pynadc

The pynadc package contains the following tools and Python modules:

Access to Sciamachy data-products

• Fast read access to Sciamachy (ENVISAT) level 0 The software attempt to read all data and offers convenient access to the parameter through structured numpy arrays. The script scia_lv0.py offers a guideline of how to use the module pynadc.scia.lv0. Products compressed by gzip can be read directly.
• Fast read access to Sciamachy (ENVISAT) level 1b The software attempt to read all data and offers convenient access to the parameter through structured numpy arrays. Both Science and calibration datasets can be read into memory, however, currently calibration of the science data is not included. The script scia_lv1.py offers a guideline of how to use the module pynadc.scia.lv1. Products compressed by gzip can be read directly.
• Build a database with Sciamachy instrument settings The script collect_scia_states.py can be used to build a database with all instrument configurations used during the mission of Sciamachy. This requires that the complete Sciamachy level 1b archive is available. Definitions of OCR states are not included in the level 1b products, and are therefore hard-coded in the software. These could be obtained from level 0 products, but this is not yet implemented.

The Sciamachy level 0 and level 1 (up to versions 8) are in a special ENVISAT format which require dedicated reading S/W tools. The ENVISAT format is a simple byte stream with a header containing byte offsets that allows the extraction of specific datasets. While this type of data format is very space efficient (all data bytes are just written one after the other with a small ASCII header), it is not future proof (dedicated S/W is needed) nor self descriptive. The latest level 1 products (from version 9 and up) are provided in netCDF4 format. This format is self-descriptive and can be read by widely available standard reading tools that are provided in all major programming languages.

Access to GOSAT and Sciamachy (local) archives

Databases of files in your archives, can be very handy when you want to query on presence, completeness, date of archiving, double entries, etc. Specially, when you are collecting data during a satellite mission. The package pynadc contains software to create SQLite databases of archives with GOSAT FTS level 1, GOSAT CAI level 2 and Sciamachy level 0, 1b and 2 (PDS/ESA format). And tools to query these databases.

Installation

Installation instructions are provided in the INSTALL file.

We installed the software succesfully on Linux and MacOS.

Websites

• Source code: http://github.com/rmvanhees/pynadc
• SRON Netherlands Institute for Space Research: https://www.sron.nl/
• Sciamachy: https://earth.esa.int/web/guest/missions/esa-operational-eo-missions/envisat/instruments/sciamachy
• GOSAT: http://global.jaxa.jp/projects/sat/gosat

Disclaimer

The software is developed for SRON internal usage, but generously shared without any warranty.

Reporing bugs

Issues and bugs should be reported to <r.m.van.hees[at]sron.nl>