across.tools.ephemeris.ground_ephem

Classes

GroundEphemeris

Ground-based ephemeris calculator.

Functions

compute_ground_ephemeris(begin, end, step_size, ...)

Compute ground-based ephemeris for a given time range and location.

Module Contents

class GroundEphemeris(begin, end, step_size=60, latitude=None, longitude=None, height=None)

Bases: across.tools.ephemeris.base.Ephemeris

Ground-based ephemeris calculator.

This class extends the base Ephemeris class to calculate ephemeris data for ground-based observations from a specific location on Earth’s surface.

Parameters:

• begin (Union[datetime, Time]) – Start time of the ephemeris calculation

• end (Union[datetime, Time]) – End time of the ephemeris calculation

• step_size (Union[int, TimeDelta, timedelta], optional) – Time step between ephemeris points in seconds, by default 60

• latitude (Optional[Latitude], optional) – Latitude of the observatory, by default None

• longitude (Optional[Longitude], optional) – Longitude of the observatory, by default None

• height (Optional[u.Quantity], optional) – Height of the observatory above sea level, by default None

latitude

Latitude of the observatory

Type:

Optional[Latitude]

longitude

Longitude of the observatory

Type:

Optional[Longitude]

height

Height of the observatory

Type:

Optional[u.Quantity]

earth_location

Location of the observatory on the Earth in astropy’s EarthLocation class.

Type:

EarthLocation

gcrs

Observatory position in Geocentric Celestial Reference System (GCRS) coordinates

Type:

SkyCoord

Raises:

ValueError – If observatory location (latitude, longitude, or height) is not set

Notes

The class calculates the position of a ground-based observatory in GCRS coordinates, which is necessary for various astronomical calculations.

longitude: astropy.coordinates.Longitude | None

latitude: astropy.coordinates.Latitude | None

height: astropy.units.Quantity | None

prepare_data()

Calculate ground-based ephemeris

compute_ground_ephemeris(begin, end, step_size, latitude, longitude, height)

Compute ground-based ephemeris for a given time range and location.

Parameters:

• begin (Union[datetime, Time]) – The start time of the ephemeris computation.

• end (Union[datetime, Time]) – The end time of the ephemeris computation.

• step_size (int) – The step size in seconds for the ephemeris computation.

• latitude (Latitude) – The latitude of the ground-based observatory.

• longitude (Longitude) – The longitude of the ground-based observatory.

• height (u.Quantity) – The height of the ground-based observatory above sea level.

Returns:

An Ephemeris object containing the computed ephemeris data.

Return type:

Ephemeris