Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011最新文献

{"title":"Deviation iterating approach for transfer orbit design with J2 perturbation","authors":"Hong-bo Zhang, W. Zheng, G. Tang","doi":"10.1109/RAST.2011.5966835","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966835","url":null,"abstract":"Referring to the process of shooting algorithm, this paper advances a new analytical method named deviation iterating approach to design transfer orbits when J2 perturbation is taken into account. The convergence of the approach is analyzed theoretically, and the transfer angle equals π is found to be a singularity. After being verified by numerical studies, the singularity is discussed again from the uniqueness of the solution of motion equations, and two treatments are proposed for practical space missions. The deviation iterating approach calculates almost analytically and converges rapidly, resulting in a great decrease in computing time. The procedure could perform well with an onboard processor, and hence can facilitate the implementation of on-line tasks, such as explicit guidance and onboard path programming.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114482298","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}

{"title":"Novel experience with the implementation of the ESA standards into the cleanroom PCB manufacturing process","authors":"Marek Šimčák","doi":"10.1109/RAST.2011.5966946","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966946","url":null,"abstract":"This paper focuses on the fundamental aspects of the small series printed-circuit board (PCB) manufacturing process related to the space electronics flight hardware. The main emphasis is laid especially on presenting the selected own in-house expert solutions that have been proposed and finally implemented to resolve all the specific technological problems. The space electronics PCB production where manual soldering is applied can be considered as an exemplary technological area where correct and precise implementation of the specific PCB assembly procedures conforming to the ESA approved standards, called ECSS-Q-ST-xx, is the key important issue.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"172 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116144104","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}

{"title":"Complete electrical model and simulation of a medium size satellite","authors":"M. A. Kaya, M. Bayrakceken","doi":"10.1109/RAST.2011.5966892","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966892","url":null,"abstract":"Aiming on the requirement of generating an accurate electrical model of a medium size satellite, the software created for this paper provides a complete simulation of a medium to bigger size satellites. The components include system design and solidification of a generic solar array, distribution system, backup battery system, load analysis system and a complete thermal model for the battery and solar array. The software includes solar cell to solar array relations, bypass systems, imbalance in array wings, array power generation and shunting model, battery charge and discharge model and a load profile. Load profile is a data stream fed into the computer including illumination or eclipse data. All cell/array/battery features are highly realistic and database or graph modeled. Initial process begins with identification of peak and average power requirements. Given the bus voltage, single cell open circuit voltage and short circuit current, the software calculates number of cells per block, number of blocks per string, number of parallel strings per circuit and number of circuits for the satellite. According to the load profile which includes the day/night flag the battery is either charged or discharged. During daylight, power is used to run the system requirements and charge the battery. Excess power is calculated and shunted. On the other hand, during darkness, the panels provide no power. The only power source is the battery. Therefore the simulation needs to have an accurate battery model for both charge and discharge features. Battery function includes slow and fast charge rates, and is a complex function of various inputs. Since the whole simulation is heavily dependent on temperature, the system also includes a built in model for thermal cooling. The motive in this study was to precisely model and simulate the complete electrical function of a satellite. An accurate model and simulation of the actual system greatly helps the design process. The goal is fulfilled utilization of the simulation during the design process of the actual satellite. Also the fast and reliable simulation allows us to take measure to adapt to environmental and internal changes.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115285231","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}

{"title":"International cooperation among space-faring countries of Africa","authors":"O. N. John, Isiaku N. Alfa, E. Eguaroje","doi":"10.1109/RAST.2011.5966962","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966962","url":null,"abstract":"The early years of space exploration were years of rivalry, panic and determination. Today, the question of having “a chance of beating the Soviets by putting a laboratory in space” or “any other space program which promises dramatic result in which we could win”, has passed on. The cooperative efforts of nations in the construction and operation of the International Space Station finally put an end to national ambition of states in space exploration. Emphasis is now on international cooperation and collaboration in journeys to the Moon, Mars and other destinations in the solar system. However, a question that needs to be asked is, “to what extent do the space-faring countries of Africa collaborate and cooperate among themselves and/or with other technologically developed nations of the world in the exploration and development of the space frontiers?” This work traces briefly the history of space exploration, dwelling more on “space age” and “space race”. It discusses international cooperation drawing emphasis from the United Nations Charter and other documents dwelling on international cooperation. It further talks about the benefits of international cooperation, using the International Space Station as a case study. It then focuses on the space programs of the space-faring and developing countries of Africa and the need for them to collaborate and cooperate among themselves and with other technologically developed nations of the world. It ends with a conclusion and some recommendations.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"174 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115474909","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}

{"title":"Impact of discharge chamber geometry on characteristics of a low-power Hall thruster","authors":"S. Mazouffre, K. Dannenmayer, G. Bourgeois, A. Lejeune, M. Guyot, S. Denise, P. Renaudin, V. Cagan","doi":"10.1109/RAST.2011.5966939","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966939","url":null,"abstract":"A 200 W permanent-magnet Hall thruster - named PPI for “Petit Propulseur Innovant” - has been operated with xenon for three values of the channel width. The mean channel diameter, the channel length and the magnetic field topology stay fixed. Series of experiments have been carried out for each geometry over a broad set of propellant mass flow rates and applied voltages to investigate the impact of a channel width variation on discharge properties. The ion current was measured in the plume far field by means of a planar Faraday probe. The equilibrium temperature of inner and outer Al2O3 channel walls was determined by means of calibrated thermal imaging. Finally, the ion velocity was measured by laser-induced fluorescence spectroscopy at 834 nm along the channel centerline.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125431498","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}

