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Prototype of the DLR operational composite clock: methods and test cases

Suess, Matthias and Hammesfahr, Jens (2009) Prototype of the DLR operational composite clock: methods and test cases. 41st Annual Precise Time and Time Interval Meeting (PTTI), 2009-11-16 - 2009-11-19, Santa Ana Pueblo, New Mexico.

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The operational implementation of the ensemble Kalman filter Composite Clock (CC developed by K. R. Brown), is subject of the paper. Although the mathematical background of the CC is well-known, its autonomous and robust operation in a clock laboratory requires further modifications of the CC. The suitable initialization of the first ensemble estimate is discussed. Due to the fact, that only difference measurements are available, there is a dimensional degree of freedom in the first as in the following ensemble estimates. Furthermore, to guarantee a robust, consistent, and autonomous estimation of the ensemble clocks, a consistency check is described. It outputs a so-called consistency matrix which describes the active and nonactive clocks. Since the identified active clocks can change from measurement to measurement, the corresponding Kalman filter (KF) parameters are adapted in a consistent way. Finally, the non-active clocks are estimated based on the KF output. The performance of the OCC using an ensemble of five DLR laboratory clocks, measured over a period of one year, is outlined. The clock ensemble consists of three high-performance Cesiumclocks (HP5071A), an active H-Maser (CH1-75) and a GPS disciplined Rb clock. Although miscellaneous anomalies like phase steps, outliers and clock exclusions arise, the OCC autonomously processes the five ensemble clocks and establishes a robust system time. Analysis results of this ensemble with different types of clocks when applying the OCC are presented.

Item URL in elib:https://elib.dlr.de/62197/
Document Type:Conference or Workshop Item (Poster)
Title:Prototype of the DLR operational composite clock: methods and test cases
AuthorsInstitution or Email of AuthorsAuthor's ORCID iDORCID Put Code
Date:November 2009
Open Access:Yes
Gold Open Access:No
In ISI Web of Science:No
Keywords:composite clock, DLR, operational, kalman filter, filtering
Event Title:41st Annual Precise Time and Time Interval Meeting (PTTI)
Event Location:Santa Ana Pueblo, New Mexico
Event Type:international Conference
Event Start Date:16 November 2009
Event End Date:19 November 2009
HGF - Research field:Aeronautics, Space and Transport (old)
HGF - Program:Space (old)
HGF - Program Themes:W KN - Kommunikation/Navigation
DLR - Research area:Space
DLR - Program:W KN - Kommunikation/Navigation
DLR - Research theme (Project):W - Projekt Galileo Advanced Applications (old)
Location: Oberpfaffenhofen
Institutes and Institutions:Institute of Communication and Navigation > Navigation
Deposited By: Süß, Matthias
Deposited On:11 Jan 2010 11:43
Last Modified:24 Apr 2024 19:27

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