I.V. Kryuchkov - Head of department of Scientific Researcher Institute of Radio-Electronic Engineering, Bauman MSTU, teaching assistant of «Radioelectronic systems and devices» chair of BMSTU. E-mail: kryuchkov@bmstu.ru
S.I. Nefedov - Ph.D. (Eng.), Associate Professor, vice director of Scientific Researcher Institute of Radio-Electronic Engineering, Bauman MSTU Associate Professor of «Radioelectronic systems and devices» chair of BMSTU. E-mail: nefedov@bmstu.ru
A.V. Saponov - Engineer, Scientific Researcher Institute of Radio-Electronic Engineering, Bauman MSTU. E-mail: asaverios@yandex.ru
A.A. Filatov - Junior Research Scientist, Scientific Researcher Institute of Radio-Electronic Engineering, Bauman MSTU, teaching assistant of «Radioelectronic systems and devices» chair of Bauman BMSTU. E-mail: andrey-rus-sky@yandex.ru

The paper considers spatially coherent distributed radars. These systems are new and perspective direction in radiolocation. The key problem of distributed radar operation is synchronization ensuring of spatially distributed transceiver elements by time and phase. The estimates show that necessary synchronization accuracy must amount from several units to tens of nanoseconds for signal envelope delay control and from twenty to thirty degrees for phase measuring of carrier frequency. The authors consider that the most rational solution under distributed radar synchronization system is to refuse of navigating satellite signals and expensive reference oscillators. Analysis of generalized correlation integral of signal processing in distributed radar is implemented for estimation reference oscillator frequency stability requirements in the context of concerned conception. The simulation results show that relative frequency instability of reference oscillators must stay 10-9 during several seconds. Traditional well designed crystal oscillators satisfy this condition. In this case reference oscillator phase comparisons must be provided by the two-way signal transfer method in the synchronization system of the distributed radar. The attached conception of synchronization system design has been realized in the small base spatially coherent distributed radar breadboard.