Ground station networks vs. GEO relay satellite systems for polar orbiting satellites

2012 ◽  
Author(s):  
Baard Eilertsen
Keyword(s):  
Satellite Systems ◽  
Ground Station

scholarly journals Ionosphere disturbance during cosmodrome “Vostochniy” launches

2018 ◽  
Vol 62 ◽  
pp. 01008
Author(s):  
Zinaida F. Dumbrava ◽  
Vladimir P. Sivokon ◽  
Yuriy A. Teslyuk ◽  
Sergey Y. Khomutov
Keyword(s):  
Acoustic Waves ◽  
Ionospheric Plasma ◽  
Global Navigation Satellite Systems ◽  
Plasma Properties ◽  
Satellite Systems ◽  
Ground Station ◽  
Ionosphere Disturbance ◽  
Global Navigation Satellite ◽  
Carrier Rocket ◽  
Supersonic Motion

It is known that during spacecraft launches ionospheric plasma properties are modified in the result of impact of shock-acoustic waves generated during carrier rocket supersonic motion. As a rule, investigation of ionospheric plasma variations is carried out by the signals of Global Navigation Satellite Systems GPS/GLONASS that implies ground station network. There is no such a system near the “Vostochniy” cosmodrome that makes it necessary to search for an alternative solution. One of them may be the application of ionosphere vertical and oblique sounding stations. Based on the analysis of such station data, the possibility of evaluation of ionosphere modification during “Vostochniy” cosmodrome launches is shown.

scholarly journals Towards Federated Satellite Systems and Internet of Satellites: The Federation Deployment Control Protocol

2021 ◽  
Vol 13 (5) ◽  
pp. 982 ◽  
Author(s):  
Joan A. Ruiz-de-Azua ◽  
Nicola Garzaniti ◽  
Alessandro Golkar ◽  
Anna Calveras ◽  
Adriano Camps
Keyword(s):  
Data Storage ◽  
Negotiation Process ◽  
Earth Observation ◽  
Low Latency ◽  
Field Campaign ◽  
Satellite Systems ◽  
Control Protocol ◽  
Ground Station ◽  
The Earth ◽  
Definition Of

Presently, the Earth Observation community is demanding applications that provide low latency and high downlink capabilities. An increase in downlink contacts becomes essential to meet these new requirements. The Federated Satellite Systems concept addresses this demand by promoting satellite collaborations to share unused downlink opportunities. These collaborations are established opportunistically and temporarily, posing multiple technology challenges to be implemented in-orbit. This work contributes to the definition of the Federation Deployment Control Protocol which formalizes a mechanism to fairly establish and manage these collaborations by employing a negotiation process between the satellites. Moreover, this manuscript presents the results of a validation campaign of this protocol with three stratospheric balloons. In summary, more than 27 federations with 63.0% of throughput were established during the field campaign. Some of these federations were used to download data to the ground, and others were established to balance data storage between balloons. These federations allowed also the extension of the coverage of a ground station with a federation that relayed data through a balloon, and the achievement of a hybrid scenario with one balloon forwarding data from a ground device. The results demonstrate that the proposed protocol is functional and ready to be embedded in a CubeSat mission.

Simplest Flow Queuing Models for LEO Satellite System

2022 ◽  
pp. 61-70
Author(s):  
S.B. Pichugin
Keyword(s):  
Communication System ◽  
Communication Systems ◽  
Satellite System ◽  
Low Earth Orbit ◽  
Analytical Models ◽  
Mathematical Apparatus ◽  
Satellite Systems ◽  
Ground Station ◽  
Queuing Models ◽  
Leo Satellite

The relevance of the work is associated with the active deployment of low-orbit communication systems and the expansion of research in the field of corresponding satellite systems. A promising low-orbit communication system based on relay satellites with the function (RSRFs) of routing message packets is considered. The low earth orbit communications systems use the BGP protocol and the AAA functionality at the ground station. For assessing the characteristics of RSRF inter-satellite paths, a scenario was created for the message packets arrival from a group of inter-satellite paths to one subscriber path. The corresponding analytical models have been developed using the mathematical apparatus of queuing systems with the simplest flows of requests and exponential distribution of the service time. The RSRF characteristics of a promising low-orbit communication system are predicted. It is proposed to make the mathematical apparatus of analytical models more complicated to take into account the dynamics of displacements and failures of the RSRF in a low-orbit communication system.

