Coordinate system stamp
The beam data (x, y and z) are referred to the vessel reference point, and in the surface coordinate system (SCS). If data are described as raw, the offsets and delays have not been applied, and data in the output datagrams are as received from input sensors.
The offsets to be used for correction are set by the operator in K-Controller, Input Setup, Position/Attitude system, Location offset and Angular offset (attitude only). Sensor data that are described as corrected have been adjusted to compensate for the offset between the sensor and the vessel reference point. Sensor data as well as the installation offsets (location offsets and angular offsets) of the sensors, are all referred to the vessel coordinate system. array, subarray 0) will be on the vessels starboard side. if the TX is installed with a heading offset of 180 degrees, the port subarray (ref. Here port/starboard refer to the array coordinate system. Subarray 0 = port subarray, 1 = centre subarray, 2 = starboard subarray. The TX transducer is seen from behind (default orientation). The figure below illustrates the offsets of the 3 subarrays for EM2040. The installation coordinates are given in the Installation parameters. If it is needed to recalculate XYZ data in post-processing, these subarray offsets should also be taken into account.įor the EM 2040, the transducer installation coordinates refers to the center of the transducer faces. The transducer subarray offsets x,y,z are taken into account by the PU when calculating the #MRZ datagram. The TX transducer has 3 separate arrays, used for port, centre and starboard sectors, and the RX array also has an along-ship offset. However, when processing in the PU, the heading angles are 180 + heading offset.įor most EM type echosounders, all elements in the TX and RX transducer arrays are used for all beams, giving a common x,y,z location for each transducer. The Offset angles (deg.) for TX and RX in the 'Angular offset' menu in the K-Controller are then relative to the orientation indicated in the figures in the menu. This misalignment must be indicated in the K-Controller, under 'Installation', 'Angular offset' menu, by choosing the right configuration (figure TX Transducer: Orientation). If the orientation of the EM 2040 TX is with the cable plug to the starboard (or aft for RX), the installation heading is 180 degrees in the #IIP datagram.