EarthQuake 300W.2 Specifications

Specifications Seismic System as part of the LOFAR Project Report: GeoLOFAR-004 (DRAFT) Version: 5.0 Date of is

10 AD controller This is a local piece of electronics that is supplied by a vendor so it is off-the-shelf. In the case for the test-site at Exloo, th

11over 10 years and that they need to be below the frost region which is often taken as 60cm below the surface. Also, a cable placed at the surface i

123.3 Local software components Locally on a sensor field, the different software systems that are running are: - Local Control System - Local Da

13 Local Meta-data System (LMS) At every LOFAR field, meta-data about the local (specific) AD-converter configuration can be entered and queried from

143.4 Power consumption In this section a summary of the power consumption for the two configurations is given. For one field of the province-sca

154 Central LOFAR network In this section, the bandwidth that is needed for the transportation over the LOFAR network is specified. To this end, a

165 Central System (Rekencentrum Groningen) The central system where all data from all sensor fields come together is at the Rekencentrum at Groni

17 Figure 5.1. Pictorial overview of the different components, centralized at Groningen.

18 Central Processing System (CPS) This system is responsible for processing the collected data from the sites. The following processes on this syste

196 Data storage and retrieval sites (TNO, KNMI) The data are only temporarily stored on a storage server at the Rekencentrum Groningen. The ultima

2Contents 1 Introduction ...

207 Data access for users (e.g., TU Delft) This section describes the data access from remote sites. Since a lot of seismic data is constantly mea

21- Query data-function: the query data function helps us to find data files of a certain period in time. We have the possibility to formulate two t

228 References [1] Drijkoningen, G.G. et al., 2007. Project Plan of the Seismic Applications in LOFAR. Report GeoLOFAR-002. [2] Drijkoningen, 2007

Appendix A: AD converters: The “GeoEel” GeoEel: This system is the system supplied by the vendor Geometrics Inc. It is an off-the-shelf system which

24 Hardware Description The GeoEel system consists of 3 boards in a set, 8 channels per set. The GeoEel consists of the analogue board, the DSP bo

25 Figure A.2. Photo of GeoEel-boards, with 14 8-channel boards. (On the left (white): 48V power supply).

26Appendix B: 220V AC to 48V DC converter The Xantrex HPD Series stands for “High Power Density”, providing 300W in a quarter-rack wide chassis. The

27En500781-2, EN50082-1 and IEC 1010-1, NRTL/C, CSA certified Analog Programming: Remote On/Off and Interlock 2-25V signal or TTL-compatible inpu

28Appendix C: Sensors and housing C.1. Geophone: SM-6 geophone from Sensor b.v. Specifications SM-6/U-B 4.5Hz 375 Ω (B-coil) Frequency Natural

29 C.2. Hydrophone: Benthos PreSeis 2520 General Characteristics Impedance 1730 Ω nominal at 100 Hz DC resistance 350 Ω ± 5% at 20o C Sensitivity

3 1 Introduction This document specifies the design and implementation of the seismic system within the LOFAR project. This document results from e

30 Figure C.2. Frequency response curves of PreSeis hydrophone C.3. Holder The 3C geophone is put in a special holder as shown in Figure C.3.

31 Figure C.3. Drawing of the holder for the 3 components of the SM-6 geophone. Photo of holder of 3C geophone, with two components of the geoph

32 C.4. Housing of 3C geophone and hydrophone. In Figure C.4 the drawing of the 4C sensor (geophone + hydrophone) housing is shown. Figure C.4. D

33 Figure C.5. Photo of housing of 4C sensor. C.5. Casting material As casting material for the housing, Scotch-cast® No.815 Resin is used. It is a

34Appendix D: Cables The cables chosen needed to be waterproof for duration of 10 years. Poly-urethane (PUR) material is the material which is often

35- Characteristic acc. to DIN 47100 - Outer diameter: ± 6,4 mm - Temperature range o Moved: 5o/+70o C o Not moved: -30o/+70o C - Bending radi

36Appendix E: GPS antenna GPS antenna, from D.D.S. Electronics. (Webpage: http://www.d-d-s.nl/gps-antenne.htm) Specifications Size 48mm (width x

37Appendix F: Different scenarios of data rates In this appendix, different scenarios are worked out. For the continuous monitoring 2000 Hz is used.

38Appendix G: GeoLOFAR Seismic Control software The following screenshots provide an overview of the web application. Figure 0.1 Main menu This i

39Acquisition control Figure 0.2 Acquisition control In this screen an overview is presented of all the configured devices and their state. There

42 Overview seismic system In this section an overview of the total seismic system is given and described. It shows the different subsystems which

40Operational settings Through the next 3 screens the user can respectively change general settings, AD-controller (SPSU) settings and AD-converters

41 Figure 0.4 AD-controller settings Internal trigger interval Not applicable Input select Single Output select Streamer on

42 Figure 0.5 AD-converter settings These settings apply to all the AD-converters of a site. Arm mode Continuous or Triggered Calibrate Not applic

43Structural information Figure 0.6 AD-controller structural information IP Address The IP address of the AD-controller device

44 Figure 0.7 Overview of structural data for the AD-converters Before an AD-converter can be used in the acquisition process on this site, its stru

45 Figure 0.8 Structural data for a AD-converter In this screen the structural attributes for AD-converters can be changed. This screen is also used

46 Appendix H: Description of the GeoLOFAR-web site Hereafter one can find a functional description of the GeoLOFAR -web site, a description of the

47Zoom-out, for zooming out of the map by means of a rubber box (mouse drag) or according to a fixed step size; Pan, for moving the map to the right

48selecting the Geophone (mouse click), the corresponding Meta-data will appear in a Popup window. By activating other layers we can select elements

49 As we can see in the popup window above, we selected the Exloo field, the status is test and we see that 48 Geophones are connected to the LOFAR

5- data-storage and retrieval sites (TNO, KNMI) - data access for users (e.g., TU Delft) This will be done in the following, noting that the discus

50After pushing the data function button, the screen above appears which gives us an overview of all the data files of the selected LOFAR field. This

51View-function, the view function gives us a graphical over view of all recently measured data. The overview appears in a popup window and is being

52 For the quick retrieval of the desired data file according to the given search criteria, a GeoLOFAR Meta-data database is has been developed. In

53 In this table we can browse through all data files that are adopted in the result. Also it is possible to create an overview from this table with

54 We have the following infrastructure components:  Web Server, a Jahia Content Management System with one iFrame that contains the Map of the M

55Appendix I: Failover and recovery To create a reliable server infrastructure each server type has his own failover system that fits to his purpose

56Appendix J: Computer Hardware In this network we identify two types of servers. Depending on the server task a system configuration, failover and

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63 Local (sensor) fields In this section the local sensor fields are further described in detail. First, the geometries as being used within the

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7 Figure 3.1 Configuration of 4C sensors for province-scale network at each antenna field (3 shown here) For the local/km-scale geometry, the sensor

8 Figure 3.2 Configuration of 4C and 1C sensors for local/km-scale network. For the final systems, most of the electric and electronics is housed in

93.2 Hardware Most of the electric and electronics is housed in one cabinet. An overview of a system is given in Figure 3.3. Figure 3.3 Overvie