Curriculum Development and Pedagogy for Teaching Web Mapping

Total Page:16

File Type:pdf, Size:1020Kb

Curriculum Development and Pedagogy for Teaching Web Mapping Curriculum Development and Pedagogy for Teaching Web Mapping By Carl M. Lemke Oliver Sack A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Geography) At the UNIVERSITY OF WISCONSIN–MADISON 2018 Date of final oral examination: 7/27/2018 The dissertation is approved by the following members of the Final Oral Committee: Robert E. Roth, Associate Professor, Geography Kristopher N. Olds, Professor, Geography Ian A. Muehlenhaus, Associate Faculty, Geography Leema K. Berland, Associate Professor, Curriculum and Instruction Creative Commons Attribution License Carl M. Lemke Oliver Sack 2018 i Table of Contents Acknowledgements iii List of Figures iv List of Tables v I. Introduction: Teaching Cartography in the 21st Century Abstract 1 1.1 Overview 1 1.2 Changes in Cartographic Practice 3 1.3 Changes in Higher Education 5 1.4 Challenges to GIScience Education 8 1.5 Research Questions and Dissertation Outline 8 II. Background Review Abstract 13 2.1 Web Mapping Definitions and History 13 2.2 Principles of Web Map Design 19 2.3 Approaches to GIScience Education 28 2.4 Why Learning Web Mapping is Unique 34 2.5 GIScience and Online Learning 39 III. Current State of Web Mapping Education: An Interview Study with Educators Abstract 43 3.1 Motivation 43 3.2 Interview and Qualitative Analysis Methods 45 3.3 Qualitative Analysis Results 48 3.3.1 Vision 48 3.3.2 Scope 49 3.3.3 Topic 51 3.3.4 Tool 53 3.3.5 Motivation 56 3.3.6 Pedagogy 58 3.3.7 Challenge 61 3.4 Discussion: Common Practices and Challenges 63 3.5 Conclusion 67 IV. Lab Curriculum Development and First-Round Evaluation Abstract 69 4.1 Web Mapping at UW–Madison 69 4.2 Transitioning to the Open Web Platform 72 4.3 An Interactive Web Mapping Curriculum 74 4.4 Evaluation Methods 77 4.5 Results 80 4.5.1 Instructor Observation Log 80 4.5.2 Student Feedback Compositions 82 4.5.3 Exit Survey 86 4.6 Discussion: Threshold Concepts and Learning Outcomes 90 ii V. Blending the Curriculum Abstract 95 5.1 The Problem of Online Learning 95 5.2 Curriculum Scope and Sequence Adjustments 100 5.3 Evaluation Methods 102 5.4 Results 104 5.4.1 Entrance Survey 104 5.4.2 Exit Survey: Competence 106 5.4.3 Computational Thinking and Confluence 110 5.4.4 Exit Survey: Sequence, Challenges, and Student Feedback 115 5.4.5 Weekly Feedback Submissions 116 5.5 Lab Outcomes and Barriers to Learning 120 VI. Findings and Applications Abstract 127 6.1 Research Findings 127 6.2 Disciplinary Contributions 134 6.2.1 Contributions to Cartography 134 6.2.2 Contributions to GIScience Education 135 6.2.3 Contributions to Online Education 138 6.3 Synthesis: A ‘Zero-to-Map’ Web Mapping Curriculum 139 6.3.1 Unit 1: ArcGIS Online Web Map 142 6.3.2 Unit 2: Web Map Story 147 6.3.3 Unit 3: Leaflet Slippy Map 149 6.3.4 Final Project and Assessment 153 6.4 Future Directions 154 6.4.1 Addressing Diversity in Web Mapping Education 154 6.4.2 Developing a Scoping Framework for Web Mapping Curriculum 156 6.4.3 Evaluating Fully Online Web Mapping Curricula 157 6.4.4 Expanding the Domain of Web Mapping Education 158 6.5 Finale 159 Glossary 160 References 165 Appendix 1: Interview Study Protocol 176 Appendix 2: 2014 Curriculum Evaluation Exit Survey Questions 181 Appendix 3: Interactive Cartography and Geovisualization Lab Curriculum Module 1 197 Appendix 4: 2016-17 Curriculum Evaluation Entrance Survey Questions 205 Appendix 5: 2016-17 Curriculum Evaluation Exit Survey Questions 207 Appendix 6: A Model Web Mapping Syllabus 215 iii Acknowledgements I am most grateful to Dr. Robert Roth for his steadfast and superb advising, feedback, encouragement, and flexibility, all of which enabled this dissertation to come to fruition. The dissertation has also benefitted from the contributions of my other committee members, Dr. Ian Muehlenhaus, Dr. Kristopher Olds, and Dr. Leema Berland, as well as the helpful feedback of Dr. A-Xing Zhu and Dr. Qunying Huang on the proposal. My gratitude further extends to Tanya Buckingham for providing a stimulating and supportive work environment in the UW Cartography Lab, to Robin Tolochko for enabling and supporting the collection of data for this project while instructing the lab component of the Interactive Cartography and Geovisualization course, and to Dr. Rich Donohue for teaching me how to code in the first place and providing the initial inspiration for this dissertation. Thanks also to Fond du Lac Tribal and Community College, and especially to Dr. Anna Fellagy, for supporting my pursuit of the dissertation’s completion while a faculty member there, and to my wife, Zee Lemke, for spousal support. Finally, thank you to my interview participants, and to all of the students who took Interactive Cartography and Geovisualization at UW–Madison between 2014 and 2017, without whom this dissertation would not have been possible. iv List of Figures 2.1: Web map taxonomy tree. 14 2.2: An illustration of client-server architecture for web maps. 18 2.3: The Cartography3 framework. 