Low Earth orbit satellites such as Earth observation satellites usually use the store and forward... more Low Earth orbit satellites such as Earth observation satellites usually use the store and forward approach to dump their data to the user during overflight over a ground station. This method relies on a large number of different ground stations or on the patience of the user. If the data is needed on time or if long-lasting real time access to the satellite itself is essential, the implementation of a relay satellite is reasonable. This paper introduces BayernSat, a micro-satellite which demonstrates the technology necessary for telepresence in space. BayernSat will use a commercial available geostationary relay satellite to send live video footage to the user on ground. Furthermore the satellite can be controlled in realtime from ground using the return link also via the relay satellite. Besides the demonstration of the telepresence technology, BayernSat will demonstrate a newly developed high performance onboard computer system, a color video camera for space application and a steerable low profile high gain S-band antenna. BayernSat also acts as a tool to inspire the public for space. The live video footage will be presented on the Internet and selected users will be able to steer the satellite via Internet.
Selected Proceedings of the 5th International Symposium of the International Academy of Astronautics, Berlin, April 4-8 2005, 2005
In this article we propose the use of geostationary relay satellites for interactive Earth observ... more In this article we propose the use of geostationary relay satellites for interactive Earth observation in real time for small satellite missions. This would provide interactive link times of at least 50 minutes during every orbit rather than those max. 7 minutes link times available for paths over ground stations. However, a drawback of such real-time communication via relay satellites is that the round-trip time of up-and downlink easily exceeds one second. This is because the large distances between spacecraft and ground segment to the relay satellite already make up a round-trip time of at least 0.5 seconds. In order to get as close as possible to this physical limit, we propose to split up the up-and downlink transmission to the relay satellite using two different ground segments. The crucial point of our concept is to minimize the time delay between the Downlink Ground Segment (DGS) and the User Observation Center (UOC). This is accomplished by physically locating the DGS as close as possible to the UOC. This may imply the Uplink Ground Segment (UGS) and the DGS to be several hundred kilometers apart. Furthermore we propose to split the transmitted payload data from the satellite into critical and non-critical data packets thereby eliminating redundancies.
A prerequisite to accomplish a system simulation is to have a system model holding all necessary ... more A prerequisite to accomplish a system simulation is to have a system model holding all necessary project information in a centralized repository that can be accessed and edited by all parties involved. At the Institute of Astronautics of the Technische Universitaet Muenchen a modular approach for modeling and dynamic simulation of satellite systems has been developed called dynamic system simulation (DySyS). DySyS is based on the platform independent description language SysML to model a small satellite project with respect to the system composition and dynamic behavior. A library of specific building blocks and possible relations between these blocks have been developed. From this library a system model of the satellite of interest can be created. A mapping into a C++ simulation allows the creation of an executable system model with which simulations are performed to observe the dynamic behavior of the satellite. In this paper DySyS is used to model and simulate the dynamic behavior of small satellites, because small satellite projects can act as a precursor to demonstrate the feasibility of a system model since they are less complex compared to a large scale satellite project.
A prerequisite to accomplish a system simulation is to have a system model holding all necessary ... more A prerequisite to accomplish a system simulation is to have a system model holding all necessary project information in a centralized repository that can be accessed and edited by all parties involved. At the Institute of Astronautics of the Technische Universitaet Muenchen a modular approach for modeling and dynamic simulation of satellite systems has been developed called dynamic system simulation (DySyS). DySyS is based on the platform independent description language SysML to model a small satellite project with respect to the system composition and dynamic behavior. A library of specific building blocks and possible relations between these blocks have been developed. From this library a system model of the satellite of interest can be created. A mapping into a C++ simulation allows the creation of an executable system model with which simulations are performed to observe the dynamic behavior of the satellite. In this paper DySyS is used to model and simulate the dynamic behavior of small satellites, because small satellite projects can act as a precursor to demonstrate the feasibility of a system model since they are less complex compared to a large scale satellite project.
Low Earth orbit satellites such as Earth observation satellites usually use the store and forward... more Low Earth orbit satellites such as Earth observation satellites usually use the store and forward approach to dump their data to the user during overflight over a ground station. This method relies on a large number of different ground stations or on the patience of the user. If the data is needed on time or if long-lasting real time access to the satellite itself is essential, the implementation of a relay satellite is reasonable. This paper introduces BayernSat, a micro-satellite which demonstrates the technology necessary for telepresence in space. BayernSat will use a commercial available geostationary relay satellite to send live video footage to the user on ground. Furthermore the satellite can be controlled in real- time from ground using the return link also via the relay satellite. Besides the demonstration of the telepresence technology, BayernSat will demonstrate a newly developed high performance onboard computer system, a color video camera for space application and a s...
