[1] Carl-Fredrik Enell, Noora Partamies, Sanna Mäkinen, Jyrki Mattanen, Laureline Sangalli, Mika Veijonsuo, Björn Gustavsson, Urban Brändström, and Torsten Aslaksen. EMCCD cameras for auroral imaging. Optics Days 2011, Oulu, Finland, May 2011. [ bib ]
During recent years several research institutes in northern Fennoscandia have deployed imaging instruments of a new generation, electron multiplying charge coupled devices (EMCCDs), for imaging the northern lights (Aurora Borealis). EMCCDs eliminate readout noise by on-chip electron multiplication before the readout amplifier, and therefore the much higher quantum efficiency of the bare CCD as compared with image-intensified cameras can be utilized[1]. Therefore EMCCDs allow high-speed imaging or imaging of very weak emissions, improving the understanding of plasma-physical processes in the Earth's environment and auroral energy deposition into the atmosphere. Other applications include meteor and airglow research. Challenges in the use of these instruments include 1. Geometrical calibration (i.e. modelling the projection from geographical to pixel coordinates). A study of different projection models based on star mapping is presented. 2. Intensity calibration, including flat-field and absolute radiometric calibration. The use of star spectra for this purpose is discussed.

[2] C.-F. Enell, B. Gustavsson, T. Sergienko, U. Brändström, and I. Sandahl. ALIS volume estimates of the 4278 and 5577 Å intensities, with applications. Talk, 37th Annual European meeting on Atmospheric Studies by Optical Methods, Valladolid, Spain, August 2010. [ bib ]
In this study applications of remote sensing of auroral volume emissions are investigated. Data from the Auroral Large Imaging System (ALIS) cameras at field stations in northern Sweden and Norway are used to calculate tomography-like estimates of the N2+(1N) emission at 4278 Å and the O(1S) emission att 5577 Å. Applications of the spectroscopic ratios include 1) estimates of electron energy spectra, which have applications in auroral theory and in estimating ionisation rates for incoherent scatter radar and ion chemistry model studies and 2) direct estimates of the chemical composition of the lower thermosphere, as the 5577 emission is excited at least partly through chemistry.

[3] Carl-Fredrik Enell, Jonas Hedin, Jacek Stegman, Georg Witt, Martin Friedrich, Werner Singer, Gerd Baumgarten, Bernd Kaifler, Ulf-Peter Hoppe, Björn Gustavsson, Urban Brändström, Mikhail Khaplanov, Antti Kero, Thomas Ulich, and Esa Turunen. Hotel Payload 2 measurements of NO, O and electron density. Talk, 4th NordAuropt workshop, Apatity, Russia, May 2010. [ bib | http ]
A summary of the submitted JASTP paper on HotPay2 was given at the 4th NordAuropt workshop

[4] Carl-Fredrik Enell, Torsten Aslaksen, Urban Brändström, Hanna Dahlgren, Björn Gustavsson, Nickolay Ivchenko, Noora Partamies, and Ingrid Sandahl. A collaborative ground-based optical infrastructure for space and atmospheric studies in the barents region. Talk, 4th NordAuropt workshop, Apatity, Russia, May 2010. [ bib | http ]
[5] Juha Vierinen, Asta Pellinen-Wannberg, Urban Brändström, Björn Gustavsson, and Carl-Fredrik Enell. Radar measurements during the Leonid campaign 2009. Presentation, Meteoroids 2010 conference, Breckenridge, Colorado, USA, May 2010. [ bib ]
We present the results of radar measurements during the 4.5-day campaign around the Leonid maximum in November 15-20 2009, in which we conducted simultaneous tristatic EISCAT UHF measurements along with optical EMCCD observations. During the last 24 hours, we also performed dual-polarization measurements with the two remote receiving stations. Due to significantly improved sensitivity of the detection algorithms, we obtained a larger meteor detection rate than in previous studies at EISCAT UHF, peaking at 200 detections per hour at 6 UT. No significant increase in meteor detection rate was observed during the peak of the Leonid shower. We detected several low altitude trail-like structures, the lowest one at 60 km. An overview plot of the results is shown in Fig 1.

