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  Subjects -> ELECTRONICS (Total: 138 journals)
Advances in Biosensors and Bioelectronics     Open Access   (Followers: 2)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 5)
Advances in Microelectronic Engineering     Open Access   (Followers: 1)
Advances in Power Electronics     Open Access   (Followers: 7)
Aerospace and Electronic Systems, IEEE Transactions on     Hybrid Journal   (Followers: 54)
American Journal of Electrical and Electronic Engineering     Open Access   (Followers: 7)
Annals of Telecommunications     Hybrid Journal   (Followers: 4)
APL : Organic Electronics and Photonics     Hybrid Journal   (Followers: 1)
APSIPA Transactions on Signal and Information Processing     Open Access   (Followers: 3)
Archives of Electrical Engineering     Open Access   (Followers: 9)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 5)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 8)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 14)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 12)
Biomedical Instrumentation & Technology     Full-text available via subscription   (Followers: 4)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 5)
BULLETIN of National Technical University of Ukraine. Series RADIOTECHNIQUE. RADIOAPPARATUS BUILDING     Open Access   (Followers: 1)
Bulletin of the Polish Academy of Sciences : Technical Sciences     Open Access  
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 13)
China Communications     Full-text available via subscription   (Followers: 1)
Circuits and Systems     Open Access   (Followers: 7)
Consumer Electronics Times     Open Access   (Followers: 3)
Control Systems     Hybrid Journal   (Followers: 19)
Electronic Markets     Hybrid Journal   (Followers: 5)
Electronic Materials Letters     Hybrid Journal   (Followers: 2)
Electronics     Open Access   (Followers: 5)
Electronics and Communications in Japan     Hybrid Journal   (Followers: 4)
Electronics Letters     Hybrid Journal   (Followers: 15)
Embedded Systems Letters, IEEE     Hybrid Journal   (Followers: 14)
EPJ Quantum Technology     Open Access  
EURASIP Journal on Embedded Systems     Open Access   (Followers: 8)
Foundations and TrendsĀ® in Communications and Information Theory     Full-text available via subscription   (Followers: 6)
Foundations and TrendsĀ® in Signal Processing     Full-text available via subscription   (Followers: 4)
Frequenz     Full-text available via subscription   (Followers: 1)
Frontiers of Optoelectronics     Hybrid Journal   (Followers: 1)
Geoscience and Remote Sensing, IEEE Transactions on     Hybrid Journal   (Followers: 19)
Haptics, IEEE Transactions on     Hybrid Journal   (Followers: 4)
IEEE Consumer Electronics Magazine     Full-text available via subscription   (Followers: 7)
IEEE Journal of Emerging and Selected Topics in Power Electronics     Hybrid Journal   (Followers: 4)
IEEE Journal of the Electron Devices Society     Open Access   (Followers: 1)
IEEE Power Electronics Magazine     Full-text available via subscription   (Followers: 1)
IEEE Transactions on Audio, Speech, and Language Processing     Hybrid Journal   (Followers: 9)
IEEE Transactions on Automatic Control     Hybrid Journal   (Followers: 20)
IEEE Transactions on Consumer Electronics     Hybrid Journal   (Followers: 11)
IEEE Transactions on Electron Devices     Hybrid Journal   (Followers: 6)
IEEE Transactions on Information Theory     Hybrid Journal   (Followers: 13)
IEEE Transactions on Power Electronics     Hybrid Journal   (Followers: 13)
IEICE - Transactions on Electronics     Full-text available via subscription   (Followers: 8)
IEICE - Transactions on Information and Systems     Full-text available via subscription   (Followers: 7)
IET Power Electronics     Hybrid Journal   (Followers: 7)
IET Wireless Sensor Systems     Hybrid Journal   (Followers: 5)
IETE Journal of Education     Open Access   (Followers: 2)
IETE Journal of Research     Open Access   (Followers: 5)
IETE Technical Review     Open Access   (Followers: 1)
Industrial Electronics, IEEE Transactions on     Hybrid Journal   (Followers: 10)
Industry Applications, IEEE Transactions on     Hybrid Journal   (Followers: 5)
Informatik-Spektrum     Hybrid Journal  
Instabilities in Silicon Devices     Full-text available via subscription  
Intelligent Transportation Systems Magazine, IEEE     Full-text available via subscription   (Followers: 1)
International Journal of Advanced Electronics and Communication Systems     Open Access   (Followers: 4)
International Journal of Advanced Research in Computer Science and Electronics Engineering     Open Access   (Followers: 18)
International Journal of Advances in Telecommunications, Electrotechnics, Signals and Systems     Open Access   (Followers: 1)
International Journal of Aerospace Innovations     Full-text available via subscription   (Followers: 11)
International Journal of Applied Electronics in Physics & Robotics     Open Access   (Followers: 1)
International Journal of Biomedical Nanoscience and Nanotechnology     Hybrid Journal   (Followers: 5)
International Journal of Computational Vision and Robotics     Hybrid Journal   (Followers: 4)
International Journal of Computer & Electronics Research     Full-text available via subscription   (Followers: 2)
International Journal of Control     Hybrid Journal   (Followers: 11)
International Journal of Electronics     Hybrid Journal   (Followers: 2)
International Journal of Electronics & Data Communication     Open Access   (Followers: 3)
International Journal of Electronics and Telecommunications     Open Access   (Followers: 3)
International Journal of Granular Computing, Rough Sets and Intelligent Systems     Hybrid Journal   (Followers: 1)
International Journal of High Speed Electronics and Systems     Hybrid Journal  
International Journal of Microwave and Wireless Technologies     Hybrid Journal   (Followers: 1)
International Journal of Nano Devices, Sensors and Systems     Open Access   (Followers: 1)
International Journal of Nanoscience     Hybrid Journal   (Followers: 1)
International Journal of Numerical Modelling:Electronic Networks, Devices and Fields     Hybrid Journal   (Followers: 2)
International Journal of Power Electronics     Hybrid Journal   (Followers: 3)
International Journal of Review in Electronics & Communication Engineering     Open Access   (Followers: 1)
International Journal of Sensors, Wireless Communications and Control     Hybrid Journal   (Followers: 2)
International Journal of Systems, Control and Communications     Hybrid Journal   (Followers: 2)
International Journal on Communication     Full-text available via subscription   (Followers: 7)
International Journal on Electrical and Power Engineering     Full-text available via subscription   (Followers: 10)
ISRN Electronics     Open Access   (Followers: 1)
ISRN Signal Processing     Open Access  
Journal of Advanced Dielectrics     Open Access   (Followers: 1)
Journal of Artificial Intelligence     Open Access   (Followers: 5)
Journal of Circuits, Systems, and Computers     Hybrid Journal   (Followers: 1)
Journal of Electrical and Electronics Engineering Research     Open Access   (Followers: 2)
Journal of Electrical Bioimpedance     Full-text available via subscription   (Followers: 2)
Journal of Electrical Engineering & Electronic Technology     Full-text available via subscription   (Followers: 1)
Journal of Electromagnetic Analysis and Applications     Open Access   (Followers: 3)
Journal of Electromagnetic Waves and Applications     Hybrid Journal   (Followers: 2)
Journal of Electronic Design Technology     Full-text available via subscription   (Followers: 1)
Journal of Electronics (China)     Hybrid Journal   (Followers: 2)
Journal of Field Robotics     Hybrid Journal   (Followers: 2)
Journal of Guidance, Control, and Dynamics     Full-text available via subscription   (Followers: 52)
Journal of Intelligent Procedures in Electrical Technology     Open Access  
Journal of Low Power Electronics     Full-text available via subscription   (Followers: 4)
Journal of Low Power Electronics and Applications     Open Access   (Followers: 1)

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Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of
   Journal TOC RSS feeds Export to Zotero [17 followers]  Follow    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 1939-1404
     Published by Institute of Electrical and Electronics Engineers (IEEE) Homepage  [172 journals]   [SJR: 1.232]   [H-I: 14]
  • IEEE Journal of Selected Topics in Applied Earth Observations and Remote
           Sensing Information for Authors
    • Pages: C3 - C3
      Abstract: Provides instructions and guidelines to prospective authors who wish to submit manuscripts.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • IEEE Transactions on Geoscience and Remote Sensing institutional listings
    • Pages: C4 - C4
      Abstract: Advertisement: IEEE.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • IEEE Journal of Selected Topics in Applied Earth Observations and Remote
           Sensing publication information
    • Pages: C2 - C2
      Abstract: Provides a listing of current staff, committee members and society officers.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Front cover
    • Pages: C1 - C1
      Abstract: Presents the front cover for this issue of the publication.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Table of contents
    • Pages: 2705 - 2706
      Abstract: Presents the table of contents for this issue of the periodical.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Foreword to the Special Issue on COSMO-Skymed First and Second Generation
    • Authors: Battiston; R.;Migliaccio, M.;Stramondo, S.;
