• Generating Spread-Spectrum Sequences by a Class of Chaotic Maps

      Chengquan, Au; Tingxian, Zhou; Yuxiang, Yang; Harbin Institute of Technology (International Foundation for Telemetering, 2001-10)
      Based on the fact that two topological conjugacy chaotic maps have identical dynamical behaviors, this paper proposes a method generating spreadspectrum sequences by creating chaotic maps topological conjugacy to Kent- Map, and analyses the correlation properties of the chaotic spread-spectrum sequences. The results of simulation verified the correctness of the theoretical analysis.
    • Auto-tracking antenna pattern effects on multipath channel model at test range

      Sung-hoon, Jang; Sung-hee, Han; Heung-bum, Kim; Agency for Defense Development (International Foundation for Telemetering, 2001-10)
      Telemetry propagation channel is modeled to predict PCM/FM telemetry receiving signal level at APG(Anheung Proving Ground), ADD(Agency for Defense Development). Channel model is composed of direct wave and reflected wave in sea surface, so-called 2-ray model. Our 2-ray model includes transmitting antenna radiation pattern, auto-tracking antenna radiation pattern, sea surface reflection coefficient and phase depending on incident angle. Vertical and horizontal polarized receiving signal strength is obtained from pre-calculated flight trajectory of transmitter. Calculated results are compared with measured data in real flight test. 2-ray channel model can predict almost identical receiving signal level and calculate starting point of multi-path fading effect. Using these results, receiving system can be moved to more proper position before flight test.
    • Enhancement of Advanced Range Telemetry (ARTM) Channels via Blind Equalization

      Ye, Zhong; Satorius, Edgar H.; Jedrey, Thomas C.; Temple, Kip; California Institute of Technology; Edwards Air Force Base (International Foundation for Telemetering, 2001-10)
      The Joint Services Advanced Range Telemetry (ARTM) Program at Edwards Air Force Base has been evaluating FQPSK-B for possible upgrades to the existing telemetry equipment. It has been found in the wideband channel sounding experiments sponsored by ARTM that the in-flight fading channel can be modeled as a 3-ray multipath channel[1]. Delay spread for a typical in-flight channel is in the order of 300 nanoseconds. Furthermore, the pre-flight channel is characterized by much more severe multipath, in which the delay spread is in the order of microseconds covering one or more symbols when the FQPSK-B transceiver operates at a rate of millions of symbols per second. This adverse channel condition inevitably causes tremendous distortion in the received signals due to severe inter-symbol interference (ISI) from the multipath. This paper provides an assessment of the potential ability of blind equalization to reduce the FQPSK-B system susceptibility to degradation caused by dynamic frequency selective fading in the aeronautical telemetry environment. In particular, a blind equalizer applique that can be inserted prior to the demodulator without knowledge of the received signal such as carrier frequency, symbol timing and sequence, etc, is proposed. Since it is desired that the equalizer applique operate independently of the carrier frequency and given that the modulation of interest is constant envelope (PCM-FM or FQPSKB), we have selected the constant modulus algorithm (CMA)[2] cost function for implementation. Extensive tests on both simulated and recorded FQPSK-B data transmitted over different ARTM channels have been conducted and the blind equalizer structure has shown substantial improvements, even on the difficult ARTM pre-flight channels. The CMA adapts the equalizer coefficients to minimize the deviation of the output envelope from an arbitrary constant level. This paper depicts the pre-flight and in-flight channel conditions using time and spectral domain measurement. It quantifies the benefit of the blind CMA tapped delay line equalizer. Due to the extensive signal processing requirements associated with the very high sampling rate (100 MHz) of the FQPSK-B system, hardware implementation complexity is very high. Complexity reduction issues regarding the implementation of the CMA using Field Programmable Gate Array (FPGA) will also be presented.
    • PYROTECHNIC SHOCK AND RANDOM VIBRATION EFFECTS ON CRYSTAL OSCILLATORS

