Photos from Inverse Days Conferences

Inverse Days is the annual scientific meeting of the Finnish Inverse Problems Society. It was organized for the first time in 1995 in Oulu, Finland, and since then every year in December in a changing venue in Finland. Over time, the meeting has developed from a one-day workshop of 20 people into an international conference of more than 100 participants spread over three days.

This page collects together photos and memories from the meetings over the years. If you have any questions about the images, or photos you would like to see here, please contact Samuli Siltanen by email (samuli.siltanen("at")

2015: Inverse Days 21 in Lappeenranta, Finland

2015 Lappeenranta, Finland. Johanna Tamminen from Finnish Meteorological Institute delivering her keynote talk that opened the conference.

2015 Lappeenranta, Finland. Matteo Santacesaria from Politecnico di Milano.

2015 Lappeenranta, Finland. Jenni Tick.

2015 Lappeenranta, Finland.

2015 Lappeenranta, Finland. Mohammad Pour-Ghaz from North Carolina State University.

2015 Lappeenranta, Finland. Matti Lassas.

2015 Lappeenranta, Finland. Zenith Purisha.

2015 Lappeenranta, Finland. Coffee break.

2015 Lappeenranta, Finland. Stratos Staboulis (right) receiving the FIPS Prize 2015.

2015 Lappeenranta, Finland. Hanne Kekkonen.

2014: Inverse Days 20 in Tampere, Finland

2014 Tampere, Finland. Anna Scherbacheva giving her talk.

2014 Tampere, Finland. Ismael Rodrigo Bleyer giving his talk.

2014 Tampere, Finland. The audience at Tampere-talo.

2014 Tampere, Finland. Ahmadi Zeleti delivering her talk.

2014 Tampere, Finland. Academy Professor Matti Lassas giving his talk.

2014 Tampere, Finland. Felix Lucka and Tapio Helin concentrating intensively.

2014 Tampere, Finland. Joonas Ilmavirta (left) receiving the FIPS Prize (formerly known as Pertti Lindfors Prize) from Samuli Siltanen.

2014 Tampere, Finland. Inverse Problems Headwear Show: by tradition, a special hat is given to Finnish researchers who defend a doctoral thesis in the field of inverse problems. From left to right: Tanja Tarvainen, Janne Huttunen, Samuli Siltanen, Eemeli Blåsten, Petteri Piiroinen and Sari Lasanen.

Below from left to right: Petteri Piiroinen, Johanna Tamminen, Samuli Siltanen, Janne Huttunen and Ossi Lehtikangas.

2013: Inverse Days 19 in Sodankylä and Inari, Finland

2013 Sodankylä, Finland. The audience at the Geophysical Observatory.

2013 Sodankylä, Finland. Filling up a balloon with hydrogen.

2013 Sodankylä, Finland. Johanna Tamminen releasing the balloon.

2013 Sodankylä, Finland. Tuomas Nikkonen, Jussi Korpela, Esa Niemi and Johanna Tamminen, in front of ionospheric radar antenna.

2013 Sodankylä, Finland. Elena Kozlovskaya delivering her lecture.

2013 Inari, Finland. Mykhaylo Yudytskiy, Hanne Kekkonen, Sarah Hamilton and Samuli Siltanen on ice.

2013 Inari, Finland. The venue: Sajos Cultural Centre.

2013 Inari, Finland. Audience in the main lecture hall.

2013 Inari, Finland. Former President of the Society, Professor Erkki Somersalo.

2013 Inari, Finland. Professor Matti Lassas.

2013 Inari, Finland. Pia Heins from University of Münster, Germany.

2013 Inari, Finland. Harri Auvinen, PhD, demonstrating glottal inverse filtering using 3D printed vocal tract models.

2013 Inari, Finland. The meeting broke the news: the local newspaper Lapin kansa reported the event.

2012: Inverse Days 18 in Jyväskylä, Finland

2012 Jyväskylä, Finland. The audience at the very beginning of the meeting. The main organiser, Professor Mikko Salo, is seen in the far left of the image.

2012 Jyväskylä, Finland. Tanja Tarvainen, PhD, delivering her lecture.

2012 Jyväskylä, Finland. Sarah Hamilton, PhD, explaining Electrical Impedance Tomography.

2012 Jyväskylä, Finland. The Inverse Problems Crowd.

2012 Jyväskylä, Finland. Aku Seppänen, PhD, talking about laser scanning forests.

2012 Jyväskylä, Finland. Professor Kim Knudsen from Technical University of Denmark telling about three-dimensional Electrical Impedance Tomography.

