In this paper, we describe, analyze and compare techniques for extracting spatial knowledge from a terrain model. Specifically, we investigate techniques for extracting a morphological representation from a terrain model based on an approximation of a Morse-Smale complex. A Morse-Smale complex defines a decomposition of a topographic surface into regions with vertices at the critical points and...

This review examines methods of terrain representation, creation and realism described in literature. In particular a combination of terrain synthesis using Fractional Brownian Motion, and erosion procedures is examined, as well as the procedural formation of rivers. Other techniques as examined, such as Triangulated Irregular Networks and ridges generation and discarded in terms of this projec...

Working with an existing wireless network simulator, we describe the addition of both a method for modeling arbitrary terrain, and for calculating signal attenuation with the Irregular Terrain Model (ITM). We also investigate ITM’s effects on upper protocol layer in comparison to the Two-Ray Ground Reflection model. Upon examination, it was found that aside from the terrain between the transmit...

Focusing on the visual effect deficiency in the application of standard LOD algorithm for 3D landscape design, 3D landscape designing model based on terrain complexity collision and shading rendering is built in this paper. First, 3D landscape design models are devided into two categories, regular terrain and irregular terrain, and different rules are respectively adopted during model building....

In this paper we describe a new high speed method for the calculation of UHF propagation over irregular terrain which is considered to be a homogeneous dielectric. The method, given that it is rigorous and includes both forward and back scattering, is very fast. The antenna pattern, tilt etc. may be specified arbitrarily. As expected, results compare very well with measurements in the case when...

We consider the problem of extracting the morphology of a terrain represented as a Triangulated Irregular Network (TIN). Our reference framework to model terrain morphology is given by the descending and the ascending Morse complexes, which define a decomposition of the terrain through its critical points and integral lines. We review several algorithms proposed in the literature to extract des...

Robotics can play a key role when dealing with environments that are inaccessible or hazardous for humans including ship hulls, bridge installations, oil rigs, and first reponse scenarios. Due to irregular terrain, wheeled vehicles are ineffective at traversing the necessary terrain. Legged systems are a salient solution. However, legged systems require special considerations regarding workspac...

This paper describes a new approach in modeling of sand surface. The terrain model is based on a triangulated irregular network while existing solutions have been based on a regular grid. Memory consumption is significantly reduced without a regular grid at the expense of more complicated algorithms. Our solution allows deforming terrain by a set of virtual tools and erosion simulation. All the...