Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158224
Ee-Eul Kim, S. Al Marri
An advanced imaging system was developed for the DubaiSat-1 satellite system, a high-resolution Earth imaging small satellite. The imaging system is designed to produce high-resolution image data of 2.5-m ground sample distance (GSD) in one panchromatic band and 5.0-m GSD in four multi-spectral bands with 20-km swath width. The result from the acceptance test and radiometric and geometric characterization of its flight model is presented and reviewed in this paper together with methodology. Its upgraded version under development is also introduced with its key features and the development status.
为高分辨率地球成像小卫星DubaiSat-1卫星系统开发了先进的成像系统。该成像系统设计用于在一个全色波段产生2.5 m地样距离(GSD)的高分辨率图像数据，在4个多光谱波段产生5.0 m GSD的高分辨率图像数据，条带宽度为20 km。本文介绍了其飞行模型的验收试验结果、辐射和几何特性，并对其方法进行了综述。介绍了其正在开发的升级版本，主要特点和开发现状。
{"title":"Testing and characterization of the DubaiSat-1 imaging system","authors":"Ee-Eul Kim, S. Al Marri","doi":"10.1109/RAST.2009.5158224","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158224","url":null,"abstract":"An advanced imaging system was developed for the DubaiSat-1 satellite system, a high-resolution Earth imaging small satellite. The imaging system is designed to produce high-resolution image data of 2.5-m ground sample distance (GSD) in one panchromatic band and 5.0-m GSD in four multi-spectral bands with 20-km swath width. The result from the acceptance test and radiometric and geometric characterization of its flight model is presented and reviewed in this paper together with methodology. Its upgraded version under development is also introduced with its key features and the development status.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132669989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158293
Nila Abolfathi Nobari, A. Novinzade
Reliability evaluation methods are applicable in various engineering fields. A specific method may be used in analyzing and evaluating the reliability in different systems. The Cut and Tie Set Analysis Method is applied to reliability analysis. Cut and Tie Set Analysis Method based on the reliability diagram, a set of minimal elements whose failure results in cutting off all incoming and outgoing routes is studied and thus the system stays operational even when at least one of the elements is still functioning properly. Through the use of this method, one can replace complex system reliability formulae with those that apply to parallel as well as series systems according to the logic behind their operation. This objective was attained by the present work through simultaneous use of this Method and programming done by the Mat Lab software. One needs to have a full grasp of a system in order to evaluate its reliability proficiently. Finally, this paper has come to providing a model of complex node for ADCS, EPS and thermal subsystem in a cube satellite whose life mission is designed to be five consecutive years, which was simplified by the simple network.
可靠性评估方法适用于各个工程领域。在分析和评价不同系统的可靠性时，可以采用特定的方法。将切结集分析法应用于可靠性分析。Cut and Tie Set分析法是基于可靠性图，研究一组最小的元件，其故障导致所有的进出线路被切断，即使至少有一个元件仍然正常工作，系统也能保持运行。通过使用这种方法，人们可以根据其运行背后的逻辑，将复杂的系统可靠性公式替换为适用于并联和串联系统的公式。通过同时使用该方法和Mat Lab软件完成的编程，目前的工作达到了这一目标。为了熟练地评估系统的可靠性，人们需要对系统有一个全面的了解。最后，本文给出了一个连续5年寿命的立方体卫星的ADCS、EPS和热分系统的复杂节点模型，并通过简单网络对模型进行了简化。
{"title":"Calculating the reliability of attitude determination control, electrical power and thermal subsystem in a satellite","authors":"Nila Abolfathi Nobari, A. Novinzade","doi":"10.1109/RAST.2009.5158293","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158293","url":null,"abstract":"Reliability evaluation methods are applicable in various engineering fields. A specific method may be used in analyzing and evaluating the reliability in different systems. The Cut and Tie Set Analysis Method is applied to reliability analysis. Cut and Tie Set Analysis Method based on the reliability diagram, a set of minimal elements whose failure results in cutting off all incoming and outgoing routes is studied and thus the system stays operational even when at least one of the elements is still functioning properly. Through the use of this method, one can replace complex system reliability formulae with those that apply to parallel as well as series systems according to the logic behind their operation. This objective was attained by the present work through simultaneous use of this Method and programming done by the Mat Lab software. One needs to have a full grasp of a system in order to evaluate its reliability proficiently. Finally, this paper has come to providing a model of complex node for ADCS, EPS and thermal subsystem in a cube satellite whose life mission is designed to be five consecutive years, which was simplified by the simple network.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115874688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158268
E. Oland, R. Kristiansen, P. J. Nicklasson
In this paper, two different thruster types are combined into an eight thruster solution for attitude control of a spacecraft. Four electric thrusters and four chemical thrusters are all used to perform slew maneuvers where the chemical thrusters are turned off during fine attitude pointing. The simulations show that a combined thruster solution is more fuel optimal than a chemical thruster system. In addition, it comprises the accuracy of the electric thruster system and at the same time makes it possible to perform slew maneuvers with the speed of the chemical system. This enables a system that does not have to rely on momentum exchange devices for fine attitude pointing and eliminates the requirement for momentum dumping. It is shown that this is a viable solution that can be implemented on spacecrafts with high pointing accuracy requirements.
