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...

Representation and Reconstruction of Triangular Irregular Networks with Vertical Walls

Point clouds obtained by aerial laser scanning are a convenient input source for high resolution 2.5d elevation models, such as the Dutch AHN-2. More challenging is the fully automatic reconstruction of 3d city models. An actual demand for a combined 2.5d terrain and 3d city model for an urban hydrology application led to the design of an...

Vibration measurement of a model wind turbine using high speed photogrammetry

We investigate the application of the photogrammetric approach to measuring the vibration of a model wind turbine in a sequence of stereo image pairs acquired by high speed cameras. The challenge of the photogrammetric measurement of a highly dynamic phenomenon is the efficiency of the point measurement process in a large number of images. We...

A new method for individual tree delineation and undergrowth removal from high resolution airborne LiDAR

High density airborne LiDAR, for example FLI-MAP 400 data, has opened an opportunity for individual tree measurement. This paper presents a method for individual tree delineation and undergrowth vegetation removal in forest area. The delineation of individual trees involves two steps namely 1) tree crown delineation based on density of high...

Roof plane extraction in gridded digital surface models

With the rapid improvement of LIDAR systems regarding point density and accuracy in relation to the (application dependent) requirements, robustness, efficiency and automation of the modeling process are becoming more important than achieving the highest possible accuracy and modeling detail from the available LIDAR data. Therefore we opt for...

Registering pointclouds of polyhedral buildings to 2D maps

This paper presents a method for automated pointcloud-to-map registration using a plane matching technique. The registration is based on estimating a transformation between a set of planes inferred from the map and their corresponding planes extracted from the pointcloud. A plane matching algorithm is developed to search for corresponding planes...

Tree crown delineation from high resolution airborne LiDAR based on densities of high points

Tree detection and tree crown delineation from Airborne LiDAR has been focusing mostly on utilizing the canopy height model (CHM). This paper presents a method for individual tree crown delineation based on densities of high points (DHP) from the high resolution Airborne LiDAR. The DHP method relies on the fact that the density of received laser...

Tree filtering for high density airborne LiDAR data

A high resolution Airborne LiDAR data creates better opportunity for an individual tree measurement and provides valuable results for more precise forest inventory. This paper presents tree filtering approach that able to separate dominant tree and undergrowth vegetation. The results can be used for a detailed individual tree measurement. This...

Individual tree detection based on densities of high points of high resolution airborne lidar

The retrieval of individual tree location from Airborne LiDAR has focused largely on utilizing canopy height. However, high resolution Airborne LiDAR offers another source of information for tree detection. This paper presents a new method for tree detection based on high points’ densities from a high resolution Airborne LiDAR. The advantage of...

Improving 2D change detection by using available 3D data

Change detection with very high resolution imagery is difficult, because 3D objects as buildings appear differently in 2D imagery due to varying viewing angles and sun positions. This research proposes a method to improve change detection by using simple 3D models of buildings. Buildings have been modelled as flat roof or gable roof buildings....

Energy function behavior in optimization based image sequence stabilization in presence of moving objects

In this paper, we address the registration of two images as an optimization problem within indicated bounds. Our contribution is to identify such situations where the optimum value represents the real transformation parameters between the two images. Consider for example Mean Square Error (MSE) as the energy function: Ideally, a minimum in MSE...

Reducing the error in terrestrial laser scanning by optimizing the measurement set-up

High spatial resolution and fast capturing possibilities make 3D terrestrial laser scanners widely used in engineering applications and cultural heritage recording. Phase based laser scanners can measure distances to object surfaces with a precision in the order of a few millimeters at ranges between 1 and 80 m. However, the quality of a laser...

FLI-MAP data possibilities for forest inventory

Optimization based image registration in the presence of moving objects

3D Buildings Modelling Based on a Combination of Techniques and Methodologies

Three dimensional architectural models are more and more important for a large number of applications. Specialists look for faster and more precise ways to generate them. This paper discusses methods to combine methodologies for handling data acquired from multiple sources: maps, terrestrial laser and additional measurements, together with...