In this study, we propose an automatic approach for tree detection and classification in registered 3-band aerial images and associated digital surface models (DSM). The tree detection results can be used in 3D city modelling and urban planning. This problem is magnified when trees are in close proximity to each other or other objects such as rooftops in the scenes. This study presents a method for locating individual trees and estimation of crown size based on local maxima from DSM accompanied by color and texture information. For this purpose, segment level classifier trained for 10 classes and classification results are improved by analyzing the class probabilities of neighbour segments. Later, the tree classes under a certain height were eliminated using the Digital Terrain Model (DTM). For the tree classes, local maxima points are obtained and the tree radius estimate is made from the vertical and horizontal height profiles passing through these points. The final tree list containing the centers and radius of the trees is obtained by selecting from the list of tree candidates according to the overlapping and selection parameters. Although the limited number of train sets are used in this study, tree classification and localization results are competitive.
PC based Flight Simulators (PC-FS) have been appeared as alternative training devices for pilot training to Enhanced
Flight Simulators due to their low cost and absolute availability. Visuals presented in PC-FS are adequate for aircraft
pilot training; this is not true for helicopter pilot training due to too low altitudes and speeds. Especially for hovering,
increased visual quality is required because of extremely low altitude (3-15 feet) and small movements. In this project,
two experiments were conducted by using simple PC-FS as a test platform and professional helicopter pilots as subjects
in order to evaluate the effect of hyper texturing on hovering performance. Results have revealed that the level of texture
resolution has no direct effect on hovering performance. Optimum texture resolution is dependent upon noticability,
recognizability and size of the 2D objects presented by textured image.
Generation of crowded realistic scenes that include thousands of 3D objects for low altitude flights is not a widely covered topic. In this study we tried to generate immersive and dynamic realistic scenes for low altitude flights by using low cost PC configuration. At the end of the study encouraging results were obtained. Some features offered by high-end image generators regarding out-the-window scene were transported into our implementation. Hundreds of moving human beings, vehicles with realistic motion and very dense forests are rendered at interactive frame rates resulting in a low cost/high performance application. Limited number of pilots reviewed the scenes generated by our application and were satisfied.