      Pages: 2707 - 2710
      Abstract: The twenty articles in this special issue provide a reliable summary of the wide spectrum of studies carried on COSMO-SkyMed (CSK) data exploitation.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • SAR and InSAR for Flood Monitoring: Examples With COSMO-SkyMed Data
    • Authors: Refice; A.;Capolongo, D.;Pasquariello, G.;DaAddabbo, A.;Bovenga, F.;Nutricato, R.;Lovergine, F.P.;Pietranera, L.;
      Pages: 2711 - 2722
      Abstract: We apply high-resolution, X-band, stripmap COSMO-SkyMed data to the monitoring of flood events in the Basilicata region (Southern Italy), where multitemporal datasets are available with short spatial and temporal baselines, allowing interferometric (InSAR) processing. We show how the use of the interferometric coherence information can help to detect more precisely the areas affected by the flood, reducing false alarms and missed identifications which affect algorithms based on SAR intensity alone. The effectiveness of using the additional InSAR information layer is illustrated by RGB composites of various combinations of intensity and coherence data. Analysis of multitemporal SAR intensity and coherence trends reveals complex behavior of various field types, which we interpret through a Bayesian inference approach, based on a manual identification of representative scattering and coherence signatures of selected homogeneous fields. The approach allows to integrate external, ancillary information to derive a posteriori probabilistic maps of flood inundation accounting for different scattering responses to the presence of water. First results of this semiautomated methodology, using simple assumptions for the SAR signatures and a priori information based on the distance from river courses, show encouraging results, and open a path to improvement through use of more complex hydrologic and topo-hydrographic information.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Power Spectra of Very High Resolution SAR Amplitude Images of Urban Areas
    • Authors: Di Martino; G.;Iodice, A.;Riccio, D.;Ruello, G.;
      Pages: 2723 - 2731
      Abstract: With the launch of COSMO/SkyMed and TerraSAR-X missions, very high resolution (VHR) Synthetic Aperture Radar (SAR) images of urban areas have become routinely available. In particular, in the spotlight acquisition mode, COSMO/SkyMed SARs are able to obtain a resolution even better than one meter. Accordingly, in principle a huge amount of information on objects present in the urban scenario can be extracted from such images; however, due to the involved interaction between incident electromagnetic wave and imaged scene, direct interpretation of VHR SAR images is not straightforward, and different methods to analyze them are being developed by the scientific community. In this paper, we explore the potentiality of using the power spectral density (PSD) of VHR SAR amplitude images of urban areas for information extraction. First, we propose a theoretical model of the PSD of such images, and then we test the validity of the developed model on COSMO/SkyMed spotlight SAR images of urban areas. Finally, some suggestions are provided on how the parameters of the obtained PSD can be exploited to extract useful information from VHR SAR amplitude images of urban areas.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Modeling Watershed Response in Semiarid Regions With High-Resolution
           Synthetic Aperture Radars
    • Authors: Amitrano; D.;Ciervo, F.;Di Martino, G.;Papa, M.N.;Iodice, A.;Koussoube, Y.;Mitidieri, F.;Riccio, D.;Ruello, G.;
      Pages: 2732 - 2745
      Abstract: In this paper, we propose a methodology devoted to exploit the outstanding characteristics of COSMO-SkyMed for monitoring water bodies in semiarid countries at a scale never experienced before. The proposed approach, based on appropriate registration, calibration, and processing of synthetic aperture radar (SAR) data, allows outperforming the previously available methods for monitoring small reservoirs, mainly carried out with optical data, and severely limited by the presence of cloud coverage, which is a frequent condition in wet season. A tool has been developed for computing the water volumes retained in small reservoirs based on SAR-derived digital elevation model. These data have been used to derive a relationship between storage volumes and surface areas that can be used when bathymetric information is unavailable. Due to the lack of direct measures of river’s discharge, the time evolution of water volumes retained at reservoirs has been used to validate a simple rainfall–runoff hydrological model that can provide useful recommendation for the management of small reservoirs. Operational scenarios concerning the improvement in the efficiency of reservoirs management and the estimation of their impact on downstream area point out the applicative outcomes of the proposed method.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • X- and C-Band SAR Surface Displacement for the 2013
           Lunigiana Earthquake (Northern Italy): A Breached Relay
    • Authors: Stramondo; S.;Vannoli, P.;Cannelli, V.;Polcari, M.;Melini, D.;Samsonov, S.;Moro, M.;Bignami, C.;Saroli, M.;
      Pages: 2746 - 2753
      Abstract: In this paper, we applied the differential interferometric synthetic aperture radar (DInSAR) technique to investigate and measure surface displacements due to the ${{mmb M}_{mmb w}}$ 5.3 ( ${{mmb M}_{mmb l}}$ 5.2), June 21, 2013 earthquake, occurred north of the Apuan Alps (NW Italy), in the discontinuity zone between the Lunigiana and Garfagnana area. Two differential interferograms showing the coseismic displacement have been generated using X-band and C-band data, taken from COSMO-SkyMed and RADARSAT-2 satellites, respectively. Both interferograms highlighted a clear pattern of subsidence of few cm located between the Lunigiana and Garfagnana basins. We then modeled the observed SAR deformation fields using the Okada analytical formulation and found them to be consistent with an extensional fault plane dipping toward NW at about 50 $^circ $ . The integrated analysis of DInSAR, geological data, modeling, and historical seismicity suggest that the fault responsible for the June 2013 earthquake corresponds to a breached relay ramp connecting the Lunigiana and Garfagnana seismogenic sources.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • The COSMO-SkyMed Dual Use Earth Observation Program: Development,
           Qualification, and Results of the Commissioning of the Overall
    • Authors: Caltagirone; F.;Capuzi, A.;Coletta, A.;De Luca, G.F.;Scorzafava, E.;Leonardi, R.;Rivola, S.;Fagioli, S.;Angino, G.;LAbbate, M.;Piemontese, M.;Zampolini Faustini, E.;Torre, A.;De Libero, C.;Esposito, P.G.;
      Pages: 2754 - 2762
      Abstract: COSMO-SkyMed (CSK) is the largest Italian investment in Space Systems for Earth Observation, commissioned and funded by the Italian Space Agency (ASI) and the Italian Ministry of Defense (It-MoD). The CSK constellation has been completely qualified in orbit since 2010 and it is still operating at full performance with a constellation of four mid-sized satellites placed in Low Earth Orbit, each carrying a high-resolution X-band Synthetic Aperture Radar (SAR), and a full-featured Ground Segment to exploit observation capabilities and providing SAR imaging servicing worldwide. The primary mission objective of CSK is the provision of services able to quickly answer to the user needs in the domains of Monitoring of land and environmental resources, Strategic Surveillance for Defense and Intelligence, Maritime Control, Topography, and Commercial applications as well. CSK fulfills civilian and defense needs, enhancing international partnerships through its interoperability, expandability, and multisensor (IEM) features and practices. Thanks to these features, CSK is an asset for international partnership such as the Italian-Argentinean Satellite System for Emergency Management (SIASGE). This paper intends to delineate how those fundamental characteristics of CSK have been qualified and commissioned from the launch of the first CSK satellite in 2007 through its progressive deployment until the system in-flight final acceptance (S-IFAR) event in 2010 that has completed the orbiting four-satellite qualified configuration. Nowadays, CSK is operating at full performance, constituting an asset for its first-class radar observation capabilities, state-of-the-art technology aimed at improving security of countries, safety, and life quality of their citizens.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Exploration of Multitemporal COSMO-SkyMed Data via Interactive
           Tree-Structured MRF Segmentation
    • Authors: Gaetano; R.;Amitrano, D.;Masi, G.;Poggi, G.;Ruello, G.;Verdoliva, L.;Scarpa, G.;
      Pages: 2763 - 2775
      Abstract: We propose a new approach for remote sensing data exploration, based on a tight human–machine interaction. The analyst uses a number of powerful and user-friendly image classification/segmentation tools to obtain a satisfactory thematic map, based only on visual assessment and expertise. All processing tools are in the framework of the tree-structured MRF model, which allows for a flexible and spatially adaptive description of the data. We test the proposed approach for the exploration of multitemporal COSMO-SkyMed data, that we appropriately registered, calibrated, and filtered, obtaining a performance that is largely superior, in both subjective and objective terms, to that of comparable noninteractive methods.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Multilook SAR Tomography for 3-D Reconstruction and Monitoring of Single
