astra.utils.time

astra.utils.time#

Julian Day conversions and astronomical time-frame calculations.

Functions

getLightTravelTimes(target, time_to_correct)

Calculate light travel times to heliocentric and barycentric frames.

interpolate_dfs(index, *data)

Interpolate multiple pandas DataFrames onto a common index.

time_conversion(jd, location, target)

Convert time to various astronomical reference frames.

to_jd(dt[, fmt])

Convert datetime object to Julian Day using standard algorithm.
astra.utils.time.interpolate_dfs(index: ndarray, *data: DataFrame) → DataFrame[source]#

Interpolate multiple pandas DataFrames onto a common index.

Merges and interpolates multiple DataFrames using a specified index array, commonly used for wavelength-dependent data processing in spectroscopy.

Parameters:

  • index (np.ndarray) – 1D array to interpolate data onto (e.g., wavelength grid).

  • *data (pd.DataFrame) – Variable number of DataFrames to interpolate.

Returns:

pd.DataFrame – Combined DataFrame with all data interpolated onto the common index.

astra.utils.time.to_jd(dt: datetime, fmt: str = 'jd') → float[source]#

Convert datetime object to Julian Day using standard algorithm.

Converts Python datetime to Julian Day format using the algorithm from Wikipedia. Supports conversion to various Julian Day formats.

Parameters:

  • dt (datetime) – Datetime object to convert.

  • fmt (str) – Output format (‘jd’, ‘mjd’, ‘rjd’). Defaults to ‘jd’.

Returns:

float – Julian Day value in specified format.

astra.utils.time.getLightTravelTimes(target: SkyCoord, time_to_correct: Time) → Tuple[Time, Time][source]#

Calculate light travel times to heliocentric and barycentric frames.

Computes corrections for light travel time from Earth to the solar system barycenter and heliocenter, essential for precise timing in astronomy.

Parameters:

  • target (SkyCoord) – Target celestial coordinates.

  • time_to_correct (Time) – Observation time requiring correction. Must be initialized with an EarthLocation.

Returns:

Tuple[Time, Time] – Light travel times as (barycentric, heliocentric).

astra.utils.time.time_conversion(jd: float, location: Any, target: SkyCoord) → Tuple[float, float, float, str][source]#

Convert time to various astronomical reference frames.

Transforms Julian Day to heliocentric and barycentric systems, calculates local sidereal time and hour angle for astronomical observations.

Parameters:

  • jd (float) – Julian Day to convert.

  • location (EarthLocation) – Observer’s geographic location.

  • target (SkyCoord) – Target celestial coordinates.

Returns:

Tuple[float, float, float, str] –

Converted times as

(hjd, bjd, lst_seconds, hour_angle_string).