ITU Regulations

The new limiting value for the power level of unwanted emission was adopted as defined in the Appendix S3 of the Radio Regulations agreed upon in the ITU Radiocommunication Assembly. The levels of the unwanted emissions of the marine radar systems to be mounted on marine vessels from January 1, 2003 onward are subject to the new limiting value.

The frequency range, where unwanted emission occurs, covers the out-of-band (Oob) domain and the spurious domain extending outside the Oob domain. The Appendix S3 of the Radio Regulations states that the level limit to be applied to unwanted emissions in the spurious domain should be the smaller of 43+log (PEP) or 60dBc, while ITU-R SM1541 ANNEX 8 defines the boundary between the Oob domain and the spurious domain.

Please refer to ITU-R SM1541 ANNEX 8 for instructions on calculating the mask.
ITU-R M-1177 informs of the method for measuring unwanted emissions.