Centre de documentation
scientifique

Analysis of decade-long time series of GPS-based polar motion estimates at 15-min temporal resolution / Aurore E. Sibois in Journal of geodesy, vol 91 n° 8 (August 2017)  

Public [article]  inJournal of geodesy > vol 91 n° 8 (August 2017) . - pp 965–983 Titre : Analysis of decade-long time series of GPS-based polar motion estimates at 15-min temporal resolution Type de document : Article/Communication Auteurs : Aurore E. Sibois, Auteur ; Shailen Desai, Auteur ; Willy I. Bertiger, Auteur ; Bruce J. Haines, Auteur Année de publication : 2017 Article en page(s) : pp 965–983 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] analyse diachronique [Termes IGN] marée océanique [Termes IGN] mouvement du pôle [Termes IGN] nutation [Termes IGN] pôle [Termes IGN] positionnement par GPS [Termes IGN] série temporelle Résumé : (auteur) We present results from the generation of 10-year-long continuous time series of the Earth’s polar motion at 15-min temporal resolution using Global Positioning System ground data. From our results, we infer an overall noise level in our high-rate polar motion time series of 60 μas (RMS). However, a spectral decomposition of our estimates indicates a noise floor of 4 μas at periods shorter than 2 days, which enables recovery of diurnal and semidiurnal tidally induced polar motion. We deliberately place no constraints on retrograde diurnal polar motion despite its inherent ambiguity with long-period nutation. With this approach, we are able to resolve damped manifestations of the effects of the diurnal ocean tides on retrograde polar motion. As such, our approach is at least capable of discriminating between a historical background nutation model that excludes the effects of the diurnal ocean tides and modern models that include those effects. To assess the quality of our polar motion solution outside of the retrograde diurnal frequency band, we focus on its capability to recover tidally driven and non-tidal variations manifesting at the ultra-rapid (intra-daily) and rapid (characterized by periods ranging from 2 to 20 days) periods. We find that our best estimates of diurnal and semidiurnal tidally induced polar motion result from an approach that adopts, at the observation level, a reasonable background model of these effects. We also demonstrate that our high-rate polar motion estimates yield similar results to daily-resolved polar motion estimates, and therefore do not compromise the ability to resolve polar motion at periods of 2–20 days. Numéro de notice : A2017-462 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-017-1001-6 En ligne : https://doi.org/10.1007/s00190-017-1001-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86408 [article]

Revisiting the pole tide for and from satellite altimetry / Shailen Desai in Journal of geodesy, vol 89 n° 12 (december 2015)  

Public [article]  inJournal of geodesy > vol 89 n° 12 (december 2015) . - pp 1233 - 1243 Titre : Revisiting the pole tide for and from satellite altimetry Type de document : Article/Communication Auteurs : Shailen Desai, Auteur ; John Wahr, Auteur Année de publication : 2015 Article en page(s) : pp 1233 - 1243 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] altimètre [Termes IGN] altimétrie satellitaire par radar [Termes IGN] analyse diachronique [Termes IGN] géocentre [Termes IGN] marée terrestre [Termes IGN] masse d'eau [Termes IGN] masse de la Terre [Termes IGN] mouvement du pôle [Termes IGN] surcharge océanique Résumé : (auteur) Satellite altimeter sea surface height observations include the geocentric displacements caused by the pole tide, namely the response of the solid Earth and oceans to polar motion. Most users of these data remove these effects using a model that was developed more than 20 years ago. We describe two improvements to the pole tide model for satellite altimeter measurements. Firstly, we recommend an approach that improves the model for the response of the oceans by including the effects of self-gravitation, loading, and mass conservation. Our recommended approach also specifically includes the previously ignored displacement of the solid Earth due to the load of the ocean response, and includes the effects of geocenter motion. Altogether, this improvement amplifies the modeled geocentric pole tide by 15 %, or up to 2 mm of sea surface height displacement. We validate this improvement using two decades of satellite altimeter measurements. Secondly, we recommend that the altimetry pole tide model exclude geocentric sea surface displacements resulting from the long-term drift in polar motion. The response to this particular component of polar motion requires a more rigorous approach than is used by conventional models. We show that erroneously including the response to this component of polar motion in the pole tide model impacts interpretation of regional sea level rise by ±0.25 mm/year. Numéro de notice : A2015-888 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-015-0848-7 Date de publication en ligne : 27/08/2020 En ligne : https://doi.org/10.1007/s00190-015-0848-7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79436 [article]

