Descripteur
Termes IGN > sciences naturelles > physique > métrologie > étalonnage > étalonnage d'instrument
étalonnage d'instrument |
Documents disponibles dans cette catégorie (553)
![](./images/expand_all.gif)
![](./images/collapse_all.gif)
Etendre la recherche sur niveau(x) vers le bas
GNSS scale determination using calibrated receiver and Galileo satellite antenna patterns / Arturo Villiger in Journal of geodesy, vol 94 n° 9 (September 2020)
![]()
[article]
Titre : GNSS scale determination using calibrated receiver and Galileo satellite antenna patterns Type de document : Article/Communication Auteurs : Arturo Villiger, Auteur ; Rolf Dach, Auteur ; Stefan Schaer, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : n° 93 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] antenne Galileo
[Termes IGN] centre de phase
[Termes IGN] chambre anéchoïque
[Termes IGN] étalonnage d'instrument
[Termes IGN] International Terrestrial Reference Frame
[Termes IGN] métadonnées
[Termes IGN] positionnement par ITGB
[Termes IGN] positionnement par télémétrie laser sur satellite
[Termes IGN] réseau géodésique terrestre
[Termes IGN] robotRésumé : (auteur) The reference frame of a global terrestrial network is defined by the origin, the orientation and the scale. The origin of the ITRF2014 is defined by the ILRS long-term solution, the orientation by no-net rotation conditions w.r.t. the previous reference frame (ITRF2008), and the scale by the mean values from global VLBI and SLR solution series (Altamimi et al. in J Geophys Res Solid Earth 121:6109–6131, 2016). With the release of the Galileo satellite antenna phase center offsets (PCO) w.r.t. the satellites center of mass (GSA in Galileo IOV and FOC satellite metadata, 2019) and the availability of new ground antenna calibrations for GNSS receivers, based on anechoic chamber measurements or on robot calibrations, GNSS global network solutions qualify to contribute to the scale determination of terrestrial networks, as well. Our analysis is based on global multi-GNSS solutions of the years 2017 and 2018 and may be seen as “proof of concept” for the contribution of GNSS data to the scale determination of the terrestrial reference frame. In a first step, the currently used Galileo PCO estimations (Steigenberger et al. in J Geod 90:773–785, 2016) are compared to the released PCO values, which show discrepancies on the decimeter-level. Eventually, the published Galileo PCOs are used in an experimental solution as known values. GNSS-specific PCOs are estimated, as well, for GPS and GLONASS, together with the “standard” parameters set up in global GNSS solutions. From the estimated network coordinates, a time series of daily scale parameters of the terrestrial network is extracted, which shows an offset of the order of 1 ppb (parts per billion, corresponding to a height difference of 6.4 mm on the Earth’s surface) w.r.t. to the ITRF2014 network and an annual variation with an amplitude of about 0.3 ppb. Numéro de notice : A2020-539 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-020-01417-0 Date de publication en ligne : 05/09/2020 En ligne : https://doi.org/10.1007/s00190-020-01417-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95739
in Journal of geodesy > vol 94 n° 9 (September 2020) . - n° 93[article]Estimates of spaceborne precipitation radar pulsewidth and beamwidth using sea surface echo data / Kaya Kanemaru in IEEE Transactions on geoscience and remote sensing, vol 58 n° 8 (August 2020)
![]()
[article]
Titre : Estimates of spaceborne precipitation radar pulsewidth and beamwidth using sea surface echo data Type de document : Article/Communication Auteurs : Kaya Kanemaru, Auteur ; Toshio Iguchi, Auteur ; Takeshi Masaki, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : pp 5291 - 5303 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] bande Ku
[Termes IGN] climat tropical
[Termes IGN] écho radar
[Termes IGN] étalonnage de capteur (imagerie)
[Termes IGN] image GPM
[Termes IGN] image TRMM-MI
[Termes IGN] impulsion
[Termes IGN] précipitation
[Termes IGN] surface de la mer
