The operating frequency range is from 200 to 400 kHz with frequency selection in steps of 10 kHz, enabling the user to choose on the fly the best operating frequency for the application. Due to the large operating bandwidth available, the system has an output sample rate of up to 60 kHz.
The system can effectively operate with very short pulse lengths, the shortest pulse being 14 microseconds giving a raw range resolution (ct/2) of 10.5 mm. By utilising both CW and FM chirp pulses, the system can achieve long-range capability still maintain a high resolution. The maximum depth range for a dual-head system in cold ocean water is 520 m at 200 kHz with a swath width up to 700 m. The angular coverage for 200 to 320 kHz modes is 140° with one sonar head, allowing coverage of 5.5 times water depth. For a dual transducer system, 200° angular coverage or 10 times the water depth is achieved on a flat bottom. As an option the EM 2040C MKII can be delivered with the dual swath capability, allowing a sufficient sounding density to meet survey coverage standards along the track while maintaining a high vessel speed.
The basic EM 2040C MKII has three components: a sonar head, a processing unit and a workstation. The EM 2040C MKII can be delivered with the standard processing unit or a IP67 rated (24 VDC) portable processing unit. For real-time motion stabilization and compensation, data input from a motion sensor, heading and a positioning system is required. A sound speed profile of the water column is recommended for real-time correction, especially for a dual-head system. 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 VDC 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. EM 2040C is also available in a 1500m depth rated version with a 130° swath for ROV or AUV operations.