Planning the Optimal Reference Flight Path of an Aircraft Using a Terrain Map

In connection with the development of aviation technology, the expansion of the functionality of modern aircraft and the complication of the tasks being solved, additional stringent requirements are imposed on the accuracy of air navigation. Along with high accuracy, navigation autonomy is also required. The autonomy of aircraft navigation implies the navigation of an aircraft without the use of active radar facilities. In this article, to calculate the optimal reference flight path of an aircraft in a horizontal plane, the Bellman dynamic programming method is proposed using a digital terrain map. A technique, algorithms have been developed, and a numerical experiment has been carried out using fragments of a digital terrain map. High accuracy and autonomy of navigation are necessary, among other things, to ensure stealth (invisibility) of aircraft by ground-based radar facilities of a potential enemy in low-altitude flight mode. The best stealth of an aircraft flight in a low-altitude flight mode is achieved not only by flying around, but also by avoiding obstacles, due to the shielding properties of the earth’s surface. Autonomy of navigation provides periodic correction of the reference flight path during long-term flight, and high accuracy prevents aircraft collisions with the earth’s surface in low-altitude flight mode. The purpose of this work is to select the optimal reference trajectory (route) of an aircraft flight in the low-altitude flight mode. This article discusses a method developed based on the principle of dynamic programming for calculating the reference flight path in the horizontal plane depending on the DEM and the implementation of the algorithm based on the proposed method with a specific numerical example. The method makes it possible to calculate the optimal flight route, which provides the greatest secrecy of the aircraft in the low-altitude flight mode using the screening properties of the earth’s surface irregularities. 

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