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Additional information

This page contains additional information concerning the International Monitoring System. 
The following monitoring service tasks are derived from the Radio Regulations (RR):  
  1. Monitoring emissions for compliance with frequency assignment conditions; 
  2. Frequency band observations and frequency channel occupancy measurements; 
  3. Investigating cases of interference;
  4. Identifying and stopping unauthorized emissions.

Monitoring measurements

Monitoring measurements carried out by stations published in List VIII:

  1. Frequency measurements -  to obtain using proper monitoring equipment, the exact frequency of transmission of a particular monitored  transmitter. 
  2. Field Strength or power flux-density measurements -  to obtain information related to the power used  by  the transmitter equipment being monitored.
  3. Direction-finding measurements -  to obtain the estimated  position of transmitting equipment, using triangulation methods.
  4. Bandwidth measurements -  to obtain the bandwidth used by the transmitter being monitored . 
  5. Automatic spectrum occupancy surveys - to obtain  the occupancy of a determined  spectrum  under a monitored situation,  with regularity and with automatic  capabilities. 
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Basic equipment

Some examples of monitoring equipment and tools are:

    1. Omnidirectional antennas;
    2. Directional antennas;
    3. Receivers;
    4. Direction finders;
    5. Frequency measuring equipment;
    6. Field strength meters;
    7. Bandwidth measurement equipment;
    8. Channel occupancy measurement equipment;
    9. Frequency spectrum registration equipment; 
    10. Spectrum analyzers; 
    11. Vector signal analyzers or modulation analyzers;
    12. Decoders;
    13. Signal generators;
    14. Recording equipment.  

Centralizing Office and international cooperation

In accordance with Articles 15 and 16 of the Radio Regulations, each Administration or common monitoring service established by two or more countries, or international organizations participating in the international monitoring system, must designate a “centralizing office” to which all requests for monitoring information must be addressed and through which monitoring information will be forwarded to the Bureau or to other Administration’s centralizing offices.

It is essential that Member States exercise the utmost goodwill and mutual assistance in the settlement of problems of harmful interference.​


The Monitoring Spectrum Handbook is not available for consultations online. This publication contains the latest information on all aspects of monitoring and represents a valuable reference for the spectrum management community. It is intended for the use by administrations of both developing and developed countries and by the Radiocommunication Bureau. The Handbook will also be useful to radiocommunication engineers everywhere.