5.11 Known problems in SEISAN

This list describe some of the known problems in SEISAN:

1:

Azimuthal of arrival (h command in MULPLT single trace), channels with orientation code 1 and 2 are handled as N and E. If the orientation of 1 and 2 is off North and East the estimated azimuth will be wrong.

2:

Particle motion (PartM or P command in MULPLT multi trace) will not work with channels that has orientation code 1 and 2.

3:

The Nordic format (Appendix A) does not include location id. One is therefore not able to distinguish phase readings done on stations with two one more similar channels with differen location id.

4:

The iterative inversion done by the location program HYPOCENTER, does in some cases end up in a local minimum and not the best solution.

5:

If waveform data from a three component sensor is rotated it is assumed that the response is the same on all three rotated channels (Z,R,T).

6:

The Nordic format (Appendix A) does not include instrument code. So, if a station is equipt with both a seismometer HHZ and a acceleroemter HNZ, one will not be able to distinguish between phase readings.

Other known problems are listed in the index.