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Titre : The role of orbit errors in processing of satellite altimeter data Type de document : Rapport Auteurs : E.J.O. Schrama, Auteur Editeur : Delft : Netherlands Geodetic Commission NGC Année de publication : 1989 Collection : Netherlands Geodetic Commission Publications on Geodesy Sous-collection : New series num. 33 Importance : 170 p. Format : 20 x 28 cm ISBN/ISSN/EAN : 978-90-6132-239-9 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Technologies spatiales
[Termes IGN] altimétrie satellitaire par radar
[Termes IGN] données altimétriques
[Termes IGN] invariance
[Termes IGN] mécanique orbitale
[Termes IGN] orbitographie
[Termes IGN] pesanteur terrestre
[Termes IGN] Seasat
[Termes IGN] vitesse radialeRésumé : (auteur) The problem of radial orbit errors in processing of satellite altimeter data is largely due to the inaccuracy of the gravity model which is required for the computation of the trajectory of the spacecraft. A commonly used technique for removing these errors consists of minimizing the crossover differences of profiles measured by the altimeter radar.
Several versions of the technique of least squares crossover minimization have been investigated using either SEASAT observations or simulated data. In these adjustments coefficients of error functions are estimated which are either locally defined over short arc segments, globally over long arc segments, or continuously over an entire arc having a length of several days. The solution of the corresponding normal equations consists of a homogeneous and a particular part.
For each crossover minimization problem (CMP) the homogeneous solution is always given as an analytical expression describing the invariances of the altimetric sea surface with respect to the crossover differences. These invariances are described by a surface deformation function which is characteristic for the problem in question. The number of coefficients in this function equals to the rank defect of the normal matrix in the CMP.
For the particular solution of a local CMP (using "tilt and bias" functions) it was found that 2 non-intersecting and non-overlapping master arc segments have to be fixed. However for global chronological segmented CMP's (using 3 parameter sine-cosine functions) only 1 master arc segment needs to be fixed for a particular solution. For continuous CMP's a particular solution is found by including 9 constraint equations in the form of pseudo observation equations. In this case the error function consists of a Fourier series truncated at a cutoff frequency of 2.3 cycles per revolution including a 2 parameter function modeling a long periodic effect in the orbit.
The underlying problem of gravitational radial orbit errors is described by means of the linear perturbations theory, which is based on the Lagrange planetary equations. Additionally the problem is formulated by means of the Hill equations describing perturbed satellite motions in an idealized circular orbit. It is shown that the non-resonant particular radial solution of the Hill equations coincides with the first-order radial solution derived from the linear perturbations theory assuming a
near circular orbit.
The first-order radial solution has been compared with a simulated signal derived by numerical integration of the equations of motion. The simulated signal consists of the radial differences between two trajectories (resembling the SEASAT 3 day repeat configuration) integrated with different gravity models. It was found that the analytical orbit error model resembles closely the simulated signal after removal of a long periodic effect.
The validity of the general solutions of two global CMP's has been investigated by means of a simulation experiment. In this experiment crossover differences are simulated by means of the radial orbit error signal described above. In a second step it is attempted to reconstruct this signal by minimizing the simulated differences.
This experiment revealed that the general solution of the segmented CMP appears to be hampered by unrealistic velocity discontinuity effects of successive arc segment error functions. In addition, it fails to describe the C11 and S11 and higher degree and order components of a geographically correlated radial orbit error. This is not surprising since one can prove that the homogeneous solution of the segmented CMP (without velocity discontinuities) corresponds to the C00 and C10 component of the geographically correlated radial orbit error. For this reason the global segmented CMP is reformulated in a continuous approach where it is shown that the homogeneous solution coincides with the geographically correlated radial orbit error. Computations showed that the simulated signal deviates to approximately 15 cm r.m.s. with respect to the general solution of the continuous CMP.
Employing the latter technique 5 independent particular solutions of a radial orbit error signal have been computed from SEASAT crossover data. These solutions appear to be highly correlated and suggest the presence of a disturbing effect likely to be caused by gravity modeling errors. Additionally it was found that the individual solutions resemble a concentration of signal near the once per revolution frequency in the radial orbit error spectrum. This solution could in principle be used to improve a part of the gravity model that is used in the trajectory computation of the satellite.