[6] H. Lamy, C. Simon, M. Echim, JM de Keyser, B. Gustavsson, T. Sergienko, I. Sandahl, and U. Brändström. Characterizing magnetospheric electrons from alis observations of discrete auroral arcs and quasi-stationary modeling of auroral acceleration. In AGU Fall Meeting Abstracts, volume 1, page 1878, 2010. [ bib ]
[7] H. Lamy, C. Simon, B. Gustavsson, J. de Keyser, T. Sergienko, U. Brändström, and I. Sandahl. Coordinated observations of auroral arcs with alis and eiscat. In 38th COSPAR Scientific Assembly, volume 38, page 1146, 2010. [ bib ]
[8] I. Sandahl, T. Sergienko, K. Axelsson, B. Gustavsson, and U. Brändström. Deducing spatial properties of auroral primary particle distributions from ground-based optical imaging. In AGU Fall Meeting Abstracts, volume 1, page 1885, 2010. [ bib ]
[9] I. Sandahl, U. Brändström, and T. Sergienko. Fine structure of aurora. Int. J. Remote Sensing, 2010. [ bib ]
[10] C. Simon, H. Lamy, B. Gustavsson, JM de Keyser, T. Sergienko, U. Brändström, and I. Sandahl. Discrete auroral arcs: coordinated alis-eiscat observations and modelling. In AGU Fall Meeting Abstracts, volume 1, page 1713, 2010. [ bib ]
[11] I. Sandahl, editor. In the light of the aurora, Optical research in northernmost Europe, volume 557 of TemaNord, Copenhagen, 2009. Nordic Council of Ministers, Copenhagen. http://www.norden.org/sv/publikationer/publikationer/2009-557. [ bib ]
[12] Urban Brändström, Ingrid Sandahl, Tima Sergienko, Asta Pellinen-Wannberg, Björn Gustavsson, M. T. Rietveld, Takehiko Aso, and Åke Steen. Alis - highlights, status and future plans. In Physics of Auroral Phenomena, volume XXIX of Annual seminar Apatity, pages 217-220. Kola Science Centre, Russian Academy of Science, 2006. [ bib ]
[13] Urban Brändström, Björn Gustavsson, Asta Pellinen-Wannberg, Ingrid Sandahl, Tima Sergienko, and Åke Steen. Groundbased multi-station spectroscopic imaging with ALIS - scientific highlights, project status and future projects. In 17th ESA Symposium on European Rocket and Balloon Programmes and Related Research, volume SP-590, pages 239-244. European Space Agency, May 2005. ISBN 92-9092-901-4. [ bib ]
[14] Ingrid Sandahl, Urban Brändström, Björn Gustavsson, and Tima Sergienko. International network for auroral optical studies of the polar ionosphere. In 17th ESA Symposium on European Rocket and Balloon Programmes and Related Research, volume SP-590, pages 607-612. European Space Agency, May 2005. ISBN 92-9092-901-4. [ bib ]
[15] Peter Rydesäter, Björn Gustavsson, Urban Brändström, and Åke Steen. Lossy compression of scientific images of aurora. Sodankylä Geophysical publication series, 92:1-4, August 2003. [ bib ]
[16] Urban Brändström, Björn Gustavsson, Åke Steen, and Asta Pellinen-Wannberg. ALIS (Auroral Large Imaging System) used for optical observations of the meteor impact process. In Barbara Warmbein, editor, Proceedings of the Meteoroids 2001 Conference, volume SP-495, pages 331-336. European Space Agency, 2001. ISBN 92-9092-805-0. [ bib ]
[17] Solveig H. Høymork, editor. Sensors and Instruments for Space Exploration, chapter 6. Measurements by optical methods, pages 71-119. Swedish Institute of Space Physics, Kiruna, 2 edition, 2000. [ bib ]
[18] Carl-Fredrik Enell, Björn Gustavsson, Åke Steen, Urban Brändström, Peter Rydesäter, P. Johansson, T. Wagner, U. Friess, K. Pfeilsticker, and U. Platt. Optical studies of polar stratospheric clouds. In Jaqueline E. Russell, editor, Proceedings of SPIE, Satellite remote sensing of clouds and the atmosphere IV, volume 3867, pages 290-297. The International Society for Optical Engineering, September 1999. [ bib ]
[19] M. Hedin, I. Häggström, Asta Pellinen-Wannberg, I. Häggström, Laila Andersson, Urban Brändström, Björn Gustavsson, Åke Steen, Assar Westman, Gudmund Wannberg, Tony van Eyken, Takehiko Aso, Cynthia Cattell, Charles W. Carlson, and Dave Klumpar. Trough observations with the EISCAT radars, ALIS auroral imaging system and FAST satellite. In Jan-Olof Gustavsson, editor, Proceedings of RadioVetenskap och Kommunikation 99, volume 1, pages 113-117, Karlskrona, Sweden, June 1999. Högskolan i Karlskrona/Ronneby. ISBN 91-630-8156-3. [ bib ]
