Windows 95 based
Pentium machine
Saves
sidescan-sonar data via network interface or on an Exabyte 8200 tape subsystem
Will accept up to 5
channels of data
Serial I/O ports
(i.e., for navigation)
Parallel
(Centronics) ports for printing the sidescan-sonar data
Array processor
handling the digitized sidescan-sonar signal
12 bit analog to
digital converter OR:
DSP card for
digital signals
The topside data acquisition computer the USGS uses to collect and store the digital signal is the ISISTM system, which runs under the Windows 95 operating system and is built by Triton Elics International, Inc., Watsonville, CA using a 12-bit (72 db effective dynamic range) A/D converter in conjunction with an array processor. ISISTM is capable of digitizing up to four channels of information at aggregate rates of up to 750 kHz, thus preserving the content and the dynamic range of the sidescan-sonar signal. An installed Digital Signal Processing (DSP) board is an alternative to handling signals digitized at the towfish (SIS-1000). Port and starboard sidescan-sonar data are displayed in real-time on a high-resolution color display (1280 x 1024 pixels). Telemetry from navigation systems and the towfish, including full towfish attitude information, is displayed in separate windows. The backup data storage media used is 8 mm Exabyte tape. The USGS WHFC is currently recording directly to disk on separate computer systems using the Network File System (NFS) protocol and archiving the data to CD-ROM.