IMO Resolution A.813 (19): General requirements for electromagnetic compatibility (EMC) for all electrical and electronic ship's equipment.
IMO Resolution A.821 (19): Performance standards for Gyro-compasses for high-speed craft.
3 Terms and definitions
For the purposes of this International Standard, the following definitions apply.
3.1 gyro-compass
Complete equipment including all essential elements of the complete design. This means both the Gyro-compass as heading sensor and the associated heading transmission system.
3.2 heading
any ship's heading to be input to the THD function.
3.3 sensing part
a sensing function of detecting any heading information connected to the transmitting part.
3.4 transmitting part
device which receives a heading information from the sensing part and convert to the required accurate signal.
3.5 true heading
horizontal angle between the vertical plane passing through the true meridian and the vertical plane passing a through the craft's fore and aft datum line. It is measured from true north (000°) clockwise through 360°.
3.6 transmission and resolution error
error which is caused by the method used to transmit the original information to a receiving device.
Such method may have a limited capability to code any possible value of the information e.g. step output with 1/6｡?esolution. This error is also caused by the method used inside the THD and at its output to code the information.
3.7 static error
error which is caused by any reason and which stays unchanged in value during the operation of the system. This error shall be measured under static conditions.
This error is the same as defined in 3.12.
3.8 dynamic error
error which is caused by dynamic influences acting on the system such as vibration, roll, pitch or linear acceleration. This error may have an amplitude and usually a frequency related to the environmental influences and the parameters of the system itself.
This error is the same as defined in 3.13.