[20] B. U. E. Brändström, T. B. Leyser, Å. Steen, M. T. Rietveld, B. Gustavsson, T. Aso, and M. Ejiri. ALIS observations of heater induced airglow at high latitudes. In B. Kaldeich-Schürmann, editor, Proceedings 14th ESA Symposium on European Rocket and Balloon Programmes and Related Research, volume SP-437, page 389. European Space Agency, May 1999. ISBN 92-9092-748-8. [ bib ]
[21] Åke Steen, Jan Englund, Urban Brändström, Ulf Stambro, Sten Hedlin, Stig Kemi, Lennart Marcus, Ola Widell, and Lars Sarri. KEOPS a networked optical research facility at high latitudes. In B. Kaldeich-Schürmann, editor, Proceedings 14th ESA Symposium on European Rocket and Balloon Programmes and Related Research, volume SP-437, pages 173-178. European Space Agency, May 1999. ISBN 92-9092-748-8. [ bib ]
[22] Takehiko Aso, Masaki Ejiri, Akira Urashima, Åke Steen, Urban Brändström, and Björn Gustavsson. Auroral tomography of ALIS images and related camera calibrations. In XXV annual European Meeting on Atmospheric Studies by Optical Methods, page 49. Instituto de Astrofísica de Andalucia, Granada, Spain, 1999. [ bib ]
[23] Carl-Fredrik Enell, Åke Steen, Björn Gustavsson, Urban Brändström, Per Johansson, Thomas Wagner, Udo Frieß, Klaus Pfeilsticker, Ulrich Platt, and Karl-Heinrich Fricke. Detection of polar stratospheric clouds at Kiruna. In K. S. Carslaw and G. T. Amanatidis, editors, Air pollution report 69, Mesoscale processes in the stratosphere, volume 18912, pages 65-68, Luxembourg, 1999. Office for Official Publications of the European Communities, European Commission. ISBN 92-828-4629-6. [ bib ]
[24] Carl-Fredrik Enell, Åke Steen, Björn Gustavsson, Urban Brändström, Per Johansson, Thomas Wagner, Udo Frieß, Klaus Pfeilsticker, and Ulrich Platt. Studies of polar stratospheric clouds occurence at Kiruna. In XXV annual European Meeting on Atmospheric Studies by Optical Methods, pages 122-126. Instituto de Astrofísica de Andalucia, Granada, Spain, 1999. [ bib ]
[25] Åke Steen, Björn Gustavsson, Carl-Fredrik Enell, and Urban Brändström. PSC dynamics investigated by multi-station imaging - techniques, results and prospects. In K.S. Carslaw and G.T. Amanatidis, editors, Air pollution research report. Mesoscale processes in the stratosphere, volume 69, pages 239-242. European Comission, 1999. ISBN 92-828-4629-6. [ bib ]
[26] Åke Steen, Björn Gustavsson, Urban Brändström, Takehiko Aso, and Masaki Ejiri. OI 846.6 nm auroral imaging. In Proceedings of the 25th annual European Meeting on Atmospheric Studies by Optical Methods, Granada, Spain, pages 90-95. Instituto de Astrofísica de Andalucia, Granada, Spain, 1999. [ bib ]
[27] Urban Brändström, Åke Steen, Peter Rydesäter, Björn Gustavsson, and Takehiko Aso. ALIS, a multi station imaging facility with possibilities of future VI applications. In Mary Lou Padget Thomas Lindbladh and Jason Kinser, editors, Ninth workshop on Virtual Intelligence / Dynamic neural networks, volume 3728, pages 108-114. Royal Institute of Technology, Stockholm, Sweden, The International Society for Optical Engineering, June 1998. ISBN 0-8194-3202-4. [ bib ]
[28] M. I. Pudovkin, Åke Steen, N. V. Nikolaev, O. I. Kornilov, Urban Brändström, Björn Gustavsson, and Peter Rydesäter. Automatic recognition of auroral forms. In Mary Lou Padget Thomas Lindbladh and Jason Kinser, editors, Ninth workshop on Virtual Intelligence / Dynamic neural networks, volume 3728, pages 121-127. Royal Institute of Technology, Stockholm, Sweden, The International Society for Optical Engineering, June 1998. ISBN 0-8194-3202-4. [ bib ]
[29] Peter Rydesäter, Åke Steen, Urban Brändström, and Björn Gustavsson. Classifying auroras using artificial neural networks. In Mary Lou Padget Thomas Lindbladh and Jason Kinser, editors, Ninth workshop on Virtual Intelligence / Dynamic neural networks, volume 3728, pages 115-120. Royal Institute of Technology, Stockholm, Sweden, The International Society for Optical Engineering, June 1998. ISBN 0-8194-3202-4. [ bib ]
[30] Åke Steen, Urban Brändström, and Björn Gustavsson. ALIS - a multi station imaging system at high latitude with multi disciplinary scientific objectives. In Proceedings 13th ESA Symposium on European Rocket and Balloon Programmes and Related Research, pages 261-266. ESA, September 1997. [ bib ]
