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A geographic information-driven method and a new large scale dataset for remote sensing cloud/snow detection / Xi Wu in ISPRS Journal of photogrammetry and remote sensing, vol 174 (April 2021)  

Public [article]  inISPRS Journal of photogrammetry and remote sensing > vol 174 (April 2021) . - pp 87 - 104 Titre : A geographic information-driven method and a new large scale dataset for remote sensing cloud/snow detection Type de document : Article/Communication Auteurs : Xi Wu, Auteur ; Zhenwei Shi, Auteur ; Zhengxia Zou, Auteur Année de publication : 2021 Article en page(s) : pp 87 - 104 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] altitude [Termes IGN] apprentissage profond [Termes IGN] classification par réseau neuronal convolutif [Termes IGN] détection des nuages [Termes IGN] extraction de traits caractéristiques [Termes IGN] fusion de données [Termes IGN] image Gaofen [Termes IGN] information géographique [Termes IGN] latitude [Termes IGN] longitude [Termes IGN] modèle statistique [Termes IGN] neige [Termes IGN] Normalized Difference Snow Index Résumé : (auteur) Geographic information such as the altitude, latitude, and longitude are common but fundamental meta-records in remote sensing image products. In this paper, it is shown that such a group of records provides important priors for cloud and snow detection in remote sensing imagery. The intuition comes from some common geographical knowledge, where many of them are important but are often overlooked. For example, it is generally known that snow is less likely to exist in low-latitude or low-altitude areas, and clouds in different geographic may have various visual appearances. Previous cloud and snow detection methods simply ignore the use of such information, and perform detection solely based on the image data (band reflectance). Due to the neglect of such priors, most of these methods are difficult to obtain satisfactory performance in complex scenarios (e.g., cloud-snow coexistence). In this paper, a novel neural network called “Geographic Information-driven Network (GeoInfoNet)” is proposed for cloud and snow detection. In addition to the use of the image data, the model integrates the geographic information at both training and detection phases. A “geographic information encoder” is specially designed, which encodes the altitude, latitude, and longitude of imagery to a set of auxiliary maps and then feeds them to the detection network. The proposed network can be trained in an end-to-end fashion with dense robust features extracted and fused. A new dataset called “Levir_CS” for cloud and snow detection is built, which contains 4,168 Gaofen-1 satellite images and corresponding geographical records, and is over 20× larger than other datasets in this field. On “Levir_CS”, experiments show that the method achieves 90.74% intersection over union of cloud and 78.26% intersection over union of snow. It outperforms other state of the art cloud and snow detection methods with a large margin. Feature visualizations also show that the method learns some important priors which is close to the common sense. The proposed dataset and the code of GeoInfoNet are available in https://github.com/permanentCH5/GeoInfoNet. Numéro de notice : A2021-209 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2021.01.023 Date de publication en ligne : 22/02/2021 En ligne : https://doi.org/10.1016/j.isprsjprs.2021.01.023 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97187 [article]

Exemplaires(3)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
081-2021041	SL	Revue	Centre de documentation	Revues en salle	Disponible
081-2021043	DEP-RECP	Revue	LASTIG	Dépôt en unité	Exclu du prêt
081-2021042	DEP-RECF	Revue	Nancy	Dépôt en unité	Exclu du prêt

On the interoperability of IGS products for precise point positioning with ambiguity resolution / Simon Banville in Journal of geodesy, vol 94 n°1 (January 2020)  

