Speed Log Systems Inst. Location of the Doppler Transducer Principal Requirements While the transducer is mounted flush with the hull, it is not affec
{"Image DocumentName": "Speed Log Systems Inst. Location of the Doppler Transducer", "Image ImageDescription": "Principal Requirements. While the transducer is mounted flush with the hull, it is not affected by boundary layer effects, because return echoes are received from undisturbed water outside the boundary layer at the hull. However, in common with other sonar devices, the performance of transducer is adversely affected by aeration. Air bubbles block acoustic energy from either being transmitted to the water or being received by echoes from reflectors in the water. If enough acoustic energy is blocked, the speed log operation will be erratic and unreliable. Proper speed log operation depends upon a transducer location that provides a clear sonar path in water that is free from sound blocking air bubbles. Typical causes for aeration are, e.g., bow wave sweep down, cavitation from hull cavities such as bow thruster tunnels, water in- and outlets and cavitation from hull protrusions such as hull zincs, rivets, weld beads, etc. The transducer is to be installed as close to the forward perpendicular of the bow as possible. The maximum aft distance from the forward perpendicular. for a flush mounted transducer is 12 metres. Northrop Grumman Private/Proprietary Level I.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}