International MODIS/AIRS Processing Package

 AIRS/AMSU/HSB Level 1 Version 5.0.22 and Level 2 Version 6.0.12 Processing Package    17 July 2017

The AIRS/AMSU/HSB Processing Package for Direct Broadcast allows any ground station capable of receiving direct broadcast from Aqua to produce calibrated and geolocated AIRS, AMSU, and HSB Level 1B (calibrated and geolocated instrument observations) and Level 2 (geophysical retrieval) products. The software accepts raw packets in PDS (Production Data Set) format and converts them into Level 1B calibrated radiances and Level 2 geophysical products. The package uses version 5.0.22 of the NASA/JPL AIRS Science Processing System (SPS) for the Level 1A and Level 1B product generation and version 6.0.12 for the Level 2 products. The software package contains binary executable files and supporting static data files, as well as input and output files for verification of a successful installation.

Please note: HSB ceased operating on 5 February 2003 at 21:50 UTC.

This package (L1 v5.0.22 and L2 6.0.12) is similar to the operational AIRS/AMSU/HSB software running at the NASA Goddard Space Flight Center (GSFC) archive, with the following additions:

  • spacecraft ephemeris and attitude data contained in the X-band downlink may be used for geolocation,
  • overpasses of arbitrary size may be processed,
  • a master control script simplifies the operation of the package.

This package was developed by the AIRS Team at NASA Jet Propulsion Laboratory (JPL). 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 Intel Linux platforms. No source code is included. This version of the package has been tested on the following computer configuration:

  • Intel or AMD CPU with 64-bit instruction support,
  • 8 GB RAM,
  • CentOS 6 64-bit Linux, and
  • 26 GB disk space.

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.

Installation and Operation

Please see the installation and execution guide that is available with the software for instructions on using the package. This software is released under the terms of a NASA GSFC Software Release and Usage Agreement.

File Formats

The format of the AIRS, AMSU, and HSB Level 1B and Level 2 output files is nearly identical to the format of the equivalent GSFC DAAC files. The format is HDF-EOS, and most 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.