On the Choice of Base Geometry, Type and Design of the Passive Radio Reflector of the Passive Radar Complex

The article presents the methods that allow to solve the problem of choosing the type, design and installation location of a control terrain feature (CTF) – a passive radio reflector for a passive location complex that implements the angle measuring-range-difference method. The CTF module must reflect the signal at angles from 0° to 180° (upper hemisphere). The rationale for choosing the CTF module and base geometry will allow receiving signals from jammers from any direction relative to the main receiving point

Sand Mountain

This chapter describes both the completion of and collapse of the Bridgeport bridge, throwing William Rosecrans’s timetable for the advance of the Army of the Cumberland beyond the Tennessee River into serious disarray. Unaware of Rosecrans’s logistical problems, Braxton Bragg continued to concentrate the Army of Tennessee at Chattanooga for offensive movement. While Bragg pondered his options, units of the Army of the Cumberland crossed another major terrain feature, Sand Mountain, and headed for the next obstacle, Lookout Mountain. A Federal crossing of Lookout Mountain would effectively outflank Bragg in Chattanooga.

Progressive Contours Simplification Approach Constrained by Terrain Feature

To maintain terrain details during contour group simplification, a progressive simplification approach is proposed. First, terrain feature points and lines are extracted from contours. Second, both the extracted terrain feature points and lines are taken as constraints and quantified as control variables. At last with the idea of progressive graphics simplification, the non-feature points, feature points, feature lines and their associated curves on contours are selected or deleted progressively to realize dynamic simplification of contours. Experimental results show that this approach can effectively improve the intellectualized degree of contours simplification.

Terrain Real-Time Rendering Based on Projected Grid and GPU Unsaturated Error Metric

To render terrain realistically and efficiently, we firstly introduce projected grid to construct terrain coarse meshes. Projected grid uses longest edge bisection, taking advantages of fracture eliminating, to implement triangle subdivision. To realize adaptive refinement of terrain coarse meshes, we introduce the concept of bounding sphere and the idea of unsaturated error metric, design GPU unsaturated error metric based on bounding sphere, in order to implement terrain LOD modeling finally. Experimental results show that projected grid avoids culling and improves the speed of terrain rendering, GPU unsaturated error metric can select terrain coarse meshes nodes accurately, reduce triangles number and keep terrain feature. As a result, the algorithm can achieve a high FPS and a good visual effect, implement terrain real-time rendering.