’n Webdiens vir tematiese kartering

The  goal  of  the  research  is  to  evaluate  proprietary software and solutions suggested by other researchers for the implementation of a mechanism for the production of thematic maps on desktop and web applications, as well as the thematic cartographic ability of standard web service implementations

Investigating the impact of different types of directions on wayfinding efficiency in an informal settlement

Informal settlements are a common occurrence in the South African landscape. These settlements are not planned and therefore lack conventional urban characteristics, such as street names and a regular grid or block structure, which are useful aids during wayfinding. As a result, it is difficult to navigate through such a settlement or to provide directions to a specific destination. The lack of street names also implies that directions provided by others play a more important role. In this paper, we present the results of a qualitative between-subjects study that assessed individuals’ wayfinding efficiency when using different types of directions in an informal settlement. Participants were divided into two groups of six participants each (3 males and 3 females). Two sets of directions were constructed for the same route, one based on left-right turn descriptors and landmarks, and the second based on cardinal directions and distances. The performance of participants was measured for each set of directions. Earlier studies reported that people preferred left-right directions but performed better when using cardinal directions. The results of our study show the opposite. We think that this is due to the lack of regular wayfinding aids in informal settlements, but further studies are required to confirm this. The results of our study are interesting for developers of navigational tools aimed at addressing the needs of people in informal settlements

Results Of and Evaluation Of Augmented Reality Mobile Development Frameworks For Addresses in Augmented Reality

Addresses displayed on dwellings and buildings play a key role in society. Amongst others, they are used for deliveries, in household surveys, to navigate, or to find friends. Sometimes, address signs are destroyed, displaced or illegible, for example, as a result of vandalism, disasters, or poor maintenance. In augmented reality, computer-generated information is superimposed onto a live view of the real world. When address signs are not available, displaying the address in augmented reality could be immensely useful. The research presented in this article is part of a larger research endeavour to investigate augmented reality for addressing. This article presents the results of an evaluation of augmented reality mobile development frameworks for the implementation of a mobile application that displays addresses in augmented reality. Firstly, the requirements for addresses in augmented reality were identified. Three use cases informed these requirements: disaster relief, e.g. address signs are destroyed by an earthquake; household surveys, e.g. locating dwellings in informal settlements or rural areas where addresses are not assigned in any specific sequence and signs do not exist; and address data quality management, e.g. validating digital address data against addresses displayed in the physical world. Due to procurement challenges in the use cases, open source licensing and integration with open source products was identified as an important requirement. The internet was searched and a list of augmented reality mobile development frameworks was compiled. Based on the requirements, the list was shortened to seven frameworks, which were evaluated against a set of criteria informed by the requirements. The evaluation results can guide developers in choosing a framework best suitable for their specific needs and/or for integration with open source products

Orchestrating standard web services to produce thematic maps in a geoportal of a spatial data infrastructure

