ICAO Doc 9849:2025

The primary purpose of this manual is to provide information on the implementation aspects of GNSS in order to assist States in the introduction of GNSS operations. It provides a general overview of GNSS-based operations, a GNSS system description and guidance on providing GNSS-based services and includes future prospects for the evolution of GNSS. This manual is to be used in conjunction with the relevant provisions in Annex 10, Volume I. This edition contains new material on dual-frequency, multiconstellation (DFMC) GNSS, on GNSS performance monitoring, assessment and reporting and on radiofrequency interference detection and mitigation.