[Termes IGN] surface équivalente radarRésumé : (auteur) Calibration consistency between Ku-band radars flown on the Tropical Rainfall Measuring Mission’s (TRMM’s) precipitation radar (PR) and the global precipitation measurement (GPM) mission’s dual-frequency PR (DPR) can be attained by the use of the normalized radar cross section (NRCS) or σ0 over the oceans. With the use of the sea surface echo (SSE) data obtained from the spaceborne PRs, this article aims to estimate the radar parameters of pulsewidth and beamwidth and to evaluate the bias in the NRCS estimates caused by the discrete range sampling. Since the SSE shape is closely related to the received pulsewidth and the two-way cross-track beamwidth, those parameters are individually estimated from the SSE shapes. The SSE shapes are also used to evaluate the impact of the discrete range sampling on the NRCS statistics. The pulsewidth and beamwidth estimated from the SSEs compare well with the level-1 values and accurately reflect changes in the configuration of the radars. The NRCS statistics in GPM version 06 show that the calibration consistency between GPM KuPR and TRMM PR is evaluated within the range of −0.39 to +0.03 dB (−0.48 to +0.11 dB) with (without) the peak correction. Numéro de notice : A2020-471 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2019.2963090 Date de publication en ligne : 22/01/2020 En ligne : https://doi.org/10.1109/TGRS.2019.2963090 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95574
in IEEE Transactions on geoscience and remote sensing > vol 58 n° 8 (August 2020) . - pp 5291 - 5303[article]Structure from motion for complex image sets / Mario Michelini in ISPRS Journal of photogrammetry and remote sensing, vol 166 (August 2020)
![]()
[article]
Titre : Structure from motion for complex image sets Type de document : Article/Communication Auteurs : Mario Michelini, Auteur ; Helmut Mayer, Auteur Année de publication : 2020 Article en page(s) : pp 140 - 152 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] appariement d'images
[Termes IGN] arbre aléatoire minimum
[Termes IGN] caméra numérique
[Termes IGN] distorsion d'image
[Termes IGN] étalonnage d'instrument
[Termes IGN] fusion de données multisource
[Termes IGN] itération
[Termes IGN] jeu de données
[Termes IGN] orientation
[Termes IGN] reconstruction 3D
[Termes IGN] SIFT (algorithme)
[Termes IGN] structure-from-motionRésumé : (auteur) This paper presents an approach for Structure from Motion (SfM) for unorganized complex image sets. To achieve high accuracy and robustness, image triplets are employed and an (approximate) internal camera calibration is assumed to be known. The complexity of an image set is determined by the camera configurations which may include wide as well as weak baselines. Wide baselines occur for instance when terrestrial images and images from small Unmanned Aerial Systems (UAS) are combined. The resulting large (geometric/radiometric) distortions between images make image matching difficult possibly leading to an incomplete result. Weak baselines mean an insufficient distance between cameras compared to the distance of the observed scene and give rise to critical camera configurations. Inappropriate handling of such configurations may lead to various problems in triangulation-based SfM up to total failure. The focus of our approach lies on a complete linking of images even in case of wide or weak baselines. We do not rely on any additional information such as camera configurations, Global Positioning System (GPS) or an Inertial Navigation System (INS). As basis for generating suitable triplets to link the images, an iterative graph-based method is employed formulating image linking as the search for a terminal Steiner minimum tree in the line graph. SIFT (Lowe, 2004) descriptors are embedded into Hamming space for fast image similarity ranking. This is employed to limit the number of pairs to be geometrically verified by a computationally and more complex wide baseline matching method (Mayer et al., 2012). Critical camera configurations which are not suitable for geometric verification are detected by means of classification (Michelini and Mayer, 2019). Additionally, we propose a graph-based approach for the optimization of the hierarchical merging of triplets to efficiently generate larger image subsets. By this means, a complete, 3D reconstruction of the scene is obtained. Experiments demonstrate that the approach is able to produce reliable orientation for large image sets comprising wide as well as weak baseline configurations. Numéro de notice : A2020-355 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2020.05.020 Date de publication en ligne : 12/06/2020 En ligne : https://doi.org/10.1016/j.isprsjprs.2020.05.020 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95242