20 2.4: The Web Map Continuum. 21 2.5: Data, representation, and animation & interaction within client-server architecture. 22 2.6: The Stages of Action model for cartographic interaction. 25 2.7: Spiral curriculum and scaffolding in the zone of proximal development. 31 2.8: Topical versus spiral curriculum sequencing. 32 2.9: Commonly used Open Web Platform web mapping technologies. 35 2.10: The Web Mapping Workflow. 37 3.1: Four disciplinary approaches to web mapping curriculum. 63 4.1: The GIScience curriculum at UW–Madison 71 4.2: Students’ overall emotional experiences while completing each lab unit in 2014. 88 5.1: Beginning of Interactive Cartography and Geovisualization online lab Module 1 98 5.2: Example code blocks and graphics in online lab Module 5 98 5.3: Lesson Self-Check quiz and Module Deliverables for online lab Module 8 99 5.4: Word clouds of students’ learning goals for Interactive Cartography and Geovizualization. 105 5.5: Comparison of computational thinking and confluence valences for 2016 and 2017 classes. 110 5.6: 2016 students’ assessments of computational thinking and confluence skills. 111 5.7: 2017 students’ assessments of computational thinking and confluence skills. 112 5.8: Comparison of students’ overall emotional experiences and difficulties for each lab unit. 113 5.9: Graph of each module’s mean challenge rating and mean student grade in 2016 and 2017. 115 6.1: The curriculum spiral of the proposed Web Mapping course. 142 6.2: Screenshots of the ArcGIS Online platform demonstrating data, representation, and interaction. 144 6.3: GeoServer layers preview interface. 150 6.4: A CodePen screenshot demonstrating Leaflet’s integration of HTML, CSS, and JavaScript. 150 v List of Tables 2.1: OGC geospatial web services. 23 2.2: Common map interaction operators. 26 2.3: Learning objectives from the GIScience & Technology Body of Knowledge Web Mapping entry. 29 2.4: Dimensions and components of computational thinking. 38 2.5: Recommendations regarding instructional design for online distance education. 40 3.1: Interview coding scheme. 47 3.2: VISION themes. 48 3.3: SCOPE themes. 50 3.4: TOPIC themes. 52 3.5: TOOL themes. 54 3.6: MOTIVATION themes. 57 3.7: PEDAGOGY themes. 59 3.8: CHALLENGE themes. 61 4.1: Outline of 2014 web mapping curriculum topics. 76 4.2: Total number of student feedback themes in each thematic category. 82 4.3: Extensiveness of difficult concept themes. 83 4.4: Extensiveness of other problem themes. 84 4.5: Extensiveness of ‘aha!’ moment themes. 84 4.6: Extensiveness of other positive experience themes. 85 4.7: Student-reported increase in expertise with Open Web Platform mapping tools. 87 4.8: Students’ mean difficulty ratings for Open Web Platform mapping tools. 88 4.9: Topic sequence with order means from exit survey. 89 4.10: Threshold concepts encountered by students. 91 4.11: Four learning outcomes for a web mapping course using Open Web Platform technologies. 93 5.1: Interactive Cartography and Geovisualization online lab units and modules. 97 vi 5.2: The revised 2016-17 topic sequence. 100 5.3: Comparison of prior expertise with Open Web Platform tools in 2016 and 2017. 107 5.4: Comparison of final expertise with Open Web Platform tools in 2016 and 2017. 107 5.5: Comparison of normalized percent change of mean expertise in 2014, 2016, and 2017. 109 5.6: Mean emotional experience and challenge valences for each curriculum unit. 114 5.7: Successes and challenges reported by students in weekly feedback submissions. 119 6.1: Focused learning objectives to support web mapping outcomes 137 6.2: Web Mapping topic and activity sequence. 