DESCRIPTION

EdgeTech manufactures a line of deep water Hydrographic Survey Systems. A system consists of a sub-bottom profiler, digital link, surface interface, and a surface data display processor. A number of additional options may be integrated on to the system as needed. The 2200-M Modular Sub-Bottom System is designed for installation on an Autonomous Underwater Vehicle (AUV) or on a Remotely Operated Vehicle (ROV). It gathers side scan and/or sub-bottom data using EdgeTech's proprietary Full Spectrum (enhanced chirp) technology in water depths up to 6,000 meters.

A modular system is provided as a complete package including sensors and pressure vessel. Alternatively, it can be integrated into the AUV pressure housing. The system can operate independent of the AUV by setting parameters before deployment, or a processor on the AUV can control it. Heave, pitch, roll, yaw, temperature and pressure are additonal optional sensors.

The Sub-Bottom Profiler

EdgeTech’s Full Spectrum "chirp" sub-bottom profiler has a number of advantages over conventional profilers. This includes increased penetration and higher resolution. The tapered waveform spectrum, results in images that have virtually constant resolution with depth. Another advantage is the reduction of side lobes in the effective transducer aperture. The wide bandwidth of the sweep frequency has an effect of smearing the side lobes of the transducer. The result is a beam pattern with almost no side lobes. This allows the system to be very near the bottom, minimizing destructive signal scattering caused by the sediment.

The frequency range of operation is determined by the acoustic characteristics of the transmitter and receiver sensor arrays that have been selected from the three options. Each sensor array can transmit acoustic pulses with different center frequencies and bandwidths. The selection of the pulse is made on-line by the operator while profiling to achieve the best imagery. The sensor array is selected based on the sub-bottom conditions at the survey site and the type of sub-bottom features that need to be imaged. Three frequency range options are offered: 1-6 kHz, 2-16 kHz, and 4-24 kHz.

Typical System Configuration

• One of 3 sub-bottom profiler arrays.
• Model FS-DW underwater Full Spectrum processor.
• StarMux digital link and power for use on a coax tow cable.
• Model 2000 topside sonar display processor hardware.
• DISCOVER software for display storage and printing of sonar data.
• Optional integration (mechanical/power/data) of sensors such as motion, heading, depth, altitude, navigation, multi-beam echo sounder, magnetometer etc.

 

ROV

EdgeTech's deep-water combined sonar can be installed on a variety of ROVs. A modular system is provided as a complete package including sensors and pressure vessel. Alternatively, it can be integrated into the ROV systems. For example, the ROV can provide power and a 2-way digital link to the surface. It can also provide a pressure housing for the underwater electronics.

Typical System Configuration

• One of three sub-bottom profiler array options.
• Model FS-DW underwater Full Spectrum Chirp processor.
• Optional StarMux digital link and power.
• Model 2000 topside sonar display processor.
• DISCOVER Software for display storage and printing of sonar data.
• Optional integration (mechanical/power/data) of sensors such as motion, heading, depth, altitude, navigation, multi-beam echo sounder, magnetometer etc.

AUV

The deep-water combined sonar has been especially designed for installation on an Autonomous Underwater Vehicle (AUV) or on an Un-tethered Underwater Vehicle (UUV). Low power electronics and techniques such as turning off the amplifier and turning the power down, if not needed, are used to reduce the power consumption. The ability to accurately set and monitor the real time clock keeps the sonar data synchronized with navigation and other sensor data on the AUV.

A modular system is provided as a complete package including sensors and pressure vessel. Alternatively, it can be integrated into the AUV pressure housing. The system can operate independent of the AUV by setting parameters before deployment, or an AUV payload controller can command, control and store the sonar data. A second decimated simultaneous data stream can be fed into an acoustic link so that real time sub-bottom profiler and side scan sonar data can be displayed on the surface.

Post mission sonar data can be offloaded to the Model 2000 Topside Display Processor running EdgeTech’s DISCOVER software. Here the sonar data can be replayed on the video monitor and printed.

Typical System Configuration

• One of three sub-bottom profiler array options.
• Model FS-AU Full Spectrum "chirp" processor.
• Model 2000 Topside sonar display processor
• DISCOVER Software for display storage and printing of sonar data.