EM 2040C Multibeam Sonar
The EA440 is a high performance hydrographic wide band single beam echo sounder. The echo sounder is developed for hydrographic use in shallow to medium depth waters. It supports portable and hull mounted side-scan and sub-bottom light for shallow waters.
The EM 2040 Compact is a shallow water multibeam echo sounder based on the EM 2040 technology, an ideal tool for any high resolution mapping and inspection application. The receiver and transmitter are integrated in a common Sonar Head, with the same dimensions as the EM 3002. The system fulfils and even surpasses the IHO-S44 special order and the more stringent LINZ specification.
The operating frequency range of the EM 2040C is from 200 to 400 kHz with frequency selection in step of 10 kHz, enabling the user to choose on the fly the best operating frequency for the application. Due to the very large operating bandwidth available the system will have an output sample rate of more than 60 kHz. The system will thus effectively operate with very short pulse lengths, less than 25 microseconds, which gives a raw range resolution (cτ/2) of 18 mm.
By utilizing both CW and FM chirp pulses, the system can achieve a much longer range capability with a high resolution.
• The maximum depth range is 490 m at 200 kHz with a swath with up to 625 m with Dual Head.
• As an option the EM 2040C can be delivered with the dual swath capability, allowing a sufficient sounding density along track at a high vessel speed.
• The EM 2040C is also available in an EM 2040CX version where the subsea components have a depth rating of 1500 m for operation on ROV or AUV.
The basic EM 2040C has three units: A Sonar Head, a processing unit and a workstation. For completeness, data input from a motion sensor and a positioning system is required, as is the sound speed profile of the water column between the transducers and the bottom. Sound speed at the transducer depth is an optional input. Optionally, the Sonar Head(s) may be delivered mounted on a frame together with the motion sensor and a sound speed sensor, factory aligned for ease of mounting. All electronics are contained in the Sonar Head(s) which is interfaced to the Processing Unit via GBit Ethernet. The Processing Unit also supplies 48 V power via the same cable. Operator control, data quality inspection and data storage is handled by the hydrographic workstation running SIS software or by 3rd party software.
The angular coverage for 200 to 300 kHz is 130 degrees with one Sonar Head, allowing coverage of 4.3 times water depth. With two Sonar Heads, tilted 35-40 degrees to each side, 200 degrees can be covered. This allows surveying to the water surface or up to 10 times water depth on flat bottoms. For frequencies above 320 kHz the angular coverage per head is gradually decreasing to 70 degrees at 400 kHz.