141 I. Introduction: Teaching Cartography in the 21st Century Abstract This chapter introduces the subject matter of web mapping education. Section 1.1 outlines recent changes to the discipline and craft of Cartography, especially those driven by the advancement of internet technologies. Section 1.2 provides a more detailed explanation of the sweeping changes that have taken place in cartographic practice due to the expansion of online media since the early 2000s. Section 1.3 presents the parallel web-driven changes occurring in higher education. Section 1.4 explores possible reasons for the lag in adoption of web development skillsets within cartography and GIS curricula. Finally, Section 1.5 presents the research questions and outlines the remainder of the dissertation. 1.1 Overview Cartography is changing. In the 20th Century, Cartography was: • Scientific and objective; • Used for presentation of information; • Based on centralized, authoritative datasets curated by institutions; • Conducted by draftsmen (and a very few women); • Done using drafting tools, film, and (in the final decade of the century) desktop graphic design software; • The production of maps on durable media.
Recommended publications
  • GIBS API for Developers
    GIBS API for Developers Overview Imagery Layers & Endpoints Layer Naming "Best Available" Layers Projections & Resolution WGS 84 / Lat-lon / Geographic (EPSG:4326) Web Mercator (EPSG:3857) NSIDC Sea Ice Polar Stereographic North (EPSG:3413) Antarctic Polar Stereographic (EPSG:3031) Service Endpoints Imagery API/Services OGC Web Map Tile Service (WMTS) Service Endpoints and GetCapabilities Time Dimension Sample Execution Example Clients Generic XYZ Tile Access OGC Web Map Service (WMS) Service Endpoints and GetCapabilities Time Dimension Sample Execution Geographic Information System (GIS) Client Usage Tiled Web Map Service (TWMS) Service Endpoints Sample Execution Vector Visualization Products Overview Access Vector Metadata Vector Styling Script-level Access via GDAL Bulk Downloading Overview The Global Imagery Browse Services (GIBS) are designed to deliver global, full-resolution satellite imagery to users in a highly responsive manner, enabling interactive exploration of the Earth. To achieve that interactivity, GIBS first ingests imagery from a given NASA data provider on a continuous basis, creates a global mosaic of that imagery, then chops the mosaic into an image tile pyramid (see figure below). By pre-generating these tiles, it relieves the servers of image rescaling and cropping duties, greatly reducing computational overhead and enabling a highly responsive system. This also means that the primary method of imagery retrieval for clients is tile-based. For more background on how tiled web maps work, see the MapBox Developers Guide. An image tile pyramid (from OGC WMTS 1.0.0 specification) While the requests made to GIBS are for individual tiles, users generally work at a higher level and configure a map library, GIS client, or script to determine which tiles to retrieve.
    [Show full text]
  • Sample Dissertation Format
    An Interactive Widget to Visualise the Allergy Symptoms of a Country A dissertation submitted to the University of Manchester for the degree of Master of Science in the Faculty of Engineering and Physical Sciences Deemah Alqahtani 2016 School of Computer Science Table of Contents Table of Contents ........................................................................................................... 2 List of Figures ................................................................................................................ 5 List of Tables ................................................................................................................. 8 Glossary of Terms .......................................................................................................... 9 Abstract ........................................................................................................................ 10 Declaration................................................................................................................... 11 Intellectual Property Statement ................................................................................... 12 Acknowledgement ....................................................................................................... 13 1 Introduction ........................................................................................................ 14 1.1 Aims and Objectives ................................................................................... 15 1.2 Report Structure .........................................................................................
