Data Services Newsletter

Volume 21 : No 1 : Spring 2019

ISPAQ V2.0 - Improvements to the IRIS System for Portable Assessment of Quality

In February 2019, IRIS released a new version of ISPAQ, a command-line tool for calculating data quality metrics, available at The IRIS MUSTANG system calculates and makes available data quality metrics for almost all seismic data in the IRIS archive, and ISPAQ enables users to calculate many of these MUSTANG metrics on their local machine using the same algorithms. With ISPAQ, users can calculate metrics for data that is on a local disk (as miniSEED), data with channels that are not routinely processed by MUSTANG, and data that is available from other Data Centers that support FDSN web services (including SeisComp3 fdsnws).

The most prominent improvement for ISPAQ version 2.0 is in its calculation of Probability Density Functions (PDFs). The initial version of ISPAQ could only produce PDF output for single days. Now with version 2.0, ISPAQ can calculate PDFs and generate PDF plots for multiple-day time spans. To do this, ISPAQ first writes the Power Spectral Density (PSD) values to text files and then aggregates these values into the PDF. The PSD calculation only needs to happen once, enabling rapid calculation of subsequent PDFs for user-specified start and end times. In addition, the appearance of the PDF plots has been changed to more closely match the output of the MUSTANG noise-pdf web service and users have more control over the plot elements.

Sample ISPAQ command line run:

(ispaq)$ ./ -M pdf -S IU.ANMO.00.BHZ —starttime=2019-04-01 —endtime=2019-04-16 —pdf_type plot
2019-04-18 18:10:32 – INFO – Running ISPAQ version 2.0.1 on Thu Apr 18 18:10:32 2019
2019-04-18 18:10:35 – INFO – Calculating noise metrics for 2019-04-01 to 2019-04-16
2019-04-18 18:10:35 – INFO – Aggregating PDFs for 1 SNCLs for 2019-04-01 through 2019-04-15
2019-04-18 18:10:35 – INFO – 000 Calculating PDF values for IU.ANMO.00.BHZ
2019-04-18 18:11:29 – INFO – Saving PDF plot to ~/ispaq/IU/ANMO/IU.ANMO.00.BHZ.2019-04-01_2019-04-15_PDF.png
2019-04-18 18:11:29 – INFOALL FINISHED!


Other changes include the removal of the dead_channel_exp metric following its retirement from MUSTANG, changes and additions to the preference file format, updates to recommended package versions for the conda installation, and a requirement to update the R-package IRISMustangMetrics to 2.2.0 (included and also available on CRAN).

Software Requirements: – Linux or macOS operating system – Anaconda ( or Miniconda (

ISPAQ was written by Jonathan Callahan (Mazama Science) and the IRIS Quality Assurance Team.

by Gillian Sharer and Laura Keyson (IRIS Data Management Center)

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