Thurs Nov 12, 13:45

PQLX - A Station Assessment & Data Quality Control System Applications and Uses

Overview PQLX System Technical Aspects Software: Components, Installation and Setup System Architecture: Server-Side Database & Client-Side GUI Functional Aspects Data Formats and Requirements Analysis Statistics Computed by Server GUI Functionality Provided by Client Data Quality Control Possibilities PDF Plots and Noise Feature Analysis Future Developments

Technical Aspects All Software Components Are Open-Source Server-side Database - MYSQL Client-side Database - gdb - GNU Graphics Library - GTK+ FFTW - Fast Fourier Transform Library - MIT miniSEED Data Reader, libmseed - IRIS DMS evalresp - SEED Response File Reader - IRIS DMS/ISTI TauP - Travel Time Calculation, algorithm - R. Buland & Chapman, updated by B. Kennet

Multi-Platform: Linux, MAC OS, Solaris Source code for PQLX is freely available for download via WWW from: Publicly Available, and Fully Searchable, Website for Bug Reporting and Enhancement Requests: cgi?product=PQLX

Installation and Setup External Software Dependencies MYSQL - from PQL II (to resolve GTK+ dependency) - from Entire System Written in C (if travel time tables are used in new version, you will need a fortran compiler) Compilation and Installation via a single command- (scripted) Provides Clear Indication of Success or Failure PQLX Database created via: Database Definition File Script to read definition file and create database

System Architecture Server-Side: MySQL Instance Holds One or More PQLX Databases pqlxSrvr - Server Process (one per database) Analyzes all waveform data, uploading all Analysis Results to Database: Can be set up via cron for regularly scheduled execution Scalable - Number of CPUs to use Specified at Execution Time- up to 4 currently Re-runnable on Renewed Data - All statistics are Replaced when Data is Updated with Newer Version Scripts - Several Scripts are provided to manage the database - ideally, there is no need to be directly involved with MySQL itself

Client-Side: GUI Access to a PQLX Database: As a Local Database: Client and Database Reside on the Same Machine Client and Database Reside on Same Local Network As a Remote Database: Client has Access to the Internet Database Server is Visible on the Internet Client Application is Fully Multi-Threaded for Efficiency Purposes

Functional Aspects Data Requirements Data can be Provided in ANY of the Following Formats (these also may be mixed within a single database instance): miniSEED SAC SEGY AH nano DR-100 -Spregnether

File Format is Auto-Detected, no Need to Explicitly Specify File Definition is Read from Header, not File Name. Thus, no Requirements for a Specific File Name Structure Data can be Provided in Any Directory Tree Structure, Under One or More Base Directories Response File in rdseed Output Format, One Channel per File, All Time Ranges Server Constructs Database Contents Based on the Existence of Data - New Station/Channel Data Can be Added At Any Time...

Analysis Statistics The PQLX Server is Responsible for Reading All Data/Trace Files, Writing All Statistics to Database Data File Statistics (Meta- and Computed): Start and Stop Times Length Maximum / Minimum / Mean Total Gaps: Their Locations and Length Total Overlaps: Their Locations and Length

Channel Statistics: First and Last Date of Existence of Data Total Number of Traces Trace Data Maximum - max / min / mean Trace Data Minimum - max / min / mean Trace File Gaps - max / min / mean Trace File Overlaps - max / min / mean

Trace File View

Magnify View

Fourier Transform View

Simultaneous Data View

Header View

PDF/ PSD Viewer Connection to Specific PQLX Database Plot System PDFs Stored on Server-Side Database Plot User-Defined PDF Based on Date and Time Parameters Sub-Select of PDFs Returning: PDF of PSDs Intersecting User-Defined Sub-Selection PSD Start Times and Durations Trace Data Corresponding to PSD of Sub-Select, i.e., User is Able to go from Frequency Domain to Time Domain

System PDF View

PDF Request View

PDF Detail View

STN (station) Viewer Connection to specific PQLX Database Bird’s-Eye View of Station/Channel Statistics & Data Existence of Data Gaps and Overlaps Pop-Up Statistics and PDF Corresponding to Time Period on Display Configurable Display Coverage Mode - Display vs. Database Info, i.e., no Waveform Data. Thus, not Necessary to have Access to Trace Files/Waveform Data Itself. Data Mode - Waveform Data Display

(Configurable Display continued) Display days of data/statistics per screen Display channels per screen Display only Specific Stations & Channels Traversal in Time & Station/Channel List

STN Viewer - Coverage Mode

STN Viewer - Data Mode

In Development: Event Record Sections Align Waveform Data on Predicted Arrivals Align Waveform Data on User Picks Sort on Epicentral Distance Simple Data Analysis Integrate/Differentiate Deconvolve Data - Remove Instrument Response Cross-Correlation of Traces

As well as the GUI Client, Additional Client-Side Functionality Includes: Scripts to Extract PSD and PDF Data from the Database. This allows the user to extract actual analysis data, either PSD or PDF format, done by specifying date and time bounding parameters for their own specific use.

Data Quality Control & Station Assessment The following aspects of Data Quality Control are Possible to Manage and Identify with PQLX, i.e., WHAT: Overall Station Performance Channel Data Existence Displayed in STN viewer Identify Instrument Problems Gaps and Overlaps Displayed in STN viewer: Identify Data Transmission Problems, e.g., Data Dropouts, Telemetry Issues, etc. Displayed in PDF Plot:

Station Performance

Meta-Data Accuracy Bad Response File Information Visible in PDF Plots

Bad Units Acceleration Instead of Velocity Input Units Extra Zero in Response File Results in Tilted PSD: Low Amps at Low Period High Amps at High Period Corrected Response

Bad Units Displacement Instead of Velocity Input Units Missing zero in Response File Results in Tilted PSD: High Amps at Low Period Low Amps at High Period Corrected Response

Bad STS2 Gain Used 20,000 counts/volt Instead of 1500 counts/volt Resulting in low corrected Amplitude across spectrum. Corrected Response

Noise Feature Analysis Selection of Noise Feature in PDF Viewer Detail Screen Precise Date and Times of Occurrence Waveform (Time Domain) Display of PSD

Diurnal Variations

Earthquakes

Rogue Waves

Nuclear Tests

Quality can be Controlled in the Following Ways: Daily Inspection and Perusal of Database Contents via GUI Application Automatic Publication of Server-Side PDF Plots to the WWW as Part of the PQLX Server’s Execution Future: User-Defined Triggers/Alerts Automatically Generated when PQLX Server Uploads Statistics, e.g.: Maximum Gap Threshold PSD Value Out-Of-Range (vs. HNM/LNM) PSD Value Within a Specific Range (vs. user-defined attribute)

Missing Data

Data Gaps

Mass Re-Centering

Future Developments The following functionality is being Considered for Future Development: PDF Animations – DONE! More Advanced Data Analysis For example Particle Motion Server and Database Management via Client-Based GUI Interface Normal Operating Bounds definition specific to Channel, i.e., a station/channel-specific HNM and LNM User-defined Noise Feature, e.g., PSD is above HNM Automatic Noise Feature Detection against User Definitions and Reporting, e.g., alert when PSD produces data in a specific noise and frequency range

Credits The following Organizations (listed alphabetically), Through Direct and Indirect Funding, have made this Software possible: IRIS - Data Management Center, Seattle, WA IRIS - PASSCAL Instrument Center, Socorro, NM National Science Foundation, Washington, D.C. United States Geological Survey - Golden, CO END