The members of the Institute are active in a number of areas of applied and basic research. They address various problems in astronomy, astrophysics, space physics, solar physics, ionospheric and magnetospheric physics, Earth observation via ground based and space-born remote sensing. In addition there is expertise in advanced wireless communication and signal processing techniques which can be used in sophisticated data analysis techniques. The institute also supports and operates and develops instruments for the 2.3m Aristarchos telescope. More specifically the basic research areas of the institute are the following:
Ground-Based Astrophysics [+/-]
IAASARS researchers have expertise in ground-based observations with optical telescopes in both photometry and spectroscopy. They mainly address problems related to stars, their evolution and complex interplay with the ISM, as well as binary stars and stellar proper motion. In addition group members are studying the morphology and evolution of nearby galaxies.
-Permanent: I. Bellas-Velidis, A. Bonanos, P. Boumis, A. Dapergolas, P. Hantzios, D. Sinachopoulos, E. Xilouris
-Adjunct Researchers: D. Hatzidimitriou
-Postdocs: P. Gavras, A. Liakos, K. Sokolovsky, M. Yang
-Graduate Students: M. Kourniotis, Z. Spetsieri
Gaia Mission Support [+/-]
IAASARS researchers actively participate in ESA's cornerstone mission Gaia as members of the Data Processing and Analysis Consortium (DPAC, 2006-2020), accepted by ESA to process the Gaia data that arrives from the satellite. IAASARS participate in three of the nine Coordination Units of DPAC, CU2 "Data Simulations", CU4 "Object Processing", and CU8 "Astrophysical Parameters". Within CU8, researchers main activity is the development and implementation in the DPAC's pipeline of an Artificial Intelligence based system for classification and parameterization of galaxies observed by Gaia, a top-level package "GWP832 Unresolved Galaxy Classifier". One of the researchers is a co-manager of the WP832 and is managing the "GWP806 Utility library and data model" package. Another is a member of the "Non-Single Stars (NSS)" subgroup of CU4 , developing DU439 "The Solution Combiner" that aims to improve the parameters estimation of a binary by combining all available solutions. The researchers also participate in preparation of synthetic and semi-empirical galaxy spectra libraries for CU8 and simulations of extended objects. These activities are in the frame of CU2/DU3 "Universe Model". The researchers participate in the ESO-Gaia Survey for ground-based observational support to the mission.
Infrared Astrophysics [+/-]
The Infrared Astrophysics group has a strong expertise in infrared data analysis obtained with the Spitzer Space Telescope of NASA and the Herschel Space Observatory and Infrared Space Observatory of ESA. The team addresses various topics in extragalactic astrophysics and in particular in galaxy evolution, dust formation and gas depletion in interacting galaxies and Active Galactic Nuclei, gas and dust properties of Luminous Infrared Galaxies, as well as radiative transfer modeling and dust properties of nearby galaxies.
X-ray Astrophysics [+/-]
The X-ray Astrophysics group is one of the largest groups of the institute with four permanent staff and six postdoctoral researchers. The group has extensive experience in X-ray data analysis mainly from the XMM-Newton space observatory and also from the Chandra X-ray observatory. The group has been focusing problems related to AGN formation and evolution as it can be probed by the X-ray emission of distant and nearby galaxies.
Group webpage: http://xraygroup.astro.noa.gr
Ionospheric Physics [+/-]
The main activities of the Ionospheric Group focus around the performance of systematic ionospheric monitoring and the development of ionospheric and trans-ionospheric nowcasting and prediction systems through the on-line implementation of advanced modelling techniques ingesting ground and space data from all geospace regions. Today, the Ionospheric Group through its research infrastructures (the Athens Digisonde and the DIAS system) and systematic funding by the EC, EOARD, NOA and ESA, provides services able to support systematically HF communication systems, satellites orbiting at LEO and MEO heights and systems relying on transionospheric propagation, at any location of the Earth's upper atmosphere up to the plasmapause, and protect these systems from ionospheric disturbances and irregularities triggered by space weather events.
