Aligning archive maps and extracting footprints for analysis of historic urban environments.

Archive cartography and archaeologist's sketches are invaluable resources when analysing a historic town or city. A virtual reconstruction of a city provides the user with the ability to navigate and explore an environment which no longer exists to obtain better insight into its design and purpose. However, the process of reconstructing the city from maps depicting features such as building footprints and roads can be labour intensive. In this paper we present techniques to aid in the semi-automatic extraction of building footprints from digital images of archive maps and sketches. Archive maps often exhibit problems in the form of inaccuracies and inconsistencies in scale which can lead to incorrect reconstructions. By aligning archive maps to accurate modern vector data one may reduce these problems. Furthermore, the efficiency of the footprint extraction methods may be improved by aligning either modern vector data or previously extracted footprints, since common elements can be identified between maps of differing time periods and only the difference between the two needs to be extracted. An evaluation of two alignment approaches is presented: using a linear affine transformation and a set of piecewise linear affine transformations

Data visualization within urban models

Models of urban environments have many uses for town planning, pre-visualization of new building work and utility service planning. Many of these models are three-dimensional, and increasingly there is a move towards real-time presentation of such large models. In this paper we present an algorithm for generating consistent 3D models from a combination of data sources, including Ordnance Survey ground plans, aerial photography and laser height data. Although there have been several demonstrations of automatic generation of building models from 2D vector map data, in this paper we present a very robust solution that generates models that are suitable for real-time presentation. We then demonstrate a novel pollution visualization that uses these models

Integration of LIDAR and IFSAR for mapping

LiDAR and IfSAR data is now widely used for a number of applications, particularly those needing a digital elevation model. The data is often complementary to other data such as aerial imagery and high resolution satellite data. This paper will review the current data sources and the products and then look at the ways in which the data can be integrated for particular applications. The main platforms for LiDAR are either helicopter or fixed wing aircraft, often operating at low altitudes, a digital camera is frequently included on the platform, there is an interest in using other sensors such as 3 line cameras of hyperspectral scanners. IfSAR is used from satellite platforms, or from aircraft, the latter are more compatible with LiDAR for integration. The paper will examine the advantages and disadvantages of LiDAR and IfSAR for DEM generation and discuss the issues which still need to be dealt with. Examples of applications will be given and particularly those involving the integration of different types of data. Examples will be given from various sources and future trends examined

Automated 3D generation and rendering of stylized building designs

Thesis (S.B. in Art and Design)--Massachusetts Institute of Technology, Dept. of Architecture, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 29).The entertainment industry relies fairly heavily on computer-generated imagery to depict built environments in current films, video games, and other forms of simulated reality. These often involve highly complex geometries that take a long time to hand-model and are too difficult or costly for many productions' rendering capacities, both in computational costs as well as time. Procedural modeling and the automation of these geometries is one option to solve these problems. Many modeling programs involve a script or procedural modeling component. This thesis explores the use of CityEngine, a commercially available software that is specialized to generate geometries for buildings in urban environments. By using the CGA Shape Grammar built into CityEngine, this project seeks to generate geometries based on complex architectural precedents using a procedural modeling system based on shape grammar and computational design principles. Results are generated and discussed, as well as applications and future work.by Anisha V. Deshmane.S.B.in Art and Desig

Information Rich 3D Computer Modeling of Urban Environments

We are living in an increasingly information rich society. Geographical Information Systems now allow us to precisely tag information to specific features, objects and locations. The Internet is enabling much of this information to be accessed by a whole spectrum of users. At CASA we are attempting to push this technology towards a three-dimensional GIS, that works across the Internet and can represent significant chunks of a large city. We believe that the range of possible uses for such technology is diverse, although we feel that urban planning is an area that can benefit greatly. An opportunity to push this “planning technology” arose when CASA won a tender from Hackney Council to develop a dynamic website for community participation in the process of regenerating the Woodberry Down Estate. This is a run down part of northeast London that is undergoing a major redevelopment. CASA has developed a system that not only informs the local residents about the redevelopment process but it also enables them to use dynamic visualisations of the “before and after effects” of different plans, and then to discuss and vote on the variety of options

