_REVISION - C1996083 ‎(2)‎

• Permit No: C1996083
• IBM Index Class Name: REVISION
• Doc Name: Seismic Event Data Acquistition and Processing Distribition and Coordination Across PC-Based Network
• Type & Sequence: PR10
• Media Type: D
• Archive: No

the processing workstation in the engineering office was established via fiber-optic cable. Signals
from nine surface stations above the longwall panels were sampled continuously with remote
digitizers and transmitted to a data acquisition node on the LAN in the engineering office via three
900-MHz, spread-spectrum transceiver pairs. Data from several isolated surface stations were also
occasionally merged with data from the main networks in post-collection processing and analysis.
A second processing and display workstation node was placed in the shift bosses' meeting room
where seismic tomography and longwall shield pressure data were also being archived and
analyzed(Westman et al.,2001).
11. [Remote digitizer
h. Spread spectrum Remote digitizer
11.
Multichannel GPS
serial port Remote digitizer
Modem (IRIG)
a
0
® o
Data acquisition
Data processing Foreman's room
Surface
Fiber optic
transceiver
E:1
Digitizer
_
In
Fiber optic Data acquisition
transceiver Geophones
Underground
Figure 4. Willow Creek Mine network.
Bowie No.2 Mine
Remote PC-104 data acquisition platforms and a wireless LAN were deployed at the Bowie No. 2
longwall coal mine in western Colorado. The surface above this mine possesses many of the
geographical barriers commonly found in western coal mines—steep, rugged terrain and dense
vegetation. It is this sort of situation that motivated the development of the distributed network
approach to seismic data acquisition. Depth of cover over individual panels varies from 50 in (165
ft)to greater than 500 in (1,600 ft). Three small seismometer arrays were deployed in areas where
convenient access through the dense vegetation was possible. Figure 5 shows two arrays deployed