[31] Urban Brändström, Åke Steen, Björn Gustavsson, Laila Andersson, Ingemar Häggström, Assar Westman, Asta Pellinen-Wannberg, Takehiko Aso, Kari Kaila, Charles W. Carlson, David Klumpar, and Cindy Catell. Preliminary results from coordinated measurements by FAST and groundbased optical and radar facilities, in Northern Scandinavia, during active auroral conditions. In Proceedings of the 24th annual European Meeting on Atmospheric Studies by Optical Methods, pages 41-46. Sentraltrykkeriet A/S Bodø, August 1997. ISBN 82-994583-0-7. [ bib ]
[32] Urban Brändström, Åke Steen, Björn Gustavsson, and Takehiko Aso. ALIS - current status, planned developement and calibration. In Proceedings of the 24th annual European Meeting on Atmospheric Studies by Optical Methods, pages 214-217. Sentraltrykkeriet A/S Bodø, August 1997. ISBN 82-994583-0-7. [ bib ]
[33] Urban Brändström, Åke Steen, Björn Gustavsson, David Rees, and M. J. Harris. Preliminary results from a comparision of observations of thermospheric neutral wind patterns and auroral emissions. In Proceedings of the 24th annual European Meeting on Atmospheric Studies by Optical Methods, pages 37-40. Sentraltrykkeriet A/S Bodø, August 1997. ISBN 82-994583-0-7. [ bib ]
[34] Åke Steen, Urban Brändström, Björn Gustavsson, and Takehiko Aso. A multistation approach in the Barents region. In Proceedings of the 24th annual European Meeting on Atmospheric Studies by Optical Methods, pages 203-206. Sentraltrykkeriet A/S Bodø, August 1997. [ bib ]
[35] Åge J. Eide, V. Becanovic, U. Brändström, C. Holmström, M. Larsson, Inge Morten Lillesand, Thomas Lindblad, C. S. Lindsey, Åke Steen, and J. Waldemark. Pulse coupled neural network pre-processing of aurora images. In AI Applications in Solar Terrestial Physics, volume WPP-148, pages 201-205. European Space Agency, July 1997. [ bib ]
[36] Peter Rydesäter, Åke Steen, Björn Gustavsson, and Thomas Lindblad. Application of selective imaging techniques to multi-station imaging. In 2nd workshop on AI Applications in Solar Terrestial Physics, volume WPP-148, pages 195-199. European Space Agency, July 1997. [ bib ]
[37] Åke Steen, Björn Gustavsson, and Urban Brändström. Temporal variation of 2D altitude distributions of lee-wave generated polar stratospheric clouds. In Proceedings of the 4th European symposium of polar stratospheric ozone, 1997. [ bib ]
[38] J. Waldemark, V. Becanovic, U. Brändström, C Holmström, M. Larsson, T. Lindblad, C. S. Lindsay, and Åke Steen. Investigation of useful image preprocessing for analysis of aurora images. In Proceedings EANN, 1997. [ bib ]
[39] Åke Steen, Urban Brändström, and Björn Gustavsson. Multi station imaging studies together with the ørsted satellite. In Proc. Ørsted meeting. Sodankylä, Finland, April 1996. [ bib ]
[40] Urban Brändström and Åke Steen. ALIS - A new ground-based facility for auroral imaging in Northern Scandinavia. In Proc. 11th Symposium on European rocket and ballon programmes and related research, Montreux, Switzerland., pages 301-306. European Space Agency, March 1994. ESA SP-355. [ bib ]
[41] Urban Brändström. Reduction and analysis of astronomical image data from the 'Stockholm' CCD camera at NOT (Nordic Optical Telescope). In Juhani Huovelin, editor, Reports of the Nordic course on astronomical image processing, pages 19-26. Observatory, University of Helsinki, August 1993. Report 3/1993. [ bib ]
[42] Åke Steen and U. Brändström. A multi station ground-based imaging system at high latitudes. STEP Int. Newslett., 3(5):11-14, May 1993. [ bib ]
[43] Åke Steen and Urban Brändström. requirements on CCD-detectors for ground-based auroral imaging. In Proc. ESA symposium on photon detectors for space instrumentation, pages 379-382, ESTEC, The Netherlands, December 1992. European Space Agency. ESA-SP-356. [ bib ]
[44] Urban Brändström and Åke Steen. Report on the ALIS project. In Åke Steen, editor, Proc. 19th Annual European meeting on atmospheric studies by optical methods, Kiruna, Sweden, pages 310-321, Kiruna, Sweden, 1992. Swedish Institute of Space Physics. IRF Scientific Report 209. [ bib ]
[45] Urban Brändström and Åke Steen. ALIS station architecture. In Proc. NSSR Annual meeting, Klintholm Havn, Møn, Denmark, pages 111-118. Nordic Society for Space Research, November 1991. [ bib ]
[46] Åke Steen, Urban Brändström, and Kari Kaila. A scientific and technical description of ALIS. In Proc. NSSR Annual meeting Bolkesjø, Norway, pages 153-164. Nordic Society for Space Research, November 1990. [ bib ]

This file was generated by bibtex2html 1.91.