Dr. Nektarios Chrysoulakis Profile

Dr. Nektarios Chrysoulakis

at Foundation for Research and Technology-Hellas

SPIE Involvement:

Conference Chair | Editor | Author

Publications (20)

Proceedings Article | 13 September 2021 Presentation + Paper

RSLab Landsat land surface temperature application assessment with the new Landsat collection 2 in urban areas

David Parastatidis, Nektarios Chrysoulakis

Proceedings Volume 11864, 1186404 (2021) https://doi.org/10.1117/12.2600277

KEYWORDS: Landsat, Earth observing sensors, Radiometry, Sensors, Clouds, Satellites, Temporal resolution, MODIS

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Proceedings Article | 21 September 2020 Presentation

Copernicus for Urban Resilience in Europe: the CURE Project

Nektarios Chrysoulakis, Zina Mitraka, Mattia Marconcini, David Ludlow, Zaheer Khan, Brigitte Holt Andersen, Tomas Soukup, Mario Dohr, Alessandro Gandini, Jürgen Kropp, Dirk Lauwaet, Christian Feigenwinter

Proceedings Volume 11535, 1153503 (2020) https://doi.org/10.1117/12.2577125

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Resilience has become an important necessity for cities, particularly in the face of climate change. Mitigation and adaptation actions that enhance the resilience of cities need to be based on a sound understanding and quantification of the drivers of urban transformation and settlement structures, human and urban vulnerability, and of local and global climate change. Copernicus, as the means for the establishment of a European capacity for Earth Observation (EO), is based on continuously evolving Core Services. A major challenge for the EO community is the innovative exploitation of the Copernicus products in dealing with urban sustainability towards increasing urban resilience. Due to the multidimensional nature of urban resilience, to meet this challenge, information from more than one Copernicus Core Services, namely the Land Monitoring Service (CLMS), the Atmosphere Monitoring Service (CAMS), the Climate Change Service (C3S) and the Emergency Management Service (EMS), is needed. Furthermore, to address urban resilience, the urban planning community needs spatially disaggregated environmental information at local (neighbourhood) scale. Such information, for all parameters needed, is not yet directly available from the Copernicus Core Services mentioned above, while several elements - data and products - from contemporary satellite missions consist valuable tools for retrieving urban environmental parameters at local scale. The H2020-Space project CURE (Copernicus for Urban Resilience in Europe) is a joint effort of 10 partners from 9 countries that synergistically exploits the above Copernicus Core Services to develop an umbrella cross-cutting application for urban resilience, consisting of individual cross-cutting applications for climate change adaptation/mitigation, energy and economy, as well as healthy cities and social environments, at several European cities. These cross-cutting applications cope with the required scale and granularity by also integrating or exploiting third-party data, in-situ observations and modelling. CURE uses DIAS (Data and Information Access Services) to develop a system capable of supporting operational applications and downstream services across Europe. The CURE system hosts the developed cross-cutting applications, enabling its incorporation into operational services in the future. CURE is expected to increase the value of Copernicus Core Services for future emerging applications in the domain of urban resilience, exploiting also the improved data quality, coverage and revisit times of the future satellite missions. Thus, CURE will lead to more efficient routine urban planning activities with obvious socioeconomic impact, as well as to more efficient resilience planning activities related to climate change mitigation and adaptation, resulting in improved thermal comfort and air quality, as well as in enhanced energy efficiency. Specific CURE outcomes could be integrated into the operational Copernicus service portfolio. The added value and benefit expected to emerge from CURE is related to transformed urban governance and quality of life, because it is expected to provide improved and integrated information to city administrators, hence effectively supporting strategies for resilience planning at local and city scales, towards the implementation of the Sustainable Development Goals and the New Urban Agenda for Europe.

