Simplified 3D city models from LiDAR

Aerial laser scan data is widely used to produce 2½D digital elevation models automatically. However, creating full 3D city models from this data is a complex task. A simplified 3D model, like a 2½D model with vertical walls will be easier to produce automatically, especially when the model is not produced to look nice, but just to give...

A study on methods to compare measured and calculated modal data

Fokker Space and Systems and the National Aerospace Laboratory NLR performed a study to integrate more systematically the experimental and analytical analysis of the dynamic behaviour of structures. The study focused on the correlation of experimental and analytical data, matrix and parameter updating methods. In this paper an overview will be...

Boundary-layer effects in unsteady pressure measurements with tubes

An experimental investigation revealed that the d5mamic response of a given pressure tube depends not only on the mean local pressure and the frequency, but also on the pressure amplitude and the boundary-layer at the tube entrance. By analyzing the flow at the entrance of the tube, the parameters are determined, which possibly play a role in...

Image data reduction with splines and segmentation with emphasis on earth observation

This report describes the results of a feasibility study on image data compression using spline approximation and image segmentation, with emphasis on earth observation applications. The main subjects dealt with, are: the data compression method, implementation aspects, the test software and test results. It appears that a reduction factor of 5...

Evaluation of a method to extract performance data from dynamic maneuvers for a jet transport aircraft

A very accurate measurement system and a data reduction method have been developed to extract performance data from a single dynamic maneuver, in order to reduce the large amoimt of flight hours required for the determination of these data by means of measurements in steady flight. In order to evaluate the applicability of this method to a modem...