Active Experiments

Sunday, December 13, 2015
San Francisco - Zelos Hotel

Presentations are now online!  All are PDFs and the PH5 posters are a .gif and a .pdf

Session 1 - SEED Data Archiving

Session 2 - Instrument Responses (given by Mary Templeton of the IRIS DMC)

Session 3 - PH5 tools and future plans

PH5 poster from AGU 2013

Here are frequently asked questions regarding data requests from PH5 data sets archived at the IRIS DMC.  The answers are based upon the perspective the user is at the Data Request Form, which is available for each PH5 data set via its "Request" link found on the PH5 data set web page of the IRIS DMC website.

1. How do I select the length of the record?

 PASSCAL SEG-Y utilizes big endian byte order and sets the various trace headers as outlined below.

PASSCAL SEG-Y Trace Header

Currently, the only controlled active source available from PASSCAL is the PEG 40Kg Propelled Energy Generator, manufactured by R.T. Clark Companies, Inc. PASSCAL has purchased its first fully automated PEG-40Kg system in 2011. The system is light weight, and highly portable, and is designed to easily mount onto a truck or SUV hitch. Seismic energy is produced when  a large hammer mass weight is propelled by an elastomer band (i.e. a very large rubber band) onto an impact plate, producing an impact frequency range of 10-250Hz. The source is controlled with a hand held motor controller,  and can operate in single cycle or continuous cycle mode. The device is powered by a 12V large capacity battery (car battery).  The PEG-40Kg was received, assembled, and field-tested by  PASSCAL staff on June 23rd-28th, 2011.

PH5 data flow. The left column shows the general process one follows during the preparation of a PH5 data set.  The right side shows the various software tools and files necessary to complete the process.

Here you will find information describing active source data formats: PH5, recommended for archiving data and SEG-Y, required by the user community for analysis and research.

PH5 is the recommended archival format for active source data sets.  PASSCAL has transitioned from SEG-Y to PH5, PASSCAL's implementation of the hierarchical data format, version 5 (HDF5) data model, as the preferred archival format for active source data sets.  The strengths of HDF5 made it an attractive model for an active source archival data format.

HDF5:

Refer to the documentations below to learn how to prepare the data you've collected for archiving.  PASSCAL supports PH5 and SEGY as the archival data formats of active-source data sets.

Data from PH5 format data sets archived at the DMC can be accessed via PH5 Web Services.

The SEG-Y file written by ph5toseg is in big endian byte order and attempts to follow the SEG-Y rev 1 standard (May 2002) as outlined in the table below.

The file does not contain a Tape Label.