This is a Python wrapper for the Apex fortran library by Emmert et al.  , which allows converting between geodetic, modified apex, and quasi-dipole coordinates as well as getting modified apex and quasi-dipole base vectors (Richmond  ). MLT calculations are also included. The package is free software (MIT license).
Install (requires NumPy):
pip install apexpy
Conversion is done by creating an
Apex object and using its methods to perform the desired calculations. Some simple examples:
>>> from apexpy import Apex >>> A = Apex(date=2015.3) # datetime objects are also supported >>> # geo to apex, scalar input >>> mlat, mlon = A.convert(60, 15, 'geo', 'apex', height=300) >>> mlat 57.469573974609375 >>> mlon 93.633583068847656 >>> # apex to geo, array input >>> glat, glon = A.convert([90, -90], 0, 'apex', 'geo', height=0) >>> glat array([ 83.09959412, -74.38826752]) >>> glon array([ -84.59458923, 125.71492767]) >>> # geo to MLT >>> import datetime as dt >>> mlat, mlt = A.convert(60, 15, 'geo', 'mlt', datetime=dt.datetime(2015, 2, 10, 18, 0, 0)) >>> mlat 56.590423583984375 >>> mlt 19.108103879292806 >>> # can also convert magnetic longitude to mlt >>> mlt = A.mlon2mlt(120, dt.datetime(2015, 2, 10, 18, 0, 0)) >>> mlt 20.893547503153481
If you don’t know or use Python, you can also use the command line. See details in the full documentation.
|||Emmert, J. T., A. D. Richmond, and D. P. Drob (2010), A computationally compact representation of Magnetic-Apex and Quasi-Dipole coordinates with smooth base vectors, J. Geophys. Res., 115(A8), A08322, doi:10.1029/2010JA015326.|
|||Richmond, A. D. (1995), Ionospheric Electrodynamics Using Magnetic Apex Coordinates, Journal of geomagnetism and geoelectricity, 47(2), 191–212, doi:10.5636/jgg.47.191.|