THE TIME WAVE IN TIME SPACE A VISUAL EXPLORATION ENVIRONMENT FOR SPATIO-TEMPORAL DATA Xia Li Examining Committee: prof.dr.ir. M. Molenaar University of Twente prof.dr.ir. A.Stein University of Twente prof.dr. F.J. Ormeling Utrecht University prof.dr. S.I. Fabrikant University of Zurich ITC dissertation number 175 ITC, P.O. Box 217, 7500 AE Enschede, The Netherlands ISBN 978-90-6164-295-4 Cover designed by Xia Li Printed by ITC Printing Department Copyright © 2010 by Xia Li THE TIME WAVE IN TIME SPACE A VISUAL EXPLORATION ENVIRONMENT FOR SPATIO-TEMPORAL DATA DISSERTATION to obtain the degree of doctor at the University of Twente, on the authority of the rector magnificus, prof.dr. H. Brinksma, on account of the decision of the graduation committee, to be publicly defended on Friday, October 29, 2010 at 13:15 hrs by Xia Li born in Shaanxi Province, China on May 28, 1977 This thesis is approved by Prof. Dr. M.J. Kraak promotor Prof. Z. Ma assistant promoter For my parents Qingjun Li and Ruixian Wang Acknowledgements I have a thousand words wandering in my mind the moment I finished this work. However, when I am trying to write them down, I lose almost all of them. The only word that remains is THANKS. I sincerely thank all the people who have been supporting, guiding, and encouraging me throughout my study and research period at ITC. First, I would like to express my gratitude to ITC for giving me the opportunity to carry out my PhD research. I am also grateful to Chang’an University for supporting me in both China and the Netherlands to finish this work. I deeply thank my promoter and supervisor Prof. Menno-Jan Kraak for carefully and patiently advising me on almost all the details of my research. During my MSc study, he opened a new door in front of me and guided me into the academia world. I appreciate all the discussions and talks about not only research, but also about personality and life, from which I will benefit for my whole life. My sincere thanks also go to my second supervisor Prof. Zhimin Ma, for his very helpful support on study and research skills, and his advice on my career and life. My appreciation go to GIVA's Eye Movement Lab, especially, Prof. Sara Fabrikant and Dr. Arzu Coltekin. Without your support and help, the usability study in this research could not go smoothly and could not make dependable final conclusions. I would like to take this opportunity to express my gratitude to all my colleagues in GIP department, especially to Dr. Connie Blok, Dr. Corné van Elzakker, Dr. Rolf de By, Dr. Otto Huisman, Dr. Ulanbek Turdukulov, Dr. Ivana Ivanova, Dr. Rob Lemmens, Dr. Javier Morales, Ellen-Wien Augustijn，Irma Kveladze, Qiuju Zhang, Dongpo Deng, Muhammad Imran, Tanmoy Das, Ioannis Delikostidis and Gaurav Singh, for their suggestions, discussions and all the happiness we have shared. My special thanks goes to Bas Retsios, for his encouragements, friendship, and his excellent programming skills which made this research successful. My sincere thanks go to Dr. Paul van Dijk, Loes Colenbrander, Gerrit Huurneman, Kees Bronsveld, Marion Pierik, Saskia Tempelman, Rebanna Spaan, Marga Koelen, Theresa van den Boogaard, Bettine Geerdink, Marie Chantal Metz, Roelof Schoppers, Rob Teekamp, actually, all ITC staff members, for their friendly help and support which I will never forget. I appreciate my dearest friends, Tina Tian, Dr. Wenxiu Gao, Dr. Ningrui Du, Xuanmei Fan, Dr. Yanqiu Xing, Wenbo Chen, Jing Xiao and Qian Zhu, for always being with me, sharing all the challenges and happiness. Special thanks to Fangfang Cheng, who always shares ideas and thoughts with me. You all are my lifelong sisters. I would like to express my gratitude to all my Chinese friends, especially to Guofeng Wu, Tiejun Wang, Pu Hao, Zhenshan Yang, Lei Bai, Shi Pu, Meng Bian, Teng Fei, Yijian Zeng, Xin Tian, Yali Si, Liang Zhou, Wenjing Lin, Zheng Zhao, Ting Zhao, Duowa Zhutian, Qian Ke, Zijing Xu, Nannan He, Jing Jing, Qi Liu, Hao Jiang and Xiaojun, Yao, for your encouragements, friendship and happiness we have shared. Special thanks to Dr. Lei Zhong, for your company and support. You were the first who read my draft and helped me in English editing. We enjoyed and suffered together, but only the beautiful moments will stay in my memory. Last but not least, my deepest thanks go to my parents, for your endless love. You always say that I am your baby and your pride. Actual, you are my everything and I will be with you for my whole life. Table of Contents Chapter 1 Introduction ......................................................................................... 1 1.1 Background and problem description .................................................. 1 1.2 Research aim, research questions and methods ................................ 