    [Show full text]
  • Design of a Multiscale Base Map for a Tiled Web Map
    DESIGN OF A MULTI- SCALE BASE MAP FOR A TILED WEB MAP SERVICE TARAS DUBRAVA September, 2017 SUPERVISORS: Drs. Knippers, Richard A., University of Twente, ITC Prof. Dr.-Ing. Burghardt, Dirk, TU Dresden DESIGN OF A MULTI- SCALE BASE MAP FOR A TILED WEB MAP SERVICE TARAS DUBRAVA Enschede, Netherlands, September, 2017 Thesis submitted to the Faculty of Geo-Information Science and Earth Observation of the University of Twente in partial fulfilment of the requirements for the degree of Master of Science in Geo-information Science and Earth Observation. Specialization: Cartography THESIS ASSESSMENT BOARD: Prof. Dr. Kraak, Menno-Jan, University of Twente, ITC Drs. Knippers, Richard A., University of Twente, ITC Prof. Dr.-Ing. Burghardt, Dirk, TU Dresden i Declaration of Originality I, Taras DUBRAVA, hereby declare that submitted thesis named “Design of a multi-scale base map for a tiled web map service” is a result of my original research. I also certify that I have used no other sources except the declared by citations and materials, including from the Internet, that have been clearly acknowledged as references. This M.Sc. thesis has not been previously published and was not presented to another assessment board. (Place, Date) (Signature) ii Acknowledgement It would not have been possible to write this master‘s thesis and accomplish my research work without the help of numerous people and institutions. Using this opportunity, I would like to express my gratitude to everyone who supported me throughout the master thesis completion. My colossal and immense thanks are firstly going to my thesis supervisor, Drs. Richard Knippers, for his guidance, patience, support, critics, feedback, and trust.
    [Show full text]
  • Policemaps Webservices V1.0.1 Access and Usage
    Direction de l'information policière et des moyens ICT Directie van de operationele informatie en de ICT-middelen DRI - Business Unit Fonctionnement Local PoliceMaps Webservices v1.0.1 Access and usage David Dabin [email protected] Version of May 9, 2016 2 Keywords GDI - PoliceMaps - Software - Map - WebServices - GIS Summary The Geo Data Infrastructure (GDI) project aims to distribute a coherent set of spatial data, spatial web services and spatial APIs in order to optimize the collection, processing and usage of high quality geographical data at operational, tactic and strategic level of the Police. PoliceMaps is the rst application deployed by the GDI project. GDI provides a collection of Lego building blocks where each brick is a spatial data, a spatial functionality or a spatial tool which can be freely used by developers to integrate spatial objects into Police App. It's up to each application to use wisely the dierent pieces to match its needs regards spatial functionalities. This document describes all the web services distributed by the GDI project through PoliceMaps. Developers will nd here how to connect to web services and how to submit requests for web maps, geocoding, reverse- geocoding, routing and re-projection. Contents 1 Technical standards 5 2 Architecture 9 2.1 Overview . .9 2.2 Servers description . 11 2.3 Portal generation . 12 2.4 Web Services generalities . 12 3 Mapping Web-services 15 3.1 Tiled Map Service . 15 3.1.1 Web service call . 15 3.2 Web Feature Service . 17 4 Geocoding & reverse-geocoding web services 21 4.1 Overview .