in ISPRS Journal of photogrammetry and remote sensing > vol 166 (August 2020) . - pp 140 - 152[article]Exemplaires(3)
Code-barres Cote Support Localisation Section Disponibilité 081-2020081 RAB Revue Centre de documentation En réserve L003 Disponible 081-2020083 DEP-RECP Revue LASTIG Dépôt en unité Exclu du prêt 081-2020082 DEP-RECF Revue Nancy Dépôt en unité Exclu du prêt Cross-calibration of MODIS reflective solar bands with Sentinel 2A/2B MSI instruments / Amit Angal in IEEE Transactions on geoscience and remote sensing, vol 58 n° 7 (July 2020)
![]()
[article]
Titre : Cross-calibration of MODIS reflective solar bands with Sentinel 2A/2B MSI instruments Type de document : Article/Communication Auteurs : Amit Angal, Auteur ; Xiaoxiong Xiong, Auteur ; Ashish Shrestha, Auteur Année de publication : 2020 Article en page(s) : pp 5000 - 5007 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] distribution du coefficient de réflexion bidirectionnelle BRDF
[Termes IGN] étalonnage croisé
[Termes IGN] étalonnage radiométrique
[Termes IGN] image Aqua-MODIS
[Termes IGN] image Sentinel-MSI
[Termes IGN] image Terra-MODIS
[Termes IGN] incertitude spectrale
[Termes IGN] Libye
[Termes IGN] nadir
[Termes IGN] pouvoir de résolution géométrique
[Termes IGN] réflectance spectraleRésumé : (auteur) Moderate resolution imaging spectroradiometer (MODIS) is a 36-band spectroradiometer that measures the Earth’s surface from 0.4 to $14.4~\mu \text{m}$ at three spatial resolutions, 250 m (two bands), 500 m (five bands), and 1000 m (29 bands). The wide-scale use of the science products derived from the two MODIS instruments on the Terra and Aqua spacecrafts is a result of their excellent on-orbit performance, calibration stability, and accuracy through the life of the mission, making them a benchmark against which the performance of newer instruments is frequently evaluated. The recently launched multispectral instrument (MSI) aboard the Sentinel 2A and Sentinel 2B spacecrafts are part of the European Union’s Copernicus program designed to acquire high spatial resolution imagery in the reflective spectrum from 0.4 to $2.2~\mu \text{m}$ . One of the popular techniques to evaluate the on-orbit calibration is by comparing the top-of-atmosphere (TOA) reflectance with an independent (well-calibrated) sensor while viewing a pseudoinvariant desert target, such as Libya 4. In this work, the TOA reflectances from Terra and Aqua MODIS and Sentinel 2A and Sentinel 2B MSI are compared using the same-day scenes from Libya 4. The corrections for spectral response function mismatch and the bidirectional reflectance distribution function (BRDF) are formulated and applied to obtain an effective TOA reflectance difference between the spectrally matching bands of these sensors. The availability of off-nadir MODIS overpass pairs with MSI facilitates the comparison across the entire MODIS scan-angle range and in turn an on-orbit evaluation of the response versus scan-angle (RVS) corrections is performed. Additionally, each MODIS instrument is used as a transfer mechanism to evaluate the calibration differences between the two MSIs, with an agreement to within 1% observed between the two MSIs. The radiometric calibration differences between Terra MODIS and the two MSIs at nadir is generally within 4%, with only the red-band pair (Terra MODIS band 1 and MSI band 4) showing disagreement beyond 4%. In general, the reflectance ratios are in better agreement with Aqua MODIS than with Terra MODIS. A better agreement between MODIS and the two MSIs is observed at nadir, indicating some residual effects associated with the BRDF correction that are observed in the off-nadir scene pairs. Also included in this article is a description of the various uncertainties associated with this cross-calibration. Numéro de notice : A2020-393 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2020.2971462 Date de publication en ligne : 11/02/2020 En ligne : https://doi.org/10.1109/TGRS.2020.2971462 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95389