Cartography is the science and art of making maps and thematic cartography is a subsection that deals with the production of thematic maps. A thematic map portrays the distribution of features, incidents or classifications related to a specific topic. With the rapidly increasing volumes of data, thematic maps allow users to efficiently analyse data and identify trends quicker. A spatial data infrastructure (SDI) focuses on making data available and ensures data interoperability through a geoportal and associated web services for discovery, display, editing, and analysis. Implementations of web service standards by the Open Geospatial Consortium (OGC), and the ISO/TC211, Geographic information/Geomatics enable the display, query and custom visualisation of spatial data in a geoportal. In the past, sophisticated cartographic methods have been mainly available on desktop applications, but with the advances in web mapping technology these methods have become increasingly popular on the Web. Currently, producing thematic maps using web services is a manual process that requires quite a lot of custom programming. The orchestrations of standard web services automate the process to produce thematic maps in a geoportal. It is preferable to use standard web services as opposed to customised programming; the standards provide flexibility, interoperability, and standard protocols, to name a few benefits. The goal of this research was to determine how standard OGC web services could be orchestrated to produce thematic maps within the geoportal of an SDI. To achieve this goal, an orchestrated thematic web service, named ThematicWS, was constructed from existing implementations of individual standard OGC web services, which are monolithic and interchangeable. The thematic cartographic process for producing choropleth and proportional symbol maps was investigated to model the process and obtain a set of steps. Experiments were performed to determine which existing web service standards could be used in the process. ThematicWS was developed using existing implementations of the following standards: WFS to retrieve the attribute data, WPS for the wrapping of custom functionalities (statistical processing and SLD generation), and a WMS to produce the thematic map image. The 52° North and ZOO project frameworks’ orchestration capabilities were evaluated for to determine the suitability for producing thematic maps. The evaluation showed that orchestration is possible in both frameworks. However, there are limitations in both frameworks for automatic orchestration such as the lack of semantic information and poor usability of the framework. The use of WPS services to wrap custom functionalities and to provide a standard interface has proved to be useful for the orchestration of standard web services. ThematicWS was successfully implemented based on standard web service implementations using both workflow scripting and workflow modelling. The orchestrated ThematicWS can be called and consumed by a geoportal of an SDI to produce thematic maps according to user defined parameters.Dissertation (MSc)--University of Pretoria, 2013.Geography, Geoinformatics and MeteorologyUnrestricte

A review of the impact of Google Code-in on OSGeo

Many open source software communities rely on volunteer contributors and it is important to motivate, engage and retain members of the community to ensure long term sustainability of the community and software. Barrier to entry can be a problem for new developers and can stop them from contributing to large projects. It is important to mentor and guide new volunteers in an open source project and organisation such as OSGeo. The question is then raised how can open source organizations bridge this gap and bring younger developers into the organizations and ensure that they remain, in order to contribute something meaningful? OSGeo participated for a third time in Google Code-in (GCI). Google Code-in is an online competition that introduces teenagers (13-17 years) to open source development over the course of seven weeks. In the 2019 Google Code-in, there were 29 participating open source organisations, over 3000 students from more than 75 countries that completed 13 000+ tasks. During GCI, OSGeo had the lowest number of mentors in its three years of the competition but its highest number of completed tasks. Many of the submissions from the students was of a high standard and some of the task submissions got accepted into the projects. Having new developers in any open source community is key to the survival of the community and retaining them is also key to the longevity of any of the projects and it gives them time to contribute something meaningful.https://www.isprs.org/publications/annals.aspxpm2021Geography, Geoinformatics and Meteorolog

Geospatial openness: from software to standards & data

Abstract This paper is the editorial of the Special Issue "Open Source Geospatial Software", which features 10 published papers. The editorial introduces the concept of openness and, within the geospatial context, declines it into the three main components of software, data and standards. According to this classification, the papers published in the Special Issue are briefly summarized and a future research agenda in the open geospatial domain is finally outlined

Geometry viewer for PGADMIN4 : a process guided by the Google Summer of Code

The latest version of pgAdmin4 was released in mid-2016 and moved to a web-based application that was written in Python and jQuery with Bootstrap, using the Flask framework. This new architecture of pgAdmin4 provided an excellent opportunity to integrate a geometry viewer into the application. This progress started as the geometry viewer was selected as a project for the 2018 Google Summer of Code (GSoC). The requirements for the geometry viewer was elicited through conversations with the mentors and emails to the discussion list of PostGIS and pgAdmin. Once the formal design was finalized the development started. The spatial technology stack implemented to expand pgAdmin4 with a geometry viewer was the JavaScript mapping library Leaflet JS and WKX - parser/serializer library that supports several spatial vector formats. Both these fulfilled the requirements of the coding standard of pgAdmin that all client-side code must be developed in JavaScript using jQuery and other plugins. Leaflet JS is well known for its ease of use and compatibility. WKX is lesser known but well supported and concise to the need to parse the spatial data before rendering on the Leaflet map. The decision on both of these libraries was motivated by their minimal size and possibilities for expansion for future extensions of the viewer. The first version of the geometry viewer was well-received and is currently integrated into the latest versions of pgAdmin4.https://www.isprs.orgpm2020Geography, Geoinformatics and Meteorolog

