Target audiences, media and messages for SDI training

This article aims to report on research conducted to identify the different target audiences and corresponding SDI education and training media and messages that will contribute towards the development of the South African Spatial Data Infrastructure (SASDI)… (more)

GNSS applications for agricultural practices

Global positioning systems are relatively new technologies when it comes to applications in agriculture. Applications in tractor guidance, variable rate supply of chemical inputs and field monitoring of crop yield were recently tested using GPS. This article studies the basic concepts of GPS as they apply to agricultural production and provides a detailed analysis of the recent developments in this area with a focus on functionality and efficiency… (more)

Towards a secure, competitive and sustainable electricity future

Some years ago, a senior Eskom Executive told me that at the heart of Eskom’s business model was “big coal, big nuclear and big networks”. I can’t think of a more Neanderthal business model… (more)

Spectral classification using lidar and hyperspectral data – Part 2

To overcome the inherent inter-species and high intra-species spectral variability, typical of savanna environments, a new novel decision tree multiple end member Spectral Angle Mapper (SAM) classification approach was introduced… (more)

Spectral classification using lidar and hyperspectral data – Part 1

To overcome the inherent inter-species and high intra-species spectral variability, typical of savanna environments, a new novel decision tree multiple end member Spectral Angle Mapper (SAM) classification approach was introduced and tested against a traditional straight forward multiple end member SAM classification approach to detect and classify eight common savanna tree species in the Sabi Sands and Bushbuckridge region in Mpumalanga, South Africa… (more)

Exploring SKA

The SKA SA project supports science and engineering students and researchers around the country for work related to MeerKAT and SKA challenges. A group is working at the University of Cape Town.  Bradley Frank, Prof. Erwin de Blok and Moses Mogotsi… (more)

Investigating automatic change detection of topographic features

Changes to the landscape are constantly occurring and it is essential for geospatial and mapping organisations that these changes are regularly detected and captured, so that map databases can be updated to reflect the current status of the landscape. The Chief Directorate of National Geospatial Information (CD:NGI), South Africa’s national mapping agency, currently relies on manual methods of detecting changes and capturing these changes. These manual methods are time consuming and labour intensive, and it is necessary to move towards more automated methods in the production process at CD:NGI… (more)

Analysis of the Lesotho cadastral system Part 2

This article presents and analyses the current, pre-reform, cadastral system of Lesotho using case study strategy and viable systems modelling (VSM). Part 1 of this article, published in the Jan/Feb 2013 issue of PositionIT, described the research methodology and provided an operational overview of the Land Surveys and Physical Planning (LSPP) department in Lesotho. Part 2 focuses on the modelling of the LSPP… (more)

Analysis of the Lesotho cadastral system Part 1

The case study strategy and viable systems modelling (VSM) can be used to understand and analyse the structures and processes of a cadastral system. This article presents and analyses the current, pre-reform, cadastral system of Lesotho using this methodology. The findings suggest that the current cadastral system in Lesotho has the potential to function effectively while maintaining self-identity, even under government bureaucracy administration, and without the introduction of an entirely new structure… (more)

Identifying the target audiences, media and messages for SDI education and training in South Africa

The objective of the South African Spatial Data Infrastructure (SASDI) is to facilitate the capture, management, maintenance, integration, distribution and use of spatial information in South Africa. To realize this objective, SASDI stakeholders have to understand the purpose and benefits of SASDI… (more)

The use of GIS to evaluate the impact of the built environment on health in Cape Town: The case study of Philippi, “Brown’s Farm”

There exists ample evidence that physical structures of and around residential neighbourhoods can influence health. This study used fine scale spatial data and local community’s perceptions to examine the spatial distribution of TB, HIV/AIDS, hypertension, diabetes and obesity across different physical environments of the Philippi township “Brown’s Farm”… (more)

Use of advisory expert system to enhance home-base care provided to HIV/AIDS patients

Human immunodeficiency virus (HIV)/Acquired immune deficiency syndrome (AIDS) is a major global health problem. It is the greatest threat to the development of South Africa. Advances in information and communication technology (ICT) have facilitated development of medical expert systems. In this paper we describe how web-based advisory expert system can enhance HIV-symptoms management… (more)

Multi-scale contextual classification of urban scenes from high resolution imagery

In this paper we presented a multi-scale approach towards the classification of urban scenes and identification of some key high level features in order to model urban scenes. The approach exploited the advantages of the multi-scale structure of image generated by the multi-resolution algorithm in e-Cognition… (more)

GIS data collection for flood risk management

Using a case study of a flood prone informal settlement in Cape Town, this article demonstrates a methodology for the collection and integration of community based information into a geographic information system (GIS) that can be used by the City of Cape Town (CC) for risk assessment. In addition, this article shows how data collected from communities can demonstrate micro levels of vulnerability and guide risk management strategies. The policies that govern development in Cape Town are typically structured to mitigate hazards such as flooding. However, rapid urbanisation in Cape Town has led to the birth and spread of informal settlements and high density townships, which do not subscribe to typical town planning norms. As of 2007, there were approximately 109 000 families living in informal settlements… (more)

3D object segmentation of point clouds (Part 2)

In the automatic processing of point clouds, higher level information in the form of point segments is required for classification and object detection purposes. Point cloud segmentation allows for the definition of these segments. In this article, an extension of a segmentation approach based on intersecting profiles is proposed. Part 1 of this article published in the March 2012 issue of PositionIT reviewed current segmentation algorithms and discussed the extension of a segmentation algorithm developed by Sithole. Part 2 of this article discusses the extension of a segmentation algorthm developed by Sithole presenting results from applications of the algorithm… (more)

3D object segmentation of point clouds (Part 1)

In the automatic processing of point clouds, higher level information in the form of point segments is required for classification and object detection purposes. Point cloud segmentation allows for the definition of these segments. In this article, an extension of a segmentation approach based on intersecting profiles is proposed… (more)

Using remote sensing for vegetation classification

Many analysts and researchers need to classify vegetation on remotely sensed images at structure level (trees, shrubs and grass, for example), at genus level or at species level. They use this information in areas such as resource planning and invasive vegetation detection. A review was compiled of some of the results of vegetation classifications published during the past 10 years. This article examines some of the more interesting studies found in the review… (more)

African Cultural Heritage Sites and Landscapes Project

In 2005 PositionIT published an article on the African Cultural Heritage Sites and Landscapes Project. This report is a follow-up on the previous publication, it describes the evolution of the project and some of the many challenges which had and still have to be faced and overcome… (more)