{"title":"Combined chemical and electric thruster solution for attitude control","authors":"E. Oland, R. Kristiansen, P. J. Nicklasson","doi":"10.1109/RAST.2009.5158268","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158268","url":null,"abstract":"In this paper, two different thruster types are combined into an eight thruster solution for attitude control of a spacecraft. Four electric thrusters and four chemical thrusters are all used to perform slew maneuvers where the chemical thrusters are turned off during fine attitude pointing. The simulations show that a combined thruster solution is more fuel optimal than a chemical thruster system. In addition, it comprises the accuracy of the electric thruster system and at the same time makes it possible to perform slew maneuvers with the speed of the chemical system. This enables a system that does not have to rely on momentum exchange devices for fine attitude pointing and eliminates the requirement for momentum dumping. It is shown that this is a viable solution that can be implemented on spacecrafts with high pointing accuracy requirements.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121565547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158206
B. Sirmaçek, C. Unsalan
Automatic detection of damaged buildings from aerial and satellite images is an important problem for rescue planners and military personnel. In this study, we present a novel approach for automatic detection of damaged buildings in color aerial images. Our method is based on color invariants for building rooftop segmentation. Then, we benefit from grayscale histogram to extract shadow segments. After building verification using shadow information, we define a new damage measure for each building. Experimentally, we show that using our damage measure it is possible to discriminate nearby damaged and undamaged buildings. We present our experimental results on aerial images.
{"title":"Damaged building detection in aerial images using shadow Information","authors":"B. Sirmaçek, C. Unsalan","doi":"10.1109/RAST.2009.5158206","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158206","url":null,"abstract":"Automatic detection of damaged buildings from aerial and satellite images is an important problem for rescue planners and military personnel. In this study, we present a novel approach for automatic detection of damaged buildings in color aerial images. Our method is based on color invariants for building rooftop segmentation. Then, we benefit from grayscale histogram to extract shadow segments. After building verification using shadow information, we define a new damage measure for each building. Experimentally, we show that using our damage measure it is possible to discriminate nearby damaged and undamaged buildings. We present our experimental results on aerial images.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"31 10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116821482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158237
Alper Kaya, M. Kartal
A New Point Scatterer Prediction Model is presented in this paper to predict RCS of an aircraft model using Inverse Synthetic Aperture Radar (ISAR) images of the aircraft.. The ISAR images are provided by Defense Agency of Sweden and Saab inc. for each 15 degrees in horizontal plane. RCS is predicted for each aspect angle by taking superposition of the dominant point scatterers whose locations and strength are calculated from these ISAR images and simulation results are given with measurement results of the same aircraft model.
