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锁相干涉仪综合了经典干涉仪原理与最新技术。在跟踪准园形轨道方面,与标准MINITRACK和DIANE跟踪网是一样的;但作为一种动态匹配接收机系统,也能与高偏心卫星轨道上的信标机一起工作。锁相干涉仪的基本特点是: (1)每一路接收机通道中采用了相关信号检波,能获得低的检波门限。应用予期轨道的先验信息来设计本振频率,就能得到一部与卫星动态相匹配的接收机。锁相检波与本振程序设计相结合就能对工作于邻近频率上的其它信标机产生的干扰提供有效的保护。 (2)测角通道仅仅处理相对于公用参考通道的差值信息;具有相同的结构,并且具有非常窄的带宽。 (3)由于相关检波和窄带使接收机灵敏度的改善远比广泛地补偿宽波束天线低增益来得好,故可以采用相同的宽角天线进行精密测角和模糊度分辨。这种装置能使地面站在方位和仰角上同时复盖整个空域。 (4)除了方向角和角变化率外,锁相干涉仪还能测量多普勒频移,这样,当加上距离模糊度分辨用的侧音提取设备后,就能作为距离一距离变化率测量系统的一部份。 (5)采用了自补偿技术,使电缆和放大器传输特性的变化对测量准确度的影响减至最小。本文讨论了工作原理和地面站方框图。介绍了差值多普勒频移的研究结果,以及它们在设计准最佳检波电路方面的结构。地面站能够通过新式的光学和电子组合方法进行校准;本文介绍了利用通常的“回声”卫星而不是专门的飞机进行校准的方法。最后给出了数字性能数据。
Phase-locked interferometer combines the classic interferometer principle and the latest technology. The same applies to the standard MINITRACK and DIANE tracking networks for tracking quasi-circular orbits; however, as a dynamic matching receiver system, it can also work with beacons in high-eccentricity satellite orbits. The basic characteristics of the phase-locked interferometer are: (1) Correlated signal detection is adopted in each channel of the receiver to obtain a low detection threshold. Using the a priori information of the pre-orbit to design the LO frequency, a receiver that matches the dynamics of the satellite can be obtained. The combination of phase-locked detection and local oscillator programming provides effective protection against interference from other beacons working on adjacent frequencies. (2) The goniometer channel only processes the difference information relative to the common reference channel; it has the same structure and has a very narrow bandwidth. (3) The same wide-angle antenna can be used to perform precise angle measurement and ambiguity resolution since the sensitivity of the receiver and the narrow-band corrections are much better than those of the wide-beam antenna. This device enables the ground station to cover the entire airspace in both azimuth and elevation. (4) The phase-locked interferometer can measure the Doppler shift in addition to the directional angle and angular rate of change, so that when added with the sidetone extraction device for ambiguity resolution, it can be used as the distance-to-distance rate of change Part of the measurement system. (5) The self-compensation technique is used to minimize the influence of changes in the transmission characteristics of cables and amplifiers on measurement accuracy. This article discusses the principle of operation and the ground station block diagram. The research results of differential Doppler shift are introduced, and their structures in the design of quasi-optimal detection circuit are introduced. Ground stations can be calibrated using the new optical and electronic combination methods; this article describes ways to calibrate using the usual “echo” satellites rather than specialized aircraft. Finally, digital performance data is given.