Description
===========
The OMI Python package is an implementation of a gridding algorithm
to project measurements of the Ozone Monitoring Instrument (OMI)
from the instrument’s frame of reference to a longitude-latitude
grid.

The algorithm is described in the following paper. Please
cite the it, if you use this software in your work:

Kuhlmann, G., Hartl, A., Cheung, H. M., Lam, Y. F., and
Wenig, M. O.: A novel gridding algorithm to create regional
trace gas maps from satellite observations, Atmos. Meas. Tech.,
7, 451-467, doi:10.5194/amt-7-451-2014, 2014.


Requirements
============
- python 2.6, 2.7 and 3.x (not all versions have been tested)
- numpy
- scipy
- h5py

- cython (only if C code shall be created from *.pyx)
- matplotlib (only for plotting)
- basemap (only for plotting)


Installing
==========
1) You can download the directory containing the source code using
the git clone command. Type:

    git clone https://github.com/gkuhl/omi

(If you don't have "git" installed on your computer, you can also
download the source code using the "Download ZIP" button on the
GitHub website.)

2) "cd" into the directory created by "git".

3) To build the C code in the package run

    python setup.py build

This requires a C compiler and "cython". If you don't want to use
"cython", please modify the "setup.py" file by changing

    USE_CYTHON = True

to

    USE_CYTHON = False


4) To finish the installation run

    python setup.py install

If you want to install the package locally, you can use the "--user"
option:

    python setup.py install --user


5) To test the installation, you can try the example script
"OMNO2_Trop.py". Please note that you have to download the OMI NO2
and PIXCOR data at 

    http://disc.sci.gsfc.nasa.gov/Aura/data-holdings/OMI

to run the example. Please read the example script for details.


Documentation
=============
The package provides functions for created Level 3 data using  either
constant values or parabolic splines. An example script for OMI
tropospheric NO2 column densities is provided in the example folder.
Please read the description in the example script ("OMNO2_Trop.py")
and the docstrings in the source code for detailed information.


Copyright
=========
Copyright (C) 2013 Gerrit Kuhlmann

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU 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/>.


Contact
=======
Gerrit Kuhlmann <gerrit.kuhlmann@gmail.com>
http://gkuhl.wordpress.com