| 1. |
- Blomberg, Erik, 1987, et al.
(författare)
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Simulated biomass retrieval from the spaceborne tomographic Saocom-CS mission at L-band
- 2016
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Ingår i: European Space Agency, (Special Publication) ESA SP. - 0379-6566. - 9789292213053 ; 740
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Konferensbidrag (refereegranskat)abstract
- This paper presents an evaluation of above-ground biomass (ABG) retrieval in boreal forests using simulated tomographic synthetic-aperture radar (SAR) data corresponding to the future SAOCOM-CS (L-band 1.275 GHz) mission. Using forest and radar data from the BioSAR 2008 campaign at the Krycklan test site in northern Sweden the expected performance of SAOCOM-CS is evaluated and compared with the E-SAR airborne Lband SAR (1.300 GHz). It is found that SAOCOM-CS data produce retrievals on par with those obtained with E-SAR, with retrievals having a relative RMSE of 30% or less. This holds true even if the acquisitions are limited to a single polarization, with HH results shown as an example.
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| 2. |
- Ulander, Lars, 1962, et al.
(författare)
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Borealscat: A tower experiment for understanding temporal changes in P- and L-band backscattering from a Boreal forest
- 2016
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Ingår i: European Space Agency, (Special Publication) ESA SP. - 0379-6566. - 9789292213053 ; 740
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Konferensbidrag (refereegranskat)abstract
- This paper describes the tower-based radar BorealScat, which is being developed for polarimetric, tomographic and Doppler measurements at the hemi-boreal forest test site in Remningstorp, Sweden. The facility consists of a 50-m high tower equipped with an antenna array at the top of the tower, a 20-port vector network analyser (VNA), 20 low-loss cables for interconnection, and a calibration loop with a switching network. The first version of BorealScat will perform the full set of measurements in the frequency range 0.4-1.4 GHz, i.e. P-band and L-band. The tower is currently under construction at a forest stand dominated by Norway spruce (Picea abies (L.) Karst.). The mature stand has an above-ground dry biomass of 300 tons/ha. Data collections are planned to commence in autumn 2016.
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| 3. |
- Volski, V., et al.
(författare)
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Overview of the software integration activities within ACE
- 2006
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Ingår i: First European Conference on Antennas and Propagation (EuCAP), 2006, Nice, France, 6 - 10 November 2006. - : IEEE. - 0379-6566. - 9789290929376 ; 626 SP
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Konferensbidrag (refereegranskat)abstract
- The ACE project initiated the start of several integration activities between European institutions involved in electromagnetic modeling of antennas with planar or conformal topologies. The goal of the integration activities was / is not to create a global software package that integrates the software of all partners, but to initiate a long term process for antenna software integration activities within the European antenna community. During the first two years of ACE the integration activities were performed in several groups with a rather small number of partners in each group. The groups were formed by partners who wanted to integrate a specific approach developed by one partner into the software code of another partner. This allows increasing the capability and efficiency of a software code. In this paper a short overview of all integration activities is given.
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| 4. |
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| 5. |
- Ban, Yifang, et al.
(författare)
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EO4Urban : First-year results on Sentinel-1A SAR and Sentinel-2A MSI data for global urban services
- 2016
-
Ingår i: European Space Agency, (Special Publication) ESA SP. - 9789292213053
-
Konferensbidrag (refereegranskat)abstract
- The overall objective of this research is to evaluate multitemporal Sentinel-1A SAR and Sentinel-2A MSI data for global urban services using innovative methods and algorithms, namely KTH-Pavia Urban Extractor, a robust algorithm for urban extent extraction and KTHSEG, a novel object-based classification method for detailed urban land cover mapping. Ten cities around the world in different geographical and environmental conditions were selected as study areas. Large volume of Sentinel-1A SAR and Sentinel-2A MSI data were acquired during vegetation season in 2015 and 2016. The preliminary urban extraction results showed that urban areas and small towns could be well extracted using multitemporal Sentinel-1A SAR data with the KTH-Pavia Urban Extractor. For urban land cover mapping, multitemporal Sentinel-1A SAR data alone yielded an overall classification accuracy of 60% for Stockholm. Sentinel-2A MSI data as well as the fusion of Sentinel-1A SAR and Sentinel-2A MSI data, however, produced much higher classification accuracies, both reached 80%.
