Circular

 1 The Maritime Safety Committee, at its 104th session (4 to 8 October 2021), pursuant to operative paragraph 4 of resolution A.1046(27) on Worldwide Radionavigation System, recognized the Japanese Quasi-Zenith Satellite System (QZSS), proposed by Japan, as a component of the Worldwide Radionavigation System.

2 The Committee's decision was based on the recommendation and assessment made by the Sub-Committee on Navigation, Communications and Search and Rescue (NCSR), at its eighth session (19 to 23 April 2021), in accordance with the requirements set out in resolution A.1046(27) and A.915(22), noting the agreement of the Sub-Committee that QZSS, using dual frequency technique, met the operational requirements to assist in the navigation of ships in ocean waters, as well as coastal, port approach, restricted waters and inland waterways within the area connecting the following seven points:

3 Administrations should note that, as a stand-alone system, QZSS will not meet the accuracy requirements in the port areas as specified in appendix 2 to resolution A.915(22). However, with differential correction techniques, such as SLAS or D-QZSS, it will enhance the accuracy and help meet the requirements in port areas, as mentioned in appendix 2 to resolution A.915(22).

4 QZSS provides some items of instantaneous integrity warning of system malfunction, required in resolution A.915(22). Administrations may wish to note that receiver autonomous integrity monitoring (RAIM) can provide this facility. It should also be noted that the accuracy and integrity of the system can be greatly enhanced by the use of differential correction techniques using either local or wide area augmentations, or both.

5 Member States are invited to bring this information to the attention of all parties concerned.