Data Services Newsletter

Volume 5 : No 3 : July 2003

New WILBER II plots

Example PHP-generated seismogram plot
Figure 1: Example PHP-generated seismogram plot.

If you’ve noticed a change in the WILBER II sample seismogram plots, you are seeing the effects of a new image generation scheme for those plots. Instead of all possible seismograms being plotted (whether a user cares to see them or not), they are now plotted “on demand” the first time, and then stored for future users.

The new approach uses a web scripting language called PHP. This language is much like Perl but has been tailored for use in the CGI web server environment. The new plots also make use of a streamlined miniSEED reading utility that generates the plots in a fraction of the time, making even the ultra long waveform plots accessible in several seconds instead of minutes.

A follow on project which is now underway will extend this seismogram plotting software for a different application: record section plots. A WILBER II user will be able to view up to 60 seismograms horizontally arranged in “record section” format with a variety of layout, filtering and phase-related options planned. This will be used as an aid for refining data product requests and also as an educational tool. Be sure to look for more about this project in our next newsletter due out in October, 2003.

by Russ Welti (IRIS Data Management Center)

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