Pub Date : 2009-03-07DOI: 10.1109/AERO.2009.4839638
T. Crockett, M. Powell, K. Shams
The rich variety of unmanned robotics at NASA's Jet Propulsion Laboratory sets the bar for innovations in activity planning. The Operations Planning Team at JPL, co-winner of the NASA Software of the Year award in 2004, is continuously working to enhance the capabilities and user experience for long term and real-time planning operations. Spatial Querying improves the efficiency of planetary surface operations. It can empower scientists by giving them the ability to search for all imagery containing a particular point of interest. Furthermore, these queries can help maximizing the amount of science by reducing the amount of redundant imagery: before planning to acquire new images of a location, planners can check if they already have sufficient data for it. In this paper, we describe our use of R-Trees, along with novel 3D to 2D projections, to delivery spatial querying capabilities to the operators and scientists of MER and MSL mission. Aside from covering the implementation details, we discuss a key aspect of our software: the user interface. To make the interface effective, we stressed low latency and fast computations on the server side to emphasize instant gratification from the user's perspective. Furthermore, we leveraged the interfaces that our customers are already familiar with to make the capability intuitive to utilize.
{"title":"Spatial planning for robotics operations","authors":"T. Crockett, M. Powell, K. Shams","doi":"10.1109/AERO.2009.4839638","DOIUrl":"https://doi.org/10.1109/AERO.2009.4839638","url":null,"abstract":"The rich variety of unmanned robotics at NASA's Jet Propulsion Laboratory sets the bar for innovations in activity planning. The Operations Planning Team at JPL, co-winner of the NASA Software of the Year award in 2004, is continuously working to enhance the capabilities and user experience for long term and real-time planning operations. Spatial Querying improves the efficiency of planetary surface operations. It can empower scientists by giving them the ability to search for all imagery containing a particular point of interest. Furthermore, these queries can help maximizing the amount of science by reducing the amount of redundant imagery: before planning to acquire new images of a location, planners can check if they already have sufficient data for it. In this paper, we describe our use of R-Trees, along with novel 3D to 2D projections, to delivery spatial querying capabilities to the operators and scientists of MER and MSL mission. Aside from covering the implementation details, we discuss a key aspect of our software: the user interface. To make the interface effective, we stressed low latency and fast computations on the server side to emphasize instant gratification from the user's perspective. Furthermore, we leveraged the interfaces that our customers are already familiar with to make the capability intuitive to utilize.","PeriodicalId":117250,"journal":{"name":"2009 IEEE Aerospace conference","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122044242","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 : 2009-03-07DOI: 10.1109/AERO.2009.4839427
R. J. Stamm, M. E. Miller, Joshua Lee, Colin Greenlaw
During the second spiral of Joint Planning and Development Office (JPDO) Network Enabled Operations (NEO) demonstrations, [1] a collaborative environment for Next Generation (NextGen) airspace management was exhibited. New automation and tools were demonstrated that improved airspace management, homeland security and disaster recovery operations in the United States National Airspace System (NAS). This paper reviews the approaches taken to reduce response times and uncertainty during simulated environmental situations and airspace security threats. These capabilities and services were provided to over 12 different decision support, defense and air traffic automation systems used by differing agencies. This paper focuses on Raytheon Company's contributions to NEO.
