.001296 ],
[2439004.5,  3.84013,  38761.0, 0.001296 ],
[2439126.5,  4.31317,  39126.0, 0.002592 ],
[2439887.5,  4.21317,  39126.0, 0.002592 ],
[2441317.5, 10.0],
[2441499.5, 11.0],
[2441683.5, 12.0],
[2442048.5, 13.0],
[2442413.5, 14.0],
[2442778.5, 15.0],
[2443144.5, 16.0],
[2443509.5, 17.0],
[2443874.5, 18.0],
[2444239.5, 19.0],
[2444786.5, 20.0],
[2445151.5, 21.0],
[2445516.5, 22.0],
[2446247.5, 23.0],
[2447161.5, 24.0],
[2447892.5, 25.0],
[2448257.5, 26.0],
[2448804.5, 27.0],
[2449169.5, 28.0],
[2449534.5, 29.0],
[2450083.5, 30.0],
[2450630.5, 31.0],
[2451179.5, 32.0],
[2453736.5, 33.0],
[2454832.5, 34.0],
[2456109.5, 35.0]]

DeltaT = 1599

[                                                      142.00, # 1599

  141.00,140.00,139.00,139.00,139.00,139.00,139.00,140.00,140.00,141.00, # 1600-
  141.00,141.00,141.00,140.00,139.00,138.00,137.00,134.00,132.00,128.00, # 1610-
  124.00,119.00,115.00,110.00,106.00,102.00, 98.00, 95.00, 91.00, 88.00, # 1620-
   85.00, 82.00, 79.00, 77.00, 74.00, 72.00, 70.00, 67.00, 65.00, 63.00, # 1630-
   62.00, 60.00, 58.00, 57.00, 55.00, 54.00, 53.00, 51.00, 50.00, 49.00, # 1640-
   48.00, 47.00, 46.00, 45.00, 44.00, 43.00, 42.00, 41.00, 40.00, 38.00, # 1650-
   37.00, 36.00, 35.00, 34.00, 33.00, 32.00, 31.00, 30.00, 28.00, 27.00, # 1660-
   26.00, 25.00, 24.00, 23.00, 22.00, 21.00, 20.00, 19.00, 18.00, 17.00, # 1670-
   16.00, 15.00, 14.00, 14.00, 13.00, 12.00, 12.00, 11.00, 11.00, 10.00, # 1680-
   10.00, 10.00,  9.00,  9.00,  9.00,  9.00,  9.00,  9.00,  9.00,  9.00, # 1690-

    9.00,  9.00,  9.00,  9.00,  9.00,  9.00,  9.00,  9.00, 10.00, 10.00, # 1700-
   10.00, 10.00, 10.00, 10.00, 10.00, 10.00, 10.00, 11.00, 11.00, 11.00, # 1710-
   11.00, 11.00, 11.00, 11.00, 11.00, 11.00, 11.00, 11.00, 11.00, 11.00, # 1720-
   11.00, 11.00, 11.00, 11.00, 12.00, 12.00, 12.00, 12.00, 12.00, 12.00, # 1730-
   12.00, 12.00, 12.00, 12.00, 13.00, 13.00, 13.00, 13.00, 13.00, 13.00, # 1740-
   13.00, 14.00, 14.00, 14.00, 14.00, 14.00, 14.00, 14.00, 15.00, 15.00, # 1750-
   15.00, 15.00, 15.00, 15.00, 15.00, 16.00, 16.00, 16.00, 16.00, 16.00, # 1760-
   16.00, 16.00, 16.00, 16.00, 16.00, 17.00, 17.00, 17.00, 17.00, 17.00, # 1770-
   17.00, 17.00, 17.00, 17.00, 17.00, 17.00, 17.00, 17.00, 17.00, 17.00, # 1780-
   17.00, 17.00, 16.00, 16.00, 16.00, 16.00, 15.00, 15.00, 14.00, 14.00, # 1790-