2012 Jyväskylä, Finland. Professor Mikko Salo, organiser of the 2012 Inverse Days.

2012 Jyväskylä, Finland. Professor Matti Lassas.

2012 Jyväskylä, Finland. Harri Auvinen, PhD, talking about glottal inverse filtering.

2012 Jyväskylä, Finland. Felix Lucka from University of Münster speaks about Bayesian inversion.

2012 Jyväskylä, Finland. Juha Vierinen (left), a new PhD, gets his special dissertation hat from Professor Samuli Siltanen, President of the society, and Professor Markku Lehtinen (right), supervisor of the thesis. It is a tradition of the Finnish Inverse Problems Society to give every new PhD a curious hat.

2011: Inverse Days 17 in Helsinki, Finland

2011 Helsinki, Finland. The audience in the very beginning of the meeting. In year 2011 the Inverse Days was combined with Finnish-Japanese-Korean Workshop in Inverse Problems.

2011 Helsinki, Finland. Professor Heikki Haario.

2011 Helsinki, Finland. Professor Hyeonbae Kang from Inha University, Korea.

2011 Helsinki, Finland. The audience is concentrating.

2011 Helsinki, Finland. International research team getting together during a coffee break. From left to right: Samuli Siltanen, Janne Tamminen, Olivier Poisson, Patricia Gaitan and Hiroshi Isozaki.

2011 Helsinki, Finland. The audience.

2011 Helsinki, Finland. Professor Takashi Kako from University of Electro-Communications, Tokyo, Japan.

2011 Helsinki, Finland. Ville Kolehmainen, PhD.

2011 Helsinki, Finland. Professor Mikyoung Lim from KAIST, Korea.

2011 Helsinki, Finland. Professor Matti Lassas.

2011 Helsinki, Finland. Nuutti Hyvönen, PhD.

2011 Helsinki, Finland. Professor Mikko Kaasalainen.

2011 Helsinki, Finland. Once more: the audience.

2010: Inverse Days 16 in Oulu, Finland

2010 Oulu, Finland. Professor Matti Lassas.

2010 Oulu, Finland. Professor Valeriy Serov, the organizer.

2010 Oulu, Finland. PhD student Esa Niemi delivering his first scientific conference talk.

2009: Inverse Days 15 in Luosto, Finland

2009 Luosto, Finland. Professor Patricia Gaitan.

2009 Luosto, Finland. Professor Michel Cristofol.

2009 Luosto, Finland. Professor Mikko Kaasalainen.

2008: Inverse Days 14 in Kuopio (Tahkovuori), Finland

2008 Kuopio, Finland.

2008 Kuopio, Finland. Professors Erkki Somersalo and Heikki Haario.

2008 Kuopio, Finland. Matti Lassas, Samuli Siltanen, Juha Vierinen and Markku Lehtinen.

2006: Inverse Days 12 in Tampere, Finland

2006 Tampere, Finland. Opening words by the organiser, Professor Samuli Siltanen.

2006 Tampere, Finland. Professor Chris Johnson, University of Utah, USA.

2006 Tampere, Finland.

2006 Tampere, Finland. Professor Giovanni Alessandrini, University of Trieste, Italy.

2006 Tampere, Finland. Professors Matti Lassas.

2006 Tampere, Finland. Professor Erkki Somersalo.

2006 Tampere, Finland. Martti Kalke from the company Palodex Group.

2006 Tampere, Finland. Collection of official hats of the society: Jenni Heino, Matti Lassas, Hanna Pikkarainen, Matti Lassas and Petteri Piiroinen.

2005: Inverse Days 11 in Helsinki, Finland

2005 Helsinki, Finland. Medical Imaging Day at the facilities of Palodex Group in Tuusula.

2005 Helsinki, Finland. Medical Imaging Day at the facilities of Palodex Group in Tuusula.

2005 Helsinki, Finland. Kenrick Bingham and Matti Lassas.

2004: Inverse Days 10 in Sodankylä, Finland

2004 Sodankylä, Finland.

2004 Sodankylä, Finland.

2003: Inverse Days 9 in Oulu (Syötekeskus), Finland

2003 Oulu, Finland. Professor Erkki Somersalo, the President of the Society.

2003 Oulu, Finland.

2003 Oulu, Finland. Matti Lassas.

2003 Oulu, Finland.

1997: Inverse Days 3 in Espoo (Otaniemi), Finland

1997 Espoo, Finland.

1997 Espoo, Finland. Excursion to the brain imaging facilities of the Cold Temperature Laboratory of Helsinki University of Technology. From left to right: Petri Ola, Mikko "Hiski" Orispää, Jan von Pfaler and Hannu Mäkiö.

1997 Espoo, Finland.

1997 Espoo, Finland.

1996: Inverse Days 2 in Sodankylä, Finland

1996 Sodankylä, Finland. PhD student Samuli Siltanen in freezing weather.

1996 Sodankylä, Finland. The participants are keenly absorbing scientific information.

1996 Sodankylä, Finland. Excursion to the EISCAT radar measurement facility.

1996 Sodankylä, Finland. EISCAT radar disc in the background, Valeriy Serov and Markku Lehtinen in the foreground.

Last updated on December 4, 2013.