{"title":"Network-centric operations spiral 1: Enhanced interagency collaboration","authors":"R. J. Stamm, M. E. Miller, Joshua Lee, Colin Greenlaw","doi":"10.1109/AERO.2009.4839427","DOIUrl":"https://doi.org/10.1109/AERO.2009.4839427","url":null,"abstract":"During the second spiral of Joint Planning and Development Office (JPDO) Network Enabled Operations (NEO) demonstrations, [1] a collaborative environment for Next Generation (NextGen) airspace management was exhibited. New automation and tools were demonstrated that improved airspace management, homeland security and disaster recovery operations in the United States National Airspace System (NAS). This paper reviews the approaches taken to reduce response times and uncertainty during simulated environmental situations and airspace security threats. These capabilities and services were provided to over 12 different decision support, defense and air traffic automation systems used by differing agencies. This paper focuses on Raytheon Company's contributions to NEO.","PeriodicalId":117250,"journal":{"name":"2009 IEEE Aerospace conference","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128801360","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 : 2009-03-07DOI: 10.1109/AERO.2009.4839556
I. Yachbes, Roopnarine, S. Sadick, B. Arritt, H. Gardenier
The ORS office has been chartered with developing the architecture that will allow a customized satellite to be designed, produced, deployed, and operational within a matter of days [1]. Every aspect of the spacecraft development process needs to be reassessed in order to achieve this ambitious responsive spacecraft architecture. Assembly, integration & testing could be drastically reduced by stocking component-ready modular panels for assembly., However, the assembly of the structure itself needs to be change from the current process of securing panels with dozens of mixed-size fasteners and the associated verification, tooling, and documentation. Additionally, the new process must take into consideration the need to pass electrical and thermal connections throughout the satellite bus in a time-effective manner. A method for rapidly providing a stiff mechanical attachment across panels of a spacecraft bus while simultaneously providing electrical and thermal continuity would help to realize the goals of ORS. In collaboration with the Air Force Research Laboratory/Space Vehicles Directorate, Honeybee Robotics Spacecraft Mechanisms Corporation has developed a fastening strategy for enabling rapid assembly of a spacecraft bus structure using our patented Quick Insertion Nut (QIN) technology. □□ With this approach, a standard bolt can be rapidly inserted into the QIN and then about one turn is required to preload the connection, without significant support equipment or operator skill. These QINs are embedded in manifolds (the manifold includes panel-to-panel electrical interconnects) that together comprise a skeleton/frame for the spacecraft panels. When the panels are assembled to the manifolds, a robust structural, electrical and thermal connection for the bus is achieved. With this method, it is possible to also quickly disassemble bus panels to swap out faulty components, accommodate upgrades, or support last-minute component changes to satisfy changing mission needs. While the concept is simple, when extrapolated across the multiple fasteners in a typical spacecraft bus (the time for threading of each bolt alone is eight to ten times faster), this results in a revolutionary decrease in the amount of time required for spacecraft assembly. With adequate margin and analysis, it may be possible that time-consuming dedicated system-level analysis and tests could also be eliminated from the AI&T process. View the video of our feasibility demonstration using a subscale prototype at: http://www.honeybeerobotics.com/168/Assembly4.mov - a representative “corner” of three satellite panels assembled using the QIN fasteners, manifold and electrical connection.
{"title":"Rapid assembly of spacecraft structures for responsive space","authors":"I. Yachbes, Roopnarine, S. Sadick, B. Arritt, H. Gardenier","doi":"10.1109/AERO.2009.4839556","DOIUrl":"https://doi.org/10.1109/AERO.2009.4839556","url":null,"abstract":"The ORS office has been chartered with developing the architecture that will allow a customized satellite to be designed, produced, deployed, and operational within a matter of days [1]. Every aspect of the spacecraft development process needs to be reassessed in order to achieve this ambitious responsive spacecraft architecture. Assembly, integration & testing could be drastically reduced by stocking component-ready modular panels for assembly., However, the assembly of the structure itself needs to be change from the current process of securing panels with dozens of mixed-size fasteners and the associated verification, tooling, and documentation. Additionally, the new process must take into consideration the need to pass electrical and thermal connections throughout the satellite bus in a time-effective manner. A method for rapidly providing a stiff mechanical attachment across panels of a spacecraft bus while simultaneously providing electrical and thermal continuity would help to realize the goals of ORS. In collaboration with the Air Force Research Laboratory/Space Vehicles Directorate, Honeybee Robotics Spacecraft Mechanisms Corporation has developed a fastening strategy for enabling rapid assembly of a spacecraft bus structure using our patented Quick Insertion Nut (QIN) technology. □□ With this approach, a standard bolt can be rapidly inserted into the QIN and then about one turn is required to preload the connection, without significant support equipment or operator skill. These QINs are embedded in