Basic Gaia data simulation, manipulation, and analysis toolkit
Python toolkit for basic Gaia data simulation, manipulation, and analysis
PyGaia provides python modules for the simulation of Gaia data and their errors, as well modules for the manipulation and analysis of the Gaia catalogue data. In particular transformations between astrometric observables and phase space variables are provided as well as transformations between sky coordinate systems. Only (very) basic functionality is provided. Full blown simulations of Gaia data in all their gory detail requires the Java tools developed by the Gaia Data Processing and Analysis Consortium (DPAC) in particular its Coordination Unit 2 (CU2).
This toolkit is basically an implementation of the performance models for Gaia which are publicly available at: http://www.cosmos.esa.int/web/gaia/science-performance. In addition much of the material in chapter 4 of the book Astrometry for Astrophysics: Methods, Models, and Applications (2012, van Altena et al.) is implemented.
Note that the code in this package is not intended for accurate astrometry applications, such as predicting in detail astrometric paths of stars on the sky, or transforming between observation epochs.
All classes and methods/functions are documented so use the python help() function to find out more. More extensive documentation will follow.
This package was developed in a python 2.7 environment and you may experience problems if you have an older version installed. In particular the scripts in the examples folder will not run because they expect the argparse module to be present.
The following python packages are required:
For the plotting tools:
Please acknowledge the Gaia Project Scientist Support Team and the Gaia Data Processing and Analysis Consortium (DPAC) if you used this code in your research.
Copyright (c) 2012-2016 Anthony Brown, Gaia Data Processing and Analysis Consortium
PyGaia is open source and free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.
1.21 (April 2018)
- Added constant AU expressed in mas*km*yr/s
- Fixed large memoery consumption in the _getJacobian method in the coordinate transformation code. Thanks to jchelly for pointing out this problem.
1.2 (December 2016)
- Add method to CoordinateTransformation for the transformation of the full (5x5) covariance matrix of the astrometric parameters.
- Add keyword to astrometric errors prediction functions that allows to specify an extended mission lifetime.
1.1 (September 2016)
- Bug fix in coordinate transformation code.
- Updated photometry and radial velocity error predictions.
- End-of-mission photometry errors, including calibration floor, introduced for the broad band fluxes.
- Photometry errors now include 20% margin for CCD-transit and end-of-mission predictions.
- Example plot of photometry errors fixed.
1.0 (November 2015)
- Added numerical constants.
- Improved setup.py, made code compatible with Python3
0.9 (September 2015)
- Photometric performance predictions updated to post-launch estimates.
0.83 (July 2015)
- Minor error in documentation of astrometryToPhaseSpace() method corrected.
0.82 (July 2015)
- Error corrected in transformSkyCoordinateErrors() method. Thanks to Teresa Antoja and Taniya Parikh!
0.81 (June 2015)
- Forgot to update changelog for version 0.8
0.8 (June 2015)
- Radial velocity performance predictions updated to post-launch estimates.
0.7 (December 2014)
- Astrometry performance predictions updated to post-launch estimates.
0.6 (July 2014)
- Warning on upcoming changes in performance predictions, following the Gaia commissioning period
- radial velocity horizons plot in examples folder
0.5 (August 2013)
- Utilities for obtaining absolute magnitudes of stars in V and G.
- Functions to obtain the upper and lower bounds on the astrometric parameter errors (corresponding to the sky regions with best/worst astrometric errors).
- Proper motion error plot.
- Parallax horizon plot.
0.4 (April 2013)
- Added transformation of proper motions and of position and proper motion errors.
0.31 (February 2013)
- Updated README. TODO added.
0.3 (February 2013)
- Added documentation on installation requirements. Added the handling of an ImportError for the argparse module to the example scripts.
0.2 (February 2013)
- Problems in setup.py fixed as well is bugs in the error simulation code.
0.1 (February 2013)
- First release
0.0 (October 2012)
- Creation from bits and pieces of python code that AB had lying around.