   13.70, 13.40, 13.10, 12.90, 12.70, 12.60, 12.50, 12.50, 12.50, 12.50, # 1800-
   12.50, 12.50, 12.50, 12.50, 12.50, 12.50, 12.50, 12.40, 12.30, 12.20, # 1810-
   12.00, 11.70, 11.40, 11.10, 10.60, 10.20,  9.60,  9.10,  8.60,  8.00, # 1820-
    7.50,  7.00,  6.60,  6.30,  6.00,  5.80,  5.70,  5.60,  5.60,  5.60, # 1830-
    5.70,  5.80,  5.90,  6.10,  6.20,  6.30,  6.50,  6.60,  6.80,  6.90, # 1840-
    7.10,  7.20,  7.30,  7.40,  7.50,  7.60,  7.70,  7.70,  7.80,  7.80, # 1850-
    7.88,  7.82,  7.54,  6.97,  6.40,  6.02,  5.41,  4.10,  2.92,  1.82, # 1860-
    1.61,  0.10, -1.02, -1.28, -2.69, -3.24, -3.64, -4.54, -4.71, -5.11, # 1870-
   -5.40, -5.42, -5.20, -5.46, -5.46, -5.79, -5.63, -5.64, -5.80, -5.66, # 1880-
   -5.87, -6.01, -6.19, -6.64, -6.44, -6.47, -6.09, -5.76, -4.66, -3.74, # 1890-

   -2.72, -1.54, -0.02,  1.24,  2.64,  3.86,  5.37,  6.14,  7.75,  9.13, # 1900-
   10.46, 11.53, 13.36, 14.65, 16.01, 17.20, 18.24, 19.06, 20.25, 20.95, # 1910-
   21.16, 22.25, 22.41, 23.03, 23.49, 23.62, 23.86, 24.49, 24.34, 24.08, # 1920-
   24.02, 24.00, 23.87, 23.95, 23.86, 23.93, 23.73, 23.92, 23.96, 24.02, # 1930-
   24.33, 24.83, 25.30, 25.70, 26.24, 26.77, 27.28, 27.78, 28.25, 28.71, # 1940-
   29.15, 29.57, 29.97, 30.36, 30.72, 31.07, 31.35, 31.68, 32.18, 32.68, # 1950-
   33.15, 33.59, 34.00, 34.47, 35.03, 35.73, 36.54, 37.43, 38.29, 39.20, # 1960-
   40.18, 41.17, 42.23, 43.37, 44.49, 45.48, 46.46, 47.52, 48.53, 49.59, # 1970-
   50.54, 51.38, 52.17, 52.96, 53.79, 54.34, 54.87, 55.32, 55.82, 56.30, # 1980-
   56.86, 57.57, 58.31, 59.12, 59.99, 60.79, 61.63, 62.30, 62.97, 63.47, # 1990-

   63.83, 64.09, 64.30, 64.47, 64.57, 64.69, 64.85, 65.15, 65.46, 65.78, # 2000-
   66.07, 66.32, 66.60                                                   # 2010-
]

Class Method Summary collapse

._is_systemtime_universal? ⇒ Boolean

処理系が閏秒を無視しているか否か.
._leap_seconds ⇒ Object

閏秒の挿入記録を取得する.
._setup_(leap_seconds = nil) ⇒ void

When::TimeStandard Module のグローバルな設定を行う.
.delta_t(jd_utc) ⇒ Numeric (also: deltaT)

ΔT.
.delta_t_coordinated(jd_utc) ⇒ Numeric

ΔT - 閏秒による(TT-UTC).
.delta_t_observed(jd_utc) ⇒ Numeric

ΔT - 観測による(TT-UT1).
.from_dynamical_time(time) ⇒ Numeric

dynamical time を universal time に変換する.
.from_time_object(time) ⇒ Numeric

Time オブジェクトを dynamical time に変換する.
.to_dynamical_time(time) ⇒ Numeric

universal time を dynamical time に変換する.
.to_time_object(time) ⇒ ::Time

dynamical time を Time オブジェクトに変換する.