In the last part an integrated approach is described where the problem of modeling errors in the orbit, the geoid and the permanent part of the sea surface topography (PST) caused by ocean circulation are considered simultaneously. It is argued that an application of the integrated approach is justified if simultaneously gravity model improvement is performed employing tracking data of other satellites at different inclinations and eccentricities. Other aspects of the integrated approach concern the modeling problems of the PST field, an omission effect of the gravity field and the relation with the global continuous CMP.Numéro de notice : 57963 Affiliation des auteurs : non IGN Thématique : IMAGERIE/POSITIONNEMENT Nature : Rapport de recherche DOI : sans En ligne : https://www.ncgeo.nl/downloads/33Schrama.pdf Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=60322 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 57963-01 21.10 Livre Centre de documentation Technologies spatiales Disponible 57963-02 21.10 Livre Centre de documentation Technologies spatiales Disponible Determination of local empirical convariance functions from residual terrain reduced altimeter data / P. Knudsen (1988)
Titre : Determination of local empirical convariance functions from residual terrain reduced altimeter data Type de document : Monographie Auteurs : P. Knudsen, Auteur Editeur : Colombus (Ohio) : Ohio State University Année de publication : 1988 Collection : Department of Geodetic Science and Surveying Reports num. 395 Importance : 57 p. Format : 21 x 27 cm Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] covariance
[Termes IGN] données altimétriques
[Termes IGN] géoïdeIndex. décimale : 30.40 Géodésie physique Numéro de notice : 12118 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=54546 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 12118-02 30.40 Livre Centre de documentation Géodésie Disponible 12118-01 30.40 Livre Centre de documentation Géodésie Disponible Interpretation of Seasat radar-altimeter data over sea ice using near-simultaneous SAR imagery / Lars M.H. Ulander in International Journal of Remote Sensing IJRS, vol 8 n° 11 (November 1987)
[article]
Titre : Interpretation of Seasat radar-altimeter data over sea ice using near-simultaneous SAR imagery Type de document : Article/Communication Auteurs : Lars M.H. Ulander, Auteur Année de publication : 1987 Article en page(s) : pp 1679 - 1686 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photo-interprétation
[Termes IGN] altimètre radar
[Termes IGN] Arctique, océan
[Termes IGN] Beaufort, mer de
[Termes IGN] données altimétriques
[Termes IGN] glace de mer
[Termes IGN] image radar
[Termes IGN] photo-interprétation
[Termes IGN] radar à antenne synthétique
[Termes IGN] rétrodiffusion
[Termes IGN] SeasatNuméro de notice : A1987-362 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431168708954807 En ligne : https://doi.org/10.1080/01431168708954807 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=24435
in International Journal of Remote Sensing IJRS > vol 8 n° 11 (November 1987) . - pp 1679 - 1686[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 080-87111 RAB Revue Centre de documentation En réserve L003 Disponible Potential applications of digital image analysis systems for displaying satellite altimetry data / R. Yazdani in Photogrammetric Engineering & Remote Sensing, PERS, vol 53 n° 11 (november 1987)
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Titre : Potential applications of digital image analysis systems for displaying satellite altimetry data Type de document : Article/Communication Auteurs : R. Yazdani, Auteur ; N. Christou, Auteur ; E. Derenyi, Auteur Année de publication : 1987 Article en page(s) : pp 1545 - 1548 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] altimétrie satellitaire par radar
[Termes IGN] données altimétriques
[Termes IGN] géoïde
[Termes IGN] image numérique
[Termes IGN] logiciel de traitement d'imageNuméro de notice : A1987-445 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : sans En ligne : https://www.asprs.org/wp-content/uploads/pers/1987journal/nov/1987_nov_1545-1548 [...] Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=24507
in Photogrammetric Engineering & Remote Sensing, PERS > vol 53 n° 11 (november 1987) . - pp 1545 - 1548[article]Filtering of digitally correlated gestalt elevation data / A.L. Kok in Photogrammetric Engineering & Remote Sensing, PERS, vol 53 n° 5 (may 1987)
[article]
Titre : Filtering of digitally correlated gestalt elevation data Type de document : Article/Communication Auteurs : A.L. Kok, Auteur ; J.A.R. Blais, Auteur ; R.M. Rangayyan, Auteur Année de publication : 1987 Article en page(s) : pp 535 - 538 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] données altimétriques
[Termes IGN] filtrage du bruit
[Termes IGN] filtrage linéaire
[Termes IGN] filtre de Wiener
[Termes IGN] spectre électromagnétiqueNuméro de notice : A1987-092 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : sans En ligne : https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ve [...] Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=24191
in Photogrammetric Engineering & Remote Sensing, PERS > vol 53 n° 5 (may 1987) . - pp 535 - 538[article]Precise orbit computation, gravity model adjustment and altimeter data processing for the ERS-1 altimetry mission / K.F. Wakker (1987)PermalinkLe niveau moyen des mers, un indicateur de l'évolution du système Terre-atmosphère-océans, Journée d'étude [du] Comité National Français de Géodésie et Géophysique / Claude Boucher (1986)PermalinkAjustement des profils altimétriques : minimisation des écarts aux noeuds / J.P. Bariot (1985)PermalinkA new Seasat altimetric geoid for the Baltic / Martin Vermeer (1983)PermalinkLes données altimétriques du satellite Seasat : étude sur la méditerranée / Pierre Cormier in Bulletin d'information de l'Institut géographique national, n° 45 (juillet 1982)PermalinkThe role of the geoid in high precision geodesy and oceanography / Chris Rizos (1982)PermalinkValidation of SEASAT-1 altimetry using ground truth in the North Sea Region / J. Brennecke (1982)PermalinkUtilisation pour l'océanologie des satellites d'observation de la Terre / J.L. Hyacinthe (1978)PermalinkAcquisition et contrôle des données par photogrammétrie numérique à grande échelle / Jean Denègre in Photogrammetria, vol 33 n° 1 (March 1977)PermalinkDetailed gravimetric geoid confirmation of short wavelenght features of sea surface topography detected by the Skylab s-193 altimeter in the Atlantic Ocean / J.G. Marsh (1975)PermalinkEtude de corrélation numérique automatique en vue de l'obtention d'un fichier altimétrique / E. Kahn in Bulletin [Société Française de Photogrammétrie], n° 57 (Janvier 1975)PermalinkSea surface determination from space / F.O. Vonbun (1975)PermalinkTests and comparisons of satellite derived geoids with Skylab altimeter data / J.G. Marsh (1975)PermalinkAuswertung von Altimetermessungen für das Modell der einfachen Schicht des Erdschwerefeldes in der Satelliten- geodäsie / W. Benning (1974)PermalinkDetailed geoid computations for GEOS-C altimeter experiment areas / J.G. Marsh (1973)PermalinkMesures altimétriques et potentiel terrestre / Georges Balmino (1973)PermalinkDas Geoid aus Beobachtungen der Satellitenaltimetrie / K. Arnold (1972)Permalink