manifolds (the manifold includes panel-to-panel electrical interconnects) that together comprise a skeleton/frame for the spacecraft panels. When the panels are assembled to the manifolds, a robust structural, electrical and thermal connection for the bus is achieved. With this method, it is possible to also quickly disassemble bus panels to swap out faulty components, accommodate upgrades, or support last-minute component changes to satisfy changing mission needs. While the concept is simple, when extrapolated across the multiple fasteners in a typical spacecraft bus (the time for threading of each bolt alone is eight to ten times faster), this results in a revolutionary decrease in the amount of time required for spacecraft assembly. With adequate margin and analysis, it may be possible that time-consuming dedicated system-level analysis and tests could also be eliminated from the AI&T process. View the video of our feasibility demonstration using a subscale prototype at: http://www.honeybeerobotics.com/168/Assembly4.mov - a representative “corner” of three satellite panels assembled using the QIN fasteners, manifold and electrical connection.","PeriodicalId":117250,"journal":{"name":"2009 IEEE Aerospace conference","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130577147","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 : 2009-03-07DOI: 10.1109/AERO.2009.4839473
Huo Xiujuan, D. Jiahao, Cheng Wushan, Zhou Zhifeng, Sang Huiping
Accurate estimation and compensation of the moving target Doppler shift are essential for the moving target detection of the airborne radar system. In this paper, an algorithm for the real-time estimation and compensation of the moving target Doppler shift due to the moving radar platform and target is presented for the airborne stepped frequency radar system. Under the condition of a small number of sample points, this new algorithm employs the twice compensation method in order to estimate and compensate the mean Doppler shift using high speed DSP based on Doppler FFT processing. Using simulated radar data, the moving target Doppler spectrum is measured and analyzed. The results of simulations show that this new algorithm can reduce the number of sample points and enhance the anti-interfering performance yet still obtain good Doppler estimation and compensation.
{"title":"An adaptive compensation of moving target doppler shift for airborne radar","authors":"Huo Xiujuan, D. Jiahao, Cheng Wushan, Zhou Zhifeng, Sang Huiping","doi":"10.1109/AERO.2009.4839473","DOIUrl":"https://doi.org/10.1109/AERO.2009.4839473","url":null,"abstract":"Accurate estimation and compensation of the moving target Doppler shift are essential for the moving target detection of the airborne radar system. In this paper, an algorithm for the real-time estimation and compensation of the moving target Doppler shift due to the moving radar platform and target is presented for the airborne stepped frequency radar system. Under the condition of a small number of sample points, this new algorithm employs the twice compensation method in order to estimate and compensate the mean Doppler shift using high speed DSP based on Doppler FFT processing. Using simulated radar data, the moving target Doppler spectrum is measured and analyzed. The results of simulations show that this new algorithm can reduce the number of sample points and enhance the anti-interfering performance yet still obtain good Doppler estimation and compensation.","PeriodicalId":117250,"journal":{"name":"2009 IEEE Aerospace conference","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123890256","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 : 2009-03-07DOI: 10.1109/AERO.2009.4839649
D. Allard, C. Edwards
Modern Mars surface missions rely upon orbiting spacecraft to relay communications to and from Earth systems. An important component of this multi-mission relay process is the collection of relay performance statistics supporting strategic trend analysis and tactical anomaly identification and tracking.
{"title":"Development of a relay performance web tool for the Mars network","authors":"D. Allard, C. Edwards","doi":"10.1109/AERO.2009.4839649","DOIUrl":"https://doi.org/10.1109/AERO.2009.4839649","url":null,"abstract":"Modern Mars surface missions rely upon orbiting spacecraft to relay communications to and from Earth systems. An important component of this multi-mission relay process is the collection of relay performance statistics supporting strategic trend analysis and tactical anomaly identification and tracking.","PeriodicalId":117250,"journal":{"name":"2009 IEEE Aerospace conference","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114219328","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 : 2009-03-07DOI: 10.1109/AERO.2009.4839456
Russel P. Kauffman, J. P. Helferty, M. Blattner
Small-target radiometric restoration (STRR) seeks to correct imagery for the blurring effects of the sensor and allow more accurate radiometric values to be extracted. This paper describes an STRR approach suitable for imaging systems whose point-spread functions are known and slowly varying across the image. The approach features a dynamic Wiener filter based on the physical properties of the target and its background. The Wiener filter is constructed based on three inputs: the modulation transfer function (MTF) of the sensor, the estimated target spectrum, and the estimated noise spectrum of the target. The target spectrum is approximated using an estimate of the target-background contrast from the detected image and the geometry of the pixels that approximately define the target. The noise spectrum is obtained from the target radiance in the detected image and the relationship between noise variance and image radiance for the sensor.