Public [article]  inJournal of geodesy > vol 94 n°1 (January 2020) Titre : On the interoperability of IGS products for precise point positioning with ambiguity resolution Type de document : Article/Communication Auteurs : Simon Banville, Auteur ; Jianghui Geng, Auteur ; Sylvain Loyer, Auteur ; et al., Auteur Année de publication : 2020 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] horloge du satellite [Termes IGN] international GPS service for geodynamics [Termes IGN] interopérabilité [Termes IGN] longitude [Termes IGN] positionnement cinématique [Termes IGN] positionnement par GNSS [Termes IGN] positionnement ponctuel précis [Termes IGN] positionnement statique [Termes IGN] précision millimétrique [Termes IGN] résolution d'ambiguïté Résumé : (auteur) Techniques enabling precise point positioning with ambiguity resolution (PPP-AR) were developed over a decade ago. Several analysis centers of the International GNSS Service (IGS) have implemented such strategies into their software packages and are generating (experimental) PPP-AR products including satellite clock and bias corrections. While the IGS combines individual orbit and clock products as standard to provide a more reliable solution, interoperability of these new PPP-AR products must be confirmed before they can be combined. As a first step, all products are transformed into a common observable-specific representation of biases. It is then confirmed that consistency is only ensured by considering both clock and bias products simultaneously. As a consequence, the satellite clock combination process currently used by the IGS must be revisited to consider not only clocks but also biases. A combination of PPP-AR products from six analysis centers over a one-week period is successfully achieved, showing that alignment of phase clocks can be achieved with millimeter precision thanks to the integer properties of the clocks. In the positioning domain, PPP-AR solutions for all products show improved longitude estimates of daily static positions by nearly 60% over float solutions. The combined products generally provide equivalent or better results than individual analysis center contributions, for both static and kinematic solutions. Numéro de notice : A2020-150 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-019-01335-w Date de publication en ligne : 03/01/2020 En ligne : https://doi.org/10.1007/s00190-019-01335-w Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94782 [article]

The problem of double longitudes on Glavač’s map / Marina Viličić in Cartographic journal (the), Vol 55 n° 3 (August 2018)  

Public [article]  inCartographic journal (the) > Vol 55 n° 3 (August 2018) . - pp 217 - 234 Titre : The problem of double longitudes on Glavač’s map Type de document : Article/Communication Auteurs : Marina Viličić, Auteur ; Miljenko Lapaine, Auteur Année de publication : 2018 Article en page(s) : pp 217 - 234 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Cartographie ancienne [Termes IGN] carte ancienne [Termes IGN] Croatie [Termes IGN] dix-septième siècle [Termes IGN] longitude [Termes IGN] méridien [Termes IGN] régression linéaire Résumé : (Auteur) Stjepan Glavač (1627-1680) produced a map of Croatia dated 1673, on which two meridians appear twice, 40°/51° and 41°/52°. The only written source regarding Glavač’s map is the dedication, which forms an integral part of the map. It does not say which prime meridians Glavač relied on, so in our research we attempted to establish what those prime meridians might have been. We approached the problem of the double longitudes using linear regression, through which we wanted to examine the relation of Glavač’s longitudes to modern values. An essential part of the research was a comparison of Glavač’s map with maps by his predecessors and contemporaries which show approximately the same prime meridians. The maps analysed, with their written values for the longitudes of certain places, indicated that the selection of prime meridians at that time was not entirely reliable. A further problem seemed to be the knowledge of the position of islands chosen as points of departure for longitudes. We concluded that the points of departure for Glavač’s dual longitudes were Palma, one of the Canary Islands, and the islands of Corvo and Flores in the Azores. Numéro de notice : A2018-517 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/00087041.2017.1386343 Date de publication en ligne : 18/10/2018 En ligne : https://doi.org/10.1080/00087041.2017.1386343 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91322 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
030-2018031	RAB	Revue	Centre de documentation	En réserve L003	Disponible

De la navigation "à vue" au calcul des longitudes / Jean-Yves Sarazin in Carto, le monde en cartes, n° 28 (mars - avril 2015)

