pure-Python (Numpy optional) 3D coordinate conversions for geospace ecef enu eci
Pure Python (no prerequistes beyond Python itself) 3-D geographic coordinate conversions and geodesy. API similar to popular $1000 Matlab Mapping Toolbox routines for Python PyMap3D is intended for non-interactive use on massively parallel (HPC) and embedded systems.
Thanks to our contributors.
Pymap3d is compatible with Python ≥ 3.7 including PyPy. Numpy and AstroPy are optional; algorithms from Vallado and Meeus are used if AstroPy is not present.
python3 -m pip install pymap3d
or for the latest development code:
git clone https://github.com/geospace-code/pymap3d
pip install -e pymap3d
One can verify Python functionality after installation by:
pytest pymap3d -r a -v
Where consistent with the definition of the functions, all arguments may be arbitrarily shaped (scalar, N-D array).
import pymap3d as pm
x,y,z = pm.geodetic2ecef(lat,lon,alt)
az,el,range = pm.geodetic2aer(lat, lon, alt, observer_lat, observer_lon, 0)
aer = (az,el,slantrange) obslla = (obs_lat,obs_lon,obs_alt)
lla = pm.aer2geodetic(*aer,*obslla)
llais comprised of scalar or N-D arrays
Example scripts are in the examples directory.
Popular mapping toolbox functions ported to Python include the following, where the source coordinate system (before the "2") is converted to the desired coordinate system:
aer2ecef aer2enu aer2geodetic aer2ned ecef2aer ecef2enu ecef2enuv ecef2geodetic ecef2ned ecef2nedv ecef2eci eci2ecef eci2aer aer2eci geodetic2eci eci2geodetic enu2aer enu2ecef enu2geodetic geodetic2aer geodetic2ecef geodetic2enu geodetic2ned ned2aer ned2ecef ned2geodetic azel2radec radec2azel vreckon vdist lookAtSpheroid track2 departure meanm rcurve rsphere geod2geoc geoc2geod
Use of pymap3d on embedded systems or other streaming data applications often deal with scalar position data. These data are handled efficiently with the Python math stdlib module. Vector data can be handled via list comprehension.
Those needing multidimensional data with SIMD and other Numpy and/or PyPy accelerated performance can do so automatically by installing Numpy. pymap3d seamlessly falls back to Python's math module if Numpy isn't present. To keep the code clean, only scalar data can be used without Numpy. As noted above, use list comprehension if you need vector data without Numpy.
As compared to PyProj:
At this time, AstroPy.Units.Quantity is not supported. Let us know if this is of interest. Impacts on performance would have to be considered before making Quantity a first-class citizen. For now, you can workaround by passing in the
.valueof the variable.