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MODIS Science Data Support Team (SDST)



About SDST

The MODIS Science Data Support Team (SDST) is dedicated to the generation of high quality Level 2 (L2) through L4 MODIS science products for distribution to the Distributed Active Archive Centers (DAACs) for archival and to the MODIS science team for quality control. SDST reports to the MODIS Team Leader, Dr V. Salomonson, and functions within a Principal Investigator (PI) processing paradigm under the terms of which SDST works closely with the MODIS PIs at every phase of the work performed. SDST has the following major responsibilities:

Development and Testing of Product Generation Executives

MODIS supports the land, oceans and atmospheres disciplines and the MODIS science team generates in excess of 140 science algorithms for L2 through L4 products for each MODIS instrument. These algorithms are combined by SDST into groups called Product Generation Executives (PGEs). SDST is responsible for:

  • Generating the PGEs for processing the L0 data to L1A data;
  • Generating the geolocation algorithm and performing trend analysis to increase the accuracy of the algorithm;
  • Testing these algorithms and, cloud mask algorithm and the L1B PGE received from the MODIS Characterization Support Team (MCST) and delivering these PGEs to the GDAAC for operational processing;
  • Developing and maintaining utility code to support the SDST environment;
  • Interacting with the EOSDIS Core System (ECS) staff in the generation of ESDTs to allow the science products to be inserted into the DAACs;
  • Receiving science algorithms from the MODIS science team and integrating them with metadata and production rules to generate PGEs for L2 through L4 processing;
  • Documenting the PGEs, production rules, and procedures generated at SDST;
  • Operating a Configuration Management group for controlling the evolution of the PGEs and the MODIS processing system described below, and;
  • Operating a science test environment with capability to process up to 32 days of data in support of the science team's efforts to validate their science algorithms.

System Development and Maintenance

The MODIS Adaptive Processing System (MODAPS) receives Geolocation, L1B, Cloud Mask, and ancillary data from the GDAAC and uses approximately 100 PGEs per MODIS instrument to generate L2 through L4 products. SDST is responsible for:

  • Developing and maintaining the MODAPS software for both IRIX and distributed linux environments, and;
  • Exploring the potential applications of MODAPS to other missions and data sets such as OMI, NPP, Landsat, and AVHRR.

Data Production

The generation of the L2 through L4 science products is accomplished using two super computers: an Origin 3000 with 64 cpus, a cluster of 136 Pentiun processors, and 50TB of disk and an Origin 2000 with 80 cpus, a cluster of 80 Pentiun processors, and 60TB of disk. The former is used for data reprocessing and the latter is used for forward processing that is normally 2-5 days behind real time. These systems have a combined production capacity for all three discipline products of 6x (6 datadays per production day). SDST is responsible for:

  • Reporting plans and accomplishments and interacting with the MODIS PIs to generate long range processing plans;
  • Generating daily production plans for operations staff and reconciling production with the science products archived at the DAACs;
  • Executing the production plans for the forward and reprocessing machines on a 7x24h basis;
  • Documenting operational and production procedures;
  • Conducting performance testing and processing special requests from the science disciplines;
  • Operating a rapid response data system for generating special data products within hours of real time to support such activities as fire fighting, and;
  • Performing sustaining engineering to support the on-going evolution of the hardware and system software associated with the operations computers.

Quality Control

As part of routine production, subsets of the science products are distributed directly to the MODIS science team members for QA purposes. Each discipline is responsible for maintaining a website identifying product quality issues. SDST is responsible for:

  • Conducting daily QA reviews of atmospheres and oceans science products and interacting with the PIs to develop plans for corrective action if necessary, and;
  • Operating the Land Data Operational Product Evaluation (LDOPE) facility for land data assessment, interacting with the land science team to improve science algorithm performance, and maintaining a land QA database.

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Last Updated: 04/28/2005