Testing of digital television broadcasting from the stratosphere

Digital TV broadcasting from the stratosphere was tested using an unmanned aerial vehicle, a Pathfinder Plus. A television transmitter installed under the wing transmitted a UHF band signal as the vehicle flew at an altitude of 20 km. The Japanese digital terrestrial broadcasting standard (ISDB-T) was used for transmission. The 13.5-hour flight time included 3 hours of transmission testing. The transmitting equipment worked as expected in spite of the cold and low-atmospheric-pressure environment. Reception at the ground station was satisfactory even when the ISDB-T parameter set used was the one least robust under poor channel conditions.