NAME

Geo::Format::Envisat - parse Envisat metadata format

INHERITANCE

 Geo::Format::Envisat
   is a Exporter

SYNOPSIS

 use Geo::Format::Envisat;

 # base info solely on filename (fast!)
 my $mph  = envisat_mph_from_name $filename;

 # collect all meta-data from inside the file
 my $meta = envisat_meta_from_file $filename;

 use Data::Dumper;
 print Dumper $meta;   # see the returned structure

 # see examples/ directory!!

DESCRIPTION

Simply transform the meta-data which leads Envisat and ERS imagery into Perl HASHes for easy access. All keys which are upper-case follow the official document. Lower-cased fields are added for each of the official names, which are preprocessed to simplify further processing, like translation of time fields to OS time values and an iso representation. The lower-cased key names will also have blanks stripped from the end and abbreviated codes extended for readability.

The formats are described in various documents available from http://earth.esa.int/pub/ESA_DOC/ENVISAT/

Used are Vol05_Structures_3d_20071122.pdf (Main Product Header description version 2007-11-22) and Vol08_Asar_4B_20071025.pdf (ASAR file format specifics version 2007-10-25).

FUNCTIONS

envisat_meta_from_file(FILENAME, OPTIONS)

Read all meta-data from the file specified by its FILENAME. The file can be in compressed form, although you may need to install some additional IO::Uncompress modules.

 -Option          --Default
  take_dsd_content  <false>

take_dsd_content => BOOLEAN

Collect the content from all non-measurement DSD records. These are binary fields.

example: envisat_meta_from_file

 my $meta = envisat_meta_from_file $fn;
 my $mph = $meta->{mph};  # Main Product Header
 my $sph = $meta->{sph};  # Specific Product Header
 my $mds = $meta->{dsd}{MSD1};  # data-set description

envisat_mph_from_name(FILENAME|STRING)

Pass the product FILENAME as STRING, and it will get decomposed into some records which are also in the Main Product Header meta-data records. This permits some easy searching in directories without the need to open the (sometimes compressed, always large) files.

Compression extensions at the end of the STRING will be ignored. The name will be upper-cased before processing. Undef is returned when there is no match. Some information can be added if the STRING actually refers to an existing FILENAME. Therefore, you may pass a filename which contains directory components.

example: envisat_mph_from_name

 my $fn  = 'ASA_IMG_1PNDPA20080903_100725_000000152071_00423_34044_1202.N1';
 my $mph = envisat_mph_from_name $fn;

SEE ALSO

This module is part of Geo-Format-Envisat distribution version 0.90, built on January 23, 2018. Website: http://perl.overmeer.net/CPAN/

LICENSE

Copyrights 2008-2018 by [Mark Overmeer]. For other contributors see ChangeLog.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See http://dev.perl.org/licenses/