The Atmospheric Infra-Red Sounder (AIRS) Science Processing System (SPS) is a collection of computer programs, known as product generation executives (PGEs). The AIRS SPS PGEs are used for processing measurements received from the AIRS suite of infrared and microwave instruments orbiting the Earth onboard NASA’s Aqua spacecraft. Early stages of the AIRS SPS development were described in a prior NASA Tech Briefs article: “Initial Processing of Infrared Spectral Data” (NPO-35243), Vol. 28, No. 11 (November 2004), page 39.
In summary: Starting from Level 0 (representing raw AIRS data), the AIRS SPS PGEs and the data products they produce are identified by alphanumeric labels (1A, 1B, 2, and 3) representing successive stages or levels of processing. The previous NASA Tech Briefs article described processing through Level 2, the output of which comprises geo-located atmospheric data products such as temperature and humidity profiles among others. The AIRS Level 3 PGE samples selected information from the Level 2 standard products to produce a single global gridded product. One Level 3 product is generated for each day’s collection of Level 2 data. In addition, daily Level 3 products are aggregated into two multi-day products: an eight-day (half the orbital repeat cycle) product and monthly (calendar month) product.
This work was done by Stephanie Granger, Robert Oliphant, and Evan Manning of Caltech for NASA’s Jet Propulsion Laboratory. For more information, download the Technical Support Package (free white paper) at www.techbriefs.com /tsp under the Software category.
This software is available for commercial licensing. Please contact Karina Edmonds of the California Institute of Technology at (626) 395-2322. Refer to NPO-42146.
This Brief includes a Technical Support Package (TSP).
Processing AIRS Scientific Data Through Level 3
(reference NPO-42146) is currently available for download from the TSP library.
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Overview
The document titled "Processing AIRS Scientific Data Through Level 3" (NPO-42146) from NASA's Jet Propulsion Laboratory outlines the processing system for data collected by the Atmospheric Infrared Spectrometer (AIRS) aboard the Aqua spacecraft. The AIRS Science Processing System (SPS) consists of a series of Product Generation Executives (PGEs) that convert raw AIRS data into higher-level geophysical products, specifically temperature and humidity profiles.
The processing is organized into four distinct phases: Level 1A, Level 1B, Level 2, and Level 3. Level 1A involves the initial collection of instrument data, which is then forwarded to Level 1B PGEs. Level 1B processing generates calibrated and geolocated radiance products from granules of AIRS data, including contributions from the Advanced Microwave Sounding Unit (AMSU) and the Humidity Sounder for Brazil (HSB). This phase produces several standard products, including brightness temperatures and radiances, as well as quality assessment products.
Level 2 processing takes the Level 1B products and derives geophysical atmospheric products through a complex retrieval process. This includes steps such as Microwave-only Retrieval, Cloud Detection and Cloud Clearing, Regression, Full Retrieval, and Rapid Transmittance Algorithm. The output of Level 2 includes standard retrieval products, cloud-cleared radiance products, and support products.
The final phase, Level 3, samples information from the Level 2 products to create gridded products. This phase produces three standard products: a daily Level 3 Standard Product, an 8-day Multi-day Product, and a Monthly Product. These products can be aggregated for broader analysis, providing valuable insights into atmospheric conditions over time.
The document emphasizes the importance of these processed data products for scientific research and applications in atmospheric science. It highlights the advancements made in the AIRS processing system, particularly the updates to existing PGEs and the introduction of new Level 3 products. Overall, the AIRS data processing framework represents a significant contribution to understanding Earth's atmosphere and improving weather forecasting and climate monitoring.