    [Show full text]
  • Performance Testing on Vector Vs. Raster Map Tiles—Comparative Study on Load Metrics
    International Journal of Geo-Information Article Performance Testing on Vector vs. Raster Map Tiles—Comparative Study on Load Metrics Rostislav Netek , Jan Masopust , Frantisek Pavlicek and Vilem Pechanec * Deptartment of Geoinformatics, Palacký University Olomouc; 17.listopadu 50, 771 46 Olomouc, Czech Republic; [email protected] (R.N.); [email protected] (J.M.); [email protected] (F.P.) * Correspondence: [email protected]; Tel.: +420-585-63-4579 Received: 8 January 2020; Accepted: 6 February 2020; Published: 6 February 2020 Abstract: Recent developments in web map applications have widely affected how background maps are rendered. Raster tiles are currently considered as a regular solution, while the use of vector tiles is becoming more widespread. This article describes an experiment to test both raster and vector tile methods. The concept behind raster tiles is based on pre-generating an original dataset including a customized symbology and style. All tiles are generated according to a standardized scheme. This method has a few disadvantages: if any change in the dataset is required, the entire tile-generating process must be redone. Vector tiles manipulate vector objects. Only vector geometry is stored on the server, while symbology, rendering, and defining zoom levels run on the client-side. This method simplifies changing symbology or topology. Based on eight pilot studies, performance testing on loading time, data size, and the number of requests were performed. The observed results provide a comprehensive comparison according to specific interactions. More data, but only one or two tiles, were downloaded for vector tiles in zoom and move interactions, while 40 tiles were downloaded for raster tiles for the same interactions.
    [Show full text]
  • Download Download
    Cartographic Perspectives The Journal of Number 76, 2013 Cartographic Perspectives The Journal of Number 76, 2013 IN THIS ISSUE LETTER FROM THE EDITOR Patrick Kennelly 3 PEER-REVIEWED ARTICLES Mountains Unseen: Developing a Relief Map of the Hawaiian Seafloor 5 Tom Patterson Identification of Partially Occluded Map Symbols 19 Jari Arvi Korpi, Mohammad Haybatollahi, Paula Ahonen-Rainio CARTOGRAPHIC COLLECTIONS Maps as the Art of Necessity: The Lilly Library War of 1812 Map Collection 33 Lori Dekydtspotter, Heiko Mühr ON THE HORIZON Time Series Proportional Symbol Maps with Leaflet and jQuery 43 Richard G. Donohue, Carl M. Sack, Robert E. Roth PRACTICAL CARTOGRAPHER'S CORNER Census Mapping Mashup 67 Paul Hunt VISUAL FIELDS Experimental Terrain Representation 77 Kelly Abplanalp REVIEWS London: A History in Maps (reviewed by Patti Day) The World at Their Fingertips: Eighteenth-Century British Two-Sheet Double- Hemisphere World Maps (reviewed by Ian Muehlenhaus) 79 Napa Valley Historical Ecology Atlas: Exploring a Hidden Landscape of Transformation and Resilience (reviewed by Lisa Sutton) Instructions to Authors 85 Cartographic Perspectives, Number 76, 2013 | 1 EDITOR Cartographic Perspectives Patrick Kennelly The Journal of Department of Earth and Environmental Science ISSN 1048-9053 LIU Post 720 Northern Blvd. www.nacis.org | @nacis_cp Brookville, NY 11548 ©2013 North American Cartographic Information Society [email protected] EDITORIAL BOARD ASSISTANT EDITOR Sarah Battersby Fritz Kessler Daniel P. Huffman University of South Carolina
    [Show full text]
  • A Short Intro to FLOSS, GIS and QGIS
    A short intro to FLOSS, GIS, and QGIS A short intro to FLOSS, GIS and QGIS Edited by Francesco Fiermonte March, April 2020 Revision 0.9 This work is published under the Creative Commons Attribution-ShareAlike 4.0 International (CC-BY-SA)[1][2] 1 https://creativecommons.org/licenses/by-sa/4.0/ 2 https://creativecommons.org/licenses/by-sa/4.0/legalcode A short intro to FLOSS, GIS, and QGIS Table of Contents A short intro to FLOSS, GIS and QGIS ............................................................................................................... 1 Table of Contents .......................................................................................................................................... 2 Index of Figures ............................................................................................................................................. 5 Index of Tables ............................................................................................................................................... 9 Preamble ..................................................................................................................................................... 10 Before Starting ............................................................................................................................................. 10 Why use an open source software instead a proprietary one? .............................................................. 11 Conventions ................................................................................................................................................
