In order to use data acquired with Cube recorders, the data has to be converted from the proprietary internal data format, including interpretation of the timing information contained in the data stream. We were made aware that the recording time computation for the samples was imperfect.
The necessary correction depends on the used sampling rate (sps) and can be computed as (0.199 / sps + 0.00030) seconds. For example a sampling rate of 100 samples per second requires an additional time correction of 2.29 milliseconds, which have not been considered so far.
The current version of GIPPtools and all following versions will automatically correct imperfect Cube timing during conversion to other data formats (using 'cube2mseed', 'cube2segy' and 'cube2ascii').
NOTE: As the timing error is only about a quarter of the sample period it is probably not a grave problem for most applications!
Many thanks to Jake Anderson from Boise State University for reporting the problem and contributing to the fix.
In the future, the supply of instruments of the „Geophysical Instrument Pool Potsdam“ (GIPP) of the GFZ will be subject to the completed archival of the data of older experiments of an applicant at the GIPP-repository or the GEOFON data centre. This was confimed by the GIPP steering board at the last meeting in Spring 2020. Since 11.8.2010 research data gathered with instruments of the GIPP has to be submitted to the GIPP- or GEOFON data archives within one year after the completion of an experiment. For 4 years the data are exclusively reserved for the user of the instruments (PI); after this period they will be made openly available to the public. This rule supports sustainable archiving and subsequent reuse of primary research data. All instrument users can check the status of their previous projects at the „GIPP Experiment and data archive“. A confirmation of the archival of older data will be part of new applications.
GPS satellite raw data contain (among others) the week number (week 0 started on January 6, 1980), Historically, the week number counter is limited to values between 0 and 1023. This can cause malfunctions of data recorders using the GPS information when the week number becomes too large (so-called week number roll-over, WNRO). This happens (again) on April 7, 2019. Here you find more information about possible consequences regarding the data acquisition with GIPP-data recorders.
We have installed a GIPP-mailing list with which we would like to inform about GIPP-relevant topics and current issues in the future. These could be upcoming deadlines for submission of applications and also technical information. You might expect 2 to 4 messages a year. We would be happy to welcome you in this mailing list. Please register here by email.
The personal data stored in connection with your person will not be passed on to any third parties. In the course of the Data Protection Regulation (DSGVO), which came into force in May 2018, we have also updated our Data Protection Policy on our website (https://www.gfz-potsdam.de/datenschutz).
The "Geophysical Instrument Pool Potsdam" (GIPP) of the GFZ has aquired a fiber-optic gyroscope which allows the highly accurate orientation of geophysical sensors. This gyroscope produced by the company IXSEA allows the orientation of sensors (relative to Earth's rotation axis) with a typical accuracy of 0.1° (secant latitude). The orientation of sensors using a magnetic compass usually suffers from magnetic deflections by metal parts (e.g. in buildings) and the magnetic declination which is locally and temporary variing. The use of the fiber-optic gyroscope avoids these pitfalls. The exact orientation of seismometers is for example essential for the analysis of seismic anisotropy.
In the future, research data gathered with instruments of the “Geophysical Instrument Pool Potsdam (GIPP)” of the GFZ has to be made available to the public within 4 years after the completion of the field work. This new guidline, which was triggered by the GIPP steering board, has been implemented on August 11, 2010. This new rule will support sustainable archiving and subsequent reuse of primary research data. This is in line with the “Priority Initiative” of the “Alliance of German Science Organisations”: “In Germany alone, the costs associated with obtaining research data as the basis for scientific knowledge (...) is in the order of magnitude of several billion euros each year. Even after a relatively short phase of scientific evaluation by individual researchers or small groups, much of this data is forgotten and/or allowed to deteriorate. All scientific institutions therefore see an urgent need for action in order to ensure the systematic backup, archiving and provisioning of scientific data for subsequent (re-)use by third parties” (http://www.allianzinitiative.de/en/start). Similar rules are in force in the US and UK for many years. Within the first 4 years after completion of the field work, data are only available to the project partners (PIs). For archiving, the “GIPP Experiment und Data Archive” and the “GFZ Seismological Data Archive (GEOFON)” can be used. Details regarding archiving can be found here and here.
GFZ-Section 2.2 “Deep Geophysical Sounding” and the Geophysical Instrument Pool Potsdam GIPP) have developed a new stand-alone 1-channel digital seismic data recorder. This robust DSS-cube recorder is characterized by a small and light-weight design and extremely low power consumption. This means that it runs on 2 D-cell batteries for up to 3 weeks (depending on temperature etc.). High timing accuracy is provided by build-in GPS. Data is downloaded via USB interface. This instrument type optimally complements the existing GIPP hardware to improve the support of controlled-source experiments and shallow investigations. The DSS-cube recorder is a GFZ hardware development; credits belong to Trond Ryberg, Mike Hönig and Karl-Heinz Jäckel who initiated and put forward the project. The development was completed in Summer 2009, the first 14 units were manufactured in August 2009. In 2009, the instruments were successfully tested in seismic experiments in Austria and Kyrgyztan. Since February 2010, 114 units of this type are available (supply on loan) through the GIPP. More details on technical specifications can be found here (link).
The Helmholz Centre Potsdam German Research Centre for Geosciences (GFZ) has started the Europe-wide procurement by public tender for the development of a new geophysical data recorder. A corresponding call has been sent to the Official Journal of the EU for publication. Interested companies submit their bids until August 17, 2009. The instrument searched for is a digital data recorder, which will replace the instruments used so far within the Geophysical Instrument Pool Potsdam (GIPP). 350 such instruments, which had been developed 10 years ago, are in operation within the GIPP. The instruments are used for investigations of the Earth by GFZ, Universities and other research institutions with seismic, seismological and magnetotelluric methods. They had been used in almost 200 experiments. Details of the call and the technical specification can be found at ted.europa.eu.
In late 2008 the GFZ has acquired a new seismic multichannel recording system. It is a Geometrics Geode system with 240 channels. This System is formed by 10 Geodes (each with 24 channels), analogue geofone cables (distance between geofone connectors 10m), corresponding interface cables, 10Hz-geofones and accessories. Maximum spread is 2.4km. Typical applications are shallow geophysical investigation and exploration in the depth range from meter to kilometer. In addition we purchased an accelerated weight drop as seismic source (PEG-40). These instruments form part of the Geophysical Instrument Pool Potsdam (GIPP).