           Structures Applied to COSMO-SKYMED Data
    • Authors: Fornaro; G.;Pauciullo, A.;Reale, D.;Verde, S.;
      Pages: 2776 - 2785
      Abstract: With reference to the application to the imaging and monitoring of infrastructures and buildings in urban areas, SAR tomography has been mainly developed and tested at full resolution. In this work, we investigate the possibility related to the use of a multilook approach for fine resolution analysis of ground structures that combines SAR tomography and a method, CAESAR, recently proposed for classical DInSAR analysis at coarse resolution over large areas. Shown results, achieved by processing two 3 m spatial resolution (stripmap mode) COSMO-SKYMED datasets relative to the urban areas of Naples and Rome (Italy), clearly indicate that the proposed multilook-based method allows achieving an impressive density of detected scatterers over buildings and infrastructures, much higher than those achievable with standard full-resolution methods.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Multisensor Satellite Monitoring of the 2011 Puyehue-Cordon Caulle
    • Authors: Bignami; C.;Corradini, S.;Merucci, L.;de Michele, M.;Raucoules, D.;De Astis, G.;Stramondo, S.;Piedra, J.;
      Pages: 2786 - 2796
      Abstract: This paper shows the main outcomes of the Puyehue volcano (Chile) eruption monitoring by means of multisensor remote sensing instruments working from thermal infrared (TIR) to microwave (MW) spectral range. Thanks to the use of Synthetic Aperture Radar (SAR) and the Moderate Resolution Imaging Spectroradiometer (MODIS), the eruption evolution was observed, capturing the deformations of volcano edifice, the lava extension, as well as the information on ash and gas emitted. On the one hand, SAR Interferometry applied to ENVISAT-ASAR data allowed the estimation of the deformation occurred just before the beginning of the eruption and the subsequent deflation, with monthly sampling. On the other hand, with the combined use of the very high-resolution (VHR) images taken by COSMO-SkyMed X-band SAR, and ENVISAT-ASAR ones, we were able to follow the lava deposition during the most intense phase of the eruption. Additionally, the joined exploitation of SAR and optical MODIS images allowed ash detection, also in cloudy sky conditions. Finally, the information gathered by both types of sensors allowed to highlight some volcanological features of the eruption and the relationship between surface deformation and the amount of ash and gases emitted by the volcano.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Spaceborne Radar Imaging of Maritime Moving Targets With the Cosmo-SkyMed
           SAR System
    • Authors: Martorella; M.;Pastina, D.;Berizzi, F.;Lombardo, P.;
      Pages: 2797 - 2810
      Abstract: Advanced satellite synthetic aperture radar (SAR) systems, such as Cosmo-SkyMed (CSK), provide high-resolution images with reasonably short revisiting time, allowing for a number of applications in areas such as homeland security and maritime surveillance. Especially in the case of maritime surveillance, moving targets imaging represents a challenge for SAR systems as the complex target motions produce evident image defocusing. In this paper, we propose a complete processing chain that aims at detecting and imaging ship targets moving inside the imaged scene. In the proposed technique, moving targets are focused by using inverse SAR (ISAR) processing, which proves effective also in the case of target’s complex motions. The implemented processing chain can be considered an innovative combination of well-established detection and ISAR imaging approaches. It is important to state that the proposed maritime ISAR mode for the CSK SAR system acts as an add-on system and, therefore, does not require any modification to the original CSK design. The effectiveness of the proposed approach is demonstrated by processing archive images acquired by CSK in spotlight mode; moreover results obtained by using CSK images acquired ad hoc against a cooperative target are also provided in order to prove the validity of the overall chain also in presence of targets with small size. As additional option of the proposed maritime ISAR it will also be shown that super-resolution techniques are applicable to targets affected by complex motions after ISAR processing is used.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • A Multipolarization Analysis of Coastline Extraction Using X-Band
           COSMO-SkyMed SAR Data
    • Authors: Buono; A.;Nunziata, F.;Mascolo, L.;Migliaccio, M.;
      Pages: 2811 - 2820
      Abstract: In this study, COSMO-SkyMed (CSK) Synthetic Aperture Radar (SAR) data, collected by the single-polarization stripmap Himage mode, are exploited for coastline extraction purposes. First, a multipolarization analysis of sea surface backscattering is undertaken using the Improved Integral Equation Method (IIEM). Then, a simple two-step approach is proposed to extract the continuous coastline from co- and cross-polarized Himage CSK SAR data. The approach is framed into two steps: 1) obtaining a binary output from the SAR image using a global threshold Constant False Alarm Rate (CFAR) detector; and 2) extracting the continuous one-pixel coastline from the binary output with a conventional Sobel edge detector. The proposed approach is verified against actual CSK SAR data and it is shown to be both effective and accurate when low-to-moderate wind conditions apply.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • The Contribution of SIASGE Radar Data Integrated With Optical Images to
           Support Thematic Mapping at Regional Scale
    • Authors: Pierdicca; N.;Chini, M.;Pelliccia, F.;
      Pages: 2821 - 2833
      Abstract: This paper aims to assess the potential of radar data combined with optical data to support local administrations in the knowledge of the land use and land cover at regional scale. The work starts from the actual available thematic maps owned by two different regional administrations in Italy to assess at what extent they can be improved or reproduced by Earth Observation data. In particular, the contribution of data available in the future through the Sistema Italo-Argentino di Satelliti per la Gestione delle Emergenze (SIASGE) project, combining L-band and X-band radar imagery, is assessed in order to produce thematic maps of the regions. Moreover, the further contribution brought by C-band and especially by optical bands has been evaluated. The classification problem is driven by the legend of already existing maps and quality checked against the same maps in order to tackle the real needs of the land managing authorities. As the combination of data from optical imagery is fundamental to achieve good thematic accuracy, the work has exploited the support vector machine (SVM) learning technique, which is more suitable than standard statistical parametric approaches in this respect. Concerning the classification steps, some algorithmic issues have been faced to improve the results, such as training set selection strategy and data fusion techniques. The work has proved that the multisource dataset (radar and optical) is fairly suitable to produce thematic maps comparable to what is already in use at local administrative level, allowing one to achieve classification accuracy in the order of 90%.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • SAR Bathymetry in the Tyrrhenian Sea by COSMO-SkyMed Data: A Novel
    • Authors: Renga; A.;Rufino, G.;D'Errico, M.;Moccia, A.;Boccia, V.;Graziano, M.D.;Aragno, C.;Zoffoli, S.;
      Pages: 2834 - 2847
      Abstract: Surface current variations generated by underwater bottom topography produce intensity modulations in SAR images. The direct inversion from image intensity to bathymetry is difficult, in general, because of the theoretical complexity of the involved physical mechanisms and the practical consideration that most of the required parameters cannot be derived from SAR data. The conventional approach for SAR bathymetry relies on the forward mechanism, i.e., the simulation of SAR images from (partially) known bottom topography and, then, the adjustment of the bathymetry through iterative comparison between simulated and collected images. This paper deals with the development of a bathymetric SAR algorithm able to perform the direct inversion limiting the need for a priori information or in situ measurements, and for human intervention in the processing chain. The proposed approach is tested on COSMO-SkyMed data collected over coastal regions in the Gulf of Naples, showing that dense coverage and metric accuracy can be achieved even when the current is not strong enough to dominate SAR response.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Flood Damage Assessment Through Multitemporal COSMO-SkyMed Data and
           Hydrodynamic Models: The Albania 2010 Case Study
    • Authors: Pulvirenti; L.;Pierdicca, N.;Boni, G.;Fiorini, M.;Rudari, R.;
      Pages: 2848 - 2855
