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A global study of NDVI difference among moderate-resolution satellite sensors / Xingwang Fan in ISPRS Journal of photogrammetry and remote sensing, vol 121 (November 2016)
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Titre : A global study of NDVI difference among moderate-resolution satellite sensors Type de document : Article/Communication Auteurs : Xingwang Fan, Auteur ; Yuanbo Liu, Auteur Année de publication : 2016 Article en page(s) : pp 177 – 191 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] analyse comparative
[Termes IGN] effet atmosphérique
[Termes IGN] image Aqua-MODIS
[Termes IGN] image multicapteur
[Termes IGN] image NPP-VIIRS
[Termes IGN] image Terra-MODIS
[Termes IGN] image TIROS-AVHRR
[Termes IGN] Normalized Difference Vegetation Index
[Termes IGN] occupation du sol
[Termes IGN] variation saisonnièreRésumé : (Auteur) Moderate-resolution sensors, including AVHRR (Advanced Very High Resolution Radiometer), MODIS (MODerate-resolution Imaging Spectroradiometer) and VIIRS (Visible-Infrared Imager-Radiometer Suite), have provided over forty years of global scientific data. In the form of NDVI (Normalized Difference Vegetation Index), these data greatly benefit environmental studies. However, their usefulness is compromised by sensor differences. This study investigates the global NDVI difference and its spatio-temporal patterns among typical moderate-resolution sensors, as supported by state-of-the-art remote sensing derived products. Our study demonstrates that the atmosphere plays a secondary role to LULC (Land Use/Land Cover) in inter-sensor NDVI differences. With reference to AVHRR/3, AVHRR/1 and 2 exhibit negative NDVI biases for vegetated land cover types. In summer (July), the area of negative bias shifts northward, and the magnitude increases in the Northern Hemisphere. For most LULC types, the bias generally shifts in the negative direction from winter (January) to summer. A linear regression of the NDVI difference versus NDVI shows a close correlation between the slope value and vegetation phenology. Overall, NDVI differences are controlled by LULC type and vegetation phenology. Our study can be used to generate a long-term, consistent NDVI data set from composite MODIS and AVHRR NDVI data. LULC-dependent and temporally variable correction equations are recommended to reduce inter-sensor NDVI differences. Numéro de notice : A2016--017 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2016.09.008 En ligne : http://dx.doi.org/10.1016/j.isprsjprs.2016.09.008 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83879
in ISPRS Journal of photogrammetry and remote sensing > vol 121 (November 2016) . - pp 177 – 191[article]Interference localization from space: theoretical background / Luca Canzian in Inside GNSS, vol 11 n° 6 (November - December 2016)
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Titre : Interference localization from space: theoretical background Type de document : Article/Communication Auteurs : Luca Canzian, Auteur ; Stefano Ciccotosto, Auteur ; Samuele Fantinato, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 59 - 68 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement du signal
[Termes IGN] détection automatique
[Termes IGN] géolocalisation
[Termes IGN] interférenceRésumé : (auteur) Radio Frequency Interference causes the satellite industry to lose millions of dollars per year due to detrimental effects, ranging from a degradation in the quality of service to the complete loss of service. As a consequence, it is becoming critical important to design space systems that are able to localize the source of interference, allowing actions that can prevent future repetitions of similar behaviors. This is the first of a series of articles on the issue of interference localization. This article discusses the theoretical aspects associated with single-interferer localization approaches, describing how to extract those features providing information on the interference source location from the received interference signal itself, and how to compute a position fix by merging the collected information. Numéro de notice : A2016--051 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans En ligne : http://www.insidegnss.com/node/5200 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83598
in Inside GNSS > vol 11 n° 6 (November - December 2016) . - pp 59 - 68[article] Voir aussiRéservation
