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Performance of miniaturized atomic clocks in static laboratory and dynamic flight environments / Ankit Jain in GPS solutions, vol 25 n° 1 (January 2021)  

Public [article]  inGPS solutions > vol 25 n° 1 (January 2021) . - 16 p. Titre : Performance of miniaturized atomic clocks in static laboratory and dynamic flight environments Type de document : Article/Communication Auteurs : Ankit Jain, Auteur ; Thomas Krawinkel, Auteur ; Steffen Schön, Auteur ; Andreas Bauch, Auteur Année de publication : 2021 Article en page(s) : 16 p. Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] décalage d'horloge [Termes IGN] fréquence [Termes IGN] horloge atomique [Termes IGN] horloge du récepteur [Termes IGN] oscillateur [Termes IGN] récepteur GNSS [Termes IGN] stabilité [Termes IGN] variance d'Allan Résumé : (auteur) Miniaturized atomic clocks with high frequency stability as local oscillators in global navigation satellite system (GNSS) receivers promise to improve real-time kinematic applications. For a number of years, such oscillators are being investigated regarding their overall technical applicability, i.e., transportability, and performance in dynamic environments. The short-term frequency stability of these clocks is usually specified by the manufacturer, being valid for stationary applications. Since the performance of most oscillators is likely degraded in dynamic conditions, various oscillators are tested to find the limits of receiver clock modeling in dynamic cases and consequently derive adequate stochastic models to be used in navigation. We present the performance of three different oscillators (Microsemi MAC SA.35m, Spectratime LCR-900 and Stanford Research Systems SC10) for static and dynamic applications. For the static case, all three oscillators are characterized in terms of their frequency stability at Physikalisch-Technische Bundesanstalt, Germany's national metrology institute. The resulting Allan deviations agree well with the manufacturer's data. Furthermore, a flight experiment was conducted in order to evaluate the performance of the oscillators under dynamic conditions. Here, each oscillator is replacing the internal oscillator of a geodetic-grade GNSS receiver and the stability of the receiver clock biases is determined. The time and frequency offsets of the oscillators are characterized with regard to the flight dynamics recorded by a navigation-grade inertial measurement unit. The results of the experiment show that the frequency stability of each oscillator is degraded by about at least one order of magnitude compared to the static case. Also, the two quartz oscillators show a significant g-sensitivity resulting in frequency shifts of − 1.2 × 10−9 and + 1.5 × 10−9, respectively, while the rubidium clocks are less sensitive, thus enabling receiver clock modeling and strengthening of the navigation performance even in high dynamics. Numéro de notice : A2021-003 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-020-01036-4 Date de publication en ligne : 13/10/2020 En ligne : https://doi.org/10.1007/s10291-020-01036-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96081 [article]

Better GNSS navigation and spoofing detection with chip scale-atomic clocks / Thomas Krawinkel in GPS world, vol 27 n° 10 (October 2016)

Public [article]  inGPS world > vol 27 n° 10 (October 2016) . - pp 50 - 55 Titre : Better GNSS navigation and spoofing detection with chip scale-atomic clocks Type de document : Article/Communication Auteurs : Thomas Krawinkel, Auteur ; Steffen Schön, Auteur Année de publication : 2016 Article en page(s) : pp 50 - 55 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement [Termes IGN] horloge atomique [Termes IGN] positionnement cinématique [Termes IGN] positionnement par GNSS [Termes IGN] précision du positionnement Résumé : (éditeur) [introduction] [...] The recent development of chip-scale atomic cloks (CSACs) offers the required frequency stability and accuracy, and opens up the possiblility of using atomic clocks in real kinematic GNSS applications without any severe restrictions regarding power supply or environmental influences on the clocks. When connecting one of these clocks to a GNSS receiver, replacing or steering the internal oscillator accordingly , and modeling its behavior in a meaningfull way instead epoch-wise estimation, the navigation performance can be improved distincltly. Numéro de notice : A2016-719 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82212 [article]