L.A. Abramov - Ph.D. (Eng.), Leading Expert, JSC «Russian Institute of Radionavigation and Time», St.-Petersburg. E-mail: alaspb@mail.ru
S.P. Zarubin - Head of Department, JSC «Russian Institute of Radionavigation and Time», St.-Petersburg. E-mail: zarubin@rirt.ru
N.S. Khokhlov - Head of Laboratory, JSC «Russian Institute of Radionavigation and Time», St.-Petersburg. E-mail: hohlov_ns@rirt.ru