2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)最新文献

{"title":"A study of near to far fields of JPL Deep Space Network (DSN) antennas for RFI analysis","authors":"V. Jamnejad","doi":"10.1109/AERO.2004.1367698","DOIUrl":"https://doi.org/10.1109/AERO.2004.1367698","url":null,"abstract":"This paper addresses the issue of calculating the gain and power distribution of DSN antennas in the Fresnel (middle zone) and Fraunhofer (far zone) as a function of the distance from the DSN antenna and the off-boresight angle. Calculating the near and mid fields of DSN antennas are of interest in the receive mode where the transmitting signals from nearby flying objects such as helicopters and airplanes transmitting in the DSN frequency range, interfere with the operation of sensitive RF receiving system of the DSN antennas, and in the transmit mode where fields from high-powered DSN antennas interfere with receivers on nearby flying objects such as helicopters or other systems. Computing the exact fields of a large DSN antenna is, in general, a very complicated and arduous task. Even far-field calculations, which are less complicated compared to near and mid zone fields, take considerable computer time. These calculations become even more involved and time-consuming in very near field and back field regions. We provide two approaches for addressing the radio frequency interference (RFI) issue. In this paper, actual fields in mid and far zones are calculated using a relatively simple formulation that is accurate enough for the purposes of RFI analysis. In a future paper, we study and develop simple reference models that provide upper limit bounds or envelopes of the far field patterns as a function of the antenna diameter and frequency, which can be used for obtaining the field at any given point in space.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123417109","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":"Aviation application over IPv6: performance issues","authors":"V. Srivastava, C. Wargo, S. Lai","doi":"10.1109/AERO.2004.1367941","DOIUrl":"https://doi.org/10.1109/AERO.2004.1367941","url":null,"abstract":"Aviation industries in United States and in Europe are undergoing a major paradigm shift in the introduction of new network technologies. In the US, NASA is also actively investigating the feasibility of IPv6 based networks for the aviation needs of the United States. In Europe, the Eurocontrol lead, Internet protocol for aviation exchange (iPAX) Working Group is actively investigating the various ways of migrating the aviation authorities backbone infrastructure from X.25 based networks to an IPv6 based network. For the last 15 years, the global aviation community has pursued the development and implementation of an industry-specific set of communications standards known as the aeronautical telecommunications network (ATN). These standards are now beginning to affect the emerging military global air traffic management (GATM) community as well as the commercial air transport community. Efforts are continuing to gain a full understanding of the differences and similarities between ATN and Internet architectures as related to communications, navigation, and surveillance (CNS) infrastructure choices. This research paper describes the implementation of the IPv6 testbed at Computer Networks & Software, Inc. and it's interface connection mechanism to Eurocontrol and NASA's (Cleveland) testbed in the first phase of the project. In the second phase this research work investigates the performance issues of aviation applications such as controller to pilot data link communication (CPDLC), on an IPv6 based backbone network. Aviation applications are grouped into different priority levels. Desired quality of service (QoS) to each priority level is implemented via Diffserv implementation. This research work looks into the possibility of providing similar QoS performance for aviation application in an IPv6 network as is provided in an ATN based network. The testbed consists of three autonomous systems. The autonomous system represents CNS domain, NASA domain and a EUROCONTROL domain. The primary mode of connection between CNS IPv6 testbed and NASA and EUROCONTROL IPv6 testbed is initially a set of IPv6 over IPv4 tunnels. The aviation application under test (CPDLC) consists of two processes running on different IPv6 enabled machines. These processes communicate with each other over the IPv6 network. One machine resides on the CNS portion of the testbed and other may reside in NASA (Cleveland) and/or in Eurocontrol. The IPv6 packets between Eurocontrol, NASA and CNS testbeds would be carried on IPv6 over IPv4 tunnels. We present some results, which suggest that IPv6 QoS has matured enough, so as to provide the QoS service, which is similar in capability to die ATN architecture. We implemented three basic priorities of flow: (1) command & control; (2) surveillance; and (3) general traffic. Various parameters like throughput, packet loss and delay are investigated. The results are analyzed to get a conceptual view of