Alcance
ISO 22090-1 specifies the construction, performance and testing of gyro-compasses as transmitting heading devices required by chapter V, SOLAS 1974 (as amended).A transmitting heading device (THD) is an electronic device that provides information about the ship's true heading.The THDs complying with the requirements contained in this part of ISO 22090 can be used for heading information as contained in chapter V of the SOLAS Convention.