PASSCAL Data Delivery Policy

November 18, 2004

The equipment in the PASSCAL facility represents a significant community resource. The quality of the data collected by this resource is such that it will be of interest to investigators for many years. In order to encourage the use of the data by others and thereby make the facility of more value to the community, IRIS policy states that all data collected by instruments from the PASSCAL Facility should be submitted to the Data Management Center so that they can be accessed by other interested investigators after the proprietary period.

This policy outlines the guidelines for data submission. IRIS’s policy is that delivery of data to the DMC is an obligation of the PI. It is important to IRIS that the PI acknowledges this obligation and meets it within the required time frame. Failure to complete this requirement not only deprives the community of a valuable data resource, but also may jeopardize future requests to borrow IRIS equipment.

IRIS expects data delivery while the experiment is in the field (for long term deployments), or immediately at the conclusion of the field deployment. The data and Data Report will remain confidential for a period of 2 years after the end of the fieldwork.

Data Report

The Data Report is not intended as a formal technical paper but it should contain enough information to allow someone to work with the data. If possible the report should be in a widely accepted electronic format such as RTF or PDF. Any figures can be included as Postscript files. The following types of information should be included:

• A short description of the experiment;

• A list of stations occupied along with coordinates and a short description of the sites;

• A description of the type of calibration information acquired; and

• For non-SEED data a description of the data archive volume.

The Data Report and completed Demobilization Form are due immediately after the completion of the experiment.

Data

The actual format of the data and the amount of data depend upon the type of experiment. Most PASSCAL experiments fall into one of the following categories: Broadband, short period or reflection /refraction. The first two are passive source experiments while the third utilizes active sources.

Broadband (continuous data)

The data from broadband experiments (that is experiments collecting continuous data from broadband sensors at sample rates less than or equal to 40 sps) can be used in a variety of different investigations. Therefore, it is in the best interest of the community to archive these data for easy access by the seismology community. Each PI conducting a broadband experiment will utilize the PASSCAL database or equivalent software to provide all of the data collected to the DMC for archive in SEED format. It is expected that the PI will ship the data to the DMC on a continuing basis during the experiment as soon as timing and other corrections are made and that the final data will arrive shortly after the experiment is over. The DMC will make the data available only to the PI or his designated representative for a period of two years after the completion of the experiment. After that, the data will be made available to the public.

Short Period (triggered)

Short period experiments are generally different from broadband experiments in both the amount and the bandwidth of the data they produce. Short period sensors are generally run at higher sample rates than broadband sensors, and the ability to record low frequency signals is very limited. As the short period data are typically recorded in a triggered mode, their principal archive will be as event data. The time windows should be long enough to include a reasonable amount of pre-event noise signal as well as all of the significant seismic phases for the event. As above, the data should be delivered to the DMC for distribution in SEED format. The PASSCAL field computers have the necessary software for this delivery.

Reflection/Refraction

Reflection/Refraction experiments differ from the above experiments in that they nearly always involve active sources. The receivers are typically arranged in regular one or two-dimensional arrays. The accepted data format for these active source experiments is conventional SEG-Y format. The data should include all of the necessary information on the geometry of the experiment (metadata) and they should be corrected for all known timing problems.

Non-Standard

There will always be some experiments that do not fit directly into one of the above categories. In those cases the exact form of the data delivery will be negotiated between the PI, the IRIS Data Management System and PASSCAL.

Proprietary Data

Data of all types should be delivered to the DMC, in the appropriate format, as soon as possible and normally well before the general release of the data. The DMC will only allow access to the waveforms to the PI and others designated by the PI. Access will be by password that will be provided by the DMC to the PI. The PI can share the password with anyone he/she wishes. The PI will be notified when anyone registers for access to a proprietary dataset.

Information about the experiment such as station locations and characteristics will be made publicly available during the experiment, only waveform data will be limited in distribution during the proprietary period.

All passive experiments with five or more stations will designate at least one station as and “open station”. The data from the “open station/s” will be made available to the public immediately upon being archived.

Support Available from IRIS

Every field computer has the software necessary to accomplish the data delivery task, and the PASSCAL Instrument Center has personnel who can provide assistance to the PI during and after the experiment. The Instrument Center also has software, computers, and large disk systems available for use by the PI. The Data Management System has additional facilities and support available to the PI. The PI is encouraged to utilize these resources at all stages of the work. In all cases, however, the ultimate responsibility for delivery of the data rests with the Principal Investigator. The PI must ensure that adequate resources are budgeted to accomplish this task.

A PASSCAL data submission is not considered complete until both the PASSCAL and DMS Program Managers certify that the information contained in the report is sufficient to allow other members of the community to utilize the data. IRIS will not certify that it has received data from any PI until the data submission is deemed useable.

This policy is effective as of November 18, 2004 and is subject to change and revision as needs dictate. For updated versions of the policy and additional information on data delivery see the PASSCAL and DMS pages on the IRIS web site (http://www.iris.edu).