in IEEE Transactions on geoscience and remote sensing > vol 58 n° 7 (July 2020) . - pp 5000 - 5007[article]Refractive two-view reconstruction for underwater 3D vision / François Chadebecq in International journal of computer vision, vol 128 n° 5 (May 2020)
![]()
[article]
Titre : Refractive two-view reconstruction for underwater 3D vision Type de document : Article/Communication Auteurs : François Chadebecq, Auteur ; Francisco Vasconcelos, Auteur ; René Lacher, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : pp 1101 - 1117 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] correction d'image
[Termes IGN] estimation de pose
[Termes IGN] étalonnage d'instrument
[Termes IGN] image sous-marine
[Termes IGN] reconstruction 3D
[Termes IGN] réfraction de l'eau
[Termes IGN] structure-from-motion
[Termes IGN] temps de pose
[Termes IGN] vision stéréoscopiqueRésumé : (auteur) Recovering 3D geometry from cameras in underwater applications involves the Refractive Structure-from-Motion problem where the non-linear distortion of light induced by a change of medium density invalidates the single viewpoint assumption. The pinhole-plus-distortion camera projection model suffers from a systematic geometric bias since refractive distortion depends on object distance. This leads to inaccurate camera pose and 3D shape estimation. To account for refraction, it is possible to use the axial camera model or to explicitly consider one or multiple parallel refractive interfaces whose orientations and positions with respect to the camera can be calibrated. Although it has been demonstrated that the refractive camera model is well-suited for underwater imaging, Refractive Structure-from-Motion remains particularly difficult to use in practice when considering the seldom studied case of a camera with a flat refractive interface. Our method applies to the case of underwater imaging systems whose entrance lens is in direct contact with the external medium. By adopting the refractive camera model, we provide a succinct derivation and expression for the refractive fundamental matrix and use this as the basis for a novel two-view reconstruction method for underwater imaging. For validation we use synthetic data to show the numerical properties of our method and we provide results on real data to demonstrate its practical application within laboratory settings and for medical applications in fluid-immersed endoscopy. We demonstrate our approach outperforms classic two-view Structure-from-Motion method relying on the pinhole-plus-distortion camera model. Numéro de notice : A2020-508 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s11263-019-01218-9 Date de publication en ligne : 18/11/2019 En ligne : https://doi.org/10.1007/s11263-019-01218-9 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96972
in International journal of computer vision > vol 128 n° 5 (May 2020) . - pp 1101 - 1117[article]Antenna phase center correction differences from robot and chamber calibrations: the case study LEIAR25 / Grzegorz Krzan in GPS solutions, vol 24 n° 2 (April 2020)
PermalinkImpact of temperature stabilization on the strapdown airborne gravimetry: a case study in Central Turkey / Mehmet Simav in Journal of geodesy, vol 94 n°4 (April 2020)
PermalinkPermalinkOptimising drone flight planning for measuring horticultural tree crop structure / Yu-Hsuan Tu in ISPRS Journal of photogrammetry and remote sensing, vol 160 (February 2020)
PermalinkA two-step approach for the correction of rolling shutter distortion in UAV photogrammetry / Yilin Zhou in ISPRS Journal of photogrammetry and remote sensing, vol 160 (February 2020)
PermalinkAbsolute field calibration for multi-GNSS receiver antennas at ETH Zurich / Daniel Willi in GPS solutions, vol 24 n° 1 (January 2020)
PermalinkCamera orientation, calibration and inverse perspective with uncertainties: a Bayesian method applied to area estimation from diverse photographs / Grégoire Guillet in ISPRS Journal of photogrammetry and remote sensing, vol 159 (January 2020)
PermalinkPermalinkGlobal iterative geometric calibration of a linear optical satellite based on sparse GCPs / Yingdong Pi in IEEE Transactions on geoscience and remote sensing, vol 58 n° 1 (January 2020)
PermalinkKalman filtering with state constraints applied to multi-sensor systems and georeferencing / Sören Vogel (2020)
Permalink