    [Show full text]
  • Onearth and MRF Now Available on Github
    OnEarth and MRF Now Available on GitHub We're pleased to announce the open source release of the GIBS tiled imagery server and its underlying tile storage format on GitHub! What is it? The "OnEarth" software is used as the Global Imagery Browse Services (GIBS) primary imagery server for a highly responsive, highly scalable service which provides client access via Open Geospatial Consortium (OGC) Web Map Tile Service (WMTS), Tiled Web Map Service (TWMS), and Google Earth KML methods along with scripted access via GDAL. It also supports time-varying access to individual layers which has been a necessity for this project in dealing with long-running, daily satellite imagery. Also included in this release is an optimized image tile storage format called Meta Raster Format, or MRF, and scripts to generate them. It's designed to reduce file system overhead by combining all tiles for a given layer into a single file similar to MapBox MBTiles. It supports arbitrary map projections and is currently being used by GIBS for storing its geographic, Web Mercator, Arctic, and Antarctic tiles. As a plugin for GDAL, MRFs can also be read by GDAL-based applications such as MapServer. Battle Tested While this release is new, the software itself has a long heritage at NASA's Jet Propulsion Laboratory. Along its travels, it has had the distinction of serving the largest image in the world at the time (a Landsat mosaic of the US circa 1998), the Earth imagery server for planetarium shows at the American Museum of Natural History (2003-present), the first 15m global Landsat mosaic of the world (2004), the original imagery and terrain server for NASA World Wind (2004), and a Martian and Lunar imagery server (2008?-present).
    [Show full text]
  • Imagery to the Crowd, Mapgive, and the Cybergis: Open Source Innovation in the Geographic and Humanitarian Domains
    Imagery to the Crowd, MapGive, and the CyberGIS: Open Source Innovation in the Geographic and Humanitarian Domains By Joshua S. Campbell Submitted to the graduate degree program in Geography and the Graduate Faculty of the University of Kansas in partial fulfillment of the requirements for the degree of Doctor of Philosophy. ________________________________ Chairperson Jerome E. Dobson ________________________________ Stephen Egbert ________________________________ Xingong Li ________________________________ Barney Warf ________________________________ Edward A. Martinko Date Defended: May 14, 2015 The Dissertation Committee for Joshua S. Campbell certifies that this is the approved version of the following dissertation: Imagery to the Crowd, MapGive, and the CyberGIS: Open Source Innovation in the Geographic and Humanitarian Domains ________________________________ Chairperson Jerome E. Dobson Date approved: May 14, 2015 ii Abstract The MapGive initiative is a State Department project designed to increase the amount of free and open geographic data in areas either experiencing, or at risk of, a humanitarian emergency. To accomplish this, MapGive seeks to link the cognitive surplus and good will of volunteer mappers who freely contribute their time and effort to map areas at risk, with the purchasing power of the United States Government (USG), who can act as a catalyzing force by making updated high resolution commercial satellite imagery available for volunteer mapping. Leveraging the CyberGIS, a geographic computing infrastructure built from open source software, MapGive publishes updated satellite imagery as web services that can be quickly and easily accessed via the internet, allowing volunteer mappers to trace the imagery to extract visible features like roads and buildings without having to process the imagery themselves.
    [Show full text]
  • A Descriptive Model for Predicting Popular Areas in a Web Map
    Recent Researches in Artificial Intelligence, Knowledge Engineering and Data Bases A Descriptive Model for Predicting Popular Areas in a Web Map RICARDO GARCIA,´ JUAN PABLO DE CASTRO, MARIA´ JESUS´ VERDU´ ELENA VERDU,´ LUISA MARIA´ REGUERAS and PABLO LOPEZ´ University of Valladolid Higher Technical School of Telecommunications Engineering Department of Signal Theory, Communications and Telematics Engineering Campus Miguel Delibes, Paseo Belen´ 15, 47011 Valladolid SPAIN fricgar, juacas, marver, elever,[email protected], [email protected] Abstract: The increasing popularity of web map services has motivated the development of more scalable services in the Spatial Data Infrastructures (SDI). Tiled map services have emerged as an scalable alternative to traditional map services. Instead of rendering image maps on the fly, a collection of pre-generated image tiles can be retrieved very fast from a server-side cache. However, storage requirements and start-up time for generating all tiles are often prohibitive for many potentially providers when the cartography covers large areas for multiple rendering scales, which forces to use partial caches containing a subset of the total tiles. This work proposes a descriptive model based on the mining of real-world logs from several nationwide public web map services in Spain. The proposed model is able to determine in advance which areas are likely to be requested in the future based exclusively on past accesses. Tiles that are anticipated to be requested soon can be pre-generated and cached for faster retrieval. As the number of tiles grows exponentially with the rendering resolution level, it is rarely feasible to work with statistics of individual tiles.
