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Simulating Future GPS Clock Scenarios With Two Composite Clock Algorithms

Suess, Matthias and Matsakis, Demetrios and Greenhall, Charles (2010) Simulating Future GPS Clock Scenarios With Two Composite Clock Algorithms. 42th Precise Time And Time Interval Meeting PTTI 2010, 15. -18. Nov. 2010, Reston, Virgina, U.S..

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Using the GPS Toolkit, the GPS constellation is simulated using thirty-one satellites (SV) and a ground network of seventeen monitor stations (MS). At every 15 minute measurement epoch, the monitor stations measure the time signals of all satellites above a parameterized elevation angle. Once a day, the satellite clock estimates are uploaded to the satellites. Two composite clock algorithms are applied to estimate the station and satellite clocks. The first composite clock (B) is based on the Brown algorithm [1], and is now used by GPS. The second one (G) is based on the Greenhall algorithm [2]. The composite clock of G and B performances are investigated using three ground clock models. Model C simulates the current GPS configuration, in which all stations are equipped with cesium clocks, except for masers at USNO and Alternate Master Clock (AMC) sites. Model M is an improved situation in which every station is equipped with active hydrogen masers. Finally, Model F is a future scenario in which the USNO and AMC stations are equipped with fountain clocks instead of masers. Each model is evaluated using three performance metrics. The timing related user range error having all satellites available is the first performance index (PI1). The second performance index (PI2) relates to the stability of the broadcast GPS system time itself. The third performance index (PI3) evaluates the stability of the time scales computed by the two composite clocks.

Item URL in elib:https://elib.dlr.de/67596/
Document Type:Conference or Workshop Item (Paper)
Title:Simulating Future GPS Clock Scenarios With Two Composite Clock Algorithms
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Suess, Matthiasmatthias.suess (at) dlr.deUNSPECIFIED
Matsakis, Demetriosdemetrios.matsakis (at) dlr.deUNSPECIFIED
Greenhall, Charlescgreenhall (at) jpl.nasa.govUNSPECIFIED
Date:November 2010
Open Access:Yes
Gold Open Access:No
In ISI Web of Science:No
Keywords:composite, clock, gps, performance, allan deviation
Event Title:42th Precise Time And Time Interval Meeting PTTI 2010
Event Location:Reston, Virgina, U.S.
Event Type:international Conference
Event Dates:15. -18. Nov. 2010
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:15 Dec 2010 12:00
Last Modified:31 Jul 2019 19:30

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