High Availability Broadband Communications Satellite System Using Satellite Constellations in Elliptical Orbits

2003 ◽  
Author(s):  
Andrew Turner ◽  
Brian Kemper ◽  
J. Nicholas LaPrade
Keyword(s):  
Satellite System ◽  
High Availability ◽  
Satellite Constellations ◽  
Broadband Communications ◽  
Elliptical Orbits

Lower Bounds on DOP

2017 ◽  
Vol 70 (5) ◽  
pp. 1041-1061 ◽  
Author(s):  
Peter F. Swaszek ◽  
Richard J. Hartnett ◽  
Kelly C. Seals
Keyword(s):  
Lower Bounds ◽  
Global Navigation Satellite System ◽  
Satellite System ◽  
Navigation Satellite ◽  
Satellite Constellations ◽  
Dilution Of Precision ◽  
Gnss Positioning ◽  
Satellite Selection ◽  
Global Navigation ◽  
Global Navigation Satellite

Code phase Global Navigation Satellite System (GNSS) positioning performance is often described by the Geometric or Position Dilution of Precision (GDOP or PDOP), functions of the number of satellites employed in the solution and their geometry. This paper develops lower bounds to both metrics solely as functions of the number of satellites, effectively removing the added complexity caused by their locations in the sky, to allow users to assess how well their receivers are performing with respect to the best possible performance. Such bounds will be useful as receivers sub-select from the plethora of satellites available with multiple GNSS constellations. The bounds are initially developed for one constellation assuming that the satellites are at or above the horizon. Satellite constellations that essentially achieve the bounds are discussed, again with value toward the problem of satellite selection. The bounds are then extended to a non-zero mask angle and to multiple constellations.

scholarly journals Dynamics and Control of Tethered Satellite System in Elliptical Orbits under Resonances

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Zhaojun Pang ◽  
Zhonghua Du ◽  
Chun Cheng ◽  
Qingtao Wang
Keyword(s):  
Chaotic Motion ◽  
Satellite System ◽  
Internal Resonances ◽  
Tethered Satellite ◽  
Tethered Satellite System ◽  
Dynamics And Control ◽  
Elliptical Orbits ◽  
And Control ◽  
Stable Domains ◽  
Parameter Relations

This paper studies resonance motions of a tethered satellite system (TSS) in elliptical orbits. A perturbation analysis is carried out to obtain all possible resonance types and corresponding parameter relations, including internal resonances and parametrically excited resonances. Besides, a resonance parametric domain is given to provide a reference for the parameter design of the system. The bifurcation behaviors of the system under resonances are studied numerically. The results show that resonant cases more easily enter chaotic motion than nonresonant cases. The extended time-delay autosynchronization (ETDAS) method is applied to stabilize the chaotic motion to a periodic one. Stability analysis shows that the stable domains become smaller in resonance cases than in the nonresonance case. Finally, it is shown that the large amplitudes of periodic solutions under resonances are the main reason why the system is difficult to control.

Nonlinear resonant analysis of space tethered satellite system in elliptical orbits

2021 ◽  
Vol 182 ◽  
pp. 264-273
Author(s):  
Zhaojun Pang ◽  
Hao Wen ◽  
Xiaoting Rui ◽  
Zhonghua Du
Keyword(s):  
Satellite System ◽  
Tethered Satellite ◽  
Tethered Satellite System ◽  
Elliptical Orbits

Сomparative study of the accuracy of Earth observation by satellite constellations in high elliptical orbits

2021 ◽  
pp. 108-118
Author(s):  
Mikhail Yu. GUNCHENKO
Keyword(s):  
Design Parameters ◽  
Trajectory Design ◽  
Preliminary Design ◽  
Satellite Constellations ◽  
Satellite Systems ◽  
Structure And Dynamics ◽  
Constellation Analysis ◽  
Accuracy Criterion ◽  
Elliptical Orbits ◽  
Onboard Equipment

The paper provides results of estimated accuracy comparisons for applied satellite constellations (ASC) in Molniya-type high elliptical orbits based on a previously presented criterion for analysis of accuracy parameters of ASC that observe targets on the Earth surface and/or in the layer above the surface, which is not dependent on specific features of the onboard equipment, but rather on the structure and dynamics of the ASC. The paper provides an algorithm for numerical simulations of ASC. The paper discusses accuracy parameters for ASC in high elliptical orbits in various orbital configurations, as well as a combined option involving spacecraft in geostationary orbit. It defines key trajectory design parameters driving the ASC accuracy. The results can be used for selecting the initial ASC configuration in high elliptical orbits during preliminary design phase. Key words: observation satellite systems, high elliptical orbits, accuracy criterion, satellite constellation analysis.

