Kongsberg EM 3002, Описание продукта

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Product description
5
855-164929 / A
2 PERFORMANCE
The operating frequency of the Kongsberg EM 3002 multibeam
echo sounder is
300 kHz
. This frequency has been chosen
carefully to achieve an optimum balance between small
dimensions, narrow beams, and good range capability even in
turbid waters. Acoustical interference between the two sonar
heads of EM 3002D is eliminated by using two different
operating frequencies (293 and 307 kHz).
The beamwidth is 1.5
°
both on transmit and receive. The
transmit fan may be electronically stabilized for pitch to always
point vertically. The receive beams are electronically stabilized
for roll. Roll, pitch, heading, heave and the applied stabilization
are fully taken into account when calculating sounding depths
and positions. In the near field the receive beams are
dynamically focused to maintain angular resolution even at very
short ranges. All beamforming is rigorously done with a time
delay algorithm.
There are 160 simultaneous receive beams for each Sonar Head.
They are either spaced in an equiangular or equidistant pattern
within the coverage specified by the operator. There is also a
high density mode where 254 soundings are acquired per head
and ping. The additional soundings are derived by using smaller
sections of the range window than what the beamwidth
provides, thus reducing the effective receive beamwidth to
minimize the interdependency of the extra soundings.
Each Sonar Head has an angular coverage of 130 degrees
corresponding to a swath width of 4 times water depth. For an
EM 3002D system with two tilted Sonar Heads a total effective
swath coverage of up to 10 times water depth with up to the
water’s edge is obtainable even if the vessel is rolling. A dual
head system may also be used for profiling of say a trench or a
pipeline from two sides simultaneously. The number of
simultaneous receive beams is then doubled to a maximum of
508 with the high density mode.
The dense beam pattern together with the high ping rate of up to
40 pings per second gives a very dense sounding spacing. A
vessel speed of 10 knots in shallow waters and even more in
deeper waters is thus possible while maintaining 100% bottom
coverage.