Lunar Grid Reference System library
The lgrs package is software to support the Lunar Grid Reference System and also provides utility functions for coordinate projections until the Lunar Transverse Mercator (LTM) and Lunar Polar Stereographic (LPS) projections are made available in the PROJ library.
At the moment, this repo is under significant development and change as we attempt to craft various pieces of code. It is very messy and a work-in-process. Nothing is guaranteed about structure until we pass the 1.0 version.
Reference document that this library follows is McClernan, M.T., Dennis, M.L., Theriot, I.H., Hare, T.M., Archinal, B.A., Ostrach, L.R., Hunter, M.A., Miller, M.J., Beyer, R.A., Annex, A.M., and Lawrence, S.J., 2025, Lunar grid systems, coordinate systems, and map projections for the Artemis missions and lunar surface navigation: U.S. Geological Survey Techniques and Methods, book 11, chap. E1, 308 p., DOI: 10.3133/tm11E1.
The code in the lgrs.reference modules are from Dr. McClernan's "mark 7.2" version.
The report is also available here: https://www.usgs.gov/publications/lunar-grid-systems-coordinate-systems-and-map-projections-artemis-missions-and-lunar
The lgrs library is available on PyPI, and can be pip-installed:
$> pip install lgrs
Alternately, you can clone or download this repository.
It is highly suggested to install this into a virtual Python environment.
Change directory to where you have downloaded this repository after you have set up your virtual environment, just do this:
$> pip install
or:
$> make install
If you use conda for your virtual environment and install dependencies via conda, you can do this:
$> conda create -n lgrs $> conda activate lgrs $> conda env update --file environment.yml $> pip install --no-deps .
Examples and how to get started with the lgrs library can be found in our usage guide.
Feedback, issues, and contributions are always gratefully welcomed. See the contributing guide for details on how to help and setup a development environment.
The lgrs library was developed in the open at the SETI Institute, based on open code originally developed by the United States Geological Survey.
See the AUTHORS file for a complete list of developers.
The lgrs software is licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0.
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.