mapping spatial variation of foliar nitrogen using hyperspectral remote sensing

178 Pages·2016·4.86 MB·English

MAPPING SPATIAL VARIATION OF FOLIAR
NITROGEN USING HYPERSPECTRAL REMOTE
SENSING

Zhihui Wang
Graduation committee:

Prof.dr. V.G. Jetten University of Twente
Prof.dr. ing W. Verhoef University of Twente
Prof.dr. K. Dabrowska-Zielinska Institute of Geodesy and Cartography
Dr. J.G.P.W. Clevers Wageningen University

ITC dissertation number 295
ITC, P.O. Box 217, 7500 AA Enschede, The Netherlands

ISBN 978-90-365-4260-9
DOI 10.3990/1.9789036542609

Cover designed by Benno Masselink
Printed by ITC Printing Department
Copyright © 2016 by Zhihui Wang
MAPPING SPATIAL VARIATION OF FOLIAR
NITROGEN USING HYPERSPECTRAL REMOTE
SENSING

DISSERTATION

to obtain the double-badged degree of doctor
at the University of Twente, Enschede, The Netherlands; and
RMIT University, Melbourne, Australia,

on the authority of the rector magnificus,
prof.dr. T.T.M. Palstra, for University of Twente

on the authority of the Chancellor, Dr Ziggy Switkowski AO; and
the Vice-Chancellor and President of RMIT University, Mr Martin Bean CBE,
for RMIT University

on account of the decision of the joint graduation committee,
to be publicly defended
on Thursday 1st of December 2016 at 11.00 hrs

by

Zhihui Wang

born on 08 March 1988

in Shandong, China
This thesis is approved by

Prof. dr. A. K. Skidmore, promoter University of Twente
Prof. dr. J. Hearne, promoter RMIT University
Dr. T. Wang, co-promoter University of Twente
To my family