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Code-barres Cote Support Localisation Section Disponibilité 238-2016061 SL Revue Centre de documentation Revues en salle Disponible An advanced GNSS code multipath detection and estimation algorithm / Negin Sokhandan in GPS solutions, vol 20 n° 4 (October 2016)
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Titre : An advanced GNSS code multipath detection and estimation algorithm Type de document : Article/Communication Auteurs : Negin Sokhandan, Auteur ; James T. Curran, Auteur ; Ali Broumandan, Auteur ; Gérard Lachapelle, Auteur Année de publication : 2016 Article en page(s) : pp 627 - 640 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] code GNSS
[Termes IGN] méthode du maximum de vraisemblance (estimation)
[Termes IGN] milieu urbain
[Termes IGN] modèle de simulation
[Termes IGN] positionnement par GNSS
[Termes IGN] système de navigation
[Termes IGN] trajet multipleRésumé : (Auteur) A novel maximum likelihood-based range estimation algorithm is designed to provide robustness to multipath, which is recognized as a dominant error source in DS-CDMA-based navigation systems. The detection–estimation problem is jointly solved to sequentially estimate the parameters of each individual multipath component and predict the existence of a next possible component. A comparison between contemporary maximum likelihood-based multipath estimation techniques and this new technique is provided. A selection of realistic channel simulation models is used to assess relative performance under different operating situations. A set of real GPS L1/CA data processing results are also presented to further assess the applicability of the proposed algorithm for urban navigation. Numéro de notice : A2016--025 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-015-0475-z En ligne : http://dx.doi.org/10.1007/s10291-015-0475-z Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83926
in GPS solutions > vol 20 n° 4 (October 2016) . - pp 627 - 640[article]Long-term soil moisture dynamics derived from GNSS interferometric reflectometry: a case study for Sutherland, South Africa / Sibylle Vey in GPS solutions, vol 20 n° 4 (October 2016)
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Titre : Long-term soil moisture dynamics derived from GNSS interferometric reflectometry: a case study for Sutherland, South Africa Type de document : Article/Communication Auteurs : Sibylle Vey, Auteur ; Jens Wickert, Auteur Année de publication : 2016 Article en page(s) : pp 641 - 654 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] Afrique du sud (état)
[Termes IGN] analyse diachronique
[Termes IGN] humidité du sol
[Termes IGN] rapport signal sur bruit
[Termes IGN] récepteur GNSS
[Termes IGN] réflectométrie par GNSS
[Termes IGN] signal GNSS
[Termes IGN] variation temporelleRésumé : (Auteur) Soil moisture is a geophysical key observable for predicting floods and droughts, modeling weather and climate and optimizing agricultural management. Currently available in situ observations are limited to small sampling volumes and restricted number of sites, whereas measurements from satellites lack spatial resolution. Global navigation satellite system (GNSS) receivers can be used to estimate soil moisture time series at an intermediate scale of about 1000 m2. In this study, GNSS signal-to-noise ratio (SNR) data at the station Sutherland, South Africa, are used to estimate soil moisture variations during 2008–2014. The results capture the wetting and drying cycles in response to rainfall. The GNSS Volumetric Water Content (VWC) is highly correlated (r2 = 0.8) with in situ observations by time-domain reflectometry sensors and is accurate to 0.05 m3/m3. The soil moisture estimates derived from the SNR of the L1 and L2P signals compared to the L2C show small differences with a RMSE of 0.03 m3/m3. A reduction in the SNR sampling rate from 1 to 30 s has very little impact on the accuracy of the soil moisture estimates (RMSE of the VWC difference 1–30 s is 0.01 m3/m3). The results show that the existing data of the global tracking network with continuous observations of the L1 and L2P signals with a 30-s sampling rate over the last two decades can provide valuable complementary soil moisture observations worldwide. Numéro de notice : A2016--026 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-015-0474-0 En ligne : http://dx.doi.org/10.1007/s10291-015-0474-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83927