{"title":"Point Scatterer Model for RCS prediction using ISAR measurements","authors":"Alper Kaya, M. Kartal","doi":"10.1109/RAST.2009.5158237","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158237","url":null,"abstract":"A New Point Scatterer Prediction Model is presented in this paper to predict RCS of an aircraft model using Inverse Synthetic Aperture Radar (ISAR) images of the aircraft.. The ISAR images are provided by Defense Agency of Sweden and Saab inc. for each 15 degrees in horizontal plane. RCS is predicted for each aspect angle by taking superposition of the dominant point scatterers whose locations and strength are calculated from these ISAR images and simulation results are given with measurement results of the same aircraft model.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124755560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158267
S. Brodsky, A. Nebylov, A. Panferov
The statement of problem of optimization of sensors system in the control system of the elastic aerospace vehicle under condition of the stochastic system control design on the base of quadratic performance index is considered. Magnitudes of time-average values of quadratic performance indexes and maximum feasible values of dispersion of estimation of state vector are considered as linear matrix-inequalities-restrictions in the sensor system optimization problem on the base of minimization of offered goal function related with the number, type and accuracy of sensors. The uniqueness of the solution and high performance of the suggested method are typical for the convex programming problems.
{"title":"Application of LMI method for optimization of sensors system for control of nonstationary elastic vehicle","authors":"S. Brodsky, A. Nebylov, A. Panferov","doi":"10.1109/RAST.2009.5158267","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158267","url":null,"abstract":"The statement of problem of optimization of sensors system in the control system of the elastic aerospace vehicle under condition of the stochastic system control design on the base of quadratic performance index is considered. Magnitudes of time-average values of quadratic performance indexes and maximum feasible values of dispersion of estimation of state vector are considered as linear matrix-inequalities-restrictions in the sensor system optimization problem on the base of minimization of offered goal function related with the number, type and accuracy of sensors. The uniqueness of the solution and high performance of the suggested method are typical for the convex programming problems.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128309386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158248
A. Sofyali, Elbrus Caferov
Two small satellite models are selected that are subject to gravity gradient in circular, low-altitude orbits. The second one is passively controlled by a pitch momentum wheel. The aim of this work is to represent how the passive pitch bias momentum method affects the nonlinear attitude dynamics. The analysis is based on phase portraits, Poincaré sections, and time responses. The phase portraits show that there are multiple equilibrium points lying on the Euler angle axes. Global behaviors remind motion about a saddle point located at the origin. The dynamics of the second model seems to have reduced nonlinear characteristics according to corresponding, less attracted motion pattern compared to the pattern for the first model observed in phase portraits and according to scattered points that do not build island-like structures, which is the case for the first model, in Poincaré sections. The time responses obtained using low initial attitude angles indicate that the nonlinear responses of the second model bring stable nonlinear motion to mind whereas the responses of the first model are divergent, so unstable. The pitch momentum wheel induces nutation that leads to high-frequency oscillation besides the low-frequency oscillation.
{"title":"Computational phase portrait analysis of two nonlinear small satellite models","authors":"A. Sofyali, Elbrus Caferov","doi":"10.1109/RAST.2009.5158248","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158248","url":null,"abstract":"Two small satellite models are selected that are subject to gravity gradient in circular, low-altitude orbits. The second one is passively controlled by a pitch momentum wheel. The aim of this work is to represent how the passive pitch bias momentum method affects the nonlinear attitude dynamics. The analysis is based on phase portraits, Poincaré sections, and time responses. The phase portraits show that there are multiple equilibrium points lying on the Euler angle axes. Global behaviors remind motion about a saddle point located at the origin. The dynamics of the second model seems to have reduced nonlinear characteristics according to corresponding, less attracted motion pattern compared to the pattern for the first model observed in phase portraits and according to scattered points that do not build island-like structures, which is the case for the first model, in Poincaré sections. The time responses obtained using low initial attitude angles indicate that the nonlinear responses of the second model bring stable nonlinear motion to mind whereas the responses of the first model are divergent, so unstable. The pitch momentum wheel induces nutation that leads to high-frequency oscillation besides the low-frequency oscillation.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128353294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158243
S. Copuroglu, O. Gultekin, I. Erer
In this work, we consider the spectral estimation of the gapped data encountered in inverse synthetic aperture radar (ISAR) imaging. For the estimation of missing data, we propose the use of Least-Square Lattice (LSL) Filters. The proposed method consists of interpolating the rows of two-dimensional backscattered data, where each row corresponds to the backscattered target data from a specific aspect angle. IFFT processing yields the enhanced spectral estimate of interpolated data. To demonstrate the effectiveness of the proposed algorithm, numerical results based on simulated data are presented.