An evaluation of solar radiation pressure strategies for the GPS constellation / Ant Sibthorpe in Journal of geodesy, vol 85 n° 8 (August 2011)  

Public [article]  inJournal of geodesy > vol 85 n° 8 (August 2011) . - pp 505 - 517 Titre : An evaluation of solar radiation pressure strategies for the GPS constellation Type de document : Article/Communication Auteurs : Ant Sibthorpe, Auteur ; Willy I. Bertiger, Auteur ; Shailen Desai, Auteur ; et al., Auteur Année de publication : 2011 Article en page(s) : pp 505 - 517 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Techniques orbitales [Termes IGN] analyse comparative [Termes IGN] constellation GPS [Termes IGN] données TLS (télémétrie) [Termes IGN] GIPSY-OASIS [Termes IGN] international GPS service for geodynamics [Termes IGN] orbitographie [Termes IGN] rayonnement solaire [Termes IGN] résolution d'ambiguïté Résumé : (Auteur) The subtle effects of different Global Positioning System (GPS) satellite force models are becoming apparent now that mature processing strategies are reaching new levels of accuracy and precision. For this paper, we tested several approaches to solar radiation pressure (SRP) modeling that are commonly used by International GNSS Service (IGS) analysis centers. These include the GPS Solar Pressure Model (GSPM; Bar-Sever and Kuang in The Interplanetary Network Progress Report 42-160, 2005) and variants of the so-called DYB model (Springer et al. in Adv Space Res 23:673–676, 1999). Our results show that currently observed differences between GPS orbit solutions from the various IGS analysis centers are in large part explained by differences between their respective approaches to modeling SRP. DYB-based strategies typically generate orbit solutions that have the smallest differences with respect to the IGS final combined solution, largely because the DYB approach is most commonly used by the contributing analysis centers. However, various internal and external metrics, including ambiguity resolution statistics and satellite laser ranging observations, support continued use of the GSPM-based approach for precise orbit determination of the GPS constellation, at least when using the GIPSY-OASIS software. Numéro de notice : A2011-358 Affiliation des auteurs : non IGN Thématique : IMAGERIE/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-011-0450-6 Date de publication en ligne : 19/02/2011 En ligne : https://doi.org/10.1007/s00190-011-0450-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31137 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
266-2011081	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Single receiver phase ambiguity resolution with GPS data / Willy I. Bertiger in Journal of geodesy, vol 84 n° 5 (May 2010)  

Public [article]  inJournal of geodesy > vol 84 n° 5 (May 2010) . - pp 327 - 337 Titre : Single receiver phase ambiguity resolution with GPS data Type de document : Article/Communication Auteurs : Willy I. Bertiger, Auteur ; Shailen Desai, Auteur ; Bruce J. Haines, Auteur ; et al., Auteur Année de publication : 2010 Article en page(s) : pp 327 - 337 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] données GPS [Termes IGN] GIPSY-OASIS [Termes IGN] mesurage de phase [Termes IGN] phase GPS [Termes IGN] positionnement cinématique [Termes IGN] positionnement par GPS [Termes IGN] positionnement ponctuel précis [Termes IGN] positionnement statique [Termes IGN] résolution d'ambiguïté [Termes IGN] traitement de données GNSS Résumé : (Auteur) Global positioning system (GPS) data processing algorithms typically improve positioning solution accuracy by fixing double-differenced phase bias ambiguities to integer values. These “double-difference ambiguity resolution” methods usually invoke linear combinations of GPS carrier phase bias estimates from pairs of transmitters and pairs of receivers, and traditionally require simultaneous measurements from at least two receivers. However, many GPS users point position a single local receiver, based on publicly available solutions for GPS orbits and clocks. These users cannot form double differences. We present an ambiguity resolution algorithm that improves solution accuracy for single receiver point-positioning users. The algorithm processes dual- frequency GPS data from a single receiver together with wide-lane and phase bias estimates from the global network of GPS receivers that were used to generate the orbit and clock solutions for the GPS satellites. We constrain (rather than fix) linear combinations of local phase biases to improve compatibility with global phase bias estimates. For this precise point positioning, no other receiver data are required. When tested, our algorithm significantly improved repeatability of daily estimates of ground receiver positions, most notably in the east component by approximately 30% with respect to the nominal case wherein the carrier biases are estimated as real values. In this “static” test for terrestrial receiver positions, we achieved daily repeatability of 1.9, 2.1 and 6.0 mm in the east, north and vertical (ENV) components, respectively. For kinematic solutions, ENV repeatability is 7.7, 8.4, and 11.7 mm, respectively, representing improvements of 22, 8, and 14% with respect to the nominal. Results from precise orbit determination of the twin GRACE satellites demonstrated that the inter-satellite baseline accuracy improved by a factor of three, from 6 to 2 mm up to a long-term bias. Jason-2/Ocean Surface Topography Mission precise orbit determination tests results implied radial orbit accuracy significantly below the 10 mm level. Stability of time transfer, in low-Earth orbit, improved from 40 to 7 ps. We produced these results by applying this algorithm within the Jet Propulsion Laboratory’s (JPL’s) GIPSY/OASIS software package and using JPL’s orbit and clock products for the GPS constellation. These products now include a record of the wide-lane and phase bias estimates from the underlying global network of GPS stations. This implies that all GIPSY–OASIS positioning users can now benefit from this capability to perform single-receiver ambiguity resolution. Numéro de notice : A2010-185 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-010-0371-9 Date de publication en ligne : 21/03/2010 En ligne : https://doi.org/10.1007/s00190-010-0371-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30380 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
266-2010051	SL	Revue	Centre de documentation	Revues en salle	Disponible