Low Earth orbit satellites such as Earth observation satellites usually use the store and forward... more Low Earth orbit satellites such as Earth observation satellites usually use the store and forward approach to dump their data to the user during overflight over a ground station. This method relies on a large number of different ground stations or on the patience of the user. If the data is needed on time or if long-lasting real time access to the satellite itself is essential, the implementation of a relay satellite is reasonable. This paper introduces BayernSat, a micro-satellite which demonstrates the technology necessary for telepresence in space. BayernSat will use a commercial available geostationary relay satellite to send live video footage to the user on ground. Furthermore the satellite can be controlled in realtime from ground using the return link also via the relay satellite. Besides the demonstration of the telepresence technology, BayernSat will demonstrate a newly developed high performance onboard computer system, a color video camera for space application and a steerable low profile high gain S-band antenna. BayernSat also acts as a tool to inspire the public for space. The live video footage will be presented on the Internet and selected users will be able to steer the satellite via Internet.
Selected Proceedings of the 5th International Symposium of the International Academy of Astronautics, Berlin, April 4-8 2005, 2005
In this article we propose the use of geostationary relay satellites for interactive Earth observ... more In this article we propose the use of geostationary relay satellites for interactive Earth observation in real time for small satellite missions. This would provide interactive link times of at least 50 minutes during every orbit rather than those max. 7 minutes link times available for paths over ground stations. However, a drawback of such real-time communication via relay satellites is that the round-trip time of up-and downlink easily exceeds one second. This is because the large distances between spacecraft and ground segment to the relay satellite already make up a round-trip time of at least 0.5 seconds. In order to get as close as possible to this physical limit, we propose to split up the up-and downlink transmission to the relay satellite using two different ground segments. The crucial point of our concept is to minimize the time delay between the Downlink Ground Segment (DGS) and the User Observation Center (UOC). This is accomplished by physically locating the DGS as close as possible to the UOC. This may imply the Uplink Ground Segment (UGS) and the DGS to be several hundred kilometers apart. Furthermore we propose to split the transmitted payload data from the satellite into critical and non-critical data packets thereby eliminating redundancies.
A prerequisite to accomplish a system simulation is to have a system model holding all necessary ... more A prerequisite to accomplish a system simulation is to have a system model holding all necessary project information in a centralized repository that can be accessed and edited by all parties involved. At the Institute of Astronautics of the Technische Universitaet Muenchen a modular approach for modeling and dynamic simulation of satellite systems has been developed called dynamic system simulation (DySyS). DySyS is based on the platform independent description language SysML to model a small satellite project with respect to the system composition and dynamic behavior. A library of specific building blocks and possible relations between these blocks have been developed. From this library a system model of the satellite of interest can be created. A mapping into a C++ simulation allows the creation of an executable system model with which simulations are performed to observe the dynamic behavior of the satellite. In this paper DySyS is used to model and simulate the dynamic behavior of small satellites, because small satellite projects can act as a precursor to demonstrate the feasibility of a system model since they are less complex compared to a large scale satellite project.
A prerequisite to accomplish a system simulation is to have a system model holding all necessary ... more A prerequisite to accomplish a system simulation is to have a system model holding all necessary project information in a centralized repository that can be accessed and edited by all parties involved. At the Institute of Astronautics of the Technische Universitaet Muenchen a modular approach for modeling and dynamic simulation of satellite systems has been developed called dynamic system simulation (DySyS). DySyS is based on the platform independent description language SysML to model a small satellite project with respect to the system composition and dynamic behavior. A library of specific building blocks and possible relations between these blocks have been developed. From this library a system model of the satellite of interest can be created. A mapping into a C++ simulation allows the creation of an executable system model with which simulations are performed to observe the dynamic behavior of the satellite. In this paper DySyS is used to model and simulate the dynamic behavior of small satellites, because small satellite projects can act as a precursor to demonstrate the feasibility of a system model since they are less complex compared to a large scale satellite project.
Low Earth orbit satellites such as Earth observation satellites usually use the store and forward... more Low Earth orbit satellites such as Earth observation satellites usually use the store and forward approach to dump their data to the user during overflight over a ground station. This method relies on a large number of different ground stations or on the patience of the user. If the data is needed on time or if long-lasting real time access to the satellite itself is essential, the implementation of a relay satellite is reasonable. This paper introduces BayernSat, a micro-satellite which demonstrates the technology necessary for telepresence in space. BayernSat will use a commercial available geostationary relay satellite to send live video footage to the user on ground. Furthermore the satellite can be controlled in real- time from ground using the return link also via the relay satellite. Besides the demonstration of the telepresence technology, BayernSat will demonstrate a newly developed high performance onboard computer system, a color video camera for space application and a s...
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Papers by Matthias Raif