Browsing International Telemetering Conference Proceedings, Volume 36 (2000) by Title
Now showing items 1-20 of 114
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800 Mbps TELEMETRY PROCESSING SYSTEMSatellites are becoming more capable and complex, as such their downlink requirements are increasing. In addition, future satellite systems will be operating at Ka-band that provides ample bandwidth to support the increase in downlink rates up to 800 Mbps. This paper describes a new generation commercial solution that can support 800 Mbps telemetry processing for data reception, frame synchronization, time tagging, Reed-Solomon forward error correction, data routing, data storage, data playback for testing, networking, and Bit Error Rate (BER) Testing.
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ADAPS TELEMETRY PROCESSOR MID-LIFE IMPROVEMENT PROGRAMThis paper will provide details on planned upgrades to the Advanced Data Acquisition and Processing System (ADAPS) Real-Time / Post Flight Processing (RT/PFP) telemetry processor. The ADAPS RT/PFP is used to process real-time telemetry at the Air Force Flight Test Center (AFFTC). The ADAPS telemetry processor is based on the L3 Communications O/S90 telemetry pre-processing system. New modifications to the ADAPS telemetry processor will provide increased processing capability, increased data throughput, and higher reliability.
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ADAPTIVE EQUALIZATION FOR OQPSK THROUGH A FREQUENCY SELECTIVE FADING CHANNELSpectral sidelobes of QPSK, OQPSK, IJF-OQPSK, and SQAM modulated signals after nonlinear amplification are compared. It is known that OQPSK has lower spectral sidelobes than QPSK. However, in the presence of frequency selective fading, a decision-feedback adaptive equalizer is able to equalize the QPSK signal but not the OQPSK signal. By using phase pre-distortion on the OQPSK waveform before nonlinear amplification, not only is the adaptive equalizer able to equalize this signal, its spectral sidelobes are also reduced. Simulations are presented to confirm these results.
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Advanced Range Telemetry (ARTM) Systems Integration at Edwards AFBThis paper describes the integration effort of ARTM systems into the existing telemetry infrastructure at the Air Force Flight Test Center (AFFTC) at Edwards AFB, California. This paper will also discuss the framework of the ARTM integration effort, which includes defining user requirements, integration approach, management approach, procurement, test and evaluation, and coordination with the ARTM Joint Program Office (JPO). Interoperability with existing equipment and with other ranges will also be discussed. ARTM is a Central Test and Evaluation Investment Program (CTEIP) under the Office of the Secretary of Defense, Undersecretary for Acquisition and Technology whose purpose is to improve the efficiency of spectrum usage. As the ARTM program approaches completion, integration efforts are underway to take advantage of the capabilities developed by the ARTM program. This integration effort brings the Test and Evaluation (T&E) community at Edwards AFB a step closer to realizing solutions to a variety of telemetering challenges including the shrinking frequency spectrum, demand for higher data rates, and the need to maintain the current level of commonality and interoperability between Major Range and Test Facility Bases (MRTFB).
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ADVANCED SUBMINIATURE TELEMETRY: A NEXT GENERATION INSTRUMENTATION SYSTEMIn performing its mission, the Air Force SEEK EAGLE Office (AFSEO) conducts a wide variety of tests with heavy emphasis on open-air flight tests. As budget pressures drive a reduction in the number of test sorties, maximizing the amount of quality data from each flight test is of paramount importance. This paper describes an AFSEO effort to develop a low cost, intelligent, subminiature telemetry and sensor system based on modern commercial wireless technologies. The instrumentation system is completely self-contained and can be externally mounted, thus eliminating the requirement for extensive aircraft modifications and minimizing the need for specially instrumented test aircraft. The system will make maximum use of Commercial Off The Shelf (COTS) components to reduce cost and insure availability. MicroElectroMechanical Systems (MEMS) technology will be incorporated as the technology matures.
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ADVANCED TELEMETRY PROCESSING AND DISPLAY SYSTEM (ATPDS)This paper describes a PC-based Advanced Telemetry Processing and Display System (ATPDS)- a highend, real-time telemetry processing and display system implemented on a COTS PC platform. for A network-centric architecture was chosen from candidate architectures as the most viable for the ATPDS. The network-centric architecture is Windows NT-based, client/server based, supporting clients and servers on both local or remote PC workstations. The architecture supports distributing processing loads across multiple workstations, optimizing mission processing requirements. The advantage of this system is its flexibility and expandability with low acquisition and life-cycle support costs. The ATPDS allows the user to configure one or more small systems into a larger high-end system based on varying mission requirements.
