Weighting
The transmission and reception of the ME70 transducer element signals are weighted. This weighting is done in order to obtain the requested beam opening and side lobe levels.
The weighting is plotted as a graph of the 20 elements in the X direction and a graph of the 40 elements in the Y direction. The weight for a specific element is the product of the weight for the element’s x and y positions in the transducer.
During transmission the weighting is performed in the transceiver boards. During reception the weighting is performed in the beamforming software.
With the weighting performed in the transceiver boards during transmission, the weighting is directly visible in a Matrix mode monitoring the transmit pulse. When you look at reception in the Matrix mode you can expect to see a couple of characteristic cases:
•  When receiving from the water column or from below the seabed, you would expect a random pattern.
•  When receiving an echo from a perfectly flat seabed, you would expect all elements to receive the same signal.
It is also possible to display the signal phase. During transmission the signal phase will rotate depending of the beam steering:
•  When receiving from the water column or below the seabed, you would expect a random pattern.
•  When receiving an echo from a perfectly flat seabed, you would expect all elements to receive the signal in phase.