Proceedings Article | 20 September 2020 Presentation

Opening Remarks by Conference Chairs

Thilo Erbertseder, Ying Zhang, Nektarios Chrysoulakis

Proceedings Volume 11535, 1153502 (2020) https://doi.org/10.1117/12.2584139

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SPIE Journal Paper | 7 February 2019

Detailed urban surface characterization using spectra from enhanced spatial resolution Sentinel-2 imagery and a hierarchical multiple endmember spectral mixture analysis approach

Dimitra Tzelidi, Stavros Stagakis, Zina Mitraka, Nektarios Chrysoulakis

JARS, Vol. 13, Issue 01, 016514, (February 2019) https://doi.org/10.1117/12.10.1117/1.JRS.13.016514

KEYWORDS: Spatial resolution, Vegetation, Image fusion, Resolution enhancement technologies, Metals, Satellites, Error analysis, Image analysis, Spectral resolution, Image resolution

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Proceedings Article | 9 October 2018 Presentation + Paper

Estimation of urban air temperature spatial patterns based on sensors network observations and satellite derived predictors

Nikolaos Nikoloudakis, Stavros Stagakis, Zina Mitraka, Yiannis Kamarianakis, Nektarios Chrysoulakis, George Kochilakis, Nektarios Spyridakis

Proceedings Volume 10793, 1079309 (2018) https://doi.org/10.1117/12.2326406

KEYWORDS: Temperature metrology, Sensor networks, Satellites, Earth observing sensors, Environmental sensing, Heat flux, Computational mathematics

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Proceedings Article | 26 October 2016 Presentation + Paper

Anthropogenic heat flux estimation from space: results of the first phase of the URBANFLUXES project

Nektarios Chrysoulakis, Mattia Marconcini, Jean-Philippe Gastellu-Etchegorry, C.S.B. Grimmond, Christian Feigenwinter, Fredrik Lindberg, Fabio Del Frate, Judith Klostermann, Zina Mitraka, Thomas Esch, Lucas Landier, Andy Gabey, Eberhard Parlow, Frans Olofson

Proceedings Volume 10008, 100080C (2016) https://doi.org/10.1117/12.2239411

KEYWORDS: Heat flux, Climatology, Earth observing sensors, Satellites, Error analysis, Sensor networks, Buildings, Spatial resolution, Environmental sensing, Temperature metrology

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Proceedings Article | 12 August 2016 Paper

Comparison of physically and image based atmospheric correction methods for Sentinel-2 satellite imagery

Giannis Lantzanakis, Zina Mitraka, Nektarios Chrysoulakis

Proceedings Volume 9688, 96880A (2016) https://doi.org/10.1117/12.2242889

KEYWORDS: Atmospheric corrections, Satellite imaging, Earth observing sensors, Satellites, Reflectivity, Atmospheric optics, Atmospheric physics, Atmospheric modeling, Multispectral imaging, Atmospheric sensing

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Proceedings Article | 23 October 2014 Paper

Web service tools in the era of forest fire management and elimination

Dimitris Poursanidis, Giorgos Kochilakis, Nektarios Chrysoulakis, Vasiliki Varella, Vassiliki Kotroni, Giorgos Eftychidis, Kostas Lagouvardos

Proceedings Volume 9245, 924513 (2014) https://doi.org/10.1117/12.2066474

KEYWORDS: Data modeling, Vegetation, Atmospheric modeling, Floods, Visualization, Visual process modeling, RGB color model, Web services, Satellites, Meteorology

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Proceedings Article | 21 October 2014 Paper

Estimation of land surface albedo time series and trends based on MODIS data

Nikolaos Benas, Nektarios Chrysoulakis

Proceedings Volume 9239, 92390Q (2014) https://doi.org/10.1117/12.2066473

KEYWORDS: MODIS, Satellites, Spatial resolution, Aerosols, Climatology, Climate change, Data modeling, Atmospheric particles, Sensors, Remote sensing

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SPIE Journal Paper | 1 November 2012

Evaluation of satellite-derived products for the characterization of the urban thermal environment

Iphigenia Keramitsoglou, Ioannis Daglis, Vasilis Amiridis, Nektarios Chrysoulakis, Giulio Ceriola, Paolo Manunta, Bino Maiheu, Koen De Ridder, Dirk Lauwaet, Marc Paganini