Towards a 20m global building map from Sentinel-1 SAR Data

This study introduces a technique for automatically mapping built-up areas using synthetic aperture radar (SAR) backscattering intensity and interferometric multi-temporal coherence generated from Sentinel-1 data in the framework of the Copernicus program. The underlying hypothesis is that, in SAR images, built-up areas exhibit very high backscattering values that are coherent in time. Several particular characteristics of the Sentinel-1 satellite mission are put to good use, such as its high revisit time, the availability of dual-polarized data, and its small orbital tube. The newly developed algorithm is based on an adaptive parametric thresholding that first identifies pixels with high backscattering values in both VV and VH polarimetric channels. The interferometric SAR coherence is then used to reduce false alarms. These are caused by land cover classes (other than buildings) that are characterized by high backscattering values that are not coherent in time (e.g., certain types of vegetated areas). The algorithm was tested on Sentinel-1 Interferometric Wide Swath data from five different test sites located in semiarid and arid regions in the Mediterranean region and Northern Africa. The resulting building maps were compared with the Global Urban Footprint (GUF) derived from the TerraSAR-X mission data and, on average, a 92% agreement was obtained.Peer ReviewedPostprint (published version

Modelling of building interiors with mobile phone sensor data

Creating as-built plans of building interiors is a challenging task. In this paper we present a semi-automatic modelling system for creating residential building interior plans and their integration with existing map data to produce building models. Taking a set of imprecise measurements made with an interactive mobile phone room mapping application, the system performs spatial adjustments in accordance with soft and hard constraints imposed on the building plan geometry. The approach uses an optimisation model that exploits a high accuracy building outline, such as can be found in topographic map data, and the building topology to improve the quality of interior measurements and generate a standardised output. We test our system on building plans of five residential homes. Our evaluation shows that the approach enables construction of accurate interior plans from imprecise measurements. The experiments report an average accuracy of 0.24 m, close to the 0.20 m recommended by the CityGML LoD4 specificatio

Immersive GeoDesign: Exploring the Built Environment through the Coupling of GeoDesign, 3D Modeling, and Immersive Geography

GeoDesign is a relatively new field that serves as a repurposing of many different disciplines concerned with design decisions about the built environment. More specifically, GeoDesign represents a coupling of urban planning concepts with the analytical capabilities of GIS. While GIS has been used in planning mostly in the two-dimensional realm, the built environment is three-dimensional and challenges GIS in the handling of the vertical dimension, notably in floor-by-floor uses in mixed-use developments, basement-level parking, light capture, and intervisibility between structures. This research advances GeoDesign by addressing these three-dimensional issues through the utilization of highly-detailed 3D models using Trimble SketchUp, the mass-model generation power of ERSI\u27s CityEngine, and the immersive Geo-Virtual CAVE at West Virginia University to explore these issues through an Immersive GeoDesign case study of the city of Morgantown, WV

Procedural 3D urban content generation in simulation and games

As virtual urban environment generation becomes a widespread research topic, the need to create enriched urban worlds, which group both the geometric and semantic properties has become a necessity, the purpose being to obtain interactive, adaptive and consistent world entities. This paper suggests a representational model of urban environment generation based on both geometric and semantic knowledge, the future work being to create a modelling tool of a 3D urban environment, which stores the semantic information and allows the final non expert user to acquire information about the environment before and after its creation and to explore this information in an interactive way

Modelling platform for schools (MPS): The development of an automated One-By-One framework for the generation of dynamic thermal simulation models of schools

The UK Government has recently committed to achieve net zero carbon status by year 2050. Schools are responsible for around 2% of the UK’s total energy consumption, and around 15% of the UK public sector’s carbon emissions. A detailed analysis of the English school building stock’s performance can help policymakers improve its energy efficiency and indoor environmental quality. Building stock modelling is a technique commonly used to quantify current and future energy demand or indoor environmental quality performance of large numbers of buildings at the neighbourhood, city, regional or national level. ‘Building-by-building’ stock modelling is a modelling technique whereby individual buildings within the stock are modelled and simulated, and performance results are aggregated and analysed at stock level. This paper presents the development of the Modelling Platform for Schools (MPS) – an automated generation of one-by-one thermal models of schools in England through the analysis and integration of a range of data (geometry, size, number of buildings within a school premises etc.) from multiple databases and tools (Edubase/Get Information About Schools, Property Data Survey Programme, Ordanance Survey and others). The study then presents an initial assessment and evaluation of the modelling procedure of the proposed platform. The model evaluation has shown that out of 15,245 schools for which sufficient data were available, nearly 50% can be modelled in an automated manner having a high level of confidence of similarity with the actual buildings. Visual comparison between automatically-generated models and actual buildings has shown that around 70% of the models were, indeed, geometrically accurate