2 1.3 Key factors ........................................................................................... 4 1.4 Thesis outline ....................................................................................... 5 Chapter 2 Time .................................................................................................... 7 2.1 Introduction .......................................................................................... 7 2.2 Nature of time ...................................................................................... 7 2.3 Time in GIScience ............................................................................. 13 2.4 Views of time in GIScience versus time visualization ........................ 19 Chapter 3 State-of-the-art in geo-visualization .................................................. 27 3.1 Introduction ........................................................................................ 27 3.2 Problem solving based on visualization theories ............................... 27 3.2.1 Data framework ......................................................................... 29 3.2.2 User tasks framework ................................................................ 30 3.2.3 Visualization framework ............................................................. 32 3.2.4 Representation .......................................................................... 33 3.2.5 Interactive environment ............................................................. 34 3.2.6 Coordinated multiple views (CMV) ............................................ 36 3.3 Existing methods for time visualization.............................................. 37 3.3.1 Taxonomies of visualizations ..................................................... 37 3.3.2 Review on taxonomies of temporal visualizations ..................... 38 3.3.3 Geo-oriented approach by Vasiliev ........................................... 38 3.3.4 Linear visualization approach by Silva and Catarci ................... 39 3.3.5 Information visualization approach by Muller ............................ 39 3.3.6 Geo-exploration approach by Andrienko and Andrienko ........... 40 3.3.7 Visualization process approach by Daassi et al. ....................... 41 3.3.8 Combination approach by Aigner et al. ..................................... 42 3.3.9 Summary of taxonomies of time visualization ........................... 42 Chapter 4 Time-space: approached from a temporal visualization concept ..... 45 4.1 Introduction ........................................................................................ 45 4.2 Temporal visualization concept ......................................................... 45 4.3 Users and applications in TTS ........................................................... 59 4.4 A summary of views on time-space ................................................... 63 Chapter 5 Time wave ........................................................................................ 67 5.1 Introduction ........................................................................................ 67 5.2 The time wave as a temporal reference system ................................ 68 5.3 Time wave as a temporal data representation system ...................... 70 5.4 Time wave as a temporal interactive tool .......................................... 72 5.5 Event wave ........................................................................................ 75 5.6 Multiple waves ................................................................................... 76 5.7 Time wave in time-space: a theoretical perspective .......................... 77 i Chapter 6 Implementing the time wave – working environment, prototype and case study on meteorological data .................................................................... 83 6.1 Introduction ........................................................................................ 83 6.2 Working environment and time wave functionality ............................ 83 6.3 Case study ......................................................................................... 92 6.4 Conclusions ..................................................................................... 109 Chapter 7 Usability evaluation of time wave ................................................... 111 7.1 Introduction ...................................................................................... 111 7.2 Evaluation objective and evaluation design .................................... 112 7.3 Selected evaluation methods .......................................................... 114 7.4 Test 1 ............................................................................................... 118 7.4.1 Test