PQL

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, EPIC 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 EPIC staff supports the code on MAC OS X, LINUX, and Solaris platforms.To install PQL II on your system, you need to go the EPIC download page, or directly to PQL II download on EPIC's FTP area.

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

EPIC provides open-source software for downloading seismic data from data recorders, for quality assessment, and for conversion to other data formats for analysis and archiving at the EarthScope Data Management Center.

PASSOFT is supported only for Mac and Linux operating systems, and not for Windows. Some Windows users have been able to use PASSOFT by first installing a Windows Subsystem for Linux.

Note - Python: We no longer support Python version lower than 3.9.

Note - MacOS: We no longer support MacOS version lower than 12 (Monterey).

Although EPIC station installations can vary according to the type of equipment being used, servicing is relatively straightforward and similar between station designs and equipment. 

Station servicing has 3 main goals:
• To retrieve waveform data recorded by the station since the previous service;
• To identify and rectify any problems with equipment or damage to the station;
• To refresh consumable items such as compact flash (CF) cards, batteries, etc.

A simple station with easy vehicular access should take around 20 man-minutes to service.

In the field, you must check:

EarthScope EPIC prepared laptops all come with a separate partition for user and experiment data that can be accessed at /data

EPIC linux laptops (PCs) come with two hard drives.  On each drive is a complete, tested installation of Fedora linux and a current version of PASSOFT. Each drive is bootable and provides a redundant system. On each drive space is allocated for data and is RAIDed together as the /data directory accessible from either installation.

If you are having a problem and want to try using the backup installation, start tapping the Escape key after the BIOS has finished loading in order to see the GRUB menu.  Then select one of the installations of Fedora to boot into it.  If you saved your data in /data, you will still have access when booted from the backup installation.

This page provides instructions for downloading Balers using the EzBaler program and reviewing the State of Health (SOH) data using PQL. EzBaler is the best option for downloading data from multiple Balers at one time. Known problems are: it will sometimes fail to connect to a Baler (just try again) and it will hang up if it encounters corrupted data.  These instructions are written specifically for use with a PASSCAL MacBook field computer, but in general apply to other platforms as well.

The data downloading is in two parts.  The first part is downloading the SOH data which contains the low sample rate seismic data and systems data to be used for doing field Quality Assurance (QA) for the station.  The second part is downloading all of the seismic data for archiving.