On the long-term stability of microwave radiometers using noise diodes for calibration / S.T. Brown in IEEE Transactions on geoscience and remote sensing, vol 45 n° 7 Tome 1 (July 2007)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 45 n° 7 Tome 1 (July 2007) . - pp 1908 - 1920 Titre : On the long-term stability of microwave radiometers using noise diodes for calibration Type de document : Article/Communication Auteurs : S.T. Brown, Auteur ; Shailen Desai, Auteur ; W. Lu, Auteur ; A.B. Tanner, Auteur Année de publication : 2007 Article en page(s) : pp 1908 - 1920 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] Advanced Microwave Radiometer [Termes IGN] bruit (théorie du signal) [Termes IGN] capteur spatial [Termes IGN] diode [Termes IGN] étalonnage de capteur (imagerie) [Termes IGN] radiomètre à hyperfréquence [Termes IGN] température de luminance [Termes IGN] water vapour radiometer Résumé : (Auteur) Results are presented from the long-term monitoring and calibration of the National Aeronautics and Space Administration Jason Microwave Radiometer (JMR) on the Jason-1 ocean altimetry satellite and the ground-based Advanced Water Vapor Radiometers (AWVRs) developed for the Cassini Gravity Wave Experiment. Both radiometers retrieve the wet tropospheric path delay (PD) of the atmosphere and use internal noise diodes (NDs) for gain calibration. The JMR is the first radiometer to be flown in space that uses NDs for calibration. External calibration techniques are used to derive a time series of ND brightness for both instruments that is greater than four years. For the JMR, an optimal estimator is used to find the set of calibration coefficients that minimize the root-mean-square difference between the JMR brightness temperatures and the on-Earth hot and cold references. For the AWVR, continuous tip curves are used to derive the ND brightness. For the JMR and AWVR, both of which contain three redundant NDs per channel, it was observed that some NDs were very stable, whereas others experienced jumps and drifts in their effective brightness. Over the four-year time period, the ND stability ranged from 0.2% to 3% among the diodes for both instruments. The presented recalibration methodology demonstrates that long-term calibration stability can be achieved with frequent recalibration of the diodes using external calibration techniques. The JMR PD drift compared to ground truth over the four years since the launch was reduced from 3.9 to $-$0.01 mm/year with the recalibrated ND time series. The JMR brightness temperature calibration stability is estimated to be 0.25 K over ten days. Copyright IEEE Numéro de notice : A2007-170 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2006.888098 En ligne : https://doi.org/10.1109/TGRS.2006.888098 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28533 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
065-07071A	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Doris satellite antenna maps derived from long-term residuals time series / Pascal Willis in Advances in space research, vol 36 n° 3 (March 2005)  

Permalink

One-centimeter orbit determination for Jason-1: New GPS-based strategies / Bruce J. Haines in Marine geodesy, vol 27 n°1-2 (January - June 2004)  

Permalink

Initial orbit determination results for Jason-1: Towards a 1 cm orbit / Bruce J. Haines in Navigation : journal of the Institute of navigation, vol 50 n° 3 (Fall 2003)  

Permalink

Topex-Jason combined GPS-DORIS orbit determination in the TanDEM phase / Pascal Willis in Advances in space research, vol 31 n° 8 (14/03/2003)  

Permalink