Public [article]  inCarto, le monde en cartes > n° 28 (mars - avril 2015) . - pp 66 - 71 Titre : De la navigation "à vue" au calcul des longitudes Type de document : Article/Communication Auteurs : Jean-Yves Sarazin, Auteur Année de publication : 2015 Article en page(s) : pp 66 - 71 Langues : Français (fre) Descripteur : [Vedettes matières IGN] Cartographie ancienne [Termes IGN] carte marine [Termes IGN] coordonnées géodésiques [Termes IGN] longitude [Termes IGN] mer [Termes IGN] navigation maritime Résumé : (Auteur) Tous les plus anciens marins de la planète commencèrent leurs périples sans aucune représentation cartographique des distances et des surfaces à parcourir. Ils progressaient le long d'un littoral, en pratiquant par atavisme la navigation "à vue" des amers naturels ou artificiels, des rochers, collines, tours et fanaux. Il fallut attendre le 13ème siècle et la multiplication des relations commerciales entre l'Orient et l'Occident pour qu'apparaissent les premiers schémas des mers traversées. Numéro de notice : A2015-450 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77098 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
154-2015021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Geolocation and time: an evolution of the millennial pair, Part 1 / J. Triglav in Geoinformatics, vol 12 n° 7 (01/10/2009)

Public [article]  inGeoinformatics > vol 12 n° 7 (01/10/2009) . - pp 44 - 49 Titre : Geolocation and time: an evolution of the millennial pair, Part 1 Type de document : Article/Communication Auteurs : J. Triglav, Auteur Année de publication : 2009 Article en page(s) : pp 44 - 49 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie ancienne [Termes IGN] chronomètre [Termes IGN] figure de la Terre [Termes IGN] géopositionnement [Termes IGN] latitude [Termes IGN] longitude [Termes IGN] temps solaire Résumé : (Auteur) [introduction] This year's 250-th anniversary of the invention of the famous watch H-4 that ultimately resolved the longitude problem and the 400-th anniversary of the first use of an astronomical telescope is also an opportunity to look at geodesy as a science of measuring the Earth's shape as a function of time. The paper gives an insight in some basic developments and describes the historical development of geodesy by pointing out and demonstrating the relations between the Earth's shape, geolocation and time measurements from the ancient times to the present time. Since the ancient times the flow of time was a natural measure of man's movements in the physical space and of movements of the Sun, the Moon, the planets and all the other celestial bodies in the vastness of space. Providing the scientific means of how to reference the 'where' and 'when' through millennia, geodesy enables to put the 'who' or "what" in the spatio-temporal space and to present the answers to "why1 and 'how' questions. Astronomy, geodesy, surveying and geography along with cartography, are the sciences that naturally combine the knowledge about space and time providing the natural and social sciences a framework for the development of the constantly growing knowledge of humankind. Copyright GEOinformatics Numéro de notice : A2009-434 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30065 [article]

Voir aussi

• Geolocation and time: an evolution of the millenial pair, Part 2 / J. Triglav in Geoinformatics, vol 12 n° 8 (01/12/2009)

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
262-09071	SL	Revue	Centre de documentation	Revues en salle	Disponible

Greenwich or not Greenwich : ou pourquoi le méridien zéro du système GPS est à plus de 100 mètres à l'est du trait méridien de l'observatoire de Greenwich / R. Vincent in XYZ, n° 120 (septembre - novembre 2009) 

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Des longitudes et des mers : science et progrès (3/3) / Frédéric Bretar in XYZ, n° 104 (septembre - novembre 2005)

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Des longitudes et des mers : la genèse de la navigation (1/3) / Frédéric Bretar in XYZ, n° 102 (mars - mai 2005)

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Une histoire du point en mer / A. Gillet (2000)

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Astronomie / Françoise Duquenne (1997)

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GPS made easy / L. Letham (1996)

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De Christophe Colomb à la géographie d'aujourd'hui / Jean Denègre in XYZ, n° 54 hors-série (mars - mai 1993)

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La connaissance de la géographie du globe à l'époque de Christophe Colomb / Raymond d' Hollander in XYZ, n° 54 hors-série (mars - mai 1993)

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Le projet de Christophe Colomb / J. Bourgoin in XYZ, n° 54 hors-série (mars - mai 1993)

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Astronomical determinations of latitude and longitude in 1981-1983 / Markku Ollikainen (1988)

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