Antenna pattern verification for Digital TV Broadcast systems in Andean countries based on UAV’s

• Published in: 2018 IEEE-APS Topical Conference on Antennas and Propagation in Wireless Communications (APWC) pp. 858 - 861
• Main Authors: Navarro Cadavid, Andres, Aristizabal, Jaime, Duvan Pineda Alhucema, Marcos
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.09.2018
• Subjects: Andean countries; Antenna arrays; Antenna measurements; Antenna radiation patterns; Broadcasting; Digital TV; measurement procedures; Radiation Pattern; Size measurement; station verification; UAVs; UHF measurements
• DOI: 10.1109/APWC.2018.8503765

Most countries in Latin America, Africa and Asia are currently in the process of migration from Analogue Broadcasting Systems to Digital systems. For such migration process, the verification of technical conditions like radiation patterns of antenna arrays and coverage are important. Antenna pattern measurements for VHF and UHF broadcasting radio services are described in UIT-R Recommendation BS.1195 and the use of aerial vehicles is described in ITU-R Report SM.2056-1: Airborne verification of antenna patterns of broadcasting stations. More recently, in Working Party 1C, contribution number 1C/78-E from Korea, proposes the inclusion of the use of UAV for field strength measurements in DTV systems, as an annex to the Report ITU-R SM.2355-0. The measurement of radiation pattern of broadcasting antennas is not easy to do in anechoic chambers, and once the system is installed, the radiation pattern may change. On the other hand, it is important for both broadcaster and regulator, to measure the realbehavior of a broadcasting station once installed, to verify the licensing conditions. The use of UAV to obtain both radiation pattern and coverage verification is a promising area for research and innovation. However, the use of UAV is challenging in some environments, like Andean mountains or windy areas. In most cases, primary DTV transmitter stations are located on higher points of the Andean mountains. Consequently, antenna arrays are located on towers over 100m, to obtain big coverage areas. Those are critical conditions that must be taken it into account, to ensure the correct operation of an UAV to assess and verify the right performance of the antenna array pattern in a DTV transmitter. This article presents ourexperience on antenna pattern verification of ground operating transmitters for UHF band, using a proper setup based on a UAV system with controlled flight over defined conditions. We use the UAV as a test device in far-field location that defines the amplitude of the flight, depending on wind, pressure and other climate factors, which imposes difficulties and could affect UAV trajectories, and can imply an uncertainty related to GPS and its relation to far field. The article shows comparative results including simulations vs. measurements that proves that this uncertainty is higher, compared to anechoic chamber tests. In the results we can conclude that UAV radiation pattern verification gives enough evidence and support to ensure TV broadcasting coverage In Andean countries, verifying the quality of Service based on DVB-T2.