June 12, 2004Synthetic Seismogram Exchange Standards But We Have A Standard. Can SEED Support Synthetics? Linus Kamb IRIS DMC

June 12, 2004Synthetic Seismogram Exchange Standards SEED Format Volume Control Headers Abbreviation Control Headers Station Control Headers Time Span Control Headers Data Records SEED Volume

June 12, 2004Synthetic Seismogram Exchange Standards Mini-SEED “Data-only” volumes Data records –Fixed Section of Data Header –Blockette 1000 –Other data record headers

June 12, 2004Synthetic Seismogram Exchange Standards What about synthetics? Standard Time Series data Additional synthetic metadata –Simulation codes, extents, Earth models, boundary conditions, source description … May correspond to a Station-Channel Volumetric (4D) data

June 12, 2004Synthetic Seismogram Exchange Standards Some Possibilities Shoe-horn into existing SEED blockettes –Blockette overloading Define new blockettes –Specific to synthetics, or –General-purpose blockettes Use blockette 2000 XML SEED

June 12, 2004Synthetic Seismogram Exchange Standards Blockette Overloading Abbreviation Control Headers –Comment blockettes Field overloading –Eg. Station Start effective time maps to simulation run time

June 12, 2004Synthetic Seismogram Exchange Standards Blockette Overloading Abbreviation Control Headers –Comment blockettes Field overloading –Eg. Station Start effective time maps to simulation run time This is a Bad Idea.

June 12, 2004Synthetic Seismogram Exchange Standards Add Blockettes Specific blockettes for synthetic metadata –Modeling software, Earth model, … Generic blockettes –Name-value pairs –XML Document blockette FDSN Standards process Changes required to SEED software

June 12, 2004Synthetic Seismogram Exchange Standards Blockette 2000 “Variable Length Opaque Data” Data Record Header –Can be included in MiniSEED volume Opaque header fields SEED readers dump out data “as is” Could be “Synthetic Metadata Document” –Use external reader

June 12, 2004Synthetic Seismogram Exchange Standards In Conclusion SEED can contain synthetic data. –People are using it. Metadata support is not there. Community needs to decide how to proceed.

June 12, 2004Synthetic Seismogram Exchange Standards The (‘93) Manual Says: “We also did not design SEED for the exchange of processed (e.g., filtered) data or synthetic data (i.e., created by computer modeling). While such use is possible, we will not support it.” To be removed in the current manual, perhaps.