      Abstract: Flood damage assessment needs not only the estimation of the flood extent but also the information on the drainage of the floodplain and the dynamics of variables as water depth and velocity. These data might be gathered by exploiting numerical models of water propagation in floodplains, which enable to build flood scenarios in real time if reliable digital elevation models are available. However, a strong limitation for the application of numerical models could be the lack of information regarding the actual flood extent and the dynamics of flooding and receding phases as well as the locations, where water overflowed and the related flood volumes. Inundation extent can be estimated through synthetic aperture radar (SAR) data and, by exploiting the short revisit time of the images provided by the COSMO-SkyMed (CSK) constellation of four satellites, it is possible to monitor also the dynamics of the flood extent. Hence, it comes out the need of a combined use of multitemporal SAR data and numerical models for the purpose of a reliable flood damage assessment. This paper presents the major outcomes of a combined use of a multitemporal series of CSK observations and a hydrodynamic model aiming at the evaluation of damage scenarios for the flood that hit Albania in January 2010. It is shown that by adjusting the outputs of the model to match the flood extent observed by SAR, the hydrodynamic inconsistencies in CSK estimates can be corrected and a reliable assessment of water depth and water velocities can be accomplished.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • The Sensitivity of Cosmo-SkyMed Backscatter to Agricultural Crop Type and
           Vegetation Parameters
    • Authors: Paloscia; S.;Santi, E.;Fontanelli, G.;Montomoli, F.;Brogioni, M.;Macelloni, G.;Pampaloni, P.;Pettinato, S.;
      Pages: 2856 - 2868
      Abstract: The capability of COSMO-SkyMed (CSK) in monitoring vegetation has been investigated in this paper. SAR data from CSK were collected on two agricultural areas in Italy from 2010 to 2012, at different dates during the vegetation cycle. X-band data have been compared to accurate ground truth measurements of soil and vegetation parameters carried out simultaneously to satellite passes. Significant sensitivity of backscatter to vegetation water content of agricultural crops was observed. However, the backscattering showed an opposite trend as a function of biomass of wheat and sunflower, which belong to two very different vegetation types, namely narrow-leaf and broad-leaf crops. Similar trends emerged at lower frequencies (i.e., C and L bands) for the same crop types. In order to investigate the role of different parameters of soil and vegetation (e.g., surface roughness and moisture, plant density and height, dimensions of leaves, stem diameter, and water content) on the backscatter behavior for these two different crop types, model simulations were performed using a discrete element radiative transfer model for vegetation, whereas soil was modeled using the advanced integral equation model (AIEM). A sensitivity analysis of the model was carried out by varying the dimensions of vegetation components within the range of parameters directly measured on ground during the experimental campaigns. The model simulations were successively compared with experimental data of backscattering. The good agreement found between experimental and simulated data encouraged the follow-up of the research toward the implementation of inversion algorithms, which can be able to retrieve vegetation biomass from SAR data and from an operative point of view.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Persistent Scatterer Pair Interferometry: Approach and Application to
           COSMO-SkyMed SAR Data
    • Authors: Costantini; M.;Falco, S.;Malvarosa, F.;Minati, F.;Trillo, F.;Vecchioli, F.;
      Pages: 2869 - 2879
      Abstract: Persistent scatterer interferometry is a widely used technique to detect and monitor slow terrain movements, with millimetric accuracy, from satellite synthetic aperture radar (SAR) data. We have recently proposed a method, named persistent scatterer pair (PSP), aimed at overcoming some limitations of standard techniques. The PSP method is characterized by the fact of exploiting only the relative properties of neighboring pairs of points for both detection and analysis of persistent scatterers (PSs), intended in the general sense of scatterers that exhibit interferometric coherence for the time period and baseline span of the acquisitions, including both point-like and distributed scatterers. Thanks to the pair-of-point approach, the PSP technique is intrinsically not affected by artifacts slowly variable in space, like those depending on atmosphere or orbits. Moreover, by exploiting a very redundant set of pair-of-point connections, the PSP approach guarantees extremely dense and accurate displacement and elevation measurements, both in correspondence of structures and when the backscattering is weak or distributed as in the case of natural terrains. In all cases, the measurements keep the full resolution of the input SAR images. In this work, the qualifying characteristics of the PSP technique are described, and several application examples and validation tests based on COSMO-SkyMed data are reported, which demonstrate the validity of the proposed approach.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • COSMO-SkyMed HH/VV PingPong Mode SAR Data to Discriminate Among Sea,
           Urban, and Vegetated Areas
    • Authors: Migliaccio; M.;Mascolo, L.;Nunziata, F.;Sarti, M.;Mazzarella, G.;
      Pages: 2880 - 2894
      Abstract: In this study, the sensitivity of COSMO-SkyMed (CSK) dual-polarimetric HH/VV Synthetic Aperture Radar (SAR) data with respect to sea, vegetated, and urban areas is investigated. A dual polarimetric feature, namely the complex correlation between the copolarized channels, is introduced to exploit the inherent peculiarities of the CSK incoherent dual-polarization PingPong mode for distinguishing the three scenarios. The dual-pol feature is contrasted with the correlation between the HH and VV amplitudes, the copolarized ratio, and with conventional single-pol ones, namely the HH and VV intensities.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Monitoring of Oil Spill Trajectories With COSMO-SkyMed X-Band SAR Images
           and Model Simulation
    • Authors: Cheng; Y.;Liu, B.;Li, X.;Nunziata, F.;Xu, Q.;Ding, X.;Migliaccio, M.;Pichel, W.G.;
      Pages: 2895 - 2901
      Abstract: The Shell North Sea Gannet Alpha platform oil spill accident occurred on August 10, 2011. This was the largest oil spill accident in United Kingdom waters in the last decade. The spills were observed on four COSMO-SkyMed (CSK) X-band synthetic aperture radar (SAR) images acquired between August 17 and 22, 2011, with revisit time from 11 h to 3 days between the SAR acquisitions. The areas of oil slicks were extracted from SAR images using an existing image classification and segmentation algorithm. It was found that the oil slicks moved toward the southwest with slick size enlarging from 3.69 to ${bf 62.01}~hbox{bf km}^{bf 2} $ in the first 24 h between the first and second SAR acquisitions. We tracked the oil spill trajectories using the General NOAA Operational Modeling Environment (GNOME) oil-drifting model. The 6-hourly surface wind fields from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis (ERA) Interim products and the 3-hourly ocean surface current fields from the Navy Coastal Ocean Model (NCOM) global operational model were used to drive the GNOME model. The simulated oil slick movement was in good agreement with that observed by the CSK SAR images. Moreover, the simulation showed that the movement of oil spills was dominated by the surface winds in the North Sea.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Localization Performance of Multiple Scatterers in Compressive Sampling
           SAR Tomography: Results on COSMO-SkyMed Data
    • Authors: Budillon; A.;Ferraioli, G.;Schirinzi, G.;
      Pages: 2902 - 2910
      Abstract: The 3-D SAR tomographic technique based on compressive sampling (CS) has been proven very performing in recovering the 3-D reflectivity function and hence in estimating multiple scatterers lying in the same range-azimuth resolution cell, but at different elevations. In this paper, a detection method for multiple scatterers, assuming the number of scatterers to be known or preliminarily estimated, has been investigated. The performance of CS processing for identifying and locating multiple scatterers has been analyzed for different number of measurements and different reciprocal distances between the scatterers, in presence of the off-grid effect, and in the case of super-resolution imaging. The proposed method has been tested on simulated and real COSMO-SkyMed data.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Multibaseline SAR Interferometry from Complex Data
    • Authors: Baselice; F.;Budillon, A.;Ferraioli, G.;Pascazio, V.;Schirinzi, G.;
      Pages: 2911 - 2918
      Abstract: Multibaseline interferometric synthetic aperture radar (In-SAR) systems are used to obtain the height profile of the observed ground scene with high accuracy. The techniques that are commonly used exploit only the interferometric phase information, and are based on maximum likelihood (ML) estimation. Due to the difficulty of expressing the multibaseline likelihood function in closed form, they adopt the statistical independence approximation of the interferometric phases. In this paper, we investigate the effect of this approximation, and analyze the performance of two statistical methods exploiting complex SAR images, which takes into account the mutual correlation among all the interferometric images. These two methods are based on a local and a contextual approach. The local one is based on an ML estimator, and processes each pixel independently from the neighboring ones. The contextual approach adopts a Bayesian estimator in order to regularize and improve the height reconstruction. The presented results show that the inclusion of SAR image correlation information allows to improve the height reconstruction accuracy. The proposed method also provides an estimation of speckle-reduced image intensity.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • COSMO-SkyMed Spotlight Interferometry Over Rural Areas: The Slumgullion
           Landslide in Colorado, USA
