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• New High Resolution deep water multibeam

• The system sets a new standard by introducing new technology for 4th Generation multibeam.

• Replaces EM 120

• Easy upgrade path for EM 120 customers, by change of TRU only. Same transducer arrays.

• Extends the coverage by 25% compared to EM 120.

• SIS Operator station using 3D graphics running under Windows and Linux

EM 122 System diagram

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EM 122 - Ordered and delivered deep sea systems

• EM 12 - 17systems deliveredCustomers include IFREMER, SHOM, NERC, CSIC…..

• EM 120 - 21 systems deliveredCustomers include BAS, Scripps, SHOM, NSF, UoHawaii, NERC, German Univ…..

• EM 122 – 29 systems delivered, 25 systems in operation Customers include NAVOCEANO, DOF, UoStockholm, Fugro, IFREMER, UTEC, EGS, Germany Univ….

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EM 122 Specifications – Frequency and range

Frequency: 12 kHz (10.5 – 13 kHz)

Range: 20 to 11000m

Max swath width: 30 km (-30dB) 6x water depth (down to 4000m)150 degrees angular coverage sector

Range sample rate: >2 kHz (37 cm)

Pingrate: Maximum 5 Hz, mainly limited by the round trip travel time in the water.

Mammal protection: ”Ramping up” TX power

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EM 122 Specifications – Frequency and range

Corrections for doppler shiftThe long FM pulse used by EM 122 are more sensitive than CW pulsesto doppler shift caused by movements of the survey vessel.Therefore active corrections are required during the signal processing.

Coverage for a 0.5x1 degree system

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EM 122 Specifications – Swath width vs Depth

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No of beams and soundings

System version 0.5x1 & 1 x1 1x2 2x2 2x4

No of beams/swath 288 288 288 144

No of soundings per swath

432 432 432 216

No of swaths per ping 2 2 1 1

No of soundings per ping

864 864 432 216

EM 122 Beams and transmission pattern

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• Water column display as a standard

• Data collection as option.• 140 dB dynamic range receivers

allowing different gains for water column and bottom simultaneously.

• No TVG is added in the receiver but added afterwards to compensate for different transmitter pulses (CW, FM).

Display and loggingwith correct gain

EM 122Focusing and water column

8 11 Apr 2023

41209 meter across

62/61º coverage

EM 122 – 1x1 degree Courtesy of NAVO

9 11 Apr 2023

Courtesy of NAVOEM 122 – 1x1 degree

10 11 Apr 2023

EM 122 – 1x1 degree

Seabed image

overlay

Water depth

95–710 m

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EM 122 – 1x1 degreeWaterfall display