User login

Flexible Array Data Policy

March 20, 2008

NSF Program Solicitation 06-562 states that:

"The intent is that all data from the EarthScope Facility will be openly available in near-real-time to maximize participation from the scientific community and to provide on-going educational outreach to students and the public."

The solicitation also states that: "Principal investigators are required to adhere to the EAR Data Policy available on the NSF website."

The EAR data policy can be found at: http://www.nsf.gov/geo/ear/EAR_data_policy_204.pdf

and it states:

" For those programs in which selected principle investigators have initial periods of exclusive data use, data should be made openly available as soon as possible, but no later than two (2) years after the data were collected. This period may be extended under exceptional circumstances, but only by agreement between the Principal Investigator and the National Science Foundation. For continuing observations or for long-term (multi-year) projects, data are to be made public annually."

If investigators requesting use of Flexible Array instruments wish to take advantage of the proprietary period of exclusive data use, they should state this explicitly in their proposals.

For more information, contact the NSF EarthScope Program Officer(s). A more recent revision (April 20, 2008) states more detail information and although preliminary, its outline is as follows:

Flexible Array Data Delivery Policy (preliminary) Earthscope Specific

Introduction

The Earthscope equipment in the Array Operations Facility (AOF) 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 AOF should be submitted to the Data Management Center (DMC)  so that they can be accessed by other interested investigators in accordance with IRIS and  National Science Foundation data policies. 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 with IRIS support. 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).  IRIS will provide support to the Principle Investigators in processing raw data into archive format at the DMC.  The PI’s are responsible for providing timely and accurate metadata for this purpose.

Earthscope Specific Policy (from NSF Program Solicitation 06-562)

All data and corresponding metadata from all permanent, continuously operating Earthscope instruments will be made freely and openly available without unnecessary delay.  In the majority of cases, this means in near-real time. Data collecting using Earthscope portable, campaign equipment are subject to the following, in addition to the EAR policy specified above.

USArray/Flexible Array

All data and corresponding metadata from all Flexible Array instruments will be archived and made publicly available as soon as they can be moved from the station to the IRIS DMC.  Investigators requesting use of Flexible Arrray instruments who wish to take advantage of the proprietary period of exclusive data use (up to 2 years) should state this explicitly in their proposals.  If an exclusivity period is granted, the data must still be immediately placed in the IRIS DMC.

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.  Any tabular data such as station geometry information should be provided in standard readable formats such as MS Excel or tab delimited text. 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 Earthscope Flexible Array 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 standalone recording)

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 provide IRIS with the raw field data and associated complete meta data following each station service run. IRIS will provide the reusable data transfer media for this data delivery process.  In the case of real-time data, the PI is responsible for providing all necessary metadata as the installation of the network is being initiated. In coordination with the PI, IRIS will ship the data to the DMC on a continuing basis during the experiment. It is the intent that data will be available to the PI and his designates as soon as possible via the DMC.  In the case where a period of data exclusivity has been granted by the NSF, data will be embargoed at the DMC for the general public until that time has expired.

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 with the broadband recording, IRIS will work with the PI to archive the data at the DMC.

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 or HDF5. 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.  It is the responsibility of IRIS to archive these data with close coordination with the PI to the DMC.  The PI is responsible for providing all necessary geometry and shot information needed for a complete archive.

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

As specified above under Earthscope Specific Policy, data are to be archived and made publicly available as soon as possible.  In the instance where a period of exclusivity has been granted by NSF, data are still required to be archived at the DMC without artificial delays though access to them will be controlled by the PI.  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.

For more information, please consult the IRIS document detailing the policies regarding release of restricted data.

Support Available from IRIS

Every field computer has the software necessary to accomplish the data delivery task, and the Array Operations Facility has personnel who can provide assistance to the PI during and after the experiment. The AOF 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 raw data and metadata rests with the Principal Investigator. The PI must ensure that adequate resources are budgeted to accomplish this task. A Flexible Array  data submission is not considered complete until both the Flexible Array 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 March 20, 2008 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 website.