    [Show full text]
  • Web Map Tile Services for Spatial Data Infrastructures: Management and Optimization
    ChapterChapter 2 0 Web Map Tile Services for Spatial Data Infrastructures: Management and Optimization Ricardo García, Juan Pablo de Castro, Elena Verdú, María Jesús Verdú and Luisa María Regueras Additional information is available at the end of the chapter http://dx.doi.org/10.5772/46129 1. Introduction Web mapping has become a popular way of distributing online mapping through the Internet. Multiple services, like the popular Google Maps or Microsoft Bing Maps, allow users to visualize cartography by using a simple Web browser and an Internet connection. However, geographic information is an expensive resource, and for this reason standardization is needed to promote its availability and reuse. In order to standardize this kind of map services, the Open Geospatial Consortium (OGC) developed the Web Map Service (WMS) recommendation [1]. This standard provides a simple HTTP interface for requesting geo-referenced map images from one or more distributed geospatial databases. It was designed for custom maps rendering, enabling clients to request exactly the desired map image. This way, clients can request arbitrary sized map images to the server, superposing multiple layers, covering an arbitrary geographic bounding box, in any supported coordinate reference system or even applying specific styles and background colors. However, this flexibility reduces the potential to cache map images, because the probability of receiving two exact map requests is very low. Therefore, it forces images to be dynamically generated on the fly each time a request is received. This involves a very time-consuming and computationally-expensive process that negatively affects service scalability and users’ Quality of Service (QoS).
    [Show full text]
  • Kaardirakenduste Tegemine Leafleti Ja Postgisi Näitel
    Tartu Ülikool Loodus- ja täppisteaduste valdkond Ökoloogia ja maateaduste instituut Geograafia osakond Magistritöö geoinformaatikas KAARDIRAKENDUSTE TEGEMINE LEAFLETI JA POSTGISI NÄITEL Risto Ülem Juhendaja: prof. Tõnu Oja Kaitsmisele lubatud: Juhendaja: /allkiri, kuupäev/ Osakonna juhataja: /allkiri, kuupäev/ Tartu 2018 Kaardirakenduste tegemine Leafleti ja PostGISi näitel Lühikokkuvõte: Käesoleva magistritöö eesmärgiks oli uurida, kuidas käib veebikaartide tegemine, millist tarkvara ja tarkvara konfiguratsiooni veebikaartide tegemiseks kasutatakse. Töö käigus tehti mitu erinevat kaardirakendust, et uurida kuidas käib mõnede enamlevinud veebikaardi komponentide programmeerimine (teekonna arvutus, aadressotsing, kasutaja poolt kaardile joonistamine ja lihtsa teemakaardi tegemine). Selleks valiti sobiv tarkvara pakett – WAMP server, mis sisaldab Apache veebiserverit, PHP- d ja laiendeid PostgreSQL/PostGIS andmebaasiga ühendumiseks. Andmebaasiks valiti PostgreSQL koos PostGIS laiendiga. Kaardi API-ks valiti Leaflet, kuna see on kõige lihtsamini õpitav. Mõne rakenduse jaoks oli kasutusel ka GeoServer. Märksõnad: Leaflet, PostGIS, GeoServer, veebikaart, kaardirakendus geoinformaatika CERCS: P510 Füüsiline geograafia, geomorfoloogia, mullateadus, kartograafia, klimatoloogia P160 Statistika, operatsioonianalüüs, programmeerimine, finants- ja kindlustusmatemaatika Web mapping with Lealfet and PostGIS Abstract: The aim of this master’s thesis was to find out how web mapping works, what kind of software and software configuration are used for web mapping. Several different web maps were developed, to learn how to make most common web map components (routing, address search, client-side drawing on the map, and making a simple thematic map). A software package was selected for this purpose, which includes WAMP server which comes with Apache web server, PHP and PostgreSQL/PostGIS database extensions. PostgreSQL with PostGIS extension was selected for the database. Lealfet was choosen for mapping API because of it’s small learning curve.
    [Show full text]