Faculty of Environment

rdseed

rdseed website

Versions available: 4.19.1

Licences: Freeware

dseed reads from the input tape (or other input file) in the format defined by the Federation of Digital Seismographic Networks (FDSN), popularly known as the Standard for Exchange of Earthquake Data (SEED). According to the command line function option specified by the user, rdseed will read the volume and recover the volume table of contents (-c option), the set of abbreviation dictionaries (-a option), or station and channel information and instrument response tables (-s option).

The desired volume on tape (or in a file) can be selected with the (-v option). The first volume is "1" , the second "2" and so forth. (Note: this option is only used when a physical volume contains more than one logical volume.

Two additional options allow access to detailed information concerning the actual contents of the volume (rather than reading files purporting to contain such information from the volume, for which one uses the -c option). The first of these options (-t) writes out a list of data start and stop times along with the starting records at which those data may be found. (For the purposes of this discussion, a record is defined as a set of station/channel/time continuous data records.) The other option (-l) is primarily a diagnostic tool; it writes a description of every record on the volume.

In order to extract data from the SEED volume for analysis by other packages, the user must run rdseed in User Prompt Mode which is discussed below. As data is extracted from the SEED volume, rdseed looks at the orientation and sensitivity of each channel and determines if channel polarity is reversed. Refer to the description of blockettes 52 and 58 in the SEED manual for a description of reversed polarity. A negative sensitivity in blockette 58 is indicative of a reversed polarity. The user can request that reversed channels be corrected. This correction is a simple multiplication by -1.0 . The output response file information is NOT adjusted for channels which rdseed inverts.