This paper proposes an efficient design method for nano satellites formation flying near a large space target to perform ultra-close inspection missions.A parametric model for periodic relative motion between two sate...This paper proposes an efficient design method for nano satellites formation flying near a large space target to perform ultra-close inspection missions.A parametric model for periodic relative motion between two satellites is firstly proposed through a detailed analysis of the relative orbital dynamics.It is proved that the existing periodic solutions of satellite relative motion such as in-plane 2:1 elliptic and circular periodic relative orbits both belong to the ellipsoid family of periodic relative orbits.The motion planes and their locations and orientations of the general periodic relative orbits are then determined as the analytic functions of the initial relative states.The maximal and minimal distances from the relative orbit to the origin are further analytically calculated too.A formation design algorithm is then proposed for optimal observation of feature points of the target considering various requirements of collision avoidance and observable distance by using this parametric model.Numerical examples about target inspection are introduced to quantitively evaluate and verify the models and methods.The simulation results are well consistent with the theoretical predictions,showing that the design proposed can be potentially applied for future practical on-orbit service missions.展开更多
This paper proposes a communication system for nanosatellite Earth observa-tion preliminary design technique as useful tools for managing and improving various aspects of regional and national resources. Under analysi...This paper proposes a communication system for nanosatellite Earth observa-tion preliminary design technique as useful tools for managing and improving various aspects of regional and national resources. Under analysis was pro-posed a design process for the low Earth orbit nanosatellite communication system. In proposed paper have been formulated and solved next goals: re-viewed Earth observation systems and studied their design parameters, ana-lyzed the on-board antennas design background and provided analytical esti-mations, such as design a passband quadrature phase shift keying transmitter and receiver in Simulink, was obtained a bit error rate curves by using a Sim-ulink/MathWorks, generated an offset quadrature phase shift keying waveform and investigated their characteristics, observed and analyzed the diagrams, constellation, and the signal trajectories of quadrature phase shift keying ac-cording contemporary design concept. As a result, this allows to propose in-novative communication system design techniques applied for the nanosatel-lite category.展开更多
micro-electro-mechanical system （MEMS） device has the advantages of both electronic system and mechanical system. With the development of MEMS devices for satellite, it is possible to establish much lighter and smal...micro-electro-mechanical system （MEMS） device has the advantages of both electronic system and mechanical system. With the development of MEMS devices for satellite, it is possible to establish much lighter and smaller nanosatellites with higher performance and longer lifecyele. The power consumption of MEMS devices is usually much lower than that of traditional devices, which will greatly reduce the consumption of power. For its small size and simple architecture, MEMS devices can be easily integrated together and achieve redundancy. Launched on April 18, 2004, NS - 1 is a nanosatellite for science exploration and MEMS devices test. A mass of science data and images were acquired during its running. NS - 1 weights less than 25 kg. It consists of several MEMS devices, including one miniature inertial measurement unit（MIMU） , three micro complementary metal oxide semiconductor （CMOS）cameras, one sun sensor, three momentum wheels, and one micro magnetic sensor. By applying micro components based on MEMS technology, NS - 1 has made success in the experiments of integrative design, manufacture, and MEMS devices integration. In this paper, some MEMS devices for nanosatellite and picosatellite are introduced, which have been tested on NS -1 nanosatellite or on the ground.展开更多
The FloripaSat-I project consists of an initiative from the Federal University of Santa Catarina(UFSC),in Brazil,to train students to design,test and integrate innovative space systems.The group just developed its fir...The FloripaSat-I project consists of an initiative from the Federal University of Santa Catarina(UFSC),in Brazil,to train students to design,test and integrate innovative space systems.The group just developed its first open-source CubeSat,the FloripaSat-I,which aims to empower students to develop space systems through a practical approach,where they have full control of the design and test of a real spacecraft.The project has already gone through all the stages of a CubeSat mission prior to the launching and operation stages.A prototype of the satellite,as well the engineering models 1 and 2(EM-I and EM-II)were built.The expertise provided by the engineering models allows the development of a functional flight model(FM).This paper presents the validation and qualification tests that pass various FloripaSat-I models,from the engineering model to the flight model.All stages of the project are described,the tests performed in each phase,as well as the lessons learned.Thus,this paper serves as a guidance for other university teams that want to test their own CubeSats,as well as teams that want to use the open-source hardware and software left as heritage by this project.展开更多
To adopt sustainable crop practices in changing climate, understandingthe climatic parameters and water requirements with vegetation is crucial on aspatiotemporal scale. The Planetscope (PS) constellation of more than...To adopt sustainable crop practices in changing climate, understandingthe climatic parameters and water requirements with vegetation is crucial on aspatiotemporal scale. The Planetscope (PS) constellation of more than 130 nanosatellites from Planet Labs revolutionize the high-resolution vegetation assessment. PS-derived Normalized Difference Vegetation Index (NDVI) maps areone of the highest resolution data that can transform agricultural practices andmanagement on a large scale. High-resolution PS nanosatellite data was utilizedin the current study to monitor agriculture’s spatiotemporal assessment for theAl-Qassim region, Kingdom of Saudi Arabia (KSA). The time series of NDVIwas utilized to assess the vegetation pattern change in the study area. The currentstudy area has sparse vegetation, and exposed soil exhibits brightness due to lowsoil moisture, constraining NDVI. Therefore, a machine learning (ML) basedRandom Forest (RF) classification model was used to compare the vegetationextent and computational cost of NDVI. The RF model has been compared withNDVI in the current investigation. It is one of the most precise classificationmethods because it can model the complexity of input variables, handle outliers,treat noise effectively, and avoid overfitting. Multinomial Logistic Regression(MLR) was implemented to compare the performance of both NDVI and RFbased classification. RF model provided good accuracy (98%) for all vegetationclasses based on user accuracy, producer accuracy, and kappa coefficient.展开更多
基金the National Natural Science Foundation of China(No.12172288)the National Key R&D Program of China(Nos.2021YFC2202601,2021YFC2202603).