JARS, Vol. 6, Issue 01, 061704, (November 2012) https://doi.org/10.1117/12.10.1117/1.JRS.6.061704

KEYWORDS: Satellites, Data modeling, Climatology, Temperature metrology, Spatial resolution, MODIS, Atmospheric modeling, Algorithm development, Environmental sensing, Earth observing sensors

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Proceedings Article | 1 November 2012 Paper

The development of air quality indices through image-retrieved AOT and PM10 measurements in Limassol Cyprus

Kyriacos Themistocleous, Diofantos Hadjimitsis, Adrianos Retalis, Nektarios Chrysoulakis

Proceedings Volume 8534, 85340B (2012) https://doi.org/10.1117/12.974701

KEYWORDS: Geographic information systems, Satellites, Atmospheric corrections, Satellite imaging, Air contamination, Algorithm development, Earth observing sensors, Aerosols, Atmospheric particles, Sun

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Proceedings Article | 1 November 2012 Paper

The use of volcanic beach sand as a pseudo-invariant target for atmospheric correction using Landsat images

Kyriacos Themistocleous, Diofantos Hadjimitsis, Adrianos Retalis, Nektarios Chrysoulakis

Proceedings Volume 8534, 85340L (2012) https://doi.org/10.1117/12.974697

KEYWORDS: Reflectivity, Atmospheric corrections, Landsat, Earth observing sensors, Satellites, Calibration, Satellite imaging, Scalable video coding, Atmospheric optics, Remote sensing

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Proceedings Article | 1 November 2012 Paper

The comparison of the darkest pixel and empirical line atmospheric correction methods to retrieve aerosol optical thickness using the radiative transfer equations

Kyriacos Themistocleous, Diofantos Hadjimitsis, Adrianos Retalis, Nektarios Chrysoulakis

Proceedings Volume 8534, 85340K (2012) https://doi.org/10.1117/12.974688

KEYWORDS: Atmospheric corrections, Reflectivity, Satellites, Satellite imaging, Earth observing sensors, Aerosols, Electroluminescence, Detection and tracking algorithms, Atmospheric optics, Landsat

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SPIE Journal Paper | 3 July 2012

Development of a new image based atmospheric correction algorithm for aerosol optical thickness retrieval using the darkest pixel method

Kyriacos Themistocleous, Diofantos Hadjimitsis, Adrianos Retalis, Nektarios Chrysoulakis

JARS, Vol. 6, Issue 01, 063538, (July 2012) https://doi.org/10.1117/12.10.1117/1.JRS.6.063538

KEYWORDS: Atmospheric corrections, Satellites, Earth observing sensors, Reflectivity, Sun, Photometry, Satellite imaging, Algorithm development, Aerosols, Detection and tracking algorithms

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Proceedings Article | 12 October 2010 Paper

Spectro-radiometric measurements of non-variant targets intended for the removal of atmospheric effects from satellite images: the case study of Lemesos area in Cyprus

G. Diofantos Hadjimitsis, Kyriacos Themistocleous, Vassilis Trigkas, Alexandros Matsas, Retalis Adrianos, Chrysoulakis Nektarios

Proceedings Volume 7827, 78270D (2010) https://doi.org/10.1117/12.864806

KEYWORDS: Reflectivity, Satellite imaging, Satellites, Earth observing sensors, Atmospheric corrections, Calibration, Landsat, Target acquisition, Laser scanners, Sensors

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Proceedings Article | 12 October 2010 Paper

Accuracy assessment of atmospheric correction algorithms using sun-photometers (AERONET), lidar system, and in situ spectroradiometers

Kyriacos Themistocleous, G. Diofantos Hadjimitsis, Adrianos Retalis, Nektarios Chrysoulakis

Proceedings Volume 7827, 78270E (2010) https://doi.org/10.1117/12.864825

KEYWORDS: Atmospheric corrections, Accuracy assessment, LIDAR, Reflectivity, Satellites, Detection and tracking algorithms, Earth observing sensors, Landsat, Calibration, Remote sensing

