Multiple incidence angle SIR-B experiment over Argentina

The Shuttle Imaging Radar (SIR-B), the second synthetic aperture radar (SAR) to fly aboard a shuttle, was launched on October 5, 1984. One of the primary goals of the SIR-B experiment was to use multiple incidence angle radar images to distinguish different terrain types through the use of their characteristic backscatter curves. This goal was accomplished in several locations including the Chubut Province of southern Argentina. Four descending image acquisitions were collected providing a multiple incidence angle image set. The data were first used to assess stereo-radargrammetric techniques. A digital elevation model was produced using the optimum pair of multiple incidence angle images. This model was then used to determine the local incidence angle of each picture element to generate curves of relative brightness vs. incidence angle. Secondary image products were also generated using the multi-angle data. The results of this work indicate that: (1) various forest species and various structures of a single species may be discriminated using multiple incidence angle radar imagery, and (2) it is essential to consider the variation in backscatter due to a variable incidence angle when analyzing and comparing data collected at varying frequencies and polarizations

Building Façade Separation in Vertical Aerial Images

Three-dimensional models of urban environments have great appeal and offer promises of interesting applications. While initially it was of interest to just have such 3D data, it increasingly becomes evident that one really would like to have interpreted urban objects. To be able to interpret buildings we have to split a visible whole building block into its different single buildings. Usually this is done using cadastral information to divide the single land parcels. The problem in this case is that sometimes the building boundaries derived from the cadastre are insufficiently accurate due to several reasons like old databases with lower accuracies or inaccuracies due to transformation between two coordinate systems. For this reason it can happen that a cadastral boundary coming from an old map is displaced by up to several meters and therefore divides two buildings incorrectly. To overcome such problems we incorporate the information from vertical aerial images. We introduce a façade separation method that is able to find individual building façades using multi view stereo. The purpose is to identify the individual façades and separate them from one another before on proceeds with the analysis of a façade’s details. The source was a set of overlapping, thus “redundant ” vertical aerial images taken by an UltraCam digital aerial camera. Therefore in a first step we determine the building block outlines using the building classification and use the height values from the Digital Surface Model (DSM) to determine approximate “façade quadrilaterals”. We also incorporate height discontinuities using the height profiles along the building outlines to enhance our façade separation. In a next step we detect repeated pattern in these “façade images ” and use them to separate the façades respectively building blocks from one another

Venus surface roughness and Magellan stereo data

Presented are results of some studies to develop tools useful for the analysis of Venus surface shape and its roughness. Actual work was focused on Maxwell Montes. The analyses employ data acquired by means of NASA's Magellan satellite. The work is primarily concerned with deriving measurements of the Venusian surface using Magellan stereo SAR. Roughness was considered by means of a theoretical analyses based on digital elevation models (DEM's), on single Magellan radar images combined with radiometer data, and on the use of multiple overlapping Magellan radar images from cycles 1, 2, and 3, again combined with collateral radiometer data

3-Dimensional Building Details from Aerial Photography for Internet Maps

This paper introduces the automated characterization of real estate (real property) for Internet mapping. It proposes a processing framework to achieve this task from vertical aerial photography and associated property information. A demonstration of the feasibility of an automated solution builds on test data from the Austrian City of Graz. Information is extracted from vertical aerial photography and various data products derived from that photography in the form of a true orthophoto, a dense digital surface model and digital terrain model, and a classification of land cover. Maps of cadastral property boundaries aid in defining real properties. Our goal is to develop a table for each property with descriptive numbers about the buildings, their dimensions, number of floors, number of windows, roof shapes, impervious surfaces, garages, sheds, vegetation, presence of a basement floor, and other descriptors of interest for each and every property of a city. From aerial sources, at a pixel size of 10 cm, we show that we have obtained positional accuracies in the range of a single pixel, an accuracy of areas in the 10% range, floor counts at an accuracy of 93% and window counts at 86% accuracy. We also introduce 3D point clouds of facades and their creation from vertical aerial photography, and how these point clouds can support the definition of complex facades

Time for Neo-Photogrammetry

https://stars.library.ucf.edu/cfm-ch-register-vol16/1489/thumbnail.jp

Column generation at strip level for the K-staged two-dimensional Cutting Stock Problem