文摘This paper proposes an efficient design method for nano satellites formation flying near a large space target to perform ultra-close inspection missions.A parametric model for periodic relative motion between two satellites is firstly proposed through a detailed analysis of the relative orbital dynamics.It is proved that the existing periodic solutions of satellite relative motion such as in-plane 2:1 elliptic and circular periodic relative orbits both belong to the ellipsoid family of periodic relative orbits.The motion planes and their locations and orientations of the general periodic relative orbits are then determined as the analytic functions of the initial relative states.The maximal and minimal distances from the relative orbit to the origin are further analytically calculated too.A formation design algorithm is then proposed for optimal observation of feature points of the target considering various requirements of collision avoidance and observable distance by using this parametric model.Numerical examples about target inspection are introduced to quantitively evaluate and verify the models and methods.The simulation results are well consistent with the theoretical predictions,showing that the design proposed can be potentially applied for future practical on-orbit service missions.
文摘This paper proposes a communication system for nanosatellite Earth observa-tion preliminary design technique as useful tools for managing and improving various aspects of regional and national resources. Under analysis was pro-posed a design process for the low Earth orbit nanosatellite communication system. In proposed paper have been formulated and solved next goals: re-viewed Earth observation systems and studied their design parameters, ana-lyzed the on-board antennas design background and provided analytical esti-mations, such as design a passband quadrature phase shift keying transmitter and receiver in Simulink, was obtained a bit error rate curves by using a Sim-ulink/MathWorks, generated an offset quadrature phase shift keying waveform and investigated their characteristics, observed and analyzed the diagrams, constellation, and the signal trajectories of quadrature phase shift keying ac-cording contemporary design concept. As a result, this allows to propose in-novative communication system design techniques applied for the nanosatel-lite category.
文摘micro-electro-mechanical system （MEMS） device has the advantages of both electronic system and mechanical system. With the development of MEMS devices for satellite, it is possible to establish much lighter and smaller nanosatellites with higher performance and longer lifecyele. The power consumption of MEMS devices is usually much lower than that of traditional devices, which will greatly reduce the consumption of power. For its small size and simple architecture, MEMS devices can be easily integrated together and achieve redundancy. Launched on April 18, 2004, NS - 1 is a nanosatellite for science exploration and MEMS devices test. A mass of science data and images were acquired during its running. NS - 1 weights less than 25 kg. It consists of several MEMS devices, including one miniature inertial measurement unit（MIMU） , three micro complementary metal oxide semiconductor （CMOS）cameras, one sun sensor, three momentum wheels, and one micro magnetic sensor. By applying micro components based on MEMS technology, NS - 1 has made success in the experiments of integrative design, manufacture, and MEMS devices integration. In this paper, some MEMS devices for nanosatellite and picosatellite are introduced, which have been tested on NS -1 nanosatellite or on the ground.
基金This work was supported by the Brazilian Space Agencythe National Council for Scientific and Technological Developmentthe Coordination for the Improvement of Higher Education Personnel.
文摘The FloripaSat-I project consists of an initiative from the Federal University of Santa Catarina(UFSC),in Brazil,to train students to design,test and integrate innovative space systems.The group just developed its first open-source CubeSat,the FloripaSat-I,which aims to empower students to develop space systems through a practical approach,where they have full control of the design and test of a real spacecraft.The project has already gone through all the stages of a CubeSat mission prior to the launching and operation stages.A prototype of the satellite,as well the engineering models 1 and 2(EM-I and EM-II)were built.The expertise provided by the engineering models allows the development of a functional flight model(FM).This paper presents the validation and qualification tests that pass various FloripaSat-I models,from the engineering model to the flight model.All stages of the project are described,the tests performed in each phase,as well as the lessons learned.Thus,this paper serves as a guidance for other university teams that want to test their own CubeSats,as well as teams that want to use the open-source hardware and software left as heritage by this project.
文摘To adopt sustainable crop practices in changing climate, understandingthe climatic parameters and water requirements with vegetation is crucial on aspatiotemporal scale. The Planetscope (PS) constellation of more than 130 nanosatellites from Planet Labs revolutionize the high-resolution vegetation assessment. PS-derived Normalized Difference Vegetation Index (NDVI) maps areone of the highest resolution data that can transform agricultural practices andmanagement on a large scale. High-resolution PS nanosatellite data was utilizedin the current study to monitor agriculture’s spatiotemporal assessment for theAl-Qassim region, Kingdom of Saudi Arabia (KSA). The time series of NDVIwas utilized to assess the vegetation pattern change in the study area. The currentstudy area has sparse vegetation, and exposed soil exhibits brightness due to lowsoil moisture, constraining NDVI. Therefore, a machine learning (ML) basedRandom Forest (RF) classification model was used to compare the vegetationextent and computational cost of NDVI. The RF model has been compared withNDVI in the current investigation. It is one of the most precise classificationmethods because it can model the complexity of input variables, handle outliers,treat noise effectively, and avoid overfitting. Multinomial Logistic Regression(MLR) was implemented to compare the performance of both NDVI and RFbased classification. RF model provided good accuracy (98%) for all vegetationclasses based on user accuracy, producer accuracy, and kappa coefficient.