Class Method Details

._is_systemtime_universal? ⇒ `Boolean`

処理系が閏秒を無視しているか否か

Returns:

(Boolean)

# File 'lib/when_exe/timestandard.rb', line 145

def _is_systemtime_universal?
  @is_systemtime_universal = ((Time.utc(1976).to_i - Time.utc(1975).to_i) % 86400 == 0) if @is_systemtime_universal == nil
  @is_systemtime_universal
end

._leap_seconds ⇒ `Object`

閏秒の挿入記録を取得する



139
140
141

# File 'lib/when_exe/timestandard.rb', line 139

def _leap_seconds
  @leap_seconds ||= TAI_UTC.reverse
end

._setup_(leap_seconds = nil) ⇒ `void`

This method returns an undefined value.

When::TimeStandard Module のグローバルな設定を行う

Parameters:

leap_seconds (String) (defaults to: nil) —

maia.usno.navy.mil/ser7/tai-utc.dat 形式のファイルのファイルパス
leap_seconds (Array<Array<Numeric>>) (defaults to: nil) —

閏秒の挿入記録 [ [ JD, TAI-UTC, (MJD, OFFSET) ] ]

JD - 閏秒を挿入した日時のユリウス日

TAI-UTC - 閏秒を挿入後の TAI と UTC の差

MJD - 周波数オフセットの基準となる日時の修正ユリウス日

OFFSET - 周波数オフセット値

# File 'lib/when_exe/timestandard.rb', line 119

def _setup_(leap_seconds=nil)
  @_lock_ = Mutex.new if When.multi_thread
  @_lock_.lock if @_lock_
  leap_seconds ||= TAI_UTC
  @leap_seconds  =
    if leap_seconds.kind_of?(String)
      OpenURI
      open(leap_seconds) do |file|
        file.read.split(/[\n\r]+/).map { |line|
          line.split(/[^\d.]+/)[3..6].map {|d| d.to_f}
        }.reverse
      end
    else
      leap_seconds.reverse
    end
  @_lock_.unlock if @_lock_
end

.delta_t(jd_utc) ⇒ `Numeric` Also known as: deltaT

ΔT

Parameters:

jd_utc (Numeric) —

ユリウス日(Universal Time, Coordinated)

Returns:

(Numeric) —

(dynamical_time - universal_time) / second 1/2048 second(≒0.5ms)未満を四捨五入



157
158
159

# File 'lib/when_exe/timestandard.rb', line 157

def delta_t(jd_utc)
  (delta_t_coordinated(jd_utc) * 4096 + 1).floor / 4096.0
end

.delta_t_coordinated(jd_utc) ⇒ `Numeric`

ΔT - 閏秒による(TT-UTC)

Parameters:

jd_utc (Numeric) —

ユリウス日(Universal Time, Coordinated)

Returns:

(Numeric) —

(Terrestrial Time - Universal Time, Coordinated) / second

# File 'lib/when_exe/timestandard.rb', line 168

def delta_t_coordinated(jd_utc)
  list = _leap_seconds
  list.each do |v|
    if jd_utc >= v[0]
      result  = 32.184 + v[1]
      result += (jd_utc - (2400000.5 + v[2])) * v[3] unless (v[3]||0) == 0
      return result
    end
  end
  delta_t_observed(jd_utc)
end

.delta_t_observed(jd_utc) ⇒ `Numeric`

ΔT - 観測による(TT-UT1)

Parameters:

jd_utc (Numeric) —

ユリウス日(Universal Time, Coordinated)

Returns:

(Numeric) —

(Terrestrial Time - Universal Time 1) / second

# File 'lib/when_exe/timestandard.rb', line 186

def delta_t_observed(jd_utc)
  c2000 = (jd_utc - When::Ephemeris::EPOCH2000)/When::Ephemeris::JCENT # 2000年からの経過世紀
  year  =  c2000 * 100.0 + 2000.0    #    0年からの経過年
  i = (year-1599.0).floor            # 1599年からの経過年(整数)
  if year >= 2009.0
    dt = 65.46 + 0.224 * (year-2009.0)
  elsif i>0
    n    = year % 1
    d0   = DeltaT[i+0] - DeltaT[i-1]
    d1   = DeltaT[i+1] - DeltaT[i+0]
    d2   = DeltaT[i+2] - DeltaT[i+1]
    d10  = d1  - d0
    d21  = d2  - d1
    d210 = d21 - d10
    dt   = DeltaT[i] + n*d1 + n*(n-1.0)/4.0*(d10+d21) + n*(n-1.0)*(n-0.5)/6.0*d210
  elsif year <948.0
    dt   = 2715.6 + 573.36 * c2000 + 46.5*c2000*c2000
  else
    dt   =   50.6 +  67.5  * c2000 + 22.5*c2000*c2000
  end
  return dt
end

