Research and development of an optical ground station supporting both GEOand LEO-to-ground links [International Communications Satellite Systems Conference]

Author(s):  
D.R. Kolev ◽  
K. Shiratama ◽  
H. Takenaka ◽  
A. Carrasco-Casado ◽  
Y. Saito ◽  
...  
2018 ◽  
Vol 62 ◽  
pp. 01008
Author(s):  
Zinaida F. Dumbrava ◽  
Vladimir P. Sivokon ◽  
Yuriy A. Teslyuk ◽  
Sergey Y. Khomutov

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.


2021 ◽  
Vol 13 (5) ◽  
pp. 982 ◽  
Author(s):  
Joan A. Ruiz-de-Azua ◽  
Nicola Garzaniti ◽  
Alessandro Golkar ◽  
Anna Calveras ◽  
Adriano Camps

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.


Author(s):  
S.B. Pichugin

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.


Author(s):  
Hiromitsu Wakana ◽  
Takashi Iida ◽  
Akio Iso ◽  
Takashi Kadowaki ◽  
Susumu Kitazume ◽  
...  

Author(s):  
Radhika Radhakrishnan ◽  
Qing-An Zeng ◽  
William E. Edmonson

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.


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