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由于对运输直升机将来任务的要求,采用自备式导航系统是必要的。可能实现的导航精度应该优于已飞距离的0.5%(圆的误差概率)。为此,必须有一种高质量的多卜勒雷达和姿态基准惯性平台。这种姿态航向平台必须具备自对准能力,尤其重要的是快速地面对准。本文讨论了来自多卜勒平台的能够满足自对准和修正的导航要求的有关信息最佳运用的各种方法。对一般的地面和空中陀螺罗盘技术以及多卜勒惯性导航只作简略介绍。主要精力放在最佳的地面空中对准以及多卜勒惯性组合导航上。就最佳化而论,一种具有10～14元素状态矢量的卡尔曼滤波技术相当于一种基于递归或不递归的最小二乘方的简单数字滤波技术。这两种技术的比较说明,它们各自的特性在数量级上大致相同,但状态的确定是不同的。这里讨论最小二次乘方技术是因为它对机载计算机的容量要求比起卡尔曼滤波来说是非常之低的。该技术和卡尔曼滤波一样,都具有补尝由于初始未对准所引起的位置误差的能力。而且这一性能并不依赖于初始未对准的大小。卡尔曼滤波器的一个优点就是当多卜勒偏差出现时它能够同时修正多卜勒和指北陀螺(这种优点是最小二次乘方技术所没有的。)建议使用的系统采用最小二次乘方技术。介绍一种假设时间为2～3分钟的地面对准的多卜勒惯性导航的工作方式,并且考虑了该系统在地面空中对准中对计算机容量的要求。
Owing to the requirements of the mission of transporting helicopters in the future, it is necessary to adopt a self-contained navigation system. Possible navigation accuracy should be better than 0.5% of the distance traveled (circular error probability). For this reason, there must be a high quality Doppler radar and attitude reference inertial platform. This attitude heading platform must have self-alignment capabilities, especially important is rapid ground alignment. This article discusses the various ways in which information from the Doppler platform can best meet the self-aligning and revising navigation requirements. Only a brief introduction to the general ground and gyro compass technology and Doppler inertial navigation. The main focus on the best ground aerial alignment and Doppler inertial integrated navigation. As far as optimization is concerned, a Kalman filtering technique with 10-14 element state vectors is equivalent to a simple digital filtering technique based on recursive or non-recursive least squares. The comparison of these two techniques shows that their respective characteristics are approximately the same in magnitude, but the determination of states is different. The least squares technique discussed here is because its capacity requirements for onboard computers are very low compared to Kalman filtering. Like Kalman filtering, this technique has the ability to compensate for positional errors due to initial misalignment. And this performance does not depend on the size of the initial misalignment. One of the advantages of a Kalman filter is that it can correct Doppler and North gyro gyros simultaneously with the Doppler shift (this advantage is not available with the least-squares power technique.) The proposed system uses a minimum quadratic Power technology. A method of operating Doppler inertial navigation with 2 to 3 minutes of ground time assuming time is introduced and the computer capacity requirements of the system in ground-air alignment are considered.