the effect of IPv6 based network on the aviatio","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125355578","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":"XTCE: a standard XML-schema for describing mission operations databases","authors":"G. Simon, E. Shaya, K. Rice, S. Cooper, J. Dunham, J. Champion","doi":"10.1109/AERO.2004.1368138","DOIUrl":"https://doi.org/10.1109/AERO.2004.1368138","url":null,"abstract":"The Object Management Group (OMG) has recently ratified the XML Telemetry and Telecommand Exchange (XTCE) as a standard means to describe the format of telemetry and telecommand data for mission operations. It is meant as a direct replacement for proprietary formats found in mission operations software. The goal of the specification is to provide for an easy means of exchanging this information between the organizations that build, test, deploy and manage spacecraft missions, and to increase the software choices for customers in the mission operations center. This work describes the genesis and design of XTCE by the original authors of the specification, and gives examples using both TDM and packet style (CCSDS) telemetry and commands. It also discusses current prototyping efforts being performed by NASA-GSFC, ESA, Lockheed Martin (AF, Colorado Springs) and others.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116584124","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":"Applying the authority-activity model to the New Millennium Program's technology selection cycle","authors":"M. Bergman, M. Buehler","doi":"10.1109/AERO.2004.1367611","DOIUrl":"https://doi.org/10.1109/AERO.2004.1367611","url":null,"abstract":"The New Millennium Program (NMP) has been validating new flight technology for eight years. Recently, a field study of how the NMP selected technology for flight validation was performed. One result of the study is that the NMP employed an authority-activity model in making its selections. This explanatory model showed how the NMP blended three different levels of authority power (organizational, project, technical) with three different primary activities (design, sensemaking, negotiation) to perform their process. In this report, we present the authority-activity model in detail. Then, we apply the model to four different stages of the selection process to illustrate how it 1) explains and captures the processes undertaken in these stages and 2) detects possible deficiencies in the execution or outcomes of these processes that demand attention. We assert that the authority-activity model is a useful analytic tool which can improve the selection process of complex, widely diverse, highly competitive systems.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122683336","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":"The RF telecommunications system for the New Horizons mission to Pluto","authors":"C. Deboy, C. Haskins, T. A. Brown, R. Schulze, M. Bernacik, J. R. Jensen, W. Millard, D. Duven, S. Hill","doi":"10.1109/AERO.2004.1367922","DOIUrl":"https://doi.org/10.1109/AERO.2004.1367922","url":null,"abstract":"This work describes the design and development of the RF telecommunications system for the New Horizons mission, NASA's planned mission to Pluto. The system includes an advanced, low-power digital receiver, and a card-based transceiver implemented within an integrated electronics module. An ultrastable oscillator (USO) provides the precision frequency reference necessary for the uplink radio science experiment. The 2.1 meter high gain antenna is the primary communications antenna, with medium gain and low gain antennas used for wider beamwidths during early operations, cruise-phase and sun-pointing mission phases. The paper will discuss the salient aspects of the system design, including design drivers from mission operations, science, and spacecraft considerations. It will also detail individual subsystems1 performance, operational modes (including beacon mode operation), and navigation technology, including the first deep-space flight implementation of regenerative ranging.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122641022","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":"Detecting heavy metals in solution using electronic-tongue 3 REDOX water quality sensors","authors":"G. Kuhlman, D. Keymeulen, M. Buehler, S. Kounaves","doi":"10.1109/AERO.2004.1367620","DOIUrl":"https://doi.org/10.1109/AERO.2004.1367620","url":null,"abstract":"This paper describes results obtained from the E-Tongue 3 apparatus used to characterize residual contaminates in water. This apparatus is intended for use in water quality measurements for the ISS (International Space Station). The apparatus contains nine planar electrochemical cells and a conductivity sensor. Detection of contaminate ions in solution uses ASV (anodic stripping voltammetry) with a detection limit in the 10 /spl mu/M range. A linear calibration curve was achieved using Zn, Pb, Cu, and Mn cations. A robust method for identifying electroactive species is presented and uses the Savitzky-Golay second derivative method.