Due to the growing demands on the radio frequency spectrum, it is of great importance that spectrum monitoring techniques keep track with advances in radiocommunication technology and to disseminate such information the world over. Since the 2002 edition of this Handbook, significant improvements in monitoring techniques have taken place. Accordingly, Radiocommunication Study Group 1 entrusted Working Party 1C (WP 1C) with the task of revising the Handbook on Spectrum Monitoring for the benefit of developing and developed countries.