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| 6. |
- Buchwitz, M., et al.
(författare)
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The GHG-CCI project of ESA's climate change initiative : Data products and application
- 2016
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Ingår i: Proceedings of Living Planet Symposium 2016. - 9789292213053 ; SP-740
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Konferensbidrag (refereegranskat)abstract
- The goal of the GHG-CCI project (http://www.esa-ghg-cci.org/) of ESA's Climate Change Initiative (CCI) is to generate global atmospheric satellite-derived carbon dioxide (CO2) and methane (CH4) data sets as needed to improve our understanding of the regional sources and sinks of these important greenhouse gases (GHG). Here we present an overview about the latest data set called Climate Research Data Package No. 3 (CRDP3). We focus on the GHG-CCI project core data products, which are near-surface-sensitive column-averaged dry air mole fractions of CO2 and CH4, denoted XCO2 (in ppm) and XCH4 (in ppb) retrieved from SCIAMACHY/ENVISAT (2002-2012) and TANSO-FTS/GOSAT (2009-today) nadir mode radiance observations in the near-infrared/shortwave-infrared spectral region. The GHG-CCI products are primarily individual sensor Level 2 products. However, we also generate merged Level 2 products ("EMMA products"). Here we also present a first GHG-CCI Level 3 product, namely XCO2 and XCH4 in Obs4MIPs format (monthly, 5°×5°).
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| 7. |
- Carlsson, Jan, 1962
(författare)
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Results and experiences from two years of benchmarking of measurements facilities for small antennas and terminals within ACE
- 2006
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Ingår i: European Conference on Antennas and Propagation: EuCAP 2006; Nice; France; 6 November 2006 through 10 November 2006. - : IEEE. - 0379-6566. - 9789290929376 ; 626 SP
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Konferensbidrag (refereegranskat)abstract
- This paper presents the test cases defined in ACE (European Antenna Centre of Excellence) for benchmarking of facilities for measuring small mobile terminals and antennas, as well as results and experiences of the round robin test. The emphasis is put on measurements in the most popular communication frequency bands. Several test cases for passive antennas as well as for active devices were defined and collected in a test kit that was sent to different test facilities around Europe in a round robin test. The measured parameters include radiation efficiency, total radiated power, diversity gain and receiver sensitivity. The test cases include different locations of the test devices relative to a lossy cylinder that has dielectric characteristics resembling that of a human head.
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| 8. |
- Cordoba-Jabonero, Carmen, et al.
(författare)
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Assessments for possible habitability in Martian polar environments : Fundaments based in ice screening of UV radiation
- 2004
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Ingår i: ESA SP. - 0379-6566 .- 1609-0438. ; 545, s. 187-188
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Tidskriftsartikel (refereegranskat)abstract
- We present a study of the solar UV radiation in Martian high latitude environments covered by ice, where the UV propagation through the polar cover depends on the ice radiative properties (layers of H2O or CO 2 ice). But also we will investigate the changes in the subsurface UV levels induced by the seasonal variations of solar UV flux on the surface, as well as by the seasonal freezing-thawing and related CO2 sublimation processes. The biological dose relative to DNA-damage will be also estimated for biological implication assessments. All these studies will be compared with the biological dose received in the Antarctic snow-ice covered environment which is seasonally exposed to high UV radiation levels (formation of "ozone hole"), where the environmental conditions could be similar to those present on Mars
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| 9. |
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| 10. |
- Diallo, A., et al.
(författare)
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Reverberation chamber evaluation of multi-antenna handset having low mutual coupling and high efficiencies
- 2006
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Ingår i: European Conference on Antennas and Propagation: EuCAP 2006; Nice; France; 6 November 2006 through 10 November 2006. - 0379-6566. - 9789290929376 ; 626 SP
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Konferensbidrag (refereegranskat)abstract
- This paper presents the evaluation of the diversity performances of several multi-antenna structures in a reverberation chamber. Firstly, a two-antenna system having low isolation between the radiators is measured. Its performances are compared with a second structure which uses a neutralization technique to enhance the radiating element's isolation. Then the performances of a four-antenna system with and without the neutralization method are measured and presented. Particularly, the total antenna efficiencies, the envelope correlation coefficients and the diversity gain of these systems are presented and discussed. We especially focus on the advantages of the neutralization technique.
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