{"title":"Dynamic Wiener filters for small-target radiometric restoration","authors":"Russel P. Kauffman, J. P. Helferty, M. Blattner","doi":"10.1109/AERO.2009.4839456","DOIUrl":"https://doi.org/10.1109/AERO.2009.4839456","url":null,"abstract":"Small-target radiometric restoration (STRR) seeks to correct imagery for the blurring effects of the sensor and allow more accurate radiometric values to be extracted. This paper describes an STRR approach suitable for imaging systems whose point-spread functions are known and slowly varying across the image. The approach features a dynamic Wiener filter based on the physical properties of the target and its background. The Wiener filter is constructed based on three inputs: the modulation transfer function (MTF) of the sensor, the estimated target spectrum, and the estimated noise spectrum of the target. The target spectrum is approximated using an estimate of the target-background contrast from the detected image and the geometry of the pixels that approximately define the target. The noise spectrum is obtained from the target radiance in the detected image and the relationship between noise variance and image radiance for the sensor.","PeriodicalId":117250,"journal":{"name":"2009 IEEE Aerospace conference","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114024036","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 : 2009-03-07DOI: 10.1109/AERO.2009.4839420
E. Grayver, Joseph Kim, Jiayu Chen, E. McDonald, A. Utter, J. Hant, David Kun
Next-generation communications satellite constellations will use advanced radio frequency (RF) technologies to provide Internet protocol (IP) packet-switched high-speed backbone transport services for various user communication applications, with ever-increasing traffic demand. These applications range from data services to imagery, voice, video, and other potential emerging applications. Satellite uplinks and downlinks may endure channel impairments that have fades of varying durations due to weather, communications on the move (COTM) blockages, scintillation, terrestrial multipath, or jamming. Satellite payloads and ground terminals must be able to mitigate this wide range of impairments and optimize the use of available spectrum to deliver the highest possible data rates while maintaining a required quality of service (QoS). A suite of mitigation techniques—including channel interleaving and forward error correction (FEC) in the physical layer, dynamic coding and modulation (DCM) and automatic repeat request (ARQ) in the data link layer, and application codec adaptation (ACA) in the application layer—has been proposed for various channel fades. Since each mitigation strategy could potentially interact with another, it is essential not only to assess the performance of each mitigation technique, but also to understand how multiple cross-layer techniques work together. This paper describes an emulation study of channel impairment mitigation using a combination of dynamic modulation (DM), ARQ, and ACA for various channel fades. A real-time emulation test bed was established by integrating Satellite-to-Terminal Real-time Ethernet Configurable Hardware (STRETCH) and SAtellite Link EMulator (SALEM) test beds, both of which are unique capabilities developed in-house at The Aerospace Corporation. STRETCH provides modulation/demodulation, coding, interleaving, and various types of channel fading. SALEM implements a range of mitigation techniques, such as ARQ, DM, and ACA. ARQ retransmissions are triggered in the absence of acknowledgment, DM is invoked upon SNR changes, and ACA is called when the available data rate changes. Results show that DM and ACA successfully mitigate channel fades of longer durations. Faster fades with fluctuating channel gains but a steady SNR average over a given time window do not trigger DM, but endure bit errors and packet drops caused by instantaneous low SNR values. ARQ retransmissions successfully mitigate these types of channel fades. This paper presents descriptions of the test bed architecture, mitigation techniques, test scenarios, and test results.
