(:{ STAT.] MITITIIATEI{A'r-TELEC()MMI NIC'ATI()NS-()CT. 2, 1947 (App. A, B RR) SECOND SERIES APPENDIX A Studies of Radio Propagation Recognizing the dependence of efficient assignment and utilization of radio frequencies upon full use of radio propa- gation data, the countries, members of the Union, shall en- deavour to promote the establishment and operation of a world-wide system of observation stations to obtain data on ionospheric, radio noise, and other phenomena affecting radio propagation, and also to provide for the study, coordination and dissemination of radio propagation data and predictions. APPENDIX B Standard Frequency and Time Broadcasts 1. The countries, members of the International Telecommu- nications Union, recognize that a standard frequency broad- cast service available to all parts of the world is essential for maximum economy in the use of the radio frequency spec- trum, the efficient operation of the telecommunication services and for the functioning of several activities of the I.T.U . The countries, members of the I.T.U., recognize that this service may also be useful for other activities outside the Union. The addition of time signals superimposed on these same broadcasts is also highly useful and should be included, if possible. 2. To this end, administrations will endeavour to provide on an international basis a coordinated system of standard fre- quency broadcasts. As regards time signals, recognizing the 2109
�
