Edgetech 3200-XS - Gaussian Shaped Amplitude Spectrum Outgoing Pulse; Reduction of Side Lobes; Full Spectrum CHIRP Technology Applications

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performance of the full spectrum sonar pulse, conventional pulse sonar would have to operate at a peak
pulse power of 100 times greater than a full spectrum pulse with a time-bandwidth product of 100.
1.1.6 Gaussian Shaped Amplitude Spectrum Outgoing Pulse
Another important feature of Full Spectrum CHIRP technology is that the signal processing optimizes the
performance of the system. The sonar contains many components, each with a unique dynamic range and
linearity characteristic, which are frequency dependent.
In addition to this characteristic, the amplitude spectrum of the outgoing pulse is chosen to be
approximately Gaussian in shape to limit the side lobe level and temporal resolution losses due to
attenuation. As a wavelet with a Gaussian shaped spectrum is attenuated by the sediment, energy is lost
but its bandwidth is nearly preserved. Therefore, even after being attenuated by sand, the acoustic pulse
has approximately the same resolution as an unattenuated pulse.
1.1.7 Reduction of Side Lobes
Use of Full Spectrum CHIRP technology reduces the side lobes in the effective transducer aperture. The
wide bandwidth of the sweep frequency has the effect of smearing the side lobes of the transducer and
thus achieving a beam pattern with virtually no side lobes. The effective spatial beam width obtained after
processing a full spectrum 2–10 kHz signal, for example is 20 degrees measured at the -3db points.
1.2 Full Spectrum CHIRP Technology Applications
Applications of Full Spectrum CHIRP Technology used in the 3200-XS Sub-Bottom Profiling System include:
• EEZ resource development
• Imaging fluidized mud to a resolution of 8 cm
• Sediment classification
• Buried pipeline and cable location and routing
• Dredging studies for inlets
• Scour/erosion surveys in rivers and streams
• Marine geotechnical surveys
• Bridge erosion surveys
• Hazardous waste target location
• Geological surveys
• Archeological surveys
• Hazard surveys
• Mining and dredging surveys
• Bridge and shoreline scour surveys