RES535 – 332 – Data query This module should enable the user to perform typical data query functions. DESCRIPTION 1 Selection of suitable frequency band(s) General In order to assist broadcasters and administrations in the preparation of their HF broadcasting requirements, the Bureau will prepare and distribute suitable computer software. This should be easy to use and the output should be easy to understand. User input data The user should be able to enter: – the name of the transmitting station (for reference purposes); – the geographic coordinates of the transmitting station; – the transmitter power; – the frequency bands which are available for use; – hours of transmission; – sunspot number; – months during which a service is required; – the available antenna types, together with the relevant directions of maximum radiation; – the required coverage area specified as a set of CIRAF zones and quadrants (or by means of relevant geographic information). It is desirable that the software should be able to store the above information, once it has been entered correctly, and provide the user with an easy means of recalling any previously entered information. Methodology and data The software should use: – Recommendation ITU-R BS.705 for the calculation of antenna patterns; – Recommendation ITU-R P.533 for the prediction of wanted field-strength values; – Recommendation ITU-R P.842 for the calculation of reliability values. The set of 911 test points (agreed at WARC HFBC-87) should be used, supplemented where necessary with test points based on a geographic grid.