in GPS solutions > vol 20 n° 4 (October 2016) . - pp 641 - 654[article]A new ZTD model based on permanent ground-based GNSS-ZTD data / M. Ding in Survey review, vol 48 n° 351 (October 2016)
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Titre : A new ZTD model based on permanent ground-based GNSS-ZTD data Type de document : Article/Communication Auteurs : M. Ding, Auteur ; W. Hu, Auteur ; X. Jin, Auteur ; L. Yu, Auteur Année de publication : 2016 Article en page(s) : pp 385 - 391 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] correction troposphérique
[Termes IGN] données GNSS
[Termes IGN] réseau neuronal artificiel
[Termes IGN] retard troposphérique zénithal
[Termes IGN] RussieRésumé : (Auteur) Tropospheric delay has a major effect on the accuracy of navigation and positioning when using the Global Navigation Satellite System (GNSS). Zenith tropospheric delay (ZTD) modelling has been used to weaken the influence of the atmosphere. The work reported here focused on ZTD modelling based on real-time surface meteorological parameters, traditionally represented by the Saastamoinen model. However, Saastamoinen accuracy only reaches scale of centimetres, even to scale of centimetres when the water vapour is active, whereas the scale of ground-based GNSS-ZTD data (i.e. ZTD derived from ground GNSS data) is on the millimetre scale and is considered to be the ‘true’ value. An important direction in GNSS studies is how to make good use of ground-based GNSS-ZTD data to improve the accuracy of the Saastamoinen model. Authors studied the residuals in the Saastamoinen model using high-precision GNSS-ZTD data provided by the International GNSS Service (IGS) product and then carried out modelling based on a back propagation neural network. A new ZTD model (ISAAS) based on real-time surface meteorological parameters is proposed based on this method. The ISAAS model has good accuracy: its BIAS and root mean square error (RMSE) at the test area in Russia were -4.4 and 20.4 mm, respectively, which are lower than the results obtained using the Saastamoinen model (-10.4 and 23.3 mm, respectively). The ISAAS model can improve the ZTD prediction accuracy by more than 12.4% and therefore has important implications for precision engineering measurements in Russia. Numéro de notice : A2016-821 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1179/1752270615Y.0000000034 En ligne : https://doi.org/10.1179/1752270615Y.0000000034 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82636
in Survey review > vol 48 n° 351 (October 2016) . - pp 385 - 391[article]On the significance of periodic signals in noise analysis of GPS station coordinates time series / Janusz Bogusz in GPS solutions, vol 20 n° 4 (October 2016)
PermalinkSMAP L-Band microwave radiometer: RFI mitigation prelaunch analysis and first year on-orbit observations / Priscilla N. Mohammed in IEEE Transactions on geoscience and remote sensing, vol 54 n° 10 (October 2016)
PermalinkThe influence of elliptical Gaussian laser beam on inversion of terrain information for satellite laser altimeter / Zhou Hui in Photogrammetric Engineering & Remote Sensing, PERS, vol 82 n° 10 (October 2016)
PermalinkDynamic occlusion detection and inpainting of in situ captured terrestrial laser scanning point clouds sequence / Chi Chen in ISPRS Journal of photogrammetry and remote sensing, vol 119 (September 2016)
PermalinkGNSS interferometric radio occultation / Manuel Martín-Neira in IEEE Transactions on geoscience and remote sensing, vol 54 n° 9 (September 2016)
PermalinkNoise removal from hyperspectral image with joint spectral–spatial distributed sparse representation / Jie Li in IEEE Transactions on geoscience and remote sensing, vol 54 n° 9 (September 2016)
PermalinkVariance components estimation of residual errors in GPS precise positioning / Darko Anđić in Geodetski vestnik, vol 60 n° 3 (September - November 2016)
PermalinkAtmospheric correction in time-series SAR interferometry for land surface deformation mapping : A case study of Taiyuan, China / Wei Tang in Advances in space research, vol 58 n° 3 (August 2016)
PermalinkA geometry-free and ionosphere-free multipath mitigation method for BDS three-frequency ambiguity resolution / Dezhong Chen in Journal of geodesy, vol 90 n° 8 (August 2016)
PermalinkInterference mitigation in the E5A Galileo band using an open-source simulator / Diego Alonso in Inside GNSS, vol 11 n° 4 (July - August 2016)
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