{"title":"On the use of Least-Squares Lattice structures for missing data in ISAR imaging","authors":"S. Copuroglu, O. Gultekin, I. Erer","doi":"10.1109/RAST.2009.5158243","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158243","url":null,"abstract":"In this work, we consider the spectral estimation of the gapped data encountered in inverse synthetic aperture radar (ISAR) imaging. For the estimation of missing data, we propose the use of Least-Square Lattice (LSL) Filters. The proposed method consists of interpolating the rows of two-dimensional backscattered data, where each row corresponds to the backscattered target data from a specific aspect angle. IFFT processing yields the enhanced spectral estimate of interpolated data. To demonstrate the effectiveness of the proposed algorithm, numerical results based on simulated data are presented.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128359544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158297
O. Shekoofa, M. Taherbaneh
This paper intends to review and analyze the approach of power source sizing, which is an important step in Electrical Power Subsystem (EPS) design, based on change in orbit parameters. There are two main objectives for doing this research: 1) understanding the impacts of the orbital parameters change and the mechanisms of their interactions with the EPS design and operation, 2) evaluation of the importance of their effects. To this end, a typical LEO micro-satellite has been considered in different orbits, to investigate the impacts of variation in the main orbit parameters e.g. altitude and inclination angle. Then the sizing, operation and performance of power sources have been evaluated via comparing the results of in-orbit simulations of EPS operation. In addition, some indirect impacts of the orbit parameters change are evaluated, by analysis and calculation of the interaction between EPS and other subsystems. The results support and show how the sizing and operation of solar array and battery are under the influence of orbit parameters change via certain factors, such as orbit period, duration and the fraction of eclipse/sunlit phases, received solar irradiance by solar panels, and received thermal fluxes from the Sun. According to the acquired results, any altitude increment leads to have better margins in power source sizing but there is an optimum value for inclination angle from this point of view.
{"title":"Power sources sizing in electrical power subsystem design based on orbit parameters change in LEO satellites","authors":"O. Shekoofa, M. Taherbaneh","doi":"10.1109/RAST.2009.5158297","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158297","url":null,"abstract":"This paper intends to review and analyze the approach of power source sizing, which is an important step in Electrical Power Subsystem (EPS) design, based on change in orbit parameters. There are two main objectives for doing this research: 1) understanding the impacts of the orbital parameters change and the mechanisms of their interactions with the EPS design and operation, 2) evaluation of the importance of their effects. To this end, a typical LEO micro-satellite has been considered in different orbits, to investigate the impacts of variation in the main orbit parameters e.g. altitude and inclination angle. Then the sizing, operation and performance of power sources have been evaluated via comparing the results of in-orbit simulations of EPS operation. In addition, some indirect impacts of the orbit parameters change are evaluated, by analysis and calculation of the interaction between EPS and other subsystems. The results support and show how the sizing and operation of solar array and battery are under the influence of orbit parameters change via certain factors, such as orbit period, duration and the fraction of eclipse/sunlit phases, received solar irradiance by solar panels, and received thermal fluxes from the Sun. According to the acquired results, any altitude increment leads to have better margins in power source sizing but there is an optimum value for inclination angle from this point of view.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122715258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158239
Lars K. Alminde, K. Laursen
This paper describes the main problems associated with developing a space technology capacity from scratch using a Cubesat approach. The paper goes on to describe development of the GomSpace-α platform, and how it can help support a strategic capacity building approach in a cost-effective manner with low risk.
{"title":"A strategic approach to developing space capabilities using Cubesat technology","authors":"Lars K. Alminde, K. Laursen","doi":"10.1109/RAST.2009.5158239","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158239","url":null,"abstract":"This paper describes the main problems associated with developing a space technology capacity from scratch using a Cubesat approach. The paper goes on to describe development of the GomSpace-α platform, and how it can help support a strategic capacity building approach in a cost-effective manner with low risk.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"112 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127310389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：