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DORIS Starec ground antenna characterization and impact on positioning / Cédric Tourain in Advances in space research, vol 58 n° 12 (15 December 2016)  

Public [article]  inAdvances in space research > vol 58 n° 12 (15 December 2016) . - pp 2707 - 2716 Titre : DORIS Starec ground antenna characterization and impact on positioning Type de document : Article/Communication Auteurs : Cédric Tourain, Auteur ; Guilhem Moreaux, Auteur ; Albert Auriol, Auteur ; Jérôme Saunier , Auteur Année de publication : 2016 Article en page(s) : pp 2707 - 2716 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux [Termes IGN] antenne DORIS [Termes IGN] caractérisation [Termes IGN] centre de phase [Termes IGN] facteur d'échelle [Termes IGN] International Terrestrial Reference Frame Résumé : (auteur) In a geodetic radio frequency observing system the phase center offsets and phase center variations of ground antennae are a fundamental component of mathematical models of the system observables. In this paper we describe work aimed at improving the DORIS Starec ground antenna phase center definition model. Seven antennas were analyzed in the Compact Antenna Test Range (CATR), a dedicated CNES facility. With respect to the manufacturer specified phase center offset, the measured antennae varied between −6 mm and +4 mm due to manufacturing variations. To solve this problem, discussions were held with the manufacturer, leading to an improvement of the manufacturing process. This work results in a reduction in the scatter to ±1 mm. The phase center position has been kept unchanged and associated phase law has been updated and provided to users of the International DORIS Service (IDS). This phase law is applicable to all Starec antennas (before and after manufacturing process consolidation) and is azimuth independent. An error budget taking into account these updated characteristics has been established for the antenna alone: ±2 mm on the horizontal plane and ±3 mm on the up component, maximum error values for antennas named type C (Saunier et al., 2016) produced with consolidated manufacturing process. Finally the impact of this updated characterization on positioning results has been analyzed and shows a scale offset only of the order of +12 mm for the Terrestrial Reference Frame. Numéro de notice : A2016--185 Affiliation des auteurs : IGN+Ext (2012-2019) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.asr.2016.05.013 Date de publication en ligne : 14/05/2016 En ligne : https://doi.org/10.1016/j.asr.2016.05.013 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91820 [article]

Initiating an error budget of the DORIS ground antenna position: Genesis of the Starec antenna type C / Jérôme Saunier in Advances in space research, vol 58 n° 12 (15 December 2016)  

Public [article]  inAdvances in space research > vol 58 n° 12 (15 December 2016) . - pp 2717 - 2724 Titre : Initiating an error budget of the DORIS ground antenna position: Genesis of the Starec antenna type C Type de document : Article/Communication Auteurs : Jérôme Saunier , Auteur ; Albert Auriol, Auteur ; Cédric Tourain, Auteur Année de publication : 2016 Article en page(s) : pp 2717 - 2724 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux [Termes IGN] antenne DORIS Résumé : (auteur) The DORIS system measures distances between phase centers of onboard and ground antennas to determine the position of the satellites in their orbits. To this end, the ground antenna phase center position must be known in a terrestrial reference frame. Its position is linked and defined with respect to the antenna reference point (ARP), a conventional physical point for which coordinates are assigned. Although the determination of the ARP position with respect to ground markers can be achieved by traditional surveys, the connection with the actual measurement point (phase center) is far more difficult to determine. This is the main concern explored in this paper. Regardless of the need for a good antenna characterization, CNES and IGN jointly worked to establish a first error budget of the ground antenna position. With this aim in view, each component was clearly identified and studied separately. We distinguished between errors from manufacturing and from site surveying and, on the other hand, errors affecting horizontal and vertical position. The knowledge of the antenna geometry and the guarantee of a good reproducibility in the manufacturing process are essential. Based on these requirements, we have defined new manufacturing specifications to create a new antenna type: Starec type C. Compared to the previous antenna (Starec type B), the standard uncertainty of the 2 GHz phase center position in the vertical direction has been reduced from 5 mm to 1 mm. Following this work, we provide for the new Starec antenna (type C) total uncertainties involved in the ground antenna positioning in a local reference frame: 2 mm in the horizontal plane, 2.5 mm for the vertical component and 3.2 mm in three-dimensional combination. We also propose for DORIS new definitions of conventional points and a new method to determine ground antennas position that were not possible before this manufacturing specifications change. Numéro de notice : A2016--190 Affiliation des auteurs : IGN+Ext (2012-2019) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.asr.2016.02.013 Date de publication en ligne : 24/02/2016 En ligne : https://doi.org/10.1016/j.asr.2016.02.013 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91823 [article]

DORIS system: the new age / Albert Auriol in Advances in space research, vol 46 n° 12 (15/12/2010)  

Public [article]  inAdvances in space research > vol 46 n° 12 (15/12/2010) . - pp 1484 - 1496 Titre : DORIS system: the new age Type de document : Article/Communication Auteurs : Albert Auriol, Auteur ; Cédric Tourain, Auteur Année de publication : 2010 Article en page(s) : pp 1484 - 1496 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] balise DORIS [Termes IGN] DORIS [Termes IGN] instrument embarqué [Termes IGN] International DORIS Service [Termes IGN] Jason [Termes IGN] mesurage de phase [Termes IGN] mesurage de pseudo-distance [Termes IGN] orbite précise [Termes IGN] orbitographie Résumé : (Auteur) The boarding of the first DGXX DORIS instrument on Jason-2 mission gives us the opportunity to present the improvements that have been implemented on the DORIS system. The goal of this paper is to present information about the new capacities of the DORIS system and to give the current status of its components. An overview of the DORIS system, the International DORIS Service and the Jason-2 satellite mission are first presented. Then the new characteristics of the on-board instrument are detailed. The capacity to track up to seven ground beacons simultaneously dramatically increases the number of measurements performed: a factor of three increase over Jason-1 is observed at the altitude of 1330 km. It also increases the diversity of directions of observation and allows low elevation measurements from 0°. The new phase measurements capability allows now phase processing. The instability of the Jason-1 USOs (Ultra-Stable Oven-controlled quartz oscillator) while crossing the South Atlantic Anomaly has been solved by decreasing the sensitivity to radiation by a factor of 10. New features of the on-board software enhance the coastal and inland water altimetry and increase the robustness of the data. The new software also improves the real time orbit accuracy for operational altimetry. The improvements introduced concurrently on the ground segment have also significantly enhanced capability. The new RINEX exchange formats provide simultaneous phase and pseudo-range measurements. The maintenance of the DORIS Beacons Network and the work done by the DORIS Signal Integrity monitoring team lead to an increased availability of the Network from 75% to 90% and so to a more homogenous orbit coverage. All these improvements including the lessons learned during the past 20 years of operations have pushed the DORIS system forward to a New Age. Numéro de notice : A2010-562 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.asr.2010.05.015 En ligne : https://doi.org/10.1016/j.asr.2010.05.015 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30754 [article]