Assessing the Utility of DMSP-OLS night-time images to propose surrogate census A thesis submitted in fulfillment of the requirements for the degree of Doctor of Philosophy Koel Roychowdhury MSc Geography (Hons) MSc GIS & Human Geography School of Mathematical and Geospatial Sciences College of Science, Engineering and Health RMIT University August 2011 Declaration I certify that except where due acknowledgement has been made, the work is that of the author alone; the work has not been submitted previously, in whole or in part, to qualify for any other academic award; the content of the thesis is the result of work which has been carried out since the official commencement date of the approved research program; any editorial work, paid or unpaid, carried out by a third party is acknowledged; and, ethics procedures and guidelines have been followed. Signature: ………………………… Name: Koel Roychowdhury Date: ………………………… II Acknowledgements The research was conducted under the Australian Federal Government funded Australian Leadership Award Scholarship (ALAS) Scheme. This thesis would not have been possible without the contribution of so many people in many different ways. Firstly, my special thanks go to my supervisors Prof. Simon Jones and Dr. Colin Arrowsmith and my advisor Dr. Karin Reinke. I gratefully acknowledge all their support and advices over the course of my PhD. I consider myself to be extremely fortunate to get them as my supervisors. Thank you to Simon for introducing me to the night-time datasets. I am also thankful to Simon and Karin for all their detailed comments and feedbacks which significantly helped to improve the drafts. I could not have completed this thesis without your words of encouragement and invaluable guidance. I would like to thank Dr. Benjamin Tuttle from NGDC, NOAA for providing me the required datasets and clearing my doubts on them. My special thanks go to Dr. Navalgund, Director, Space Application Centre, India and Dr. S.K. Pathan, Project Director, NRDB and Head, GIDD, Space Application Centre, India for giving me the privilege of using the spatial datasets of the administrative regions for this study. I would also like to thank Dr. Anthony Bedford for going through all the statistical methods used in this research. Thanks to all my fellow researchers in the “Yellow Lab” in RMIT; especially to Danni, Kat, Alex, Naoko, Grant, Rakhesh, Liz, Steve, Samia and Vaibhav for providing such a supportive and fun – filled ambience to share ideas and experiences. You all made the “Yellow Lab” my second home for the last three years. Vaibhav, thank to you very much for all your support in one of the most stressful times. My special thanks to Liz for going through some important parts of this thesis. I wish to thank all my friends for their contribution. My special thanks to Vaishnav and Taz , Pooja and Chaitali for all those moments of laughter. Marie, thank you for the coffee breaks in Starbucks. My earnest gratitude to Towfiq, NeelDa, Mou and AyonDa, for being there and helping me in so many different ways - from giving a patient hearing to uplifting my mood. I couldn’t have managed without you. Finally to my parents, a “Thank You” seems so very inadequate but without you I could have never reached to this stage. To Ma (Mum) and Baba (Dad), thank you for your love, encouragement, support, trust and confidence. I’m coming back to you Ma! III Table of Contents Declaration ........................................................................................... II Acknowledgements ............................................................................ III List of Figures .................................................................................. VIII List of Tables ..................................................................................... XI List of Equations .............................................................................. XIII List of Acronyms ............................................................................ XIV List of Publications: ....................................................................... XVII Abstract: .......................................................................................... XIX 1. Introduction .................................................................................... 22 1.1: Background: ................................................................................................................................ 22 1.2: Research Questions: .................................................................................................................... 24 1.3: Thesis Structure and outline of chapters ..................................................................................... 24 1.3.1: Outline of Chapters: ............................................................................................................ 25 2. Literature Review ........................................................................... 28 2.1: The Defense Meteorological Satellite Programme – Operational Linescan System (DMSP- OLS) ................................................................................................................................................... 28 2.1.1: The Satellite: ........................................................................................................................ 28 11/04/03 - Present .......................................................................................................................... 30 2.1.2: OLS Gain Control: ............................................................................................................... 32 2.1.3: DMSP-OLS Images: ............................................................................................................. 33 2.1.3.1: The Stable lights dataset: .............................................................................................. 34 2.1.3.2: The Radiance calibrated product: ................................................................................ 36 2.1.3.3: Average Digital Number: .............................................................................................. 37 2.2: Census ......................................................................................................................................... 39 2.2.1: History of the Indian Census: .............................................................................................. 40 2.2.2: Hierarchy of regions for census enumeration: .................................................................... 41 2.2.3 Census Personnel: ................................................................................................................. 42 2.2.4: Method of enumeration: ....................................................................................................... 42 2.2.5: Collection, Assimilation and Publication of the census: ..................................................... 43 2.3: Indian Census 2001: .................................................................................................................... 44 2.3.1: Summary of results as obtained from the 2001 census: ....................................................... 46 IV 2.4: Application of Remote Sensing in census and population studies: ............................................. 47 2.4.1: Association of remote sensing and socio-economic data: ................................................... 48 2.4.2: Estimation of intra-settlement population: .......................................................................... 49 2.4.3: Estimating socio-economic variables: ................................................................................. 50 2.5: Applications of DMSP-OLS datasets: ......................................................................................... 51 2.5.1: Application in mapping urban areas and settlements: ........................................................ 52 2.5.2: Application in population studies: ....................................................................................... 54 2.5.3: Applications in studying economic activities: ...................................................................... 56 2.5.4: Applications in environmental studies and disaster management: ...................................... 57 2.5.5: Atlas of night-time sky: ........................................................................................................ 60 2.6: Limitations of DMSP-OLS Datasets: .......................................................................................... 61 2.6.1: Other sources of night-time datasets: ....................................................................................... 62 2.7: Summary: .................................................................................................................................... 64 3. Study Area ..................................................................................... 66 3.1: Maharashtra: A Geographical Profile: ........................................................................................ 66 3.2: Maharashtra in the Indian Census: .............................................................................................. 67 3.3: Summary ..................................................................................................................................... 69 4. Preparation of datasets for further analyses ................................... 70 4.1: