ITU-R REPORT RA.2195 PDF

Introduction

Television has become a fundamental form of communication in every region of the world. Its utility as a source of news, entertainment, and emergency information has been evident since its inception more than 60 years ago. Presently providing coverage to a global population numbering in the billions, terrestrial television broadcasting is one of the most ubiquitous uses of the radio spectrum.

The radio astronomy service does not share any allocations with terrestrial television broadcasting; however, such broadcasts generally occupy spectrum that is extremely important to low-frequency astrophysics and the observation of red shifted neutral hydrogen (HI) arising from early epochs in the formation of the universe. To date, radio astronomers have made use of TV bands to conduct observations, in accordance with No. 4.4 of the Radio Regulations (RR).

At the present time, many countries are transitioning from analogue to digital television broadcast standards (see Fig. 1), and some are also revising their broadcast allocations to recover spectrum that is expected to be freed up by the so-called "digital dividend". Some aspects of the digital transition are expected to result in a reduction in the ability of radio astronomers to make use of the terrestrial television broadcast bands for observations that are currently conducted on an unprotected basis (see Fig. 2). Some aspects may improve the ability to make passive observations in the TV bands.

Annex 1 summarizes the plans for the transition to digital television for several countries around the world with current radio astronomy programmes operating within bands used for terrestrial television broadcasting, and for countries of strategic importance to future radio astronomy stations presently under design and development that intend to utilize such bands. The impact of service rules for digital television on the use of the television broadcast bands for radio astronomy is discussed.

The material in this report is specific to the impact of the digital transition on the radio astronomy service. A more general introduction to the transition to digital TV is available in Report ITU-R BT.2140 – Transition from analogue to digital terrestrial broadcasting.