    • Authors: Milillo; P.;Fielding, E.J.;Shulz, W.H.;Delbridge, B.;Burgmann, R.;
      Pages: 2919 - 2926
      Abstract: In the last 7 years, spaceborne synthetic aperture radar (SAR) data with resolution of better than a meter acquired by satellites in spotlight mode offered an unprecedented improvement in SAR interferometry (InSAR). Most attention has been focused on monitoring urban areas and man-made infrastructure exploiting geometric accuracy, stability, and phase fidelity of the spotlight mode. In this paper, we explore the potential application of the COSMO-SkyMed Spotlight mode to rural areas where decorrelation is substantial and rapidly increases with time. We focus on the rapid repeat times of as short as one day possible with the COSMO-SkyMed constellation. We further present a qualitative analysis of spotlight interferometry over the Slumgullion landslide in southwest Colorado, which moves at rates of more than 1 cm/day.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Processing of MEMPHIS Ka-Band Multibaseline Interferometric SAR Data: From
           Raw Data to Digital Surface Models
    • Authors: Magnard; C.;Frioud, M.;Small, D.;Brehm, T.;Essen, H.;Meier, E.;
      Pages: 2927 - 2941
      Abstract: MEMPHIS is an experimental millimeter-wave synthetic aperture radar (SAR) system that acquires cross-track multibaseline interferometric data at high resolution in a single pass, using four receive horns. In this paper, we present the SAR system and navigation data, and propose a processing chain from the raw data input to a digital surface model (DSM) output. This processing chain includes full bandwidth reconstruction of the stepped-frequency SAR data, azimuth focusing with an Extended Omega-K algorithm, generation of interferograms for each available baseline, phase unwrapping using the multibaseline data, and phase-to-height conversion. The hardware and processing chain were validated through the analysis of experimental Ka-band data. The SAR image resolution was measured with point targets and found to be $sim! {bf {2%}}$ and $sim!{bf {15%}}$ coarser than the theoretical value in range and azimuth, respectively. The geolocation accuracy was typically better than 0.1 m in range and 0.2 m in azimuth. Observed depression angle-dependent interferometric phase errors were successfully removed using a correction function derived from the InSAR data. Investigation of the interferometric phase noise showed the utility of a multibaseline antenna setup; the number of looks and filter size used for the DSM generation were also derived from this analysis. The results showed that in grassland areas, the height difference between the $sim! {bf {2}nbsp {hbox{m}}}$ -resolution InSAR DSMs and the reference ALS models was ${bf 0} pm {bf {0. 25}nbsp {hbox{m}}}$ .
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Sparse Apertures ISAR Imaging and Scaling for Maneuvering Targets
    • Authors: Xu; G.;Xing, M.;Zhang, L.;Duan, J.;Chen, Q.;Bao, Z.;
      Pages: 2942 - 2956
      Abstract: In advanced multifunctional radar, inverse synthetic aperture radar (ISAR) imaging of sparse apertures for maneuvering targets is a challenge problem. In general, the Doppler modulation of rotation motion can be modeled as linear frequency for uniformly accelerated rotation targets, which is spatial-variant in two-dimension (2-D). The signal diversity inherently reflects the maneuverability and provides a rationale of rotation motion estimation. In this paper, we focus on the problem of sparse apertures ISAR imaging and scaling for maneuvering targets. The maneuvering signal model is formulated as chirp code and represented using a chirp-Fourier basis. Then sparse representation is applied to realize range-Doppler (RD) imaging from the sparse apertures, where the superposition of chirp parameters is acquired using the modified discrete chirp Fourier transform (MDCFT). After preprocessing, such as sample selection, rotation center determination, and noise reduction, the chirp parameters are used to estimate the parameters of rotation motion using the weighted least square (WLS) method. Finally, a high-resolution scaled-ISAR image is achieved by rescaling the acquired RD image using the estimated rotation velocity. Experiments are performed to confirm the effectiveness of the proposal.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Compressed Sensing ISAR Reconstruction in the Presence of Rotational
    • Authors: Khwaja; A.S.;Zhang, X.;
      Pages: 2957 - 2970
      Abstract: In this paper, we present an inverse synthetic aperture radar (ISAR) reconstruction method from compressively sensed data using a new dictionary that takes into account rotational acceleration. Unlike traditional compressed sensing (CS) ISAR imaging methods, where the dictionary either ignores this acceleration or assumes the scatterers as static, our method can deal with maneuvering motion consisting of rotational acceleration. The method can also focus images when data are not acquired in a continuous frame. The effectiveness of the method is demonstrated by analysis. Simulation examples verify this analysis and show that the presented method can focus data consisting of scatterers undergoing rotational acceleration.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • ISAR Imaging of Maneuvering Target Based on the Local Polynomial Wigner
           Distribution and Integrated High-Order Ambiguity Function for Cubic Phase
           Signal Model
    • Authors: Wang; Y.;Kang, J.;Jiang, Y.;
      Pages: 2971 - 2991
      Abstract: This paper focuses on the novel approaches for inverse synthetic aperture radar (ISAR) imaging of maneuvering target. It is based on the assumption that the azimuth echoes in a range bin are modeled as multi-component cubic phase signal (CPS) after the translational motion compensation, and the ISAR image quality will be deteriorated by the conventional Fourier transform in the azimuth focusing. In this paper, two novel algorithms for parameters estimation of multi-component CPS based on the local polynomial Wigner distribution (LPWD) and integrated high-order ambiguity function (IHAF) are proposed, and the high-quality instantaneous ISAR image can be obtained by the estimated CPS parameters. The results of simulated and real aircraft data are provided to validate the effectiveness of the proposed methods.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • An Analysis of the Uncertainty in InSAR Deformation Measurements for
           Groundwater Applications in Agricultural Areas
    • Authors: Reeves; J.A.;Knight, R.;Zebker, H.A.;
      Pages: 2992 - 3001
      Abstract: Interferometric synthetic aperture radar (InSAR) is a remote sensing method that maps relative ground surface deformation. In previous work, we investigated the relationship between deformation and hydraulic head change in the San Luis Valley, CO, USA, and determined that we must quantify the spatially variable uncertainty in the InSAR deformation measurement in order for these data to be used to predict hydraulic head. In this study, we modify a commonly applied multitemporal technique, Small Baseline Subset (SBAS) analysis, to process InSAR data in an area where pumping for crop irrigation creates seasonally variable deformation. We propagate the uncertainty due to decorrelation through the InSAR processing chain and calculate the uncertainty in the deformation for all selected pixels. The standard deviation of the uncertainty in the deformation ranges from 1 to 5 mm. Finally, we investigate how the InSAR coherence affects the standard deviation of the estimated deformation. Through a synthetic study, we show that given the mean coherence and standard deviation of coherence, we can determine the mean standard deviation of the final deformation estimates. This allows us to optimize InSAR processing to identify which pixels can provide the uncertainty desired in the final deformation time series.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • The Improvement for Baran Phase Filter Derived From Unbiased InSAR
    • Authors: Jiang; M.;Ding, X.;Li, Z.;Tian, X.;Zhu, W.;Wang, C.;Xu, B.;
      Pages: 3002 - 3010
      Abstract: We present an improvement for the adaptive Goldstein phase filter guided by interferometric synthetic aperture radar (InSAR) coherence (Baran phase filter). The proposed method addresses the under-filtering over incoherent area where the filter parameter alpha is underestimated by the biased coherence estimation. Through correcting the overestimate of the sample coherence, the correct filter parameter alpha is derived and the performance of the filter is optimized. Experimental results from different data sets demonstrate the advantages of the approach.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Remocean System for the Detection of the Reflected Waves from the Costa
           Concordia Ship Wreck
    • Authors: Ludeno; G.;Brandini, C.;Lugni, C.;Arturi, D.;Natale, A.;Soldovieri, F.;Gozzini, B.;Serafino, F.;
      Pages: 3011 - 3018
      Abstract: This paper presents the validation of the Remocean X-band wave radar as a tool for sea state monitoring in coastal zones, by processing the data collected and processed by the radar platform installed at the port of Giglio Island. In particular, the effectiveness of the sea wave height reconstruction has been tested during the storm on November 27, 2012, by focusing on the analysis of the spectral slope and the statistical properties of the ocean waves. A further proof of the effectiveness of the system has been shown by comparing both the estimated sea state parameters and 2-D directional spectrum with the benchmark forecasting models WaveWatchIII (WW3) and Simulating Wave Nearshore (SWAN).
