The work for this thesis was carried out in the Space Science and Engineering Center of the University of Wisconsin--Madison, USA. I would like to express my gratitude to my supervisor, Dr. Edwin W. Eloranta, for discussions and comments during the study as well as providing the facilities of the University of Wisconsin Lidar group.
I wish to thank Dr. Tapio Tuomi from the Finnish Meteorological Institute and Prof. Mike Hardesty from WPL/ERL NOAA for their excellent reviews of the manuscript of this thesis. I value their comments and suggestions which helped me to improve this work.
I am grateful to my wife and collegue Päivi for support, discussions, and sharing ideas during these years.
I wish to express my gratitude to Dan Forrest for managing the lidar data acquisition during field experiments, professional suggestions on programming, and providing Figure 19 showing a three-dimensional raytraced cloud map. I also wish to thank Susan Sowinski and Beth O'Brien for proofreading this thesis and helping me to improve my English writing.
Special thanks to Leena Kirkkomäki. Dedicated people like her make life better for hard working researchers. Thanks to Dr. Timo Jääskeläinen for comments and advice during preparation of the thesis. Thanks to Kari Hassinen for technical help on printing this thesis.
Kiitokset taustatuesta vanhemmilleni Arvolle ja Almalle, sisaruksilleni Veikolle, Vapulle perheineen ja Jukalle perheineen, appivanhemmilleni Erkki ja Helvi Liukolle sekä Juhalle ja Marjalle.
The comparisons between the VIL and the other instruments were made possible by several research groups attending to the FIFE program. AVHRR satellite images were produced by the FIFE Information System staff. The radiosonde data were measured by a team from Cornell University, USA, directed by Prof. W. Brutsaert. The aircraft data was provided by a team from Canadian National Aeronautical Establishement directed by Dr. J.I. MacPherson. The dedicated work of these groups is gratefully acknowledged.
This work was done under grants from the University of Joensuu, Finland, Finnish Academy, Alfred Kordelin Foundation, Finland, and Suomen Kulttuurin Edistämissäätiö Foundation, Finland, whose support is gratefully acknowledged. The Volume Imaging Lidar was supported by National Aeronautics and Space Administration under grant NAG-5-902 and by Army Research Office under grants DAAL03-86-K-0024, DAAL03-91-C-0222, and DAAH04-94-G-0195.
Madison, USA, August 1, 1994