Class: Astronoby::Observer

Inherits:
Object
  • Object
show all
Defined in:
lib/astronoby/observer.rb

Constant Summary collapse

DEFAULT_ELEVATION = 
0
DEFAULT_TEMPERATURE = 
BigDecimal("283.15")
PRESSURE_AT_SEA_LEVEL = 
BigDecimal("1013.25")
PASCAL_PER_MILLIBAR = 
BigDecimal("0.01")
EARTH_GRAVITATIONAL_ACCELERATION = 
BigDecimal("9.80665")
MOLAR_MASS_OF_AIR = 
BigDecimal("0.0289644")
UNIVERSAL_GAS_CONSTANT = 
BigDecimal("8.31432")

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(latitude:, longitude:, elevation: DEFAULT_ELEVATION, temperature: DEFAULT_TEMPERATURE, pressure: nil) ⇒ Observer

Returns a new instance of Observer.

Parameters:

  • latitude (Angle) —

    geographic latitude of the observer

  • longitude (Angle) —

    geographic longitude of the observer

  • elevation (Numeric) (defaults to: DEFAULT_ELEVATION) —

    geographic elevation (or altitude) of the observer above sea level in meters

  • temperature (Numeric) (defaults to: DEFAULT_TEMPERATURE) —

    temperature at the observer’s location in kelvins

  • pressure (Numeric) (defaults to: nil) —

    atmospheric pressure at the observer’s location in millibars



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# File 'lib/astronoby/observer.rb', line 23

def initialize(
  latitude:,
  longitude:,
  elevation: DEFAULT_ELEVATION,
  temperature: DEFAULT_TEMPERATURE,
  pressure: nil
)
  @latitude = latitude
  @longitude = longitude
  @elevation = elevation
  @temperature = temperature
  @pressure = pressure
end

Instance Attribute Details

#elevation ⇒ Object (readonly)

Returns the value of attribute elevation.



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# File 'lib/astronoby/observer.rb', line 13

def elevation
  @elevation
end

#latitude ⇒ Object (readonly)

Returns the value of attribute latitude.



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# File 'lib/astronoby/observer.rb', line 13

def latitude
  @latitude
end

#longitude ⇒ Object (readonly)

Returns the value of attribute longitude.



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# File 'lib/astronoby/observer.rb', line 13

def longitude
  @longitude
end

#temperature ⇒ Object (readonly)

Returns the value of attribute temperature.



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# File 'lib/astronoby/observer.rb', line 13

def temperature
  @temperature
end

Instance Method Details

#pressure ⇒ BigDecimal

Compute an estimation of the atmospheric pressure based on the elevation and temperature

Returns:

  • (BigDecimal) —

    the atmospheric pressure in millibars.



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# File 'lib/astronoby/observer.rb', line 41

def pressure
  @pressure ||= PRESSURE_AT_SEA_LEVEL * pressure_ratio
end