Thread: Release of the MUSTANG noise-spectrogram web service

Started: 2019-01-08 19:22:43
Last activity: 2019-01-08 19:22:43
2019-01-08 19:22:43
Dear MUSTANG Users,

We are happy to announce the release of the MUSTANG noise-spectrogram Web Service

The noise-spectrogram service makes it easy to quickly visualize how the noise characteristics of seismic channels vary over time. The spectrograms returned by the service reveal temporal noise characteristic variations. More specifically, plots generated by the service are color coded representations of the most commonly occurring noise levels per frequency per day based on Probability Density Function (PDF) estimates (i.e., the PDF daily mode).

The information displayed by the noise-spectrogram web service is similar to that which is displayed by the noise-mode-timeseries service:

While the noise-mode-timeseries service displays time series line plots of noise levels for selected frequencies as a function of time the noise-spectrogram service displays color coded noise levels as a function of time for all measured frequencies. The noise-spectrogram noise service is useful for viewing long range changes in noise characteristics for time ranges going from days to years.

Characteristics which the plots can reveal include, but is not limited do:

* Seasonal variations of noise level
* Cultural noise level changes, for example weekend vs weekday variations
* Instrumentation changes
* Instrumentation metadata changes and errors
* Dead channels

The web service accepts a wide range of plot customization options. Options allow for the customization of:

* Size
* Orientation
* Font label sizes
* Time scale formatting
* Displayed power range
* Plot title and subtitle

As with the noise-mode-timeseries web service, the noise-spectrogram service allows for the comparison of measured noise levels with noise models. In addition, the service allows noise levels to be compared with median values per frequency.

For a full description of the noise-spectrogram service, please visit:

To complement the addition of the noise-spectrogram service and to increase its usefulness, the noise-pdf-browser service has been updated (version 1.1.2):

The new version of service includes a new ‘spectrogram' endpoint:

When called, this endpoint generates HTML which, when displayed in a web browser, shows a list of spectrogram images. The spectrogram endpoint accepts wild card and comma separated selections of target, network, station, location and channel codes. It also accepts optional starttime and endtime parameters. One nice feature is that all plots generated for any given call will have identical time ranges regardless of data availability.

For a full description of the new spectrogram endpoint please visit

Bruce Weertman
IRIS Quality Assurance

22:10:46 v.ad6b513c