File name:      Readme.txt

Authors:        Norman Fomferra
                Sabine Embacher

Affiliation:    BEAM Development Team
                Brockmann Consult GmbH
                Max-Planck-Strasse 1
                D-21502 Geesthacht, Germany
                www.brockmann-consult.de

E-mails:        norman.fomferra@brockmann-consult.de
                sabine.embacher@brockmann-consult.de

Document title: Brief Documentation of the GeoPosCorrector plugin
                A plug-in for MERIS/(A)ATSR Toolbox (BEAM)

Release date:	March 24, 2005


Introduction
------------

This file briefly describes the installation and use of the
accompanying software package.


Requirements
------------

The GeoPosCorrector is a plug-in module for the BEAM software developed
by Brockmann Consult for ESA. This latter software must of course be
installed prior to the plugin.

The BEAM software includes an application programming interface (API) and
a set of executable tools to facilitate the use of MERIS, AATSR and further
ASAR data products of the ESA ENVISAT satellite.

It can be freely downloaded from:

http://www.brockmann-consult.de/services/beam2/software/


Installation
------------

The BEAM package (here : BEAM VISAT Version 3.2) is installed within a
particular, user-selectable, directory. For the purpose of this documentation
file, that directory will be denoted $BEAM_HOME$. After installation of the
BEAM package, this directory should contain the following subdirectories
and files:

    $BEAM_HOME$
        |- auxdata/
        |- bin/
        |- docs/
        |- extensions/
        |- jre/
        |- lib/
        |- license/
        |- log/
        |- api-doc.zip
        |- changelog.txt
        |- epr_api-2.0.5.zip
        |- examples.zip
        |- known-issues.txt
        |- readme.txt
        |- src.zip
        |- version.txt

The GeoPosCorrector plug-in, named 'geopos_corrector.jar', must simply be added
to the $BEAM_HOME$/extensions/ subdirectory. The BEAM application (VISAT)
will automatically integrate the plugin into its interface.


Operation
---------

After starting the VISAT application you will find the new menu entry
   'Compute Geodetic Corrections'
inside the Tools menu.

This new tool uses the GETASSE30 elevation model. If you haven't downloaded this
elevation model before, you can download it automatically by trying to orthorectify
a MERIS product by specifying the GETASSE30 as the elevation model to be used.
VISAT will recognise that the GETASSE30 elevation model has not been downloaded before,
VISAT starts the download and installation process automatically.
Warning! The GETASSE30 elevation model requires 2,6 GB free harddisk space.

After successful installation of the elevation model you can run this tool.
It will add the following bands to the source product:
dem_elevation   :  the elevation corresponding to the geodetic lon lat
ortho_corr_lat  :  the orthorectified correct latitude
ortho_corr_lon  :  the orthorectified correct longitude
ortho_delta_x   :  the delta of the corrected position and the origin position as pixel x value
ortho_delta_y   :  the delta of the corrected position and the origin position as pixel y value
ortho_delta_lat :  a virtual band as delta lat
ortho_delta_lon :  a virtual band as delta lon


Warranties and copyright information
------------------------------------

The plugin described in this document is provided
'as is', with no warranty of merchantability or fitness to any particular
purpose. Although every effort has been made to ensure accuracy of computations
and conformity to the algorithms as published in the references below, the
authors assume no responsibility whatsoever for any direct, indirect or
consequential damage resulting from the use of this software. The plugin
is distributed free of charge and cannot be sold or re-sold. It
can be copied and distributed further, provided all documentation is attached
and provided the original source of the software is explicitly and
prominently described.

Questions, concerns and problems should be referred to the authors of the
software package at the address indicated at the start of this file.

The copyright on this file and the associated software remains with the
Brockmann Consult GmbH.