The benefits of GNSS have created dependencies on navigation in modern day aviation systems. Many of these systems operate with no backup navigation source. This makes the capabilities supported by precise navigation vulnerable. This paper investigates a contemporary approach to terrain‐referenced navigation (TRN), used to preserve an aircraft's navigation solution during periods of GNSS denial. Traditionally, TRN has been accomplished using a single measurement sensor pointed nadir to an aircraft. Although shown to be effective, this approach limits the achievable navigation accuracy by restricting the measurable terrain gradients to those below an aircraft. This paper explores an alternative approach to TRN that maximizes navigation information through optimal steering of a gimbaled laser. A Cramér‐Rao lower bound analysis as well as a high‐fidelity simulation establishes the utility of optimal steering while employing TRN. This original approach to TRN shows the order of magnitude improvements in navigation performance over existing methods.

中文翻译：

---

使用可控激光测量传感器进行地形参考导航

GNSS的好处已导致对现代航空系统中导航的依赖。这些系统中的许多系统都没有备用导航源。这使得精确导航支持的功能易受攻击。本文研究了一种现代的地形参考导航（TRN）方法，该方法用于在GNSS被拒绝期间保留飞机的导航解决方案。传统上，TRN是通过将最低点指向飞机的单个测量传感器来完成的。尽管被证明是有效的，但是该方法通过将可测量的地形梯度限制为飞机下方的地形梯度，限制了可达到的导航精度。本文探讨了TRN的替代方法，该方法通过对万向节激光器的最佳控制来最大化导航信息。Cramér-Rao下限分析以及高保真模拟在采用TRN的同时确立了最佳转向的效用。TRN的原始方法显示出导航性能比现有方法提高了一个数量级。