Modelling the Erechteion

Extracting Information from Very Large Datasets

Modern terrestrial laser scanners (TLS) generate between 10 and 50 million 3D coordinates per minute: about 500Mbytes of data. Together with high-resolution images for texturing purposes, this is enough information to choke high-end PCs running commercial software. The National Research Council in Canada has developed a framework for extracting information from very large TLS and imagery datasets, an evolution demonstrated in the Erechtheion project. This monument has been modelled in 3D to a spatial resolution of 2mm. The fully textured 3D model containing 348 million polygons can be interactively visualised and analysed in real time. Creation of an accurate... (read more)

2009-12-04 11:26:58

Watershed Modelling in Kentucky

The recently completed Kentucky Watershed Modeling Information Portal (KWMIP), funded through a 750,000USD Co-operative Agreement with the US Environmental Protection Agency (EPA), is an innovative, standards-based data provisioning portal for watershed modellers in the Commonwealth of Kentucky, USA. The portal is integrated with the Kentucky Division of Geographic Information (DGI) web mapping services - KYGeonet (http://kygeonet.ky.gov), KYRaster and KYVector, served over state government LAN, and the US Geological Survey (USGS) StreamStats (http://streamstats.usgs.gov/html/idaho.html). It uses data from the Kentucky Climate Data Generator portals and the EPA’s Environmental Information Exchange Network (EIEN) and STORET (STOrage and RETrieval) repository for water-quality, biological and... (read more)

2006-11-20 12:00:00

Propagation Modelling Accuracy

Mentum and Intermap Technologies, USA, have entered into a collaboration for the delivery of a new generation of height-attributed land-use geodata that addresses the propagation modelling needs of the wireless industry. The telecom-grade product, Cityscapes HD, offers an unmatched level of X, Y and Z accuracy at a price point that enables network operators to manage the large geographical areas required by today's wireless networks. Cityscapes HD is offered at a native resolution of 15m and is available immediately in the USA, Western Europe and parts of Asia. Cityscapes HD accurately includes the height of vegetation and man-made structures... (read more)

2011-12-13 09:51:25

Long Live Modelling!

An Assessment of the LADM from the Cadastre 2014 Perspective

The Land Administration Domain Model (LADM) makes a significant contribution to understanding the importance of data modelling in the domain of land, land administration and land management. The ‘Cadastre 2014’ vision of the International Federation of Surveyors (FIG) stated back in 1998: “Cadastral mapping will be dead! Long live modelling!”. While one might think that this message was clear enough, few professional colleagues took it seriously. The editorial team of the LADM were the first to undertake action to get to the bottom of this important issue. Now that the LADM has become an official ISO standard, that statement is... (read more)

2013-07-09 04:47:47

GIS for Hydrological Modelling

Gagetown Hydrologic Model

Estimating rainfall discharge is difficult in large catchment areas with varying topography. This leads to widespread inadequacy in culvert design, with resultant damage to these and other drainage infrastructure during storms, when water runoff is high. The authors developed three ArcGIS-based hydrological models which accurately estimate rainfall discharge for storms that occur anywhere between once every two weeks up to once a century, enabling improvements in culvert infrastructure design. The test results prove the potential for GIS to aid in the creation of highly accurate hydrological models. Although there have been hydrological models in existence for decades, we designed our... (read more)

2011-06-28 04:05:50

REDD Deforestation Modelling Video

Clark Labs of Clark University has added a new video to the video series on its website. This latest video, entitled REDD Deforestation Modelling with Land Change Modeller in IDRISI, introduces the new REDD modelling feature tool included in the latest release of IDRISI, the Selva Edition. This video demonstrates how to model baseline land cover change and to predict future scenarios, as well as how these scenarios will impact projected GHG emissions through the implementation of a REDD project. A REDD project proposal, or the Project Design Document submitted to the Verified Carbon Standard (VCS) Organization, requires maps and... (read more)

2012-03-05 10:31:13

Lidar and Sound Modelling

Improving Existing Propagation Models

Simulation of sound propagation is key for today’s urbanised society, in which sound is omnipresent and often negatively affects people’s lives. Existing methods of sound-propagation modelling fail to capture the complexity of terrain. Airborne Lidar in conjunction with aerial photos is able to fill this gap. The authors propose a programme of research to find out how high-resolution terrain data might improve the efficiency of sound models. Sound propagation is affected by obstructing objects such as buildings and trees, and influenced by the relative location of sound source and receiver, type of intermediate ground and meteorological conditions. Computation of sound... (read more)

2007-08-11 12:00:00

Modelling REDD Baselines

Clark Labs has recently published a Focus Paper on modeling REDD baselines with the Land Change Modeller application in their IDRISI GIS and Image Processing software. Reducing Emissions from Deforestation and Forest Degradation (REDD) is a climate change mitigation strategy for the protection and maintenance of forests that has gained momentum with conservation organisations, project developers and governments in developing countries. As forests play a major role in the sequestration of carbon, especially tropical forests, REDD offers great potential for reducing greenhouse gas emissions. Carbon offset payments, based on an assigned financial value for the likely carbon storage capacity of... (read more)

2010-07-02 10:05:14

Geospatial Analysis and Modelling

The development of GIS and carto-graphy can be characterised as information rich and knowledge poor. That is, the amount of geospatial information collected using geospatial technologies, including remote sensing, global positioning systems and digital mapping technology, has been growing rapidly, whereas geospatial knowledge or ‘useful information’, for decision making in terms of real-world problem solving is rather limited. Terabytes of geospatial information in the form of satellite imagery, aerial photos and maps have been integrated into Google Maps and Google Earth so that ordinary people using a decent internet-connected home computer can zoom from space right down to street level... (read more)

2006-11-20 12:00:00

Modelling Facade Geometry

Facade Recognition Using Mobile Laser Scanner Data

Due to the rapid changes of urbanisation, up-to-date, complex and realistic building models enriched with facade features are increasingly in demand in many countries. The Mobile Laser Scanning technique is progressively being used to capture objects in urban settings and it is becoming a leading source for modelling of facade geometry. This article describes an efficient and cost-effective method for automatically extracting and recognising building-facade features from a complex city environment using MLS point clouds. Mobile Laser Scanning (MLS) is a state-of-the-art technology for accurately and densely capturing the 3D geometry of various objects as 3D point clouds over large... (read more)

2013-10-28 02:03:48