{"title":"Research of equilibrium-glide guidance method based on the generalized reference-trajectory","authors":"Jun Liu, Ke-jun Chen, G. Tang","doi":"10.1109/RAST.2011.5966841","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966841","url":null,"abstract":"A new equilibrium-glide guidance method based on the generalized reference-trajectory was proposed for the glide phase of high lift-to-drag radio entry vehicles considering all path constrains. The 3DOF dynamic equations of high lift-to-drag radio entry vehicles were established, and the path constraints were specified. Then, the principle of the guidance method was explained in detail. At the same time, the basic guidance law was designed, and its longitudinal parameter was set by using the LQR (linear quadratic regular) method. Finally, the feasibility of this method was analyzed by emulation mode. Comparing from the former re-entry guidance method, the new guidance method adjusts the trajectory by the change of angle of attack, and the bank angle profile was small in the glide phase. The obtained results show that, the new guidance method can satisfy the glide guidance requirement of high lift-to-drag radio entry vehicles.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125544694","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}

{"title":"Communication link improvement through antenna optimization for satellite, space, and radio astronomy systems","authors":"O. Kilic, V. Dang, A. Zaghloul","doi":"10.1109/RAST.2011.5966866","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966866","url":null,"abstract":"This paper studies the concept of improving the satellite link quality by optimizing the pattern of the receive antenna on board the satellite and at the ground terminal to reduce the antenna temperature. Accurate antenna temperature is calculated by accounting for the temperature difference between land and water bodies in the antenna coverage. The optimization process works on the antenna aperture distribution taking into account the temperature distribution in the antenna pattern. Similar concepts can be used for space and radio astronomy applications.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129410374","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}

{"title":"Automatic crowd analysis from airborne images","authors":"B. Sirmaçek, P. Reinartz","doi":"10.1109/RAST.2011.5966803","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966803","url":null,"abstract":"Recently automatic detection of people and crowded areas from images became a very important research field, since it can provide crucial information especially for police departments and crisis management teams. Detection of crowd and measuring the density of people can prevent possible accidents or unpleasant conditions to appear. Understanding behavioral dynamics of large people groups can also help to estimate future states of underground passages, shopping center like public entrances, or streets which can also affect the traffic. In order to bring a solution to this problem, herein we propose a novel approach using airborne images. Although their resolutions are not enough to see each person in detail, we can still notice a change of color components in the place where a person exists. Therefore, we propose a color feature detection based probabilistic framework. First, we extract local features from invariant chroma bands of the image. Extracted local features behave as observations of the probability density function (pdf) of the crowd to be estimated. Using an adaptive kernel density estimation method, we estimate the corresponding pdf. The estimated pdf gives information about crowded regions, and also helps to extract quantitative measures about them. Our experimental results show that the proposed approach can provide crucial information to police departments and crisis management teams to achieve more detailed observations of crowds to prevent possible accidents or unpleasant conditions in robust and fast manner.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128531989","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}

{"title":"Research of multi-restriction energy management of solid rocket","authors":"Luhua Liu, Ke-jun Chen, G. Tang","doi":"10.1109/RAST.2011.5966839","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966839","url":null,"abstract":"In order to implement depleted shutdown and improve guidance precision in launching process of a solid rocket, the trajectory energy management approaches should be studied. First, the rocket inserting trajectory problem is described. The real velocity and the required velocity calculating model are given. Second, under the multi-restriction conditions, the spline energy management model is given. Third, required velocity is parameterized by a B-spline function. Take required velocity function to initial conditions, terminal conditions and process conditions, the energy management problem can be solved by an optimum approach. The optimum trajectory can be followed up with trajectory tracking control approach, and make the velocity vector track the required velocity vector. The simulation results show that the terminal and process restrictions are met.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124670557","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}

{"title":"Synthetic aperture radar feature selection for dual polarized ScanSAR data","authors":"N. G. Kasapoglu","doi":"10.1109/RAST.2011.5966858","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966858","url":null,"abstract":"Synthetic aperture radar (SAR) ScanSAR data has advantages on oceanographic remote sensing applications regarding its large coverage and sufficient resolution. However terrestrial downlink bandwidth is limited and therefore up to dual polarized (e.g., HH and HV) ScanSAR data can be achieved today's spaceborn systems (e.g., RadarSAT-2). In this study grey level co-occurrence matrix was employed to extract SAR features for both HH and HV channels. Additionally some of band math products such as HH/HV and HH-HV were used as candidate SAR features. Selection of optimum SAR features is crucial and application dependent. In this study, selection strategies based on SAR data assimilation was introduced and relation of conventional separability criterions on SAR data assimilation and pattern recognition were discussed.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130604358","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}