Zusammenfassung in deutscher SpracheViele industrielle Anwendungen existieren für das Packen von kleineren Objekten in größere Behälter, so-genannte Bins, sodass die Anzahl der verwendeten Bins minimal ist. Beispiele sind die Holz, Metall oder Glass Industrien, in der die Kundenbestellungen aus größeren Stücken Lagermaterial zugeschnitten werden müssen.Wenn sowohl Bins, als auch die kleineren Objekte, so-genannte Elements, rechteckig sind, ist vom 2-dimensionalem Bin Packing Problem (2BP) bzw. dem 2-dimensionalem Cutting Stock Problem (2CS) die Rede. In dieser Diplomarbeit werden weiters nur so-genannte Guillotinenschnitte erlaubt, was orthogonale Schnitte von einer Seite des Bins zur anderen sind. Diese Schnitte haben zur Folge, dass man das 2CS weiters über ihre Anzahl an Stages definieren kann, die mit K bezeichnet wird. Ein Stage ist hier eine Reihe paralleler Schnitte. Das Ziel dieser Diplomarbeit ist es, eine neue Variante von Column Generation für das 2-staged und 3-staged 2CS zu präsentieren, die auf der Generation von so-genannten Strips basiert. Zuerst wird das Problem formal definiert, und das Prinzip der Column Generation genauer erläutert. Darauf folgt eine Untersuchung der Litertur über das 2CS. Literatur zu dem Knapsack Problem wird auch vorgestellt, da es sich dabei um ein relevantes Subproblem der Column Generation handelt. Dies beinhaltet Varianten für das Unbounded als auch für das Bounded Knapsack Problem (UKP und BKP). Danach wird das Stage Shifted Column Generation (SSCG) präsentiert. Dazu gehören Definitionen für das Master Problem als auch für die relevanten Pricing Probleme für den Fall K = 2 und K = 3. Das Master Problem wird als ILP formuliert, genauer einem Set Covering Problem, während die Pricing Probleme Varianten eines Knapsack Problems darstellen. Für das UKP wird der effiziente algorithmus EDUK implementiert, während für das BKP ein neuer Algorithmus vorgestellt wird, der den gesamten Knapsack immer Element für Element bearbeitet, und BKP-Generator heißt. Für K = 3 wird BKP-Generator adaptiert, und DP-Generator genannt. Zwei Heuristiken, die auf der Randomisierung von DP-Generator beruhen, werden ebenfalls vorgestellt. Es wird außerdem eine Integrality Heuristic vorgestellt, da die Ergebnisse des Master Problems meist nicht integral sind. Die verschiedenen Pricing Probleme werden experimentell miteinander, und mit einer Insertion Heuristic als auch einer Dynamic Programming Implementation verglichen. Die Resultate zeigen gute Lösungen für die LP Relaxierung, und auch die integralen Lösungen können teils besser als die vorherigen Implementationen sein.Several industrial applications exist for packing non overlapping objects, called elements, into larger objects, called bins, such that the total number of used bins is minimal. Examples are wood, metal and glass industries, where the customers- orders must be cut from larger pieces of stock material. Particularly when high volumes of stock material are used, even small improvements can directly increase profitability. Assuming both elements and bins are rectangular, the problem is called the 2-dimensional bin packing problem (2BP) or cutting stock problem (2CS), both of which are NP-hard. Only guillotine cuts are allowed, which are orthogonal cuts from one side to another. This leads to a further specification of the 2CS, which is the number of stages it allows, denoted by K. A stage is a series of parallel cuts. The aim of this thesis is to present an efficient implementation of a new strip-based column generation approach for the 2-staged and 3-staged 2CS with guillotine cuts. First, the problem and column generation are introduced and formally defined. This is followed by a study of relevant literature concerning the 2CS and 2BP. Literature for the knapsack problem is also studied, as this is a relevant subproblem of column generation. This includes variants of dynamic programming both for the unbounded and bounded knapsack problem (UKP and BKP). After that, the Stage Shifted Column Generation (SSCG) is presented. This entails both definitions for the master problem and the relevant pricing problems for K = 2 and K = 3. The master problem is formulated as a set covering problem, while the pricing problems are variants of knapsack problems. EDUK is an efficient implementation for the UKP, while a new algorithm is developed for the BKP, called BKP-Generator. It essentially processes the entire knapsack element by element. For K = 3, BKP-Generator is adapted, and called DP-Generator. Two heuristic algorithms are also presented, which rely on randomizing DP-Generator. Finally, an integrality heuristic is introduced, as the master problem offers possibly fractional results. The different pricing problems are experimentally tested and compared to an insertion heuristic and a dynamic programming implementation. The results show good LP relaxed solutions, and integral results are competitive with previous implementations.7