Science Computing Facility for ICESat/GLAS Data

The Science Computing Facility (SCF) for ICESat/GLAS data consists of a data base management system for temporal and geographic subsetting of GLAS products, autonomous tools for electronic distribution to geographically-distributed remote sites, and a data analysis and visualization package. The SCF also maintains a website that conveys instrument state and GLAS product information, displays browse products of all GLAS products produced to date, and hosts a bulletin board for communicating product and tool problems. The 15 GLAS science and engineering data products produced daily by the ICESat Science Investigator-led Processing System (I-SIPS) are distributed electronically by the SCF to GLAS Science Team members and their associates at nine remote sites, as requested. Interactive Graphical User Interfaces easily enable the remote users to subscribe to customized data sets from the standard products by defining the product, temporal spans, and geographic regions. As data are received from the I-SIPS, the individual subscriptions are automatically filled and the customized data sets are electronically transferred to the remote users. Normally, receipt of these data sets at the remote sites occurs within hours of the I-SIPS processing. Subsetting is accomplished using a Data Management System (DMS) that quickly determines if data for a subscription are present in the newly received product and then allows fast, direct, efficient access to each second of data that falls within the subscription's temporal and geographic span, instead of reading through the files sequentially. The distribution is accomplished via secure-shell communications, a MYSql database, a series of Perl and Tcl scripts, and a collection of IDL and Fortran 90 software.