Orbit Simulator for Satellite and Near Space Platforms Supporting Observing System Simulation Experiments

2021 ◽  
Author(s):  
Likun Wang ◽  
Narges Shahroudi ◽  
Eric Maddy ◽  
Kevin Garrett ◽  
Sid Boukabara ◽  
...  
Keyword(s):  
System Simulation ◽  
Weather Prediction ◽  
Satellite System ◽  
Satellite Constellations ◽  
Near Space ◽  
Satellite Applications ◽  
Joint Center ◽  
Global Navigation Satellite ◽  
Cross Track ◽  
Observing System Simulation Experiment

AbstractDeveloped at the National Oceanic and Atmospheric Administration (NOAA) and the Joint Center for Satellite Data Assimilation (JCSDA), the Community Global Observing System Simulation Experiment (OSSE) Package (CGOP) provides a vehicle to quantitatively evaluate the impacts of emerging environmental observing systems or emerging in-situ or remote sensing instruments on NOAA numerical weather prediction (NWP) forecast skill. The typical first step for the OSSE is to simulate observations from the so-called “nature run”. Therefore, the observation spatial, temporal, and view geometry are needed to extract the atmospheric and surface variables from the nature run, which are then input to the observation forward operator (e.g., radiative transfer models) to simulate the new observations. This is a challenge for newly proposed systems for which instruments are not yet built or platforms are not yet deployed. To address this need, this study introduces an orbit simulator to compute these parameters based on the specific hosting platform and onboard instrument characteristics, which has been recently developed by the NOAA Center for Satellite Applications and Research (STAR) and added to the GCOP framework. In addition to simulating existing polar-orbiting and geostationary orbits, it is also applicable to emerging near space platforms (e.g., stratospheric balloons), cube satellite constellations, and Tundra orbits. The observation geometry simulator includes not only passive microwave and infrared sounders but also Global Navigation Satellite System/Radio Occultation (GNSS/RO) instruments. For passive atmospheric sounders, it calculates the geometric parameters of proposed instruments on different platforms, such as time varying location (latitude and longitude), scan geometry (satellite zenith and azimuth angles), and Ground Instantaneous Field of View (GIFOV) parameters for either cross-track or conical scanning mechanisms. For RO observations, it determines the geometry of the transmitters and receivers either on satellites or stratospheric balloons and computes their slant paths. The simulator has been successfully applied for recent OSSE studies (e.g., evaluating the impacts of future geostationary hyperspectral infrared sounders and RO observations from stratospheric balloons).

COMPARATIVE STUDY OF THE ACCURACY OF EARTH OBSERVATION BY SATELLITE CONSTELLATIONS IN HIGH ELLIPTICAL ORBITS

2021 ◽  
pp. 108-118
Author(s):  
Mikhail Yu. GUNCHENKO
Keyword(s):  
Design Parameters ◽  
Trajectory Design ◽  
Preliminary Design ◽  
Satellite Constellations ◽  
Satellite Systems ◽  
Structure And Dynamics ◽  
Constellation Analysis ◽  
Accuracy Criterion ◽  
Elliptical Orbits ◽  
Onboard Equipment

The paper provides results of estimated accuracy comparisons for applied satellite constellations (ASC) in Molniya-type high elliptical orbits based on a previously presented criterion for analysis of accuracy parameters of ASC that observe targets on the Earth surface and/or in the layer above the surface, which is not dependent on specific features of the onboard equipment, but rather on the structure and dynamics of the ASC. The paper provides an algorithm for numerical simulations of ASC. The paper discusses accuracy parameters for ASC in high elliptical orbits in various orbital configurations, as well as a combined option involving spacecraft in geostationary orbit. It defines key trajectory design parameters driving the ASC accuracy. The results can be used for selecting the initial ASC configuration in high elliptical orbits during preliminary design phase. Key words: observation satellite systems, high elliptical orbits, accuracy criterion, satellite constellation analysis.

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