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Here are some of the articles that have been recently posted to the PASSCAL website:

SEG-Y files produced from PH5 data sets


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.

Borrowing Equipment

PASSCAL equipment is available to any research or educational institution to use for research purposes within the guidelines of established Governing Policies. These policies provide that data collected with PASSCAL equipment be archived at the IRIS Data Management Center and that the data are openly available to the community. Instruments can be requested online using the PASSCAL Instrument Request Forms.

Who Can Borrow Equipment

Instrument Use Policy

What is Required if You Borrow Equipment

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Ground Penetrating Radar (GPR) System

The IRIS Education and Public Outreach program acquired a Sensors and Software Noggin GPR System with SmartCart configuration to enhance the IRIS PASSCAL equipment pool (see image at left). The system has onboard GPS, data acquisition programming, and preliminary data interpretation capabilities. The system has both line-scan or grid-scan data collection modes. The onboard software allows for quick survey setup, on-the-go viewing of the waveforms collected, and initial waveform depth estimates. Processed onboard data can be visualized as depth versus position along a line, or as a slice view of grid data. The PASSCAL Instrument Center offers additional software for more in-depth post acquisition processing and interpretation of the data.

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Three-component Node Procurement Update

As a response to the seismological community's desire to deploy a larger number of 3-component nodal seismic systems, the IRIS PASSCAL standing committee has guided IRIS management to procure more nodes for the PASSCAL pool. IRIS already has 73 Magseis Fairfield ZLAND 3-component 5Hz nodes in the pool and these have been subscribed for more than 2 years out. We have now begun the procurement of another 460 Magseis Fairfield nodes for general PASSCAL pool use. We expect to receive these new nodes in the fall of 2018. The new nodes should be ready for general pool usage starting in February, 2019 after evaluation and acceptance is complete (bringing the general node pool to 533 units). Please feel free to include the new nodes in instrument requests for experiments with start dates after February 2019.

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PQL II - Program for Viewing Data

April 21, 2009


PQL II is a program for viewing time-series data in any of four formats: MSEED, SEGY,  SAC, or AH (though, to be honest, PASSCAL staff has not used the AH option). It is the second generation PQL, hence the name PQL II. Both generations of code were written by Richard Boaz and PASSCAL staff supports the code on MAC OS X, LINUX, and Solaris platforms.To install PQL II on your system, you need to go the PASSCAL download page, or directly to PQL II download on PASSCAL's FTP area.

The HELP menus for PQL II are actually helpful. Use them a lot till you get to know the program.

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December 31 2016 Leap Second

Leap Second's effect on PASSCAL RT-130 and Q330



Data time starting at 2017:001:00:00:00 is +1 second from truth for 1-2 minutes (seen in controlled tests) until a clock correction, followed by a gap of 2-40 seconds per channel depending on sample rate.


Data time starting at 2017:001:00:00:00 is +1 second from truth for 15min - 9:42hrs (seen in controlled tests) until a clock correction. Some data (~6secs in tests) around the time correction is mistimed, sometimes 11 years in the future, or missing.

IRIS PASSCAL Data Policy Update

IRIS/PASSCAL has updated our Data Policy. The new Policy, which was published on November 1, 2017,  can be perused here. It details the archiving requirements for data collected with IRIS PASSCAL equipment through the PASSCAL Instrument Center (PIC)

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ref2sac fixes and enhancements

ref2sac incorrectly converts Ref Tek RT 130 data files to SAC. I found and fixed a number of bugs in the Mac OS X PASSOFT release of ref2sac. I added LAT, LON, and ELEV to the SAC files. I set the dependent variable type in the SAC file to UNKNOWN, since the data are in counts, not engineering units. I added an option to create the SAC output files in a single, flat directory structure, with unique file names. Those names include an .R. to identify that they contain raw counts.

Attached are my patched files and a README of the changes, plus several sample data files. (The sample data files should not be redistributed without permission.) The sample data files were converted to SAC using the following commands:

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Sensor Certification


All equipment, especially sensors and cables, are cleaned and comprehensively tested when they arrive at the PIC, regardless of whether the equipment are newly delivered from the manufacturer or being returned from an experiment.  PASSCAL makes every effort to ensure that all equipment are operating to the manufacturers specifications.

This article outlines the procedures undertaken and metrics employed by the PIC to verify that sensors operate within manufacturers specifications.


All sensors returning from a field experiment are subject to the following procedures:

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All files are in .png format with clear backgrounds.

PASSCAL (gradient gray) PASSCAL (legacy, gradient color)   PASSCAL (slide)  


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