SMAP Science Data System Architecture

Abstract:

NASA’s Soil Moisture Active Passive (SMAP) mission will retrieve global surface soil moisture and freeze/thaw state based on measurements acquired by remote sensing instruments that fly on an Earth orbiting satellite. The SMAP observatory will launch no earlier than January 8, 2015 into a near-polar, sun-synchronous orbit for a three-year mission. The SMAP instrument suite includes a L-band radiometer and a L-band synthetic aperture radar. This paper will describe the architecture of the Science Data System (SDS) that processes the SMAP raw data into higher-level products. All of the SMAP products appear in the Hierarchical Data Format-5 (HDF5) format. Metadata that conform to the ISO 19115 standard accompany each product. SMAP products range from raw data (Level 0) through parsed and organized telemetry (Level 1A), calibrated signals (Level 1B/1C), retrieved geophysical values (Level 2), daily composite maps (Level 3), to analysis and modeling data (Level 4). This paper will describe an architecture that automates the challenge of delivering multiple products with large data volumes within a few hours to a few days of instrument acquisition. Additional challenges include handling data for a diverse user community as well as rapid data visualization. SMAP faces the additional complexity that the archive and access to the SMAP data processes through two NASA Data Active Archive Centers (DAAC): The Alaska Satellite Facility (ASF) hosts and distributes SMAP Radar data, while the National Snow and Ice Data Center (NSIDC) hosts and distributes all other SMAP products.