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Proceedings Article | 24 October 2007 Paper

The georeferencing errors of satellite data in remote sensing applications

Corina Alecu, Nektarios Chrysoulakis, Simona Oancea, Gheorghe Stancalie

Proceedings Volume 6748, 67481Q (2007) https://doi.org/10.1117/12.747001

KEYWORDS: Error analysis, Computer simulations, Satellites, Remote sensing, Georeferencing, Sensors, Short wave infrared radiation, Distortion, Infrared imaging, Thermography

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Proceedings Article | 20 October 2006 Paper

Updating the 1:50.000 topographic maps using ASTER and SRTM DEM: the case of Athens, Greece

Konstantinos Nikolakopoulos, Nektarios Chrysoulakis

Proceedings Volume 6366, 636606 (2006) https://doi.org/10.1117/12.689016

KEYWORDS: Interferometric synthetic aperture radar, Spatial resolution, Imaging systems, Satellite imaging, Earth observing sensors, Satellites, Space operations, Radar, Radiometry, Remote sensing

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The 1:50.000 topographic maps present a nominal horizontal accuracy of 20 meters and a nominal vertical accuracy of 10 meters with 90% confidence. The data were in most cases extracted with photogrammetric techniques from aerial stereo-photographs during the 80's. The usual update rate for these maps ranges from ten to twenty years. The Advanced Spaceborn Thermal Emission and Reflection Radiometer (ASTER) offers along-track stereoscopic viewing capability. Its viewing geometry is suitable for DEM generation even without the use of ground control points. Recent studies have proved that in this case the vertical accuracy of DEM is about 20m with 95% confidence. The horizontal geolocation accuracy appears to be limited by the spacecraft position accuracy which is considered to be better than 50 m. Other studies have shown that the use of GCP's resulted in a plannimetric accuracy of 15 m and in a near pixel size vertical accuracy. The Shuttle Radar Topography Mission (SRTM), used an Interferometric Synthetic Aperture Radar (IFSAR) instrument to produce a near-global digital elevation map of the Earth's land surface with 16 m absolute vertical height accuracy at 30 meter postings. An SRTM 3-arc-second product (90m resolution) is available for the entire world. In this paper we examine the possibility of updating the 1:50.000 topographic maps using ASTER and SRTM DEMs. The area of study is the broader area of Athens, Greece. Presupposing, that the horizontal and vertical accuracy of the ASTER and SRTM DEM is similar to the relative accuracies of the DEM from digitized contours, optical comparison of the DEMs and statistical analysis (difference, correlation) can immediately prove if there is any need for update to the topographic maps. A DEM from digitized contours from the 1:50.000 topographic maps was created and compared with ASTER and SRTM derived DEMs. Almost three hundreds points of known elevation have been used to estimate the accuracy of these three DEMs. The resulted accuracy of the SRTM and ASTER derived DEMs was satisfactory, therefore they are considered as suitable for updating 1:50.000 topographic maps.

Proceedings Article | 13 February 2004 Paper

Hydrologic land-cover classification mapping at the local level with the combined use of ASTER multispectral imagery and GPS measurements

Nektarios Chrysoulakis, Iphigenia Keramitsoglou, Constantinos Cartalis

Proceedings Volume 5239, (2004) https://doi.org/10.1117/12.515575

KEYWORDS: Image classification, Vegetation, Global Positioning System, Multispectral imaging, Satellites, Short wave infrared radiation, Sensors, Associative arrays, Earth observing sensors, Spatial resolution

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Proceedings Article | 14 March 2003 Paper

Integration of Earth observation and in-situ spatial data for the development of a decision support tool for technological risk management

Nektarios Chrysoulakis

Proceedings Volume 4886, (2003) https://doi.org/10.1117/12.463236

KEYWORDS: Satellites, Geographic information systems, Roads, Data modeling, Environmental monitoring, Flame detectors, Detection and tracking algorithms, Vegetation, Spatial resolution, RGB color model

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