      Carwell, James W.; CMC Electronics Cincinnati (International Foundation for Telemetering, 2001-10)
      Today’s telemetry specifications are requiring electronic systems to not only survive, but operate through severe dynamic environments. Pyrotechnic shock and Random Vibration are among these environments and have proven to be a challenge for systems that rely on highly stable, low phase noise signal sources. This paper will mathematically analyze how Pyrotechnic shock and Random Vibration events deteriorate the phase noise of crystal oscillators (XO).
    • Precious Bits: Frame Synchronization in Jet Propulsion Laboratory's Advanced Multi-Mission Operations System (AMMOS)

      Wilson, Elizabeth (Betsy); Jet Propulsion Laboratory (International Foundation for Telemetering, 2001-10)
      The Jet Propulsion Laboratory’s (JPL) Advanced Multi-Mission Operations System (AMMOS) system processes data received from deep-space spacecraft, where error rates are high, bit rates are low, and every bit is precious. Frame synchronization and data extraction as performed by AMMOS enhance data acquisition and reliability for maximum data return and validity. Unique aspects of data phase determination, sync acquisition and sync loss and other bit-level topics are covered.
    • A SMALL SATELLITE FOR MEASURING ATMOSPHERIC WATER CONTENT; PART II, CROSSLINK AND DATA COLLECTION

      Schooley, L. C.; Hittle, K.; Braga, A.; Ackerman, R.; Afouni, F.; Khalid, H.; Coleman, J.; Keena, T.; Page, A.; University of Arizona (International Foundation for Telemetering, 2001-10)
      This student paper was produced as part of the team design competition in the University of Arizona course ECE 485, Radiowaves and Telemetry. It describes a telemetering system design recommendation for a small satellite capable of conducting scientific research regarding atmospheric water content. This paper focuses on the cross-link subsystem required to make the scientific measurements and on the power generation and distribution subsystem for the satellite. A companion paper (Cramer, et. al.) focuses on the subsystems required to send the scientific data and monitored operational conditions from the satellite to, and commands to the satellite from, a ground station. The central objective is to validate a new technique for precisely measuring water vapor profiles of clouds throughout the troposphere. This method involves the detection of 4 SHF tones sent out from the International Space Station (ISS), providing high-resolution amplitude and phase delay data.
    • LESSONS LEARNED AND PROCESS IMPROVEMENT FOR PAYLOAD OPERATIONS AT THE LAUNCH SITE

      Catena, John; Gates, Donald, Jr.; Blaney, Kermit, Jr.; National Aeronautics and Space Administration; Omitron, Inc. (International Foundation for Telemetering, 2001-10)
      For every space mission, there are challenges with the launch site/field operations process that are addressed too late in the development cycle. This potentially causes schedule delays, cost overruns, and adds risk to the mission success. This paper will discuss how a single interface, representing the payload at the launch site in all phases of development, will mitigate risk, and minimize or even alleviate potential problems later on. Experience has shown that a single interface between the project and the launch site allows for issues to be worked in a timely manner and bridges the gap between two diverse cultures.
    • THE ART OF INTERNATIONAL SPACE STATION TELEMETRY BANDWIDTH MANAGEMENT

      Cerna, Peter J.; Klein, Pamela R.; Mullett, Joy; National Aeronautics and Space Administration; United Space Alliance; Hernandez Engineering, Inc. (International Foundation for Telemetering, 2001-10)
      The technicalities of sharing telemetry bandwidth have been addressed in design and specification for the builders of the International Space Station. But success in sharing bandwidth comes from building relationships, documenting guidelines, negotiating, understanding human nature, peer review and willingness to participate in an evolving process. The station, 240 miles above Earth, moves through space at 17,000 mph, has its mass added to by humans and machines, regularly docks with visiting spacecraft, has year-round residents, and communicates with space agencies around the globe. Each new module -- with associated computers, multiplexers, and communications buses -- creates additional telemetry demands.
    • REENGINEERING A TRADITONAL SPACECRAFT CONTROL CENTER