EXPLORING THE IMPACT OF VISUAL COMPLEXITY LEVELS IN 3D CITY MODELS ON THE ACCURACY OF INDIVIDUALS’ ORIENTATION AND COGNITIVE MAPS

In this paper we report results from a qualitative user experiment (n=107) designed to contribute to understanding the impact of various levels of complexity (mainly based on levels of detail, i.e., LoD) in 3D city models, specifically on the participants’ orientation and cognitive (mental) maps. The experiment consisted of a number of tasks motivated by spatial cognition theory where participants (among other things) were given orientation tasks, and in one case also produced sketches of a path they ‘travelled’ in a virtual environment. The experiments were conducted in groups, where individuals provided responses on an answer sheet. The preliminary results based on descriptive statistics and qualitative sketch analyses suggest that very little information (i.e., a low LoD model of a smaller area) might have a negative impact on the accuracy of cognitive maps constructed based on a virtual experience. Building an accurate cognitive map is an inherently desired effect of the visualizations in planning tasks, thus the findings are important for understanding how to develop better-suited 3D visualizations such as 3D city models. In this study, we specifically discuss the suitability of different levels of visual complexity for development planning (urban planning), one of the domains where 3D city models are most relevant

Towards evaluating the map literacy of planners in 2D maps and 3D models in South Africa

South Africa is faced with numerous socioeconomic problems, such as poverty and resource depletion. Sustainable planning is of great importance to ensure that the necessary resources are available for future generations. However, research has suggested that South African planners do not have the necessary level of map literacy and that new geovisualizations may be required. The goal of this paper is to present preliminary results of comparative experiments to evaluate map literacy of planners in 2D maps and 3D models in South Africa. In these experiments, participants performed equally well when exposed to 2D maps and 3D models. These preliminary results were used to inform the conceptual design of an experiment to evaluate map literacy of users with 2D maps and 3D models. The new experiment was developed using a mixed factorial design and aims to address the challenges identified in the preliminary results. The implementation and execution of the new experiment design will contribute to understanding the strengths and limitations of 3D geovisualization for planning in South Africa. Results will inform guidelines for the appropriate use of these non-traditional technologies for development planning.http://www.geo.uzh.ch/~arzu/publications/rautenbach-etal-2014-AfricaGEO.pd

Development and evaluation of a specialized task taxonomy for spatial planning – a map literacy experiment with topographic maps

Topographic maps are among the most commonly used map types, however, their complex and information-rich designs depicting natural, human-made and cultural features make them difficult to read. Regardless of their complexity, spatial planners make extensive use of topographic maps in their work. On the other hand, various studies suggest that map literacy among the development planning professionals in South Africa is not very high. The widespread use of topographic maps combined with the low levels of map literacy presents challenges for effective development planning. In this paper we address some of these challenges by developing a specialized task taxonomy based on systematically assessed map literacy levels; and conducting an empirical experiment with topographic maps to evaluate our task taxonomy. In such empirical studies if non-realistic tasks are used, the results of map literacy tests may be skewed. Furthermore, experience and familiarity with the studied map type play a role in map literacy. There is thus a need to develop map literacy tests aimed at planners specifically. We developed a taxonomy of realistic map reading tasks typically executed during the planning process. The taxonomy defines six levels tasks of increasing difficulty and complexity, ranging from recognising symbols to extracting knowledge. We hypothesized that competence in the first four levels indicates functional map literacy. In this paper, we present results from an empirical experiment with 49 map literate participants solving a subset of tasks from the first four levels of the taxonomy with a topographic map. Our findings suggest that the proposed taxonomy is a good reference for evaluating topographic map literacy. Participants solved the tasks on all four levels as expected and we therefore conclude that the experiment based on the first four levels of the taxonomy successfully determined the functional map literacy of the participants. We plan to continue the study for the remaining levels, repeat the experiments with a group of map illiterate participants to confirm that the taxonomy can also be used to determine map illiteracy.http://www.elsevier.com/ locate/ isprsjprs2018-05-3