The difference between the timing of the systems is determined by which channels are derived from firmware and which are derived by the configurable software. The correction values in these tables should be added to existing data time tags. This station epoch is listed as Table A, so the correction from Table A is applied. The data acquisition systems are fixed to output correctly timed data. The data centers apply corrections to incorrectly timed data at the time of publication.
Individual users apply corrections to data already distributed.
The SEED data format, as it exists now, is only capable of cataloging a single, summary, timing correction. Thus, SEED cannot contain the timing correction discussed here while still maintaining the historical record of any other type of applied timing correction. Generalized solutions have been proposed ranging from external tables to changing SEED itself. Discussions are ongoing. However, the existing SEED structure does allow in Field 16 of the Fixed Section of Data Header for a single time correction.