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"186 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122650891","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":"Nanotube memories for space applications","authors":"M. Lovellette, A. Campbell, H. Hughes, R.K. Lawerence, J. Ward, M. Meinhold, T.R. Bengtson, G.F. Carleton, B. Segal, T. Rueckes","doi":"10.1109/AERO.2004.1368024","DOIUrl":"https://doi.org/10.1109/AERO.2004.1368024","url":null,"abstract":"The radiation hardness characteristics of nano-electromechanical single-walled carbon nanotube (SWNT) memory elements has been studied. The NRAM bits have been exposed to 100 krad, 1 Mrad and 10 Mrad of gamma-radiation. Initial test results indicate that NRAM is an extremely radiation hard memory.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122177732","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":"Improved downward-looking terrain database integrity monitor and terrain navigation","authors":"A. Vadlamani, M. U. de Haag","doi":"10.1109/AERO.2004.1367934","DOIUrl":"https://doi.org/10.1109/AERO.2004.1367934","url":null,"abstract":"Terrain database integrity monitors and terrain referenced navigation systems are both based on performing a comparison between stored terrain elevation data and data obtained from airborne sensors such as radar altimeters, inertial measurement units (IMUs), Global Positioning System (GPS) receivers etc. The concept of consistency checking as used for the integrity monitor function originated from terrain referenced navigation systems. This paper discusses the extension to a previously proposed method of improving the performance of a spatial integrity monitor for terrain elevation databases. Furthermore, this paper discusses an improvement of the terrain-referenced aircraft position estimation for aircraft navigation using only the information from downward-looking sensors, GPS and the terrain databases, and not the information from the IMU. Horizontal failures have been characterized based on the sensed terrain information. Kalman filter methods have been designed to achieve the integrity monitor and terrain navigation performance improvements. The performance of the proposed position estimator and integrity monitor is evaluated using flight test data from NASA's flight trials at Eagle/Vail (EGE), CO and Ohio University's flight trials at Albany (KUNI), OH, Asheville (AVL), NC, and Juneau (JNU), AK.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116872621","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":"A technology program that rescues spacecraft","authors":"L. Deutsch, J. Lesh","doi":"10.1109/AERO.2004.1367918","DOIUrl":"https://doi.org/10.1109/AERO.2004.1367918","url":null,"abstract":"There has never been a long-duration deep space mission that did not have unexpected problems during operations. JPL's Interplanetary Network Directorate (IND) Technology Program was created to develop new and improved methods of communication, navigation, and operations. A side benefit of the program is that it maintains a cadre of human talent and experimental systems that can be brought to bear on unexpected problems that may occur during mission operations. Solutions fall into four categories: applying new technology during operations to enhance science performance, developing new operational strategies, providing domain experts to help find solutions, and providing special facilities to trouble-shoot problems. These are illustrated here using five specific examples of spacecraft anomalies that have been solved using, at least in part, expertise or facilities from the IND Technology Program: Mariner 10, Voyager, Galileo, SOHO, and Cassini/Huygens. In this era of careful cost management, and emphasis on returns-on-investment, it is important to recognize this crucial additional benefit from such technology program investments.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128299009","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":"Essential autonomous science inference on rovers (EASIR)","authors":"T. Roush","doi":"10.1109/AERO.2004.1367680","DOIUrl":"https://doi.org/10.1109/AERO.2004.1367680","url":null,"abstract":"Existing constraints on time, computational, and communication resources associated with Mars rover missions suggest on-board science evaluation of sensor data can contribute to decreasing human-directed operational planning, optimizing returned science data volumes, and recognition of unique or novel data, all of which act to increase the scientific return from a mission. Many different levels of science autonomy exist and each impacts the data collected and returned by, and activities of, rovers. Several computational algorithms, designed to recognize objects of interest to geologists and biologists, are discussed. The algorithms represent various functions producing scientific opinions and several scenarios illustrate how the opinions can be used.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128640282","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}