Seismographs - Marine

CNT-1 Marine Seismic Controller

Features:

• Multi-tasking windows show real-time shot, gather, tape status and observer’s log
• Fast cycle times for all sources: air guns, water guns, even sparkers and boomers
• Real-time waterfall and bar graph noise displays
• Auto switches up to 4 tape drives, audible operator alarms
• ‘Sure-Save’ eliminates lost shots by disk buffering, even if ALL tape drives fail.

The CNT-1 Marine Seismic Control System combines professional multi-tasking marine survey data management with the StrataView series of high resolution, ultra low distortion seismic recorder.

Extensive Quality Control

Quality control monitoring of your data underlies the design of the CNT-1. Watch a real time bar-graph of streamer noise levels, calibrated to your streamer and measured between shots to avoid shots to avoid shot noise. Display each shot in a user sizeable window with AGC or manual scaling, even at the fastest cycle times. Build a user selectable near trace gather, displayed in a separate window to monitor data quality, Or change your acquisition parameters on the fly - without stopping the survey. The CNT-1 creates an observer’s log, displayed in its own window and saved to disk for use in later processing.

True Multi-tasking on Multiple Platforms

The CNT-1 controller system runs under the Windows NT operating system on either our splash-proof, ruggedized computer for portable applications or built into a rack mounted StrataView seismograph.

Specifications:

Interfaces to:

• StrataView R or RX System, 12 to 480 channels.

Data Displays:

• Shot display
• Near Trace (Common Offset) Gather
• Log file shows tape status, acquisition parameter changes, channels exceeding noise threshold, navigation and other external input strings
• Noise histogram with user definable thresholds
• Shot timing bar-graph
• Gun energy bar-graph

Audible Warnings:

• System is user programmable for audible warnings for several cautionary or error conditions:
  • "Tape Drive Full, Switching Drives"
  • "Tape not ready, going to disk"
  • "Tape Drive Rewound, replace tape"
  • "Peak noise threshold exceeded"
  • "Trigger time threshold exceeded"
  • "Overdriven channels warning"
  • "Navigation Input not received"

Tape Drives:

• DAT, DLT, 3480, 3490 SCSI drives, other SCSI drives consult factory. Automatically switches between drives when one is full or disabled.

CPU:

• Pentium PC based.

1. Portable, ruggedized, splash resistant 12 Volt control computer with built in LCD 640 x 480 display. Suitable for system from 12 to 120 channels. Includes external 640 x 480 video for separate monitor.
2. Portable, ruggedized 12 Volt control computer with high resolution graphics card to drive external CRT with 1280 x 1024 resolution. Suitable for systems from 12 to 480 channels. Requires separate monitor.
3. Rack mount computer with external monitor

Navigation, Gun and Streamer Position Input:

• Data accepted via RS-232 at sufficiently high baud rate to not effect cycle time. Provide specifications of your system.

Tape Management:

• Tape Status can be displayed continuously in its own window and monitors writing and ready operations. Robust error checking reduces or eliminates the need for additional read-after-write or read-while-write systems.

Sure-Save Data Protection Feature:

• In the event that all tape drives fail, the CNT-1 system automatically buffers data to disk, recording up to several hours of data until the problem is addressed.

Standard Components:

• CNT-1 controller with software and manuals.

StrataVisor NX

Land and Marine High-Performance Seismic Recording System

FEATURES:

• Multitasking Windows show real-time shot, gather, tape status and observer's log.
• Real-time waterfall and bar graph noise displays.
• Auto-switching of up to 6 tape drives, dual tape writing.
• Visual and audible operator alarms.
• "Sure-Save" eliminates lost shots by disk buffering, even when all tape drives fail.
• Real-time integration of NAV, Gun and Streamer positioning data to tape header.
• Recording parameters changeable during acquisition with no lost shots.

The StrataVisor can be deployed with multiple processors so several tasks can be handled independently. Multiple tape drives, integration of position data, plotting near trace gathers and controlling multiple printers are all handled simultaneously.

Optional processing software lets you see answers directly in the field to help you make survey decisions. An integrated brute stack is available for marine acquisition. Refraction surveys can be picked and interpreted directly on the screen. Even reflection processing software will run in the background without affecting acquisitions.

NX SERIES SPECIFICATIONS:

• A/D Conversion: 24 bit A/D conversion using Crystal Semiconductor sigma delta 2nd generation converters
• Dynamic Range: 144 dB theoretical, 125 dB (instantaneous measured) @ 2 ms, 0 dB
• Distortion: 0.0003% @ 2 ms, 0.3 to 206 Hz
• Bandwidth: 0.3 to 1.7 kHz (Lower frequency options available)
• Common Mode Rejection: > -110 dB @ <= 100Hz, 48dB
• Crosstalk: -120 @ 100 Hz, 0 dB
• Noise Floor: 0.18 uV, RFI @ 2 ms, 3 to 206 Hz
• Trigger Accuracy: 1/128 of sample interval
• Maximum Input Signal: 10 V, P-P
• Input Impedance: 20 kOhm, 0.02 uf
• Preamplifier Gains: 0, 24, 36, and 48 dB
• Anti-alias Filters: 82% of Nyquist, down 130 dB
• Sample Interval: 0.25, 0.5, 1.0,2.0, 4.0, 8.0, 16.0 ms
• Record Lengths: 16,000 samples / channel standard, 64,000 optional, independent of the number of channels.
• Line Testing: Real-time noise monitor, pulse diagnostics, continuity.
• Power Consumption: 40 W plus 0.8 W per channel
• Data Formats/Storage: SEG-D 8048 AND 8058. Operates with DAT, DLT, Exabyte, 3480, 3490, 3590, 9-track, Optical and hard disk storage through SCSI interface.
• Pretrigger Data: Up to 4096 samples.
• Stacker/Correlator: Full 32-bit Hardware DSP Correlator operates before or after stack. Minisosie option available to condition pilot.

• Low cut: out, 10, 15, 25, 35, 50, 70, 100, 140, 200, 280, 400 Hz, 24 or 48 dB / Octave, Butterworth. Display filters do not affect data.
• Notch: 50, 60, 150, 180 Hz and out, with the 50 dB Rejection Bandwidth 2% of Center Frequency
• High Cut: OUT, 250, 500, or 1000 Hz, 24 or 48 dB/ Octave

• Processor: Single or Dual Pentium based processors available. Consult Heritage Geophysics for current speeds.
• Automatic Gain Control: Digital AGC with user adjustable window. Display only - does not affect raw data.
• Number of channels: 12 to 72 channels per portable module, 12 to 132 channels per rack mount module. Modules connect to create systems up to 600 channels.
• Auxiliary Channels: Channels can be programmed as either AUX or DATA.
• Plotters: Drives a variety of NT compatible printers including Printex 8 and 12 inch plotters. Supports multiple printers simultaneously for shot, gather and log files. Consult Heritage Geophysics.
• Triggering: Positive, negative, or contact closure, software adjustable threshold.
• Delay: 0 to 9999 ms in 1 ms steps
• Environmental: -10 to 40 degrees C. Portable will operate in a light rain.
• Operating System: Windows NT
• Display: Built-in 480x640 LCD display, will drive external monitors at 600x800.
• Higher resolutions to 1024x768 available on external monitors, contact Heritage Geophysics to discuss options.