Acknowledgements
I would like to thank a girl who decided to do a PhD four years ago, which brought
me numerous wonderful adventures in the following journey. Through this long
journey, I managed to find my research interests and become to what I expected.
A number of elements are essential in doing a PhD, among which I value
motivation, curiosity, commitment, and perservance, and more importantly the
guidance and help I gained from the following people. Without their support, this
thesis could not be completed.
My first gratitude goes to my promoter Prof. Dr. Andrew K. Skidmore. I was
amazingly fortunate to have you as my promoter. Thank you for guiding me
toward this challenging and intriguing research. I appreciate the freedom you
gave me to explore on my own, as well as your enlightenment when I got stuck.
You were always optimistic about my work, which boosted my confidence. From
you, I learned the way of thinking critically, and that of defending my idea when
it conflicted with others. Your words “work hard and work smart” echoed in my
mind from time to time. I always received your critical and constructive
comments and corrections on my manuscripts within short time, which
dramatically improved their quality. I am indebted to you for recommending me
to join the double-badged PhD program between UT and RMIT University,
which greatly enriched my PhD life through the six months stay in Melbourne.
Thank you for being my ideal promoter and advisor not just in academic field but
also in everyday life.
Special thanks go to my daily supervisor, Dr. Tiejun Wang, who spotted my
potential to do a PhD in my application nearly five years ago. The interview was
the first time we discussed about doing research, which continued for four years
after I started my PhD. I appreciate your guidance and support in writing the
research proposal as well as later articles. I cannot remember how many times
you helped me out of maize when I was writing a paper. Your logical thinking
showed me how to shape my idea and tell a good story. You always replied to me
promptly and gave back comments on my manuscripts within a few days. You
aided me to keep on a good track. I would also like to thank you for joining my
fieldwork in the first week and assisting me to set up the initial experiments. In
addition, I learned from you the skills in dealing with interpersonal relationship
and cooperation. Thank you for always being there to listen to me and giving me
advice.
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I would express my gratitude to Dr. Roshanak Darvishzadeh for your excellent
supervision. Thank you for sharing your experiences of working on radiative
transfer models. I also got plenty of inspirations from your publications when
conducting some chapters of this thesis. Your detailed and critical comments
highly improved my manuscripts. I am grateful to your efforts into advising me,
also your support and kindness to me.
I am indebted to Prof. Dr. John Hearne, who was willing to be my promoter in
RMIT University. I am grateful for our weekly meeting during my stay in RMIT,
and appreciate our discussions on optimization and model inversion, which
helped me a lot in revising one of my chapter. I would like to thank you for the
corrections and comments on my manuscripts.
I am thankful to Prof. Dr. Simon Jones for providing me the working space in
RMIT, sharing ideas on my research, and collaborating in one of my manuscripts.
Thanks also go to Dr. Lola Suarez and Dr. William Woodgate for the discussion
on my work while I was in RMIT. I appreciate the comments and experiences
shared by Lola, and the help of William with processing digital hemispherical
photos. I would like to thank other colleagues in the Remote Sensing Lab in
RMIT who made me feel welcome, they are Phil, Mariela, Rob, Luke, and Bryan.
I am grateful to the staffs Beebee, Sharon, Erin and Eliza in RMIT for their kind
support.
I acknowledge the support of the “Data Pool Forestry” data-sharing initiative of
the Bavarian National Park. I am indebted to the “Applied spectroscopy” team of
the German Aerospace Center (DLR) and Bavarian Forest National Park for
assistance in the fieldwork. Special thanks go to Dr. Uta Heiden and Dr. Macro
Heurich for the contribution to my manuscripts. I appreciate that Dr. Jörg Müller
patiently showed me how to operate the crossbow, was so kind when the
crossbow was damaged during the fieldwork, and contacted with Dr. Martin
Goßner in Technische Universität München to lend me another one, which
ensured the completion of the fieldwork on time. I would also acknowledge the
following people for the assistance in the fieldwork as well as collection and
preprocessing of airborne hyperspectral images, they are: Dr. Nicole Pinnel
(DLR), Stefanie Holzwarth (DLR), Horst Burghart (BFNP), Burkhard Beudert
(BFNP), Dr. Hooman Latifi (University of Würzburg), and Dr. Martin Goßner
(TUM).
I would also thank Abebe Ali for conducting the fieldwork together with me. We
had worked together to overcome a variety of hardships and unexpected
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circumstances both in sample collection and measurements. I appreciate your
cooperation in later data analysis and all discussions on research. I would also
thank Maria Buitrago for the assistance and help in the fieldwork, your efficient
working impressed me a lot.
I am grateful to Esther Hondebrink for answering my inquiries, being supportive
and translating the summary of the thesis into Dutch. I would like to express my
gratitude to Loes Colenbrander for being kind and helpful to me, as well as
formatting the thesis. Thanks go to other colleagues in NRS for their support and
kindness, they are William, Thomas, Iris, Anton, Andy, and etc. I would also like
to thank Benno Masselink and Job Duim for their excellent service, particularly
thank Benno for the assistance in making posters and the efforts into designing
the thesis cover. I express my sincere gratitude to Bouderwijn de Smeth for the
assistance with laboratory measurements. I would also like to thank the support
of Watse Siderius in the ITC lab.
I extend my special gratitude to Linlin Li for her company and support in the past
four years, we had plenty of fun in daily life as well as all types of trips. Thank
all the office mates in our lady’s room who are still here or has left, they are
Anahita, Maitreyi, Adrie, Milica and Jing. I also thank other PhD candidates in
NRS department for sharing joy and ideas, as well as the discussion in the PhD
tutorial, they are Fangyuan Yu, Yiwen Sun, Jing Liu, Xi Zhu, Yifang Shi, Sonia,
Elnaz, Mitra, Parinaz, Festus, Yifei Xue, Tawanda, Trini, Alby, and Haidi. I
express my thanks to the Chinese friends for their support and company, they are
Xiaojing Wu, Ying Zhang, Linlin Pei, Tina, Xiaoling Wang, Donghai Zheng,
Xuelong Chen, Yijing Zeng, Junping Du, Xu Yuan, Hong Zhao, Xiaolong Yu,
Peiqi Yang, Chengliang Liu, Shaoning Lv, and so on.
I would like to thank my family and friends in China for always being on my side.
Thank Xuejun for your long-term support and company. I am most grateful to my
father and mother for their tremendous support and unconditional love. I would
thank my brother and sister in law who supported me and cared my parents when
I was away. Lastly, I would like to thank my boyfriend Nanfeng for being my
rock. Thank you for your support of each decision I made. I am sincerely grateful
to you for patience, tolerance and most importantly your love.

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