S.P. Polkovnikov - Ph. D. (Eng.), Associate Professor of Research Institute «Vector» (Saint Petersburg). E-mail: PSP7@yandex.ru
D.A. Konnov - Research Institute «Vector» (Saint Petersburg)

In order to expand the radio visibility area it is necessary to lift antenna systems and passive monitoring systems to an altitude that is unattainable by traditional, either mobile or stationary, lifting equipment. Early detection, recognition and determination of radio emission sources positions require extension of the horizon to hundreds of kilometers. This, in turn, leads to the positioning of the radar antenna systems at the height ranging from several hundred meters to several kilometers. This is especially important for the monitoring of remote and sparsely populated areas. To achieve the acceptable accuracy of the monitoring results, antenna systems should be precisely topographically binded and keep a stable position over time. The above requirements are entirely fulfilled by tethered aerostats. Problems of building tethered aerostat passive radar systems as well as related solutions and concerns are discussed.