{"title":"Cross-layer mitigation techniques for channel impairments","authors":"E. Grayver, Joseph Kim, Jiayu Chen, E. McDonald, A. Utter, J. Hant, David Kun","doi":"10.1109/AERO.2009.4839420","DOIUrl":"https://doi.org/10.1109/AERO.2009.4839420","url":null,"abstract":"Next-generation communications satellite constellations will use advanced radio frequency (RF) technologies to provide Internet protocol (IP) packet-switched high-speed backbone transport services for various user communication applications, with ever-increasing traffic demand. These applications range from data services to imagery, voice, video, and other potential emerging applications. Satellite uplinks and downlinks may endure channel impairments that have fades of varying durations due to weather, communications on the move (COTM) blockages, scintillation, terrestrial multipath, or jamming. Satellite payloads and ground terminals must be able to mitigate this wide range of impairments and optimize the use of available spectrum to deliver the highest possible data rates while maintaining a required quality of service (QoS). A suite of mitigation techniques—including channel interleaving and forward error correction (FEC) in the physical layer, dynamic coding and modulation (DCM) and automatic repeat request (ARQ) in the data link layer, and application codec adaptation (ACA) in the application layer—has been proposed for various channel fades. Since each mitigation strategy could potentially interact with another, it is essential not only to assess the performance of each mitigation technique, but also to understand how multiple cross-layer techniques work together. This paper describes an emulation study of channel impairment mitigation using a combination of dynamic modulation (DM), ARQ, and ACA for various channel fades. A real-time emulation test bed was established by integrating Satellite-to-Terminal Real-time Ethernet Configurable Hardware (STRETCH) and SAtellite Link EMulator (SALEM) test beds, both of which are unique capabilities developed in-house at The Aerospace Corporation. STRETCH provides modulation/demodulation, coding, interleaving, and various types of channel fading. SALEM implements a range of mitigation techniques, such as ARQ, DM, and ACA. ARQ retransmissions are triggered in the absence of acknowledgment, DM is invoked upon SNR changes, and ACA is called when the available data rate changes. Results show that DM and ACA successfully mitigate channel fades of longer durations. Faster fades with fluctuating channel gains but a steady SNR average over a given time window do not trigger DM, but endure bit errors and packet drops caused by instantaneous low SNR values. ARQ retransmissions successfully mitigate these types of channel fades. This paper presents descriptions of the test bed architecture, mitigation techniques, test scenarios, and test results.","PeriodicalId":117250,"journal":{"name":"2009 IEEE Aerospace conference","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127725164","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 : 2009-03-07DOI: 10.1109/AERO.2009.4839433
B. Jau, M. Badescu, R. Goullioud, B. Trease, Z. Chang, J. Carson, D. Braun, B. Cook
The paper describes the Siderostats (SID) of the Space Interferometry Mission (SIM) that is being developed at JPL. The description focuses on the generic design for the SIDs, having a 336 mm diameter mirror with a double corner cube at the mirror's vertex. Mirror positioning is controlled by single stage linear actuators (no fine stage). The mirror's 8° dual axis tip/tilt rotation is enabled through sets of hexfoil flexures. The entire SID configuration is described, key requirements listed, and results from preliminary analyses mentioned. Design details, positioning and sensing capabilities, as well as results from an actuator life test, are presented.
{"title":"The space interferometer siderostats","authors":"B. Jau, M. Badescu, R. Goullioud, B. Trease, Z. Chang, J. Carson, D. Braun, B. Cook","doi":"10.1109/AERO.2009.4839433","DOIUrl":"https://doi.org/10.1109/AERO.2009.4839433","url":null,"abstract":"The paper describes the Siderostats (SID) of the Space Interferometry Mission (SIM) that is being developed at JPL. The description focuses on the generic design for the SIDs, having a 336 mm diameter mirror with a double corner cube at the mirror's vertex. Mirror positioning is controlled by single stage linear actuators (no fine stage). The mirror's 8° dual axis tip/tilt rotation is enabled through sets of hexfoil flexures. The entire SID configuration is described, key requirements listed, and results from preliminary analyses mentioned. Design details, positioning and sensing capabilities, as well as results from an actuator life test, are presented.","PeriodicalId":117250,"journal":{"name":"2009 IEEE Aerospace conference","volume":"PP 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126528159","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 : 2009-03-07DOI: 10.1109/AERO.2009.4839623
T. Kurtoglu, David Jensen, S. Poll
Automated health management is a critical functionality for complex aerospace systems. A wide variety of diagnostic algorithms have been developed to address this technical challenge. Unfortunately, the lack of support to perform large-scale V&V (verification and validation) of diagnostic technologies continues to create barriers to effective development and deployment of such algorithms for aerospace vehicles. In this paper, we describe a formal framework developed for benchmarking of diagnostic technologies. The diagnosed system is the Advanced Diagnostics and Prognostics Testbed (ADAPT), a real-world electrical power system (EPS), developed and maintained at the NASA Ames Research Center. The benchmarking approach provides a systematic, empirical basis to the testing of diagnostic software and is used to provide performance assessment for different diagnostic algorithms.
