investigating space radiation
Roghieh Karimzadeh Baee; Hamideh Daneshvar; Amir Hossin Ahmadi; Parvin Sojoodi
Volume 16, Issue 1 , March 2023, , Pages 59-74
Abstract
With the advent of GaN technology, achieving microwave power with high efficiency by solid-state devices has become more available. Therefore, the use of SSPA amplifiers with GaN technology in satellites, especially LEO satellites, has been considered. space radiation can affect the performance and reliability ...
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With the advent of GaN technology, achieving microwave power with high efficiency by solid-state devices has become more available. Therefore, the use of SSPA amplifiers with GaN technology in satellites, especially LEO satellites, has been considered. space radiation can affect the performance and reliability of components in space systems, which needs to be investigated. One of the most important technologies that can be affected by radiation effects is GaN transistors. In this paper, the effect of TID on GaN transistors in the SSPA amplifier board is investigated. Since commercial components have been used in the engineering sample of the SSPA amplifier and the calculations obtained from the RDM estimates under the worst conditions show that it is necessary to conduct a test for these components, the radiation resistance test was performed for this amplifier. The results of the test conducted in this article show that the SSPA GaN board has radiation tolerance up to a dose of approximately 16 krad. Therefore, mismatched GaN transistors are resistant up to this amount of dose. This is while the sequencer board actually has less tolerance than 5.5 krad
Reza Omidi Gosheblagh; Karim Mohammadi
Volume 5, Issue 3 , October 2012, , Pages 1-9
Abstract
Due to high design and launch cost of satellites, their failure probability should be minimized. Single Event Effects (SEUs) are one of the most common error sources in satellite microelectronic. To cope with these unwanted errors, various techniques are used. The reliability analysis of these methods ...
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Due to high design and launch cost of satellites, their failure probability should be minimized. Single Event Effects (SEUs) are one of the most common error sources in satellite microelectronic. To cope with these unwanted errors, various techniques are used. The reliability analysis of these methods is one of the major acceptance criteria to validate these techniques. In order to evaluate the reliability of satellite subsystems, it is required to determine the SEU rate as a primary factor. A practical method to determine this rate is based on Weibull approach in which the SEU cross section is used as an initialized parameter. In this paper, the SEU rate is calculated based on weibull method for Low Earth Orbit (LEO) satellites, as case study Iranian demonstrated Rasad and Omid satellites. Furthermore, based on the proton density, an accurate time-varying SEU rate model is proposed which determines the rejuvenation time for SEU susceptible subsystems.
Shahrokh Marzban; Kamal Mohamedpour; Somye Pirzadi
Volume 5, Issue 3 , October 2012, , Pages 21-31
Abstract
After setteling the LEO satellite in the given circuit, the ground station needs to communicate with it for the received of information and control of its subsystems. Due to the fact that satellite communication channels are influenced by shadowing conditions, if a line of sight (LOS) signal exists between ...
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After setteling the LEO satellite in the given circuit, the ground station needs to communicate with it for the received of information and control of its subsystems. Due to the fact that satellite communication channels are influenced by shadowing conditions, if a line of sight (LOS) signal exists between the receiver and the transmitter, then the radio channels conditions are good and the Additive White Gaussian Noise channel is modeled as Rician distribution. However, under poor conditions and in the lack of LOS, channel model is Rayleigh, and due to the radio link conditions the channel will be switched between these two models. In a proper model, the time varying behavior of the station – satellite radio link should be considered. The importance attached to this issue is due to its considerable effect on the selection of modulation type, design of channel access method, and error control. In this view, the present study has sought to momentarily determine the range of variations in error probability. Through calculations and simulation, the Bit Error Rate received during the satellite trajectory has been obtained for any given moment and its range of variations has been determined.
A. H. Adami; M. Nosratollahi
Volume 4, Issue 2 , January 2012, , Pages 1-10
Abstract
New algorithm is presented in this paper for attitude determination of LEO nanosatellite with 2 accuracy in attitude determination independent of time. The most important limitation in nanosatellites is about subsystems’s masses so, reduction of subsystems’s masses is always considered. ...
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New algorithm is presented in this paper for attitude determination of LEO nanosatellite with 2 accuracy in attitude determination independent of time. The most important limitation in nanosatellites is about subsystems’s masses so, reduction of subsystems’s masses is always considered. ADS plays the important role in the successful orbital maneuver missions. ADS accuracy is connected with increasing of sensors and complex processors which lead to increase the ADS mass. The presented algorithm uses one magnetometer sensor and one horizon sensor and position data receiving by GPS sensor as minimum required sensors. The selected configuration is resulted to minimum ADS mass and mission cost. Finally, error analysis at two most important orbit zones is done and the performance of the presented algorithm is confirmed.
