Data Services Newsletter

Volume 11 : No 4 : Winter 2009

PDCC 3.6

The IRIS DMC has released version 3.6 of its Portable Data Collection Center software (PDCC), which enables seismic network operators to describe, maintain, and exchange their instrument metadata using the FDSN SEED format.

PDCC is designed to make the process of creating metadata descriptions easy. The tool consists of a main editor window for reading, viewing, editing, and writing SEED metadata files by providing specialized tools that facilitate the construction of station metadata entries. PDCC represents a continued effort by IRIS to support the seismological community with tools to enable data collection and research.

All that is required to run PDCC is a recent version of a Java virtual machine (JVM), version 5.0 or later. (Refer to

Screenshot of PDCC
Figure 1: User editing a channel blockette in PDCC.

Features in PDCC include:

  • input and output of dataless SEED files
  • the ability to create new station and channel entries
  • duplication of stations and channels for creating new entries of similar instruments
  • creation and editing of response coefficients
  • automatic sorting of blockettes from the station name down to the response stages

Perhaps the most prominent addition to PDCC is the Nominal Response Library Tool (NRLTool), which makes it easy to generate station responses for equipment that meets manufacturer specifications. This project was managed by the IRIS DMC and developed by Instrumental Software Technologies, Inc. The tool makes use of the Nominal Response Library, available online at the IRIS DMC (see accompanying article) as a database of instrument definitions for the user to select from. The tool’s library is automatically updated over the network when the IRIS master library is updated, providing users with an always-current, authoritative resource for instrument responses.

Screenshot of NRL
Figure 2: Nominal Response Library Tool showing a nominal datalogger response.

The NRL Tool behaves like a wizard tool, walking the user through selections of manufacturer, model, and instrument-specific parameters to arrive at a response that matches to that instrument. The user can navigate forward and backward in their search for the right selection. This process is carried out for both the sensor and the datalogger parts of the station.

The end result of the NRL Tool’s output is a compound set of response stages in SEED format that are automatically added to a selected channel. A final step uses JEvalResp code to calculate the sensitivity for the entire channel response at the normalization frequency.

PDCC 3.6 was featured at a recent workshop in Cairo, Egypt that allowed participants to create dataless SEED descriptions of their own network during the allotted time in the computer lab. Based on the success we had in Cairo, we are looking forward to the continued development of PDCC and will feature it in future workshops.

You can register for access to PDCC and the PDF manual at the following URL:

by Rob Casey (IRIS Data Management Center)

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