Simrad SL 30, Руководство пользователя

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SL 30/35 Hull Sonar Operators Manual 974-25007001/2.0
Selecting Settings Page 5.19
Kongsberg Simrad Mesotech Ltd.
Port Coquitlam, BC - Canada
5.7.6 Maximize Range
The pulse length calculation can be optimized to increase the detection range of the
sonar. Generally, the longer the pulse length, the more energy is transmitted into the
water, which could then travel a longer distance and not get reflected from the
targets that are further away from the sonar. The pulse length corresponding to 80%
of the sample period can increase the detection distance of the targets without major
drain on the sonar power supply. This pulse length increases linearly with increasing
the operating range.
5.7.7 Peak Detection
The Peak detection feature can only be described as follows.
The older sonar was not capable of changing the acoustic pulse length. They were
generally operated at a pulse length of 100 Microseconds. This meant that at range
greater than 50 meters, there would be a good chance of not detecting small
targets. The reason for this is that the combination of small target size, short pulse
length and long sample period could result in the acoustic return from the target to
fall in between two samples and therefore not seen on the sonar image.
The remedy this, it was decided to take additional samples and select the strongest
echo target for the sonar image. This is generally referred to as “Peak Detection”
because we are detecting the peak value of the signal in between two samples. The
user can select the number of optional samples that the system takes in order to
detect the peak value.