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Robust Estimation of Water Chlorophyll Concentrations With Gaussian
           Process Regression and IOWA Aggregation Operators
    • Authors: Bazi; Y.;Alajlan, N.;Melgani, F.;AlHichri, H.;Yager, R.R.;
      Pages: 3019 - 3028
      Abstract: In this paper, we propose a new framework for estimating water chlorophyll concentrations in remote sensing data based on Gaussian process regression (GPR) and induced ordered weighted averaging (IOWA) operators. First, we construct an ensemble of GPR estimators modeled with different covariance functions. Then, in a second step, we aggregate the predictions of these estimators using IOWA operators. To learn the weights associated with these nonlinear operators, we propose three different approaches called ${bf IOWA}^{{bf MVO}}$ , ${bf IOWA}^{{bf MOP}}$ , and ${bf IOWA}^{{bf PA}}$ . The ${bf IOWA}^{{bf MVO}}$ is based on the minimization of the variance of the weights with a given orness level. In ${bf IOWA}^{{bf MOP}}$ , we replace the orness level constraint by an objective related to data fitting. Then we solve the modified optimization problem using a multiobjective optimization evolutionary algorithm based on decomposition. Finally, in ${bf IOWA}^{{bf PA}}$ , we generate the weights directly from the confidence measures (i.e., output variances) provided by the set of GPR estimators using the concept of prioritization aggregation. Experimental results on in situ and satellite data are reported and discussed.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Diagnosis of Vegetation Recovery in Mountainous Regions After the Wenchuan
    • Authors: Wang; M.;Yang, W.;Shi, P.;Xu, C.;Liu, L.;
      Pages: 3029 - 3037
      Abstract: The Ms 8.0 Wenchuan Earthquake in 2008 resulted in numerous landslides disturbing vast areas of vegetation. However, almost 5 years following the catastrophic event, vegetation recovery in the affected regions experienced dynamic changes. In this paper, a new method is proposed to detect poor vegetation recovery areas (PVRAs) where vegetation recovery has experienced significant difficulty. By using 8-day interval Moderate-Resolution Imaging Spectroradiometer (MODIS) images from 2000 to 2012, Normalized Difference Vegetation Index (NDVI) values after the Wenchuan earthquake are compared with past NDVI distributions before the earthquake. This method fully considers the dynamic processes of vegetation recovery, including both seasonal and annual variation in NDVI values, and identifies landslide disturbances from natural fluctuations. Then, the method has been applied in the study area in Pingwu County to detect vegetation recovery and its validity has been checked by field works and manual interpretation of different periods of SPOT5 imageries. By comparing unrecovered vegetation sites, the optimal threshold to define PVRA is determined. This research has singled out four types of PVRA (namely “deposition,” “back scar,” “mixed large,” and “land use change” types) in the study area, with each type of PVRA linked to different reasons for poor vegetation recovery. Finally, the proposed method is applied to the mostly affected counties, where Modified Mercalli Intensity (MMI) is greater than VIII. Spatial patterns of PVRA indicate that vegetation has experienced significantly poor process over relatively widespread regions.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Mapping Two Competing Grassland Species from a Low-Altitude Helium Balloon
    • Authors: Silva; B.;Lehnert, L.;Roos, K.;Fries, A.;Rollenbeck, R.;Beck, E.;Bendix, J.;
      Pages: 3038 - 3049
      Abstract: This paper describes a method of low-altitude remote sensing in combination with in situ measurements (leaf area, spectroscopy, and position) to monitor the postfire canopy recovery of two competing grassland species. The method was developed in the Andes of Ecuador, where a tethered balloon with a digital camera was deployed to record a time series of very high spatial resolution imagery ( ${bf nominal} {bf resolution} = {bf 2}nbsp{bf cm}$ ) of an experimental plot covered by two competing species: 1) the pasture grass, Setaria sphacelata; and 2) the invasive southern bracken, Pteridium arachnoideum. Image processing techniques were combined to solve geometric issues and construct high-quality mosaics for image classification. The semiautomatic and object-oriented classification method was based on geometrical and textural attributes of image segments and showed promising results for detecting the invasive bracken fern in Setaria pastures (performance by area under the curve, ${bf AUC} = {bf 0.88}$ ). Valuable insights are given into vegetation monitoring applications using unmanned aerial vehicles, which produces a time series of species-specific maps, including foliage projective cover (FPC) and leaf area index (LAI). This new method constitutes an important and accessible tool for ecological investigations of competing species in pastures and validation of remote sensing information on mountain environments.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Modification of Multichannel Reconstruction Algorithm on the SAR With
           Linear Variation of PRI
    • Authors: Luo; X.;Wang, R.;Xu, W.;Deng, Y.;Guo, L.;
      Pages: 3050 - 3059
      Abstract: This paper focuses on the signal processing for synthetic aperture radar (SAR) with fast linear variation of PRI which was introduced to settle the blind range problem in conventional SAR with constant PRI. Since periodic pulse loss is resulted from the variation of PRI, the distribution of the completely received pulses strongly deviates from the ideal uniform one. To settle the problem of nonuniform sampling, multichannel reconstruction algorithm is employed. As the reconstruction requires a priori knowledge of the precise distribution of the samples, this paper first derives the position of the lost pulses. Further, in order to reduce the nonuniformity, an optimal PRI variation scheme is designed. Moreover, considering the drastic degradation of the AASR and the SNR caused by the conventional multichannel reconstruction, we propose a modification where the number of processed frequency bands is reduced, and then the increased degrees of freedom (DOF) are exploited to minimize the power of the residual ambiguities and the noise via a linear constraint minimum power (LCMP) method. Compared to the conventional reconstruction, the modified one dramatically improves the ISLR, the AASR, and the SNR, which is validated by simulation experiments.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • A Novel Algorithm to Estimate Algal Bloom Coverage to Subpixel Resolution
           in Lake Taihu
    • Authors: Zhang; Y.;Ma, R.;Duan, H.;Loiselle, S.A.;Xu, J.;Ma, M.;
      Pages: 3060 - 3068
      Abstract: Remote sensing has often been used to monitor the distribution and frequency of floating algae in inland aquatic environments. However, due to the spatial resolution of the most common satellite sensors, accurate determination of algae coverage remains a major technical challenge. Here, a novel algorithm to estimate floating algae area to subpixel scales, denominated the algae pixel-growing algorithm (APA), is developed and evaluated for a series of image data from the Moderate Resolution Imaging Spectroradiometer (MODIS). The algorithm utilizes the Rayleigh-corrected reflectance (Rrc) and a floating algae index (FAI) derived from Rrc in three spectral bands. Comparison with concurrent Landsat ${bf {TM}/{ ETM} +} $ data indicate that the APA provides more accurate estimates of both algal bloom area and algal bloom intensity (i.e., floating algae coverage) ( ${bf RSE} = 15.2nbsphbox{km}^ {2}$ and ${bf RE = 9.9% }$ ), compared to other commonly used methods such as the linear unmixing algorithm (LA). Furthermore, this study confirms that FAI is a better index with respect to normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI) for the estimation of algae area coverage, especially when combined with the APA. Finally, the study provides a theoretical basis for the objective assessment of bloom severity in complex inland waterbodies.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • A New Inversion Model to Estimate Bulk Refractive Index of Particles in
           Coastal Oceanic Waters: Implications for Remote Sensing
    • Authors: Nasiha; H.J.;Shanmugam, P.;Hariharasudhan, V.G.;
      Pages: 3069 - 3083
