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skyfield.toposlib.
Topos
(latitude=None, longitude=None, latitude_degrees=None, longitude_degrees=None, elevation_m=0.0, x=0.0, y=0.0)¶A vector function that knows the position of a place on Earth.
The constructor needs:
Angle
for the latitude
or
else a plain float latitude_degrees
providing the angle in
degrees.Angle
for the longitude
or
else a plain float longitude_degrees
providing the angle in
degrees.elevation_m
of the location, in meters above
mean sea level on a WGS-84 globe. If not specified, the location
will be assumed to sit at exactly sea level.The center
of a topos object is always 399
, the center of
gravity of the Earth, so every call to the at(t)
method of a
topos object returns a Geocentric
position.
Once the object has been created, here are its attributes and methods:
elevation
¶A Distance
object
specifying the elevation of the topocentric position
above mean sea level on a WGS-84 globe.
center
¶The integer 399, which identifies this topocentric position’s vector as having its origin at the center of the Earth.
itrf_xyz
()¶Return this location as an (x,y,z) vector in the ITRF frame.
Returns a 3-element Distance
object.
refract
(altitude_degrees, temperature_C, pressure_mbar)¶Predict how the atmosphere will refract a position.
Given a body that is standing altitude_degrees
above the
true horizon, return an Angle
predicting its apparent
altitude given the supplied temperature and pressure, either of
which can be the string 'standard'
to use 10°C and a
pressure of 1010 mbar adjusted for the elevation of this
geographic location.
rotation_at
(t)¶Compute the altazimuth rotation matrix for this location’s sky.