.from_dynamical_time(time) ⇒ `Numeric`

dynamical time を universal time に変換する

Parameters:

time (Numeric) —

dynamical time

Returns:

(Numeric) —

universal time

# File 'lib/when_exe/timestandard.rb', line 227

def from_dynamical_time(time)
  return time unless -Float::MAX/4 < time && time < Float::MAX/4
  jd_tt = When::TM::JulianDate._t_to_d(time)
  utc   = time - delta_t(jd_tt) * When::TM::Duration::SECOND
  diff  = time - to_dynamical_time(utc)
  return utc if diff == 0 # 間に閏秒なし
  utc  += diff
  diff  = time - to_dynamical_time(utc)
  return utc if diff == 0 # 間に閏秒なし
  return When::Coordinates::LeapSeconds.new(utc+diff, -diff, When::TM::Duration::SECOND)
end

.from_time_object(time) ⇒ `Numeric`

Time オブジェクトを dynamical time に変換する

Parameters:

time (::Time)

Returns:

(Numeric) —

[dynamical time

# File 'lib/when_exe/timestandard.rb', line 245

def from_time_object(time)
  time = time.to_f * When::TM::Duration::SECOND
  _is_systemtime_universal? ? to_dynamical_time(time) : time + DeltaT0
end

.to_dynamical_time(time) ⇒ `Numeric`

universal time を dynamical time に変換する

Parameters:

time (Numeric) —

universal time

Returns:

(Numeric) —

dynamical time

# File 'lib/when_exe/timestandard.rb', line 215

def to_dynamical_time(time)
  return time unless -Float::MAX/4 < time && time < Float::MAX/4
  jd_utc = When::TM::JulianDate._t_to_d(time * 1)
  +time + delta_t(jd_utc) * When::TM::Duration::SECOND
end

.to_time_object(time) ⇒ `::Time`

dynamical time を Time オブジェクトに変換する

Parameters:

time (Numeric) —

dynamical time

Returns:

(::Time)

# File 'lib/when_exe/timestandard.rb', line 256

def to_time_object(time)
  time = _is_systemtime_universal? ? from_dynamical_time(time) : time - DeltaT0
  ::Time.at(+time / When::TM::Duration::SECOND)
end

Module: When::TimeStandard

Overview

Defined Under Namespace

Constant Summary collapse

Class Method Summary collapse

Class Method Details

._is_systemtime_universal? ⇒ Boolean

._leap_seconds ⇒ Object

._setup_(leap_seconds = nil) ⇒ void

.delta_t(jd_utc) ⇒ Numeric Also known as: deltaT

.delta_t_coordinated(jd_utc) ⇒ Numeric

.delta_t_observed(jd_utc) ⇒ Numeric

.from_dynamical_time(time) ⇒ Numeric

.from_time_object(time) ⇒ Numeric

.to_dynamical_time(time) ⇒ Numeric

.to_time_object(time) ⇒ ::Time

._is_systemtime_universal? ⇒ `Boolean`

._leap_seconds ⇒ `Object`

._setup_(leap_seconds = nil) ⇒ `void`

.delta_t(jd_utc) ⇒ `Numeric` Also known as: deltaT

.delta_t_coordinated(jd_utc) ⇒ `Numeric`

.delta_t_observed(jd_utc) ⇒ `Numeric`

.from_dynamical_time(time) ⇒ `Numeric`

.from_time_object(time) ⇒ `Numeric`

.to_dynamical_time(time) ⇒ `Numeric`

.to_time_object(time) ⇒ `::Time`