      Abstract: An inversion model is developed to estimate bulk refractive index ( ${etab _{mbi{bp}}}$ relative to water) for understanding the particle assemblages and dynamics in coastal oceanic waters. The model is based on an inversion of Mie theory combined with parameterizations such as the backscattering ratio, hyperbolic slope of the particle size distribution, and bulk density (relative to water). With the advent of high-frequency in-situ spectral attenuation and fluorescence-turbidity sensors, these parameters can be easily measured and used in the new model to estimate the ${etab _{mbi{bp}}}$ values. To test the robustness of this model, the ${etab_{mbi{bp}}}$ values estimated from the new model are verified with the Mie input refractive index values (relative to water) and those produced by an existing model. The new model is also applied to spatial, temporal, and vertical in-situ profile data measured from turbid coastal waters off Point Calimere and clear waters off Chennai, southeast part of India. The ${etab_{mbi{bp}}}$ values estimated by the present model are generally agreeable with the previously reported ${etab _{mbi{bp}}}$ values (1.02–1.28) for these waters. By contrast, the existing model tends to provide relatively high ${etab _{mbi{bp}}}$ values (1.10) for clear waters and low ${etab _{mbi{bp}}}$ values (1.215) for relatively clear and sediment-laden waters. Application of these models to time-series in-situ data from moderately turbid and highly turbid waters reveal- that the vertical distribution patterns of ${etab _{mbi{bp}}}$ from the new model correspond better with turbidity patterns (with an increasing ${etab _{mbi{bp}}}$ trend in sediment-laden bottom waters) that display large variations depending on the tidal cycles of the day. However, the existing model produces a very narrow range of ${etab _{mbi{bp}}}$ values displaying nearly homogenous patterns regardless of the turbidity variation along the depth. The new model enables more reliable estimates of ${etab _{mbi{bp}}}$ for living cells (1.02–1.07 because of higher water content) in clear waters, detrital particles (1.07–1.15) and minerals/mineral-detrital particles (>1.15 because of lower water content). These results suggest that the new model will have important implications for studies of the particle assemblages in coastal oceanic waters, with the feasibility of remote estimation of ${etab_{mbi{bp}}}$ with the proof-of-concept approaches which will inspire further research into the nature of particles in the ocean and their variability on regional and global scales.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Estimation of Marine Primary Productivity From Satellite-Derived
           Phytoplankton Absorption Data
    • Authors: Ma; S.;Tao, Z.;Yang, X.;Yu, Y.;Zhou, X.;Ma, W.;Li, Z.;
      Pages: 3084 - 3092
      Abstract: The global ocean net primary production (NPP) was estimated from satellite-derived information using a phytoplankton pigment absorption ( ${a}_{{bf ph}}$ )-based model. Satellite-derived spectral-averaged ${a}_{{bf ph}}$ was used as the key predictor of phytoplankton photosynthetic efficiency in the model. The ${a}_{{bf ph}}$ -based model yields an annual integrated NPP of approximately $bf 55~hbox{Pg C year}^{-1}$ for the global oceans over the period 2003–2010. The accuracy of the model was validated by comparing it with in situ NPP at three sites, and the logarithmic root-mean-square error of the model was approximately 0.18. The model performance was also compared with two existing NPP models (chlorophyll-based model and carbon-based model) in terms of spatial distribution, seasonal cycles, and accuracy. The comparison results indicated that the ${a}_{{bf ph}}$ -based model has improved accuracy in describing NPP variation for monthly timescales compared with the other two models. We were surprised to find that the spatial distribution of global ocean NPP provided by the ${a}_{{bf ph}}$ -based model is more similar to the carbon-based model than the chlorophyll-based model. Although many additional studies need to be conducted, the performance of the ${a}_{{bf ph}}$ -based model in this work may encourage us to estimate ocean NPP from satellite-derived phytoplankton pigment absorption.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Toward a Near Real-Time Product of Air Temperature Maps from Satellite
           Data and In Situ Measurements in Arid Environments
    • Authors: Lazzarini; M.;Marpu, P.R.;Eissa, Y.;Ghedira, H.;
      Pages: 3093 - 3104
      Abstract: Earth observation data and in situ measurements were used to derive a method for the estimation of Air Temperature (AirT) and thereby produce maps. The methodology was developed and validated using data acquired at five stations located in the United Arab Emirates (UAE) during the year 2012. In the first step, the effect of different variables on the estimation of AirT values was investigated and the variables of high importance were used to build the final model. Land surface temperature (LST), relative humidity, global horizontal irradiance, direct normal irradiance, and diffuse horizontal irradiance were identified as the most important inputs for AirT estimation. Models were developed separately for four different cases based on the seasons (Winter/Summer) and the time of the day (Day/Night). The models were evaluated using jackknife validation on the stations resulting in root mean square errors of ${bf 2.25}^circ{bf C}$ (Winter/Day), ${bf 2.24},^circ {bf C}$ (Winter/Night), ${bf 2.56},^circ {bf C}$ (Summer/Day), and ${bf 2.69},^circ {bf C}$ (Summer/Night) and an overall average accuracy of ${bf 2.44},^circ {bf C}$ . Finally, the model has been applied on a larger scale by assimilating the relevant Earth observation data and in situ measurements for the creation of AirT maps for the entire country. The resulting AirT maps were generated in near real time at a temporal resolution of 15 min from METEOSAT/SEVIRI LST and the above-mentioned in situ measurements. These maps can be considered as important resources for several a- plications (e.g., climate studies, solar energy applications, thermal comfort studies, etc.).
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Water Vapor Retrieval Over Cloud Cover Area on Land Using AMSR-E and MODIS
    • Authors: Ji; D.;Shi, J.;
      Pages: 3105 - 3116
      Abstract: This study mainly discusses atmospheric water vapor retrieval over cloud cover area on land with the help of a newly developed surface emissivity parameter estimation method in microwave bands. In the retrieval method, the atmospheric water vapor sensitivity parameter—ratio of brightness temperature polarization difference at frequencies 18.7 and 23.8 GHz ( ${{Deltab}} {bf Tb}_{bf 18.7}/{{Deltab}} {bf Tb}_{bf 23.8}$ )—is used to retrieve water vapor, and the surface emissivity parameter—ratio of surface emissivity polarization difference at frequencies 18.7 and 23.8 GHz ( ${{Deltab}} {{varepsilonb}_{bf 18.7}}/{{Deltab}} {varepsilonb}_{bf 23.8}$ ) that corresponds to ${{Deltab}} {bf Tb}_{bf18.7}/{{Deltab}} {bf Tb}_{bf 23.8}$ —is a key parameter that affects the final precision of retrieved atmosphere water vapor. In order to estimate ${{Deltab}} {{varepsilonb}_{bf 18.7}}/{{Deltab}} {{varepsilonb}_{bf 23.8}}$ in cloudy condition, we first estimated the value of ${{Deltab}} {{varepsilonb}_{bf 18.7}}/{{Deltab}} {{varepsilonb}_{bf 23.8}}$ in clear condition using Advanced Microwave Scanning Radiometer for EOS (AMSR-E) brightness temperature and related MODIS atmospheric products. At the same time, it was found that gradient information derived separately from ${{Deltab}} {bf Tb}_{bf 18.7}/{{Deltab}} {bf Tb}_{bf 23.8}$ and ${{Deltab}} {{varepsilonb}_{bf 18.7}}/{{Deltab}} {{varepsilonb}_{bf 23.8}}$ has very good correlati- n with each other. Based on this good correlation, the ${{Deltab}} {{varepsilonb}_{bf 18.7}}/{{Deltab}} {{varepsilonb}_{bf 23.8}}$ in cloudy condition was estimated using corresponding ${{Deltab}} {bf Tb}_{bf 18.7}/{{Deltab}} {bf Tb}_{bf 23.8}$ and adjacent 8 days ${{Deltab}} {{varepsilonb}_{bf 18.7}}/{{Deltab}} {{varepsilonb}_{bf 23.8}}$ in clear condition. With the estimated ${{Deltab}} {{varepsilonb}_{bf 18.7}}/{{Deltab}} {{varepsilonb}_{bf 23.8}}$ , we retrieved atmospheric column water vapor using lookup table method in cloudy condition over land. As a validation source data, the SuomiNet GPS-retrieved precipitable water (PW) vapor is used to validate the retrieved water vapor in this study. According to validation, the correlation coefficient of the two is 0.94 and the root-mean-square-error (RMSE) is 4.85 mm. It is a great improvement in water vapor retrieval using microwave in cloud cover area on land.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Comparative Assessment of Broadband Vegetation Indices Over Aquatic
    • Authors: Villa; P.;Bresciani, M.;Braga, F.;Bolpagni, R.;
      Pages: 3117 - 3127
      Abstract: Remote sensing is one of the most useful tools for mapping and studying vegetation because of the advantages of synoptic view (in time and space) compared to traditional in situ survey. Remotely sensed vegetation indices (VIs) derived from airborne and satellite images represent a powerful and effective way to monitor vegetation status, growth, and bio-physical parameters. This is especially true for aquatic ecosystems, whose characterization is extremely time-consuming and expensive. This work runs a comparison of different VIs in mapping aquatic vegetation (AV) and assesses the capabilities of two recently developed indices specifically designed to analyze aquatic ecosystems: the Normalized Difference Aquatic Vegetation Index (NDAVI) and the Water Adjusted Vegetation Index (WAVI). Three aquatic ecosystems in northern Italy are studied: Lake Garda, Mantua lake system, and Venice Lagoon. A multispectral and multisensor dataset is utilized, ranging from aerial to satellite data, with varying spatial (2–90 m) and spectral resolutions ( $ 0.01 - 0.15~micro{hbox{m}}$ ). Literature VIs (NDVI, SAVI, and EVI), and two recently proposed VIs (NDAVI and WAVI) are derived and their performance in terms of both AV mapping capabilities and vegetation features separability is assessed. Best performances are shown in most of the cases by the recently introduced indices and by WAVI, in particular, thus demonstrating the usefulness of a specific index for mapping AV. Their use in integration with other VIs can be envisaged in order to effectively describe a wide range of AV features from multispectral remotely sensed data.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • A Sampling Strategy for Remotely Sensed LAI Product Validation Over
