Data Services Newsletter

Volume 20 : No 2 : Summer 2018

Enhancements to the PH5 Web Services

PH5 is PASSCAL’s preferred archival format for active (controlled) source and nodal experiments. In summer 2017, IRIS Data Services released PH5 compatible services for the three International Federation of Digital Seismograph Networks (FDSN) standard web services; dataselect, station and event web services, providing access to the DMC’s PH5 data holdings. Outlined here are some of the infrastructural enhancements made to these services over the last year.

More experiments supported via web services

The entire IRIS PH5 archive has been updated to support web services. As of July 16, 2018 the PH5 archive contains 65 datasets for a total of approximately 15 terabytes of timeseries data. This is up from just 5 initial datasets when the web services were first unveiled.

GeoCSV output format

All three of the PH5 web services now support the GeoCSV output format. GeoCSV is a human and machine readable tabular text format that is used to represent a variety of geophysical data. The format supports generic headers that contain metadata for processing PH5 datasets.

PH5 GeoCSV Example
Figure 2 – An example of PH5 timeseries data from the IRIS Community Wavefields Experiment in GeoCSV format

GMAP Support

Geographic locations of stations stored in the PH5 format may now be plotted using the IRIS GMAP web application. GMAP enables users to search for PH5 datasets along with data from other Federated datacenters.

PH5 in GMAP
Figure 3 – All PH5 experiments (left image) and the IRIS Community Wavefields Experiment (right image) plotted in GMAP

Coming soon

Browse PH5 metadata with the Federated MDA

The IRIS Meta Data Aggregator (MDA) web application has long served the IRIS community as a convenient way to browse seismic metadata. Coming soon is a new version of MDA that is designed to display metadata for timeseries archived at the IRIS DMC as well as other federated datacenters. This updated version will also allow users to view network, station, and channel level PH5 metadata in an easy to navigate webpage.

PH5 web service request clients

New web service request clients are being developed for requesting active source experiment data as common shot or receiver gathers. Unlike the PH5 web form, requested data is streamed directly from the web services to the client’s computer. On the client’s computer, data is then sorted and outputted as a gather.

PH5 Shot Gather
Figure 1 – A shot gather plot produced from active source PH5 experiment 15-016 (ZI 2015).

by Nick Falco (IRIS-DMC)