DATASONICS SIS-1500, System Manual

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1-6 DATASONICS
Volume I System Manual June 1998
Advantages of Chirp Sonar
Chirp sonar technology employs swept FM transmitted signals along with
digital signal processing for matched-filter processing of reflected energy.
This delivers the following performance advantages:
a greater dynamic range is attained as long FM pulses provide an
additional 20 dB to 30 dB of dynamic range over conventional sidescan
sonar systems;
enhanced resolution is achieved with matched-filter processing, as
compared to systems using standard processing in the same frequency
band, by correlating the return signals with a replica of the outgoing
pulse;
transmitted waveforms are repeatable from pulse to pulse;
the temporal resolution is constant throughout the entire range;
the pulse characteristics are programmable , as the pulse length,
span of frequency sweep and phase/amplitude calibration of the transmit
waveform can be varied without hardware changes; and
the sidescan sonar data can be stored for off-line processing , on a
hard disk, a magneto-optical disk, or an Exabyte 8 mm cartridge tape.
SIP-150 Sonar Image Processor
The SIP-150 Sonar Image Processor comprises the SIP-150 Sonar Image
Processor Workstation , which includes the Chirpscan
3
software, and the
Chirplink II Digital Multiplexer . Together the workstation, the Chirpscan
3
software and the digital multiplexer serve to process, display and store the
sonar data, the tow vehicle status information and the sensor data that are
received from the tow vehicle. In addition, they monitor and control the tow
vehicle’s functions while sending commands and the sonar and responder
keys to the tow vehicle.