           Heterogeneous Land Surfaces
    • Authors: Zeng; Y.;Li, J.;Liu, Q.;Li, L.;Xu, B.;Yin, G.;Peng, J.;
      Pages: 3128 - 3142
      Abstract: The development of efficient and systematic ground-based spatial sampling strategies is critical for the validation of medium-resolution satellite-derived leaf area index (LAI) products, particularly over heterogeneous land surfaces. In this paper, a new sampling strategy based on high-resolution vegetation index prior knowledge (SSVIP) is proposed to generate accurate LAI reference maps over heterogeneous areas. To capture the variability across a site, the SSVIP is designed to 1) stratify the nonhomogeneous area into zones with minimum within-class variance; 2) assign the number of samples to each zone using Neyman optimal allocation; and 3) determine the spatial distribution of samples with a nearest neighbor index. The efficiency of the proposed method was examined using different vegetation types and pixel heterogeneities. The results indicate that the SSVIP approach can properly divide a heterogeneous area into different vegetation cover zones. Whereas the LAI reference maps generated by SSVIP attain the target accuracy of 0.1 LAI units in cropland and broadleaf forest sites, the current sampling strategy based on vegetation type has a root mean square error (RMSE) of 0.14 for the same number of samples. SSVIP was compared with the current sampling strategy at 24 VALERI sites, and the results suggested that samples selected by SSVIP were more representative in the feature space and geographical space, which further indicated the reasonable validation over heterogeneous land surfaces.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Forest Biomass and Carbon Stock Quantification Using Airborne LiDAR Data:
           A Case Study Over Huntington Wildlife Forest in the Adirondack Park
    • Authors: Li; M.;Im, J.;Quackenbush, L.J.;Liu, T.;
      Pages: 3143 - 3156
      Abstract: In response to the need for a better understanding of biosphere–atmosphere interactions as well as carbon cycles, there is a high demand for monitoring key forest parameters such as biomass and carbon stock. These monitoring tasks provide insight into relevant biogeochemical processes as well as anthropogenic impacts on the environment. Recent advances in remote sensing techniques such as Light Detection and Ranging (LiDAR) enable scientists to nondestructively identify structural and biophysical characteristics of forests. This study quantified forest biomass and carbon stock at the plot level from small-footprint full-waveform LiDAR data collected over a montane mixed forest in September 2011, using seven modeling methods: ordinary least squares, generalized additive model, Cubist, bagging, random forest, boosted regression trees, and support vector regression (SVR). Results showed that higher percentiles of canopy height and intensity made significant contributions to the predictions, while other explanatory variables related to canopy geometric volume, structure, and canopy coverage were generally not as important. Boosted regression trees provided the highest accuracy for model calibration, whereas SVR and ordinary least squares performed slightly better than the other models in model validation. In this study, the simple ordinary least squares approach performed just as well as any advanced machine learning method.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Estimation of Forest Canopy Height Over Mountainous Areas Using Satellite
    • Authors: Fang; Z.;Cao, C.;
      Pages: 3157 - 3166
      Abstract: The full waveform data of the large-footprint Geoscience Laser Altimeter System (GLAS) on the Ice, Cloud, and land Elevation Satellite, together with airborne light detection and ranging (lidar) data, were employed to retrieve the basal-area weighted mean height (Lorey’s height) over sloping terrain in the Qilian mountains region, western China. Over mountainous areas with high relief and complex terrain, a GLAS waveform is characterized by multiple energy peaks, which ground and surface objects may be broadened and mixed, making the extraction of canopy height difficult. This study focuses on forests in a mountainous area to derive mean tree height directly from the GLAS waveform information and Gaussian decomposition results. We derived a relationship between the weighted mean tree height derived from airborne lidar data and the predicted mean tree height within the GLAS footprints; the resulting equation explained 82.8% of variance, with an RMSE of 2.8 m. Based on the analysis of different slope categories, it can be demonstrated that the proportion of energy and characteristics of the Gaussian curves greatly influenced the extraction of mean tree height in mountainous areas.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Validation of Mobile Laser Scanning for Understory Tree Characterization
           in Urban Forest
    • Authors: Lin; Y.;Holopainen, M.;Kankare, V.;Hyyppa, J.;
      Pages: 3167 - 3173
      Abstract: This study was dedicated to validating mobile laser scanning (MLS) for understory tree characterization, which now is still an open issue of interest in the fields of forest inventory and remote sensing. The program of validation was divided into three steps aiming at its three premise questions, respectively: 1) Can MLS record echoes with precise coordinates in the scenario of forest overstory shading satellite wireless positioning signals? 2) Can MLS samplings subject to spatial distribution inconsistency show the basic structures of understory trees? and 3) Can MLS data, further, present the local details of understory tree structures? The examinations were carried out based on the related typical feature variables, i.e., 1) overstory tree stem positioning accuracy as a substitute and 2) understory tree height and crown width and the newly proposed measure of object detail characterization, i.e., 3) primary nearest point distance (PNPD). The results proved to be positive. Overall, although the discussions suggested that MLS has its shortages, e.g., its cover still restricted by tree obscuration, this endeavor has primarily validated MLS for understory tree characterization in urban forest.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Delineation of Tree Crowns and Tree Species Classification From
           Full-Waveform Airborne Laser Scanning Data Using 3-D Ellipsoidal
    • Authors: Lindberg; E.;Eysn, L.;Hollaus, M.;Holmgren, J.;Pfeifer, N.;
      Pages: 3174 - 3181
      Abstract: Individual tree crowns can be delineated from dense airborne laser scanning (ALS) data and their species can be classified from the spatial distribution and other variables derived from the ALS data within each tree crown. This study reports a new clustering approach to delineate tree crowns in three dimensions (3-D) based on ellipsoidal tree crown models (i.e., ellipsoidal clustering). An important feature of this approach is the aim to derive information also about the understory vegetation. The tree crowns are delineated from echoes derived from full-waveform (fwf) ALS data as well as discrete return ALS data with first and last returns. The ellipsoidal clustering led to an improvement in the identification of tree crowns. Fwf ALS data offer the possibility to derive also the echo width and the amplitude in addition to the 3-D coordinates of each echo. In this study, tree species are classified from variables describing the fwf (i.e., the mean and standard deviation of the echo amplitude, echo width, and total number of echoes per pulse) and the spatial distribution of the clusters for pine, spruce, birch, oak, alder, and other species. Supervised classification is done for 68 field plots with leave-one-out cross-validation for one field plot at a time. The total accuracy was 71% when using both fwf and spatial variables, 60% when using only spatial variables, and 53% when using discrete return data. The improvement was greatest for discriminating pine and spruce as well as pine and birch.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Special Issue on Data Fusion in Remote Sensing
    • Pages: 3182 - 3182
      Abstract: Describes the above-named upcoming special issue or section. May include topics to be covered or calls for papers.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • IEEE Geoscience and Remote Sensing Magazine
    • Pages: 3183 - 3183
      Abstract: Prospective authors are requested to submit new, unpublished manuscripts for inclusion in the upcoming event described in this call for papers.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
  • Open Access
    • Pages: 3184 - 3184
      Abstract: Advertisement: This publication offers open access options for authors. IEEE open access publishing.
      PubDate: July 2014
      Issue No: Vol. 7, No. 7 (2014)
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