Volume 16, Number 2, July 2000
By Natalia Papitashvili and Joseph King
NSSDC has a number of pathways through which users may graphically display data, subset data by time and parameter, and retrieve data in user-selected formats. These pathways include the CDF-based OMNIWeb, COHOWeb, (Space Physics Data Facility [SPDF]-sponsored) CDAWeb systems, and the ASCII-based ATMOWeb system.
Separately, NSSDC has long hosted both the near-line NASA Data Archive and Distribution System (NDADS) and an on-line anonymous FTP environment from which whole files can be downloaded in the formats in which NSSDC holds the data. As reported elsewhere, it is NSSDC's intent to retire NDADS and its related interfaces (e.g., the Space Physics Catalog [SPyCAT]) in favor of simple disk-based anonymous FTP in the coming months.
Ideally, users want to find and download readily usable data files, as provided by FTP, but in many cases also want a relatively simple browse functionality to invoke as part of the data selection process. NSSDC has just provided this functionality in an interface called FTP Helper. This interface runs against selected FTP-accessible ASCII and gzipped ASCII data sets through data-set-specific Web pages. It provides the ability to graphically browse (or to create screen lists or downloadable files) of user-selected data words from the file's data records for user-specified times.
At this writing FTP Helper supports the following ATMOWeb data sets: two IMP 8 data sets (University of Iowa plasma and University of Chicago cosmic ray data) and magnetometer data from the Prognoz 6, 7, and 9 spacecraft. FTP Helper will be used on a demand and resource-available basis to support other data sets whose incorporation into the CDF-based CDAWeb system is not imminent, yet whose access potential is significant.
CDAWeb remains NSSDC's primary long-term tool for providing browsing of multiple data sets concurrently while FTP Helper provides a browse-as-a-data-selection tool for some individual data sets that NSSDC makes FTP-accessible. FTP Helper is at http://nssdc.gsfc.nasa.gov/ftphelper/.
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Author: Miranda Beall