Data Services Newsletter

Volume 2 : No 1 : March 2000

Gap/Overlap Analysis Tool (GOAT)

Gap/Overlap Analysis Tool, or GOAT, is a Web-based tool (associated with SeismiQuery) which graphically displays gaps, overlaps, and continuous time spans of the time series data in the DMC’s database. GOAT was developed as a quality control tool for the DMC’s database and takes as input query results from the SeismiQuery time span query which are formatted into a synchronization file. GOAT’s graphical display allows for easy identification of problems and trends in the time spans of the time series data. Besides being useful for quality control, GOAT also provides a convenient graphical display of the DMC’s data holdings and can be used by data providers to view their data holdings at the DMC when the appropriate query is done.

GOAT displays a color coded graph and table depicting overlaps in blue, gaps in red, and continuous data in green. The “raw” time spans found in the synchronization file can also be displayed. The user can set a variety of options to display the data in different ways including setting a gap/overlap time tolerance and selecting which channels should be displayed.

Example of the GOAT graphical display
Figure 1: Example of the GOAT graphical display

Making a GOAT query

From the DMC’s home page, a database query and resulting GOAT display may be done by selecting: 1) SeismiQuery, 2) by timeseries (from the SeismiQuery index), and then 3) Query 2 (from the list of timeseries options). Enter your query parameters and when the query returns, press the Display data button to start GOAT.

Data providers who have developed methods to generate synchronization files from their own database can view them with GOAT by ftp’ing the Sync files to the DMC’s anonymous ftp area ( has been set up for this) and selecting their Sync files from those listed by

by Sandy Stromme (IRIS Data Management Center)

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