pyModis/docs/source/examples/full_example_gdal.rst

Example of a full process with GDAL library
===========================================

In this short example you will learn how to run a series of
scripts to obtain a GeoTIFF file for each band of the
chosen product using as backend GDAL library.

.. warning::

  This example is based on a Linux based system. If you use
  another operating system you need to change the paths where data will be saved

.. _download-data:

Downloading data
----------------

For first you need to obtain data, so you need to use :doc:`../scripts/modis_download`

.. warning::

  Remember to register in the NASA portal following the instructions at :ref:`userpw-label` session

::

  mkdir $HOME/tmp
  modis_download.py -I -f 2012-12-05 -O -t h28v05,h29v05,h28v04 $HOME/tmp

.. warning::

  In this example we are working on the spatial extent of Italy:
  for your area of interest, change the tile name(s) according to your region.

  User and password are passed through standard input.

  We are going to download data for only one day (2012-12-05) using the option "-O".

Inside the ``$HOME/tmp/`` directory you will find a file called *listfileMOD11A1.005.txt*
containing the names of downloaded files. The name of file is related to
the product that you want to download.

.. warning::

  Every time that you download new files of the same product they will be overwritten,
  so if you need them, you must rename the file before.

Mosaic data
-----------

At this point you need to create the mosaic of the tiles downloaded.
:doc:`../scripts/modis_mosaic` is the script to use. We create a *VRT*
file (``flag -v``) to improve the speed of analysis, without losing any data
only for the first layer ::

    modis_mosaic.py -s "1" -o $HOME/tmp/mosaic -v $HOME/tmp/listfileMOD11A1.005.txt

The command will create a file called ``mosaic_LST_Day_1km.vrt`` in $HOME/tmp/
directory

Convert data
------------

The last part of the procedure is to convert the mosaic using
:doc:`../scripts/modis_convert`. Using *VRT* format it create dataset
of only one later, so you are forced to use ``-s "( 1 )"``. The
following command create a GeoTIFF file called
final_mosaic_LST_Day_1km.vrt.tif ::

    modis_convert.py -v -s "( 1 )" -o $HOME/tmp/final -e 4326 $HOME/tmp/mosaic_LST_Day_1km.vrt