Aqua AIRS/AMSU/HSB Level 1 Processing Package

Part of the International MODIS/AIRS Processing Package (IMAPP)

November 5, 2003: Version 1.0 released


    The polar-orbiting Aqua spacecraft, launched by NASA in May 2002, provides an X-band direct broadcast service where data from all science instruments is downlinked to the Earth in near real-time. The AIRS/AMSU/HSB Level 1 Processing Package allows any ground station capable of receiving direct broadcast from Aqua to produce calibrated and geolocated AIRS, AMSU, and HSB Level 1B products. This package is functionally identical to the operational AIRS/AMSU/HSB package running at the GSFC DAAC, with the following additions:

    This package was developed by the AIRS Team at NASA Jet Propulsion Laboratory, and distribution and support is provided by the Space Science and Engineering Center at the University of Wisconsin-Madison.


    This is a binary-only release for Red Hat Intel Linux and Sun Solaris (SPARC) platforms. No source code is included. This version of the package has been tested on the following platforms:

Red Hat Intel Linux: 7.3, 8.0, 9
Sun Solaris (SPARC): 7, 8, 9

    The input expected by the package is Level 0 AIRS, AMSU, HSB, and GBAD files, defined as reconstructed time-ordered CCSDS packets with all communication artifacts (including duplicate and bad packets) removed. This includes PN and Reed Solomon decoding as well as reassembly of the raw telemetry packets. Processing of the data stream to this stage is the responsibility of the user. Data in this format is known as a Production Data Set (PDS).
    The Direct Readout Laboratory at NASA GSFC has developed a software application named RT-STPS (Real-Time Software Telemetry Processing System), which synchronizes the data, performs PN and RS decoding and packet reassembly, and writes the output in PDS format. This package is know to be compatible with Level 0 PDS files created by RT-STPS. In addition, many X-band ground station vendors supply processing hardware and/or software that creates compatible Level 0 files.


    The package is available for download by anonymous FTP at

    Please read the AIRS_README.txt file for instructions on installing and running the package. If you are unable to download the package because of a slow Internet connection, please contact us and we will arrange to ship the package to you on DVD, CD, or DLT media. This package is released under the terms of a NASA GSFC Software Release and Usage Agreement.

Revision History

November 5, 2003 (v 1.0) First release

File Formats

    The format of the AIRS, AMSU, and HSB Level 1B output files is identical to the format of the equivalent GSFC DAAC Level 1B files. The format is HDF-EOS, and all ECS metadata fields are present. Regardless of the size of the direct broadcast pass, the output files will be split into standard AIRS 6-minute granules. Therefore the leading and/or trailing granules created from a direct broadcast pass will contain some missing data.


    This package was developed at NASA Jet Propulsion Laboratory by Quyen Nguyen, Richard Forrister and Evan Manning under NASA RTOP 622-40-45-03 in support of the AIRS Project at NASA Jet Propulsion Laboratory under NASA NPO-21132.
    This package is supported at SSEC by Liam Gumley, Allen Huang, Kevin Baggett, and Elisabeth Weisz, as part of the International MODIS/AIRS Processing Package (IMAPP). IMAPP is funded by NASA under grant NAG5-13402.

Related Links for AIRS/AMSU/HSB

Ancillary data:
    leapsec.dat | utcpole.dat | definitive attitude/ephemeris

Level 0 data:
    Univ. of Wisconsin | NASA GSFC

Level 1B data:
    Univ. of Wisconsin | GSFC DAAC Data Pool

    Home | GSFC DAAC | Algorithm Theoretical Basis Documents

Aqua spacecraft:
    Home | Orbit Tracks | Overpass Prediction | NORAD TLE orbital elements

EOS direct broadcast information:
    Home | GSFC Direct Readout Laboratory

Liam Gumley (last update November 5, 2003)