The whole airspace phased array telemetry,track and command(TT&C)system is regarded as the development tendency of next generation TT&C system,and the distribution of the antenna units and the beamforming tech...The whole airspace phased array telemetry,track and command(TT&C)system is regarded as the development tendency of next generation TT&C system,and the distribution of the antenna units and the beamforming technology have sparked wide interest in this field.A method for antenna distribution is proposed based on the linear subarrays technology.A symmetrical truncated cone conformal array is composed of the linear subarrays placed on the generatrix.The impact of truncated cone bottom radius and elevation angle on beamforming are studied and simulated.Simulation results verify the system design.展开更多
The first photoelectric light curve analysis of the TT And system in a broad band filter (400 - 700 nm) was carried out using the PHOEBE program. The absolute dimensions of the system are determined and its evolution ...The first photoelectric light curve analysis of the TT And system in a broad band filter (400 - 700 nm) was carried out using the PHOEBE program. The absolute dimensions of the system are determined and its evolution is discussed. The most distinct feature of the system is a comparatively very low mass of the cooler component i.e. M2 = 0.26M⊙. Moreover, using the Observed-minus-Calculated data, the period changes of the system are studied, which reveal the presence of a third body orbiting the system with a period P3 = 63.89 yr, superimposed on which is a secular period increase, which is ascribed to mass transfer with a rate −7.60 × 10−12 M⊙ yr−1 from the cooler secondary component.展开更多
The Tianlian 1-03 satellite, the third geosynchronous data relay satellite of China, was successfully launched into space on a LM-3C launch vehicle from the Xichang Satellite Launch Center at 23:43 Beijing time on Jul...The Tianlian 1-03 satellite, the third geosynchronous data relay satellite of China, was successfully launched into space on a LM-3C launch vehicle from the Xichang Satellite Launch Center at 23:43 Beijing time on July 25. Twenty-six minutes after the liftoff, the satellite展开更多
文摘The whole airspace phased array telemetry,track and command(TT&C)system is regarded as the development tendency of next generation TT&C system,and the distribution of the antenna units and the beamforming technology have sparked wide interest in this field.A method for antenna distribution is proposed based on the linear subarrays technology.A symmetrical truncated cone conformal array is composed of the linear subarrays placed on the generatrix.The impact of truncated cone bottom radius and elevation angle on beamforming are studied and simulated.Simulation results verify the system design.
文摘The first photoelectric light curve analysis of the TT And system in a broad band filter (400 - 700 nm) was carried out using the PHOEBE program. The absolute dimensions of the system are determined and its evolution is discussed. The most distinct feature of the system is a comparatively very low mass of the cooler component i.e. M2 = 0.26M⊙. Moreover, using the Observed-minus-Calculated data, the period changes of the system are studied, which reveal the presence of a third body orbiting the system with a period P3 = 63.89 yr, superimposed on which is a secular period increase, which is ascribed to mass transfer with a rate −7.60 × 10−12 M⊙ yr−1 from the cooler secondary component.
文摘The Tianlian 1-03 satellite, the third geosynchronous data relay satellite of China, was successfully launched into space on a LM-3C launch vehicle from the Xichang Satellite Launch Center at 23:43 Beijing time on July 25. Twenty-six minutes after the liftoff, the satellite
