Results 201 to 210 of about 13,063 (249)
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Measurement science and technology, 2021
Low Earth orbit (LEO) satellites are a promising type of navigation augmentation satellite for current global navigation satellite systems. Aiming at the navigation function, an effective broadcast ephemeris model needs to be designed for LEO satellites.
Lingdong Meng +3 more
semanticscholar +1 more source
Low Earth orbit (LEO) satellites are a promising type of navigation augmentation satellite for current global navigation satellite systems. Aiming at the navigation function, an effective broadcast ephemeris model needs to be designed for LEO satellites.
Lingdong Meng +3 more
semanticscholar +1 more source
IEEE Transactions on Aerospace and Electronic Systems
The modeling and compensation of timing and spatial ephemeris errors of low Earth orbit (LEO) satellites is considered. First, models are derived capturing the effect of temporal and spatial errors of publicly available uncertain LEO ephemerides on ...
S. Hayek, Z. M. Kassas
semanticscholar +1 more source
The modeling and compensation of timing and spatial ephemeris errors of low Earth orbit (LEO) satellites is considered. First, models are derived capturing the effect of temporal and spatial errors of publicly available uncertain LEO ephemerides on ...
S. Hayek, Z. M. Kassas
semanticscholar +1 more source
Ephemeris and Timing Error Disambiguation Enabling Precise LEO PNT
IEEE Transactions on Aerospace and Electronic SystemsThe ephemeris and timing errors of low Earth orbit (LEO) satellites are modeled, leading to an approach to disambiguate these errors from pseudorange-type measurements.
Joe Saroufim, Z. M. Kassas
semanticscholar +1 more source
IEEE Transactions on Aerospace and Electronic Systems
A comprehensive study is performed for low Earth orbit (LEO) space vehicles (SVs) tracking by a receiver opportunistically extracting navigation observables from their downlink radio frequency signals.
Nadim Khairallah, Z. M. Kassas
semanticscholar +1 more source
A comprehensive study is performed for low Earth orbit (LEO) space vehicles (SVs) tracking by a receiver opportunistically extracting navigation observables from their downlink radio frequency signals.
Nadim Khairallah, Z. M. Kassas
semanticscholar +1 more source
Proceedings of the second ACM symposium on Symbolic and algebraic manipulation - SYMSAC '71, 1970
Delaunay's reduced Hamiltonian of the main problem in lunar theory is checked against a new analytical theory based on Lie transforms. It is found to be correct up to order 9 with the exception of one error in addition at order 7.
Deprit, A., Henrard, Jacques, Rom, A.
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Delaunay's reduced Hamiltonian of the main problem in lunar theory is checked against a new analytical theory based on Lie transforms. It is found to be correct up to order 9 with the exception of one error in addition at order 7.
Deprit, A., Henrard, Jacques, Rom, A.
openaire +3 more sources
Ephemeris Error Correction for Tracking Non-Cooperative LEO Satellites with Pseudorange Measurements
IEEE Aerospace ConferenceCorrecting the ephemeris of a poorly known "non-cooperative" low Earth orbit (LEO) satellite, by utilizing pseudorange measurements by a ground-based receiver is considered.
S. Hayek, Joe Saroufim, Z. M. Kassas
semanticscholar +1 more source
IEEE Aerospace Conference
Low Earth orbit (LEO) satellite ephemeris error is analyzed for standalone (non-differential) and differential navigation. First, the range residual due to ephemeris error is derived for a standalone stationary receiver making range-type measurements to ...
Joe Saroufim, S. Hayek, Z. M. Kassas
semanticscholar +1 more source
Low Earth orbit (LEO) satellite ephemeris error is analyzed for standalone (non-differential) and differential navigation. First, the range residual due to ephemeris error is derived for a standalone stationary receiver making range-type measurements to ...
Joe Saroufim, S. Hayek, Z. M. Kassas
semanticscholar +1 more source
Planetary and lunar ephemeris EPM2021 and its significance for Solar system research
Proceedings of the International Astronomical Union, 2021We present an updated public version of EPM (Ephemerides of Planets and the Moon). Since the last public version, EPM2017, many improvements were made in both the observational database and the mathematical model.
E. Pitjeva +3 more
semanticscholar +1 more source
Empire Survey Review, 1955
A New measure of time, Ephemeris Time, has recently been introduced by astronomers. The purpose of this short article is to explain briefly why this has been necessary and how it will affect navigation.
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A New measure of time, Ephemeris Time, has recently been introduced by astronomers. The purpose of this short article is to explain briefly why this has been necessary and how it will affect navigation.
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IEEE Systems Journal
In signals of opportunity (SOPs)-based positioning utilizing low Earth orbit (LEO) satellites, ephemeris data derived from two-line element files can introduce increasing error over time.
Md. Ali Hasan +4 more
semanticscholar +1 more source
In signals of opportunity (SOPs)-based positioning utilizing low Earth orbit (LEO) satellites, ephemeris data derived from two-line element files can introduce increasing error over time.
Md. Ali Hasan +4 more
semanticscholar +1 more source