PyEci

class cysgp4.PyEci(PyDateTime pydt=None, PyCoordGeodetic geo_loc=None)

Bases: object

Thin wrapper around sgp4 (C++) Eci class.

The Eci class holds an ECI location (latitude, longitude, altitude) for a particular datetime.

Note, internally, the coordinates (and velocities) are stored in Cartesian form (read-only!). One can access these, via the loc and vel properties. Setting new parameters is only possible via a geographic location.

Parameters:

pydtPyDateTime

Date and time.

geo_locPyCoordGeodetic

Geographic location.

Returns:

eciPyEci object

Examples

Constructing and using a PyEci object is straightforward:

>>> from cysgp4 import PyEci, PyCoordGeodetic, PyDateTime

>>> pydt = PyDateTime.from_mjd(55555.)
>>> lon_deg, lat_deg = 6.88375, 50.525
>>> alt_km = 0.366
>>> geo = PyCoordGeodetic(lon_deg, lat_deg, alt_km)
>>> eci = PyEci(pydt, geo)
>>> eci
<PyEci: 6.8837d, 50.5250d, 0.3660km 2010-12-25 00:00:00.000000 UTC>

>>> # Access is also possible via properties, e.g.:
>>> eci.loc
(-725.3304166274728, 3997.924210010933, 4900.402205553537)
>>> eci.pydt = PyDateTime.from_mjd(55556.)

>>> # or the update method:
>>> eci.update(pydt, PyCoordGeodetic(0, 0, 0))

Constructor PyEci(PyDateTime pydt, PyCoordGeodetic geo_loc)

Attributes Summary

geo_loc	Geographic location (see also Class documentation).
loc	Cartesian location (readonly, see also Class documentation).
pydt	Datetime (see also Class documentation).
vel	Cartesian velocity (readonly, see also Class documentation).

Methods Summary

update(self, PyDateTime pydt=None, ...)

Update PyEci object.

Attributes Documentation

geo_loc

Geographic location (see also Class documentation).

loc

Cartesian location (readonly, see also Class documentation).

pydt

Datetime (see also Class documentation).

vel

Cartesian velocity (readonly, see also Class documentation).

Methods Documentation

update(self, PyDateTime pydt=None, PyCoordGeodetic geo_loc=None)

Update PyEci object.

Parameters:

pydtPyDateTime

Date and time.

geo_locPyCoordGeodetic

Geographic location.