Research on Time-Frequency Synchronization Technology of Multistatic Joint Observation

The multi-station joint detection of non-cooperative targets, such as high-dynamic space debris and aircraft, requires the synchronization of time, frequency and phase between stations, and the synchronization performance could affect the observation accuracy. In view of the requirement, the time, frequency synchronization requirements and resource conditions of space debris joint exploration platform has been analyzed in this paper. Based on the capability of satellite Common-View/All-View time transfer and time steering algorithm, a method of time-frequency signal remote synchronization which is not limited by distance and can be flexibly networking has been proposed. The time synchronization performance of three types of frequency references, including passive hydrogen clock, rubidium clock and crystal oscillator, which have been compared under the 300 km, 30 km and zero km baseline. The results show that the accuracy and stability of the frequency reference is directly proportional to the synchronization performance between stations. When the passive hydrogen maser or rubidium atomic clock is used as the frequency reference, the synchronization deviation between stations can be less than ±5 ns, and the frequency deviation is better than 5E−14. When the OCXO is used as the reference, the frequency deviation is less than 5E−12, which can meet the requirements of positioning of tens to several meters.