Inter-Satellite Communications for Small Satellite Systems

2013 ◽  
Vol 5 (3) ◽  
pp. 11-22 ◽  
Author(s):  
Radhika Radhakrishnan ◽  
Qing-An Zeng ◽  
William E. Edmonson
Keyword(s):  
Formation Flying ◽  
Satellite Communications ◽  
Space Mission ◽  
Satellite Networks ◽  
Small Satellite ◽  
New Era ◽  
Small Satellites ◽  
Satellite Systems ◽  
Satellite Technology ◽  
Ground Station

Small satellite technology has opened a new era in aerospace engineering by decreasing space mission costs, without greatly reducing the performance. The concept of formation flying using small satellites is becoming popular because of their potential to perform coordinated measurements of remote sensing space missions. The current state of art in satellite communications is a one hop link between satellite and ground station. Very little work has been done on inter-satellite communications. This paper aims to design and evaluate feasible MAC and routing layer protocols for distributed small satellite networks. The possibility to implement proposed MAC and routing protocols for two different formation flying patterns are investigated. To validate the authors’ proposed system model, they use extensive simulations to evaluate the performance of the system using throughput, access delay and end-to-end delay.

Novel Integrity Concept for CAT III Precision Approaches and Taxiing: Extended GBAS (E-GBAS)

2011 ◽  
Vol 64 (4) ◽  
pp. 695-710 ◽  
Author(s):  
Wolfgang Schuster ◽  
Washington Ochieng
Keyword(s):  
Measurement Errors ◽  
High Performance ◽  
Performance Monitoring ◽  
Global Navigation Satellite Systems ◽  
Monitoring Scheme ◽  
Satellite Systems ◽  
Accuracy Requirement ◽  
Ground Station ◽  
Full Benefit ◽  
Global Navigation Satellite

Future air navigation envisages increased use of Global Navigation Satellite Systems (GNSS) together with advanced communications and surveillance technologies to facilitate the required increase in capacity, efficiency and safety without adversely impacting the environment. The full benefit of GNSS is expected from its ability to support en-route to en-route or gate-to-gate air navigation. This presents challenges particularly for the phases of flight with stringent required navigation performance. Significant work has so far been devoted to the phases of flight up to CAT I. However, more work is required for CAT III precision landing (with an accuracy requirement at the metre level) and taxiing (with an accuracy requirement at sub-metre level) and both with very high integrity and continuity requirements. The main limitation in using GBAS for CAT III landings is the potential decorrelation of the measurement errors between the GBAS ground station (GGS) and the user. The threats in this respect are the atmospheric anomalies. Periods of strong solar activity can cause large local spatial and temporal gradients in the delays induced on the GNSS signals by the ionosphere. The local nature of the effects results in significant decorrelation between GGS measurements and the user. Therefore, a reliable ground based ionospheric anomaly monitoring scheme is required to guarantee integrity.This paper critically reviews state-of-the-art monitors, identifies their limitations and addresses them by proposing a high-performance monitoring scheme for the ionosphere. Preliminary analyses suggest that the proposed scheme has the potential to enable GNSS to meet the navigation requirements for CAT III and taxiing.

scholarly journals C3 in UAS as a Means for Secondary Navigation

2012 ◽  
Vol 66 (1) ◽  
pp. 115-134
Author(s):  
Jorge Ramirez ◽  
Dagoberto Salazar ◽  
Xavier Prats ◽  
Cristina Barrado
Keyword(s):  
Kalman Filter ◽  
Global Navigation Satellite Systems ◽  
Civil Aviation ◽  
Navigation Satellite ◽  
International Civil Aviation Organization ◽  
Satellite Systems ◽  
Ground Station ◽  
Performance Based Navigation ◽  
Global Navigation Satellite ◽  
Navigation Accuracy

Unmanned Air Systems (UAS) navigate using Global Navigation Satellite Systems (GNSS), but GNSS vulnerability precludes its use as the only means of navigation and requires a secondary means of navigation. A differentiating characteristic of UAS is their periodic communications with the ground station. This paper analyses the adequacy of employing UAS Command, Control and Communications (C3) as a secondary means of navigation. With no additional infrastructure, an Extended Kalman Filter (EKF) is used to process C3 messages and to obtain the positions of the UAS. Navigation accuracy and integrity are calculated in a scenario with three UAS. The obtained results meet the International Civil Aviation Organization (ICAO) Performance-Based Navigation (PBN) requirements.

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