The purpose of this Supplement to the ITU-R Handbook - Spectrum Monitoring (Edition 2002) is to provide up-to-date information on several issues before the publication of the next complete edition of the Handbook. It provides a complete and self-contained revision of the following chapters of the Handbook: - Chapter 3 (Monitoring equipment and automation of monitoring operations), - Section 5.1 (Spacecraft emission monitoring) of Chapter 5, and - Annex 1 (Monitoring system planning and tenders).