{"title":"Systematic benchmarking of diagnostic technologies for an electrical power system","authors":"T. Kurtoglu, David Jensen, S. Poll","doi":"10.1109/AERO.2009.4839623","DOIUrl":"https://doi.org/10.1109/AERO.2009.4839623","url":null,"abstract":"Automated health management is a critical functionality for complex aerospace systems. A wide variety of diagnostic algorithms have been developed to address this technical challenge. Unfortunately, the lack of support to perform large-scale V&V (verification and validation) of diagnostic technologies continues to create barriers to effective development and deployment of such algorithms for aerospace vehicles. In this paper, we describe a formal framework developed for benchmarking of diagnostic technologies. The diagnosed system is the Advanced Diagnostics and Prognostics Testbed (ADAPT), a real-world electrical power system (EPS), developed and maintained at the NASA Ames Research Center. The benchmarking approach provides a systematic, empirical basis to the testing of diagnostic software and is used to provide performance assessment for different diagnostic algorithms.","PeriodicalId":117250,"journal":{"name":"2009 IEEE Aerospace conference","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125659183","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 : 2009-03-07DOI: 10.1109/AERO.2009.4839409
W. Hsieh, Chieh-Fu Chang, M. Kao
In satellite communications, the footprint is characterized by contour lines with specific receiving power. When data is delivered to the area within a specific footprint, called the designated footprint, illegal users outside the boundary of designated footprint (BDF) can still receive the signal with degraded power. In other words, illegal users can obtain the transmitted data with higher error probability. In this paper, we present a special two-stage serially concatenated (2-SC) coding scheme to more precisely define the designated footprint. Hence users outside the BDF are excluded from obtaining the data, i.e. they cannot correctly decode the data. The key technique, 2-SC coding scheme, achieves the brick-wall effect in error performance regarding bit energy-to-noise density ratio ( Eb / N0 ). The brick-wall effect has sharp cutoff at a critical Eb / N0 . When the transmitted data is protected by the 2-SC coding scheme, only the users within the designated footprint can successfully decode the data. Otherwise, for users outside the BDF with received Eb / N0 slightly less than critical Eb / N0 , even if the coding structure is known, they cannot correctly decode the data. Thus the BDF is sharply defined by the critical Eb / N0 . Moreover, by means of purposely-introduced error in the codewords, we can adjust the critical Eb / N0 and the BDF. We provide comprehensive analysis of the coding performance and further discuss the application of the proposed scheme to enhance secure satellite communications.
{"title":"An approach attaining adjustable designated footprint","authors":"W. Hsieh, Chieh-Fu Chang, M. Kao","doi":"10.1109/AERO.2009.4839409","DOIUrl":"https://doi.org/10.1109/AERO.2009.4839409","url":null,"abstract":"In satellite communications, the footprint is characterized by contour lines with specific receiving power. When data is delivered to the area within a specific footprint, called the designated footprint, illegal users outside the boundary of designated footprint (BDF) can still receive the signal with degraded power. In other words, illegal users can obtain the transmitted data with higher error probability. In this paper, we present a special two-stage serially concatenated (2-SC) coding scheme to more precisely define the designated footprint. Hence users outside the BDF are excluded from obtaining the data, i.e. they cannot correctly decode the data. The key technique, 2-SC coding scheme, achieves the brick-wall effect in error performance regarding bit energy-to-noise density ratio ( Eb / N0 ). The brick-wall effect has sharp cutoff at a critical Eb / N0 . When the transmitted data is protected by the 2-SC coding scheme, only the users within the designated footprint can successfully decode the data. Otherwise, for users outside the BDF with received Eb / N0 slightly less than critical Eb / N0 , even if the coding structure is known, they cannot correctly decode the data. Thus the BDF is sharply defined by the critical Eb / N0 . Moreover, by means of purposely-introduced error in the codewords, we can adjust the critical Eb / N0 and the BDF. We provide comprehensive analysis of the coding performance and further discuss the application of the proposed scheme to enhance secure satellite communications.","PeriodicalId":117250,"journal":{"name":"2009 IEEE Aerospace conference","volume":"14 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125760778","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}
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