      Knauer, Christian; Nötzel, Klaus Ralf; CAM GmbH; Deutsche Telekom AG (International Foundation for Telemetering, 2001-10)
      Deutsche Telekom is operating various communication satellites since 1989. The SCC (spacecraft control center) is located near Frankfurt / Germany. The entire system is based on antenna/RF equipment, baseband and computer software packages running on a computer network of different machines. Due to increased maintenance effort the old baseband system needed to be replaced. This also had effects to the computer system, especially to the M&C. The aim was to design the entire system in a way that the operation effort in costs aspects and human intervention are minimized. This paper shows the successful real world project of reengineering a traditional spacecraft control center (SCC). It is shown how a fifteen year old hardware (baseband system) and software design was replaced by a modern concept during normal operations. The new software packages execute all necessary tasks for spacecraft- and ground station control. The Monitor and Control System (M&C) is a database driven design (FRAMTEC, from CAM Germany).
    • SENSATE-LINER EPLRS TELEMETERED DATA INPUT FOR ENCOMPASS

      Lind, Eric J.; Murray, Steve; Stevens, Ilya; Drozdowski, Nick; SPAWARSYSCEN; High Technology Systems Inc. (International Foundation for Telemetering, 2001-10)
      A systems engineering development for acquisition, transmission, processing, dissemination and display of information vital to combat casualty care and related first responder activities is presented. It utilizes a synergistic combination of two existing state-of-the-art Defense Advanced Research Projects Agency/Space and Naval Warfare Systems Center San Diego (DARPA/SSCSD) technologies (Sensate-Liner and ENCOMPASS) coupled via the Enhanced Position Location Reporting System (EPLRS), an existing wireless military tactical communication data system. Transmission Security and Communication Security (TRANSEC/COMMSEC) of environmental and biomedical data is thus accomplished from the battlefield via selected data links and Ethernet. System functionality and appropriate candidate interfacing technologies will be discussed.
    • SYNTHETIC APERTURE GROUND PENETRATING RADAR IMAGING FOR NONDESTRUCTIVE EVALUATION OF CIVIL AND GEOPHYSICAL STRUCTURES

      Brown, Andrew; Lee, Hua; University of California Santa Barbara (International Foundation for Telemetering, 2001-10)
      Synthetic-aperture microwave imaging with ground penetrating radar systems has become a research topic of great importance for the potential applications in sensing and profiling of civil and geophysical structures. It allows us to visualize subsurface structures for nondestructive evaluation with microwave tomographic images. This paper provides an overview of the research program, ranging from the formation of the concepts, physical and mathematical modeling, formulation and development of the image reconstruction algorithms, laboratory experiments, and full-scale field tests.
    • SERVING INTERACTIVE WEB PAGES TO TechSat21 CUSTOMERS

      Self, Lance; Kirtland Air Force Base (International Foundation for Telemetering, 2001-10)
      TechSat21 is an innovative satellite program sponsored by the Air Force Research Laboratory Space Vehicles Directorate and the Air Force Office of Scientific Research. Its mission is to control a cluster of satellites that, when combined, create a “virtual satellite” with which to conduct various experiments in sparse aperture sensing and formation flying. Because TechSat21 customers have a need to view very large data sets that vary from the payload to the satellite state of health1 a modern viewing method using Java Server Pages and Active Server Pages is being developed to meet these interactive dynamic demands.
    • APPLYING INTERACTIVE WEB PAGES

      Self, Lance; Kirtland Air Force Base (International Foundation for Telemetering, 2001-10)
      Visitors to web pages are, in most cases, restricted to viewing information the page designer has anticipated they will be interested in viewing. Many times this is adequate, but there are instances where the visitor wants the information they view to be based on selections they choose. The Air Force Research Laboratory (AFRL) Space Vehicles Directorate anticipates selected customers will have a need to view very large data sets that vary from the satellite payload to the satellite state of health1, and will require controlling what they view in an “ad hoc” manner. In response, AFRL is using Java Server Pages developed within the data center to bring interactive and dynamic web page content to these customers.
    • VIDEO COMPRESSION DECK FOR A MODULAR FLIGHT PCM ENCODER SYSTEM

      Gammill, Troy; Stoner, Mark; New Mexico State University (International Foundation for Telemetering, 2001-10)
      Overview of video compression modules developed and flown as part of PSL’s flight-proven family of modular PCM components. Wavelet based video compression deck is compatible with PCM Encoder modules, allowing video to be included in instrumentation data stream. Video compression modules allow the user to select video frame rate and video quality, supports 8-16 bits/word, and non-symmetrical PCM matrices. Video Compression and formatting is achieved with a wavelet compression IC and specialized DSP code. Video output is achieved with PSL PCM