1.2 Data Management and Archiving

Data management refers to all the steps from initial data collection at the GPS receiver to placing quality-checked data in an archive. These steps include downloading the data from the receiver to an intermediate platform such as a PC, transmission of the data over a robust and reliable communications link, quality checking and formatting of the data, and entry of the data into the archive. Support for these activities is provided by the Boulder Facility Data Management and Archiving Group (DMAG). Details of data management and archiving support activities are discussed in Appendix C. In FY97, several new software packages to control and automate data download from various receivers to multiple computing platforms were completed (LAPDOGS and ADP), new technologies for data transmission were developed and implemented (LDM), and a new data editing, translation and quality check software (TEQC) was implemented. Activity in FY98 will include expanding these capabilities to additional GPS receiver and download platform types, making the code more robust, and improving user documentation.

GPS data and metadata from 38 NSF-supported projects were added to the Boulder archive in FY97, fully accessible through the relational database query features, with a comparable number of projects slated to be entered in FY98. Recovery of older GPS campaign data in FY98 will continue with assistance from the Universities of Miami and Texas at Austin. Capabilities were developed in FY97 to manage and archive data from a rapidly growing set of NSF-supported permanent stations (Table 7). These stations, 67 by the end of FY97 and 28 more in FY98, are installed for regional investigations and will contribute over 100 Gigabytes of continuous data per year to the Boulder archive.

Table 7: NSF-Supported Permanent Stations Targeted for Long-Term Data Archiving at UNAVCO

With the increase in continuous GPS data collection from permanent stations in FY97, considerable engineering effort was expended by the Facility in developing improved data archiving tools. The UNAVCO Archive Database was upgraded and now allows data users to query the database by a multitude of data descriptors, referred to as meta-data, including project name, investigator, location, receiver type, antenna type, and many more. A 500 Gbyte Digital Linear Tape (DLT) system was installed for stable, long term, near-line storage and access to the Archive Database. A temporal and map interface to the database was created in FY97 with initial implementation planned for early FY98.

The dissemination of GPS data collected by a multitude of global and regional networks including the IGS, CORS, SCIGN, and BARD[4] and archived in numerous locations is the goal of the seamless archive (Figure 1). The UNAVCO Boulder Facility worked with the Scripps Institution of Oceanography and the NASA/Goddard Crustal Dynamics Data Information Service (CDDIS) in FY97 to agree upon a set of standards for a data interface that allows the sharing of data without requiring a common archive database or strategy. In FY98, the Boulder Facility will implement a Web User Interface that will take advantage of this common interface to present GPS metadata in a map, temporal, or tabular report. The Boulder Facility, Scripps and the CDDIS will collaborate on the initial implementation of the seamless archive in early FY98.

Figure 1. Components of the Seamless GPS Data Archive (dashed components and links will be developed in FY98).

[Next][Previous][Up][Contents]

Last modified Tuesday, 08-Nov-2005 02:34:59 UTC

Home | About Us | Contact Us | Support | Search | Facility | PBO | Education & Outreach

Comments: webmasterunavco.org
© 2009 UNAVCO, Inc.