Group webpage: http://www.iono.noa.gr
Group webpage: http://www.iono.noa.gr
Solar and Heliospheric Physics Group [+/-]
The Solar and Heliospheric Physics Group studies the Sun using observational data from satellites (such as SoHO, TRACE and Hinode) and/or ground-based observatories (such as THEMIS in Tenerife and DOT in La Palma) in combination with modelling and theoretical tools (such as radiative transfer). These observational data provide, through a multi-wavelength analysis, coverage of the solar atmosphere from the lower layers to the outer corona and permit the extraction of quantitative information about the physical parameters that describe the thermodynamic state of the solar plasma. The group is currently investigating a wide range of solar phenomena occurring in active and quiet regions that include sunspots, loops, surges and small-scale structures.
Moreover, analysis and interpretation of Solar Energetic Particle (SEP) data, as well as complementary plasma and magnetic field data collected by ESA and NASA spacecraft (e.g. STEREO, Ulysses, ACE, Wind, Cluster) is carried out in order to study the effects of eruptive solar events in the interplanetary space and the Earth's environment. Research is performed on the solar origin, acceleration and transport of SEPs in the Heliosphere, Heliospheric Particle Reservoirs, Space Weather forecasting, the effect of solar storms to the environment of Mars and to astronauts of future Manned Space Missions. In collaboration with European and American partners the first European Space Weather Alert System is being implemented.
Space Research and Technology [+/-]
The Space Research and Technology Group specializes in studies of planetary and interplanetary plasmas, geomagnetism and space magnetism, and space weather prediction. It operates the HellENIc GeoMagnetic Array (ENIGMA) an array of 3 ground-based magnetometer stations in the areas of Trikala, Attiki and Lakonia that provides measurements for the study of geomagnetic pulsations, resulting from the solar wind - magnetosphere coupling. The group has developed and operates the Solar Energetic Proton Flux (SEPF) tool, which is a European space weather asset, as well as the FORecasting Solar Particle Events and Flares (FORSPEF) tool. Furthermore, the group participates to the Swarm/ESA mission as a member of the Validation Team. The main scientific objective of the group is the detailed investigation of interconnected space plasma physics phenomena at the Sun, the interplanetary space and the Earth and other planets. The group has become involved in the design and implementation of space instrumentation and in the application of innovative space communications for efficient space-data exploitation.
Group webpage: http://proteus.space.noa.gr/~srtg
-Permanent: A. Anastasiadis, G. Balasis, O. Giannakis
-Adjunct Researchers: I. A. Daglis, N. Sergis, A. Vourlidas
-Postdocs: I. Sandberg, A. Papaioannou
-Graduate Students: M. Georgiou, S. A. Giamini, C. Papadimitriou, Ch. Katsavrias
-Support Staff: G. Vasalos
Remote Sensing [+/-]
The research activities in this area are: a) design and implementation of sensor systems for Earth-Atmosphere-Sea observations b) dynamical modeling of physical systems and model development, c) development of novel data analysis algorithms for extracting and storing sensor data, d) development of databases for Earth observation and monitoring. Furthermore, a substantial effort is invested in producing new complex value added products, such as a) temporal mapping of the earth, b) monitoring changes in sensitive ecosystems and human environment as a result of climate change and economic activity, d) natural disaster management (forest fires, floods, earthquakes, volcanic activity, air pollution) and e) monitoring the Urban Heat Island phenomenon.
-Permanent: V. Amiridis, P. Elias, I. Keramitsoglou, H. Kontoes, K. Koutroumbas, D. Paronis, A. Rontogiannis, N. Sifakis, O. Sykioti
-Adjunct Researchers: Ch. Kiranoudis
-Postdocs: E. Ieronymidi, P. Kokkalis, D. Konsta, I. Papoutsis, A. Polychroniou, S. Solomos, A. Tsekeri
-Graduate Students: E. Marinou, E. Proestakis, P. Sismanidis, N. Svigkas, A. Tsouni
-Support Staff: E. Christia, T. Herekakis, G. Kalampokis, M. Kaskara, Ch. Petala, Ch. Psychogiou, V. Tsironis, I. Kantartzi
Signal Processing, Pattern Recognition and Communications [+/-]
The research activities in this area are focused on the development, validation and study of techniques and algorithms for a) adaptive estimation of digital signals and systems, b) pattern recognition (classification and clustering) of signals and images, c) spectral unmixing and classification of hyperspectral images, d) compressive sensing and sparse signal representations, e) processing of communication signals at the physical layer in the framework of conventional single-carrier transmission, multicarrier transmission and cooperative transmission and f) performance evaluation of digital communication systems.