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AFFORDABLE, ALTERNATIVE TEST METHOD FOR MEETING CIVIL AVIATION REDUCED VERTICAL SEPARATION MINIMUM (RVSM) REQUIRMENTS ON MILITARY/COMMERCIAL AIRCRAFTA recent Air Traffic Management (ATM) initiative has reduced certain oceanic routes from a 2,000-foot vertical separation minimum to a 1,000-foot (300 m) separation minimum between flight levels of 29,000 feet and 41,000 feet. As a result of this initiative, an aircraft transitioning from the Continental United States (CONUS) to Europe or Asia will be required to have a validated, certified altimeter reporting system within the specified tolerances. The aging military airframes are not currently Reduced Vertical Separation Minimum (RVSM) certified. The impact on military deployment time to foreign theatres as well as high- fuel cost makes this a high-priority DoD issue. This paper describes the test and evaluation (T&E) challenge, viable solutions and test method for meeting the RVSM requirements in an approved, affordable, and least down-time (minimal aircraft modification) manner. The test method described herein utilizes a PACER aircraft in formation with the RVSM candidate aircraft. The RVSM is just one of the many Global Air Traffic Management (GATM) requirements which must be met for military aircraft to fly within premium airspace during overseas deployment. The commercial equivalent of GATM is Communications Navigation and Surveillance/Air Traffic Management (CNS/ATM). Our focus will be on meeting the RVSM certification requirements as related to the test environment.
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AIR TRAFFIC CONTROL COMMUNICATIONS TEST FACILITY AND AVIONICS SYSTEM TEST (ACTFAST): GEARING UP FOR NEXT GENERATION AVIONICS SYSTEMS TESTINGGrowth in civil aviation is overwhelming worldwide airspace and air traffic services. The International Civil Aviation Organization (ICAO), Federal Aviation Administration (FAA) and Department of Defense (DoD) are proposing or implementing numerous changes to address this growth. The changes are broadly contained in what the civil aviation community calls Communication, Navigation, and Surveillance/Air Traffic Management (CNS/ATM) and the DoD calls Global Air Traffic Management (GATM). A major component of both civil and DoD proposed changes are data link systems digitally transmitting information between aircraft, air traffic control centers, and aircraft operations centers. The real-time interactive nature of these data-link systems and the integration of the aircraft avionics into a worldwide network are forcing aircraft test agencies to acquire access to this capability. Aircraft flighttesting must address both the specific aircraft avionics test requirements and the system-of-systems aspects of data-link applications. This paper describes the factors driving changes in the worldwide CNS/ATM system and identifies specific proposed or implemented changes. Various flight-test requirements, both civil and military, of the proposed changes are enumerated. Particular attention is paid to the DoDs GATM certification requirements. Finally, we present the Air Traffic Control Communications Test Facility and Avionics System Test (ACTFAST) program and explain its capabilities. Rationale for ACTFAST component parts is included along with a brief outline of how the capabilities represented by each component part are used during flight test to acquire the necessary information to meet civil and DoD aircraft certification requirements.
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ANTENNA CONTROL FOR TT&C ANTENNA SYSTEMSA thinned array sensor system develops error voltages for steering dish antennas from signals arriving over a broad range of angles, thereby eliminating need for a priori knowledge of signal location.
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APPLICATION OF INTRUSION DETECTION SOFTWARE TO PROTECT TELEMETRY DATA IN OPEN NETWORKED COMPUTER ENVIRONMENTS.Over the past few years models for Internet based sharing and selling of telemetry data have been presented [1] [2] [3] at ITC conferences. A key element of these sharing/selling architectures was security. This element was needed to insure that information was not compromised while in transit or to insure particular parties had a legitimate right to access the telemetry data. While the software managing the telemetry data needs to be security conscious, the networked computer hosting the telemetry data to be shared or sold also needs to be resistant to compromise. Intrusion Detection Systems (IDS) may be used to help identify and protect computers from malicious attacks in which data can be compromised.
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THE APPLICATION OF MAP MATCHING METHOD IN GPS/INS INTEGRATED NAVIGATION SYSTEMMap matching method plays an important role in vehicle location and navigation systems. It employs the information in a digital map to compensate the positioning error. This paper presents a fuzzy-logic-based probabilistic map-matching algorithm used in GPS/INS integrated navigation systems, in which the reliability degree of map matching resolution is given explicitly as the decision basis in selecting matching road segment by utilizing the fuzzy comprehensive judgement. The results of experimental simulations have shown that the system performance gained significant enhancement by introducing this algorithm.
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AUTOMATIC TOOLS FOR TELEMETRY TEST RANGE SPECTRUM MANAGEMENTAutomatic spectrum management and monitoring systems are very useful to manage frequencies at test ranges and assure interference-free transmission of telemetry signals. Spectrum management systems assign telemetry frequencies using database information on available and occupied channels and analysis tools which can determine whether a data link will support telemetry. Modern, DSP-based spectrum monitoring systems, in fixed or mobile configurations, automate the process of performing spectrum occupancy to verify clear channels and identify and locate sources of interference; they are integrated with and utilize the management system database. Such systems are important to assure reliable communications channels for telemetry.
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BACKWARD PROPAGATION BASED ALGORITHMS FOR HIGH-PERFORMANCE IMAGE FORMATIONIn this paper, we present the recent results of theoretical development and software implementation of a complete collection of high-performance image reconstruction algorithms designed for high-resolution imaging for various data acquisition configurations.
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BANDWIDTH EFFICIENCY AND BER PERFORMANCE OF ENHANCED AND FEC CODED FQPSKBit error rate (BER) and bandwidth efficiency of several variations of enhanced Feher patented quadrature phase shift keying (FQPSK) [1] are described. An enhanced FQPSK increases the channel packing density of that of the IRIG 106-00 standardized FQPSK-B by approximately 50% in adjacent channel interference (ACI) environment. As the bandwidth efficiency of FQPSK-B DOUBLES (2×) that of pulse code modulation/Frequency modulation (PCM/FM) [5], the enhanced FQPSK, with a simpler transceiver than FQPSK-B, has a channel packing density of TRIPLE (3×) that of PCM/FM. One of the other enhanced FQPSK prototypes has an end to end system loss of only 0.4 dB at BER=1x10^(-3) and 0.5 dB at BER=1x10^(-4) from ideal linearly amplified QPSK theory. The enhanced FQPSK has a simple architecture, thus is inexpensive and has small size, for ultra high bit rate implementation. With low redundancy forward error correction (FEC) coding which expands the spectrum by approximately 10%, further improvement of about 3-4.5dB E N b o is attained with NLA FQPSK-B and enhanced FQPSK at BER=1x10^(-5) .
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BIT ERROR PERFORMANCE ANALYSIS OF BPSK IN THE PRESENCE OF MULTIPATH FADINGThe presence of multipath fading has been shown to degrade the performance of a wireless channel. This paper quantifies the effects of multipath interference on signal performance based on the estimated parameters of the multipath signal. Theoretical results are compared with actual results obtained through the Advanced Range Telemetry (ARTM) program.
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CDMA SATELLITE MOBILE COMMUNICATION SYSTEM MULTI-SIGNAL RECEIVING AND SOFTWARE IMPLEMENTATIONThis paper presents one new type CDMA multi-signal receiving protocol, which is suitable for satellite mobile communication systems. Then it gives the principle analysis and describes the realization of this protocol. Meanwhile, it gives the software protocol implementation scheme. From the long point of view, it will more increase the system flexibility, which is easier to update; and will solve the interoperability and integration application problems. Finally, the simulation results conclude that software implementation of CDMA multi-signal receiving in satellite mobile communication system is feasible, and it may be used in other wireless communication systems.
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CODED OFDM FOR AERONAUTICAL TELEMETRYThree Quadrature Phase Shift Keying (QPSK) mapped COFDM systems demonstrating a continuum of complexity levels are simulated over an evolving three ray model of the multipath fading channel with parameters interpolated from actual channel sounding experiments. The first COFDM system uses coherent QPSK and convolutional coding with interleaving in frequency, channel equalization and soft decision decoding; the second uses convolutional coding with interleaving in frequency, Differential Phase Shift Keying (DPSK) and soft decision decoding; the third system uses a quaternary BCH code with DPSK mapping and Error and Erasure Decoding (EED). All three systems are shown to be able to provide reliable data communication during frequency selective fade events. Simulations demonstrate QPSK mapped COFDM with reasonable complexity performs well in a multipath frequency selective fading environment under parameters typically encountered in aeronautical telemetry.
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A COMMERCIAL CCSDS TELECOMMAND PROCESSORAfter a slow start, the CCSDS Telecommand Recommendation is finally being embraced by a large number of NASA, ESA and NASDA space missions. Even some commercial satellites are exploring the possibility of using this advanced protocol. The CCSDS Telecommand is a closed-loop space communication protocol that offers its users a guaranteed data delivery service, which is essential for the satellite control operations. This paper describes a commercial product that supports the CCSDS Telecommand protocol. This product provides Telecommand uplink segmentation, transfer, coding and physical layer services and Command Operations Procedures (COP). Optionally, it provides corresponding functions at the receiving end for command link verification.
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A COMMERCIAL OFF THE SHELF CONTINUOUSLY TUNABLE HIGH DATA RATE SATELLITE RECEIVERTSI TelSys, Inc. is in the process of developing a production level, continuously tunable satellite receiver designed to support multiple high data rate, low earth and geostationary orbit missions in the 20 Mbps to 800 Mbps composite QPSK data rate range. This paper will evaluate market demands on satellite receivers and outline receiver design technique as a solution to high rate, multi-mission support.
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A COMPARISON OF METHODS FOR MEASUREMENT OF PRESSURE IN HYDRAULIC LINESThis presentation summarizes a study characterizing strain gages and pressure transducers used to measure the fluid pressure within aircraft hydraulic lines. A series of laboratory calibrations and finite element analyses was performed to demonstrate the quality of data from both pressure transducers and strain gages under variations in both temperature and external strains on the hydraulic lines. Strain gages showed a marked susceptibility to external strains on hydraulic lines, and wide variations in susceptibility to temperature changes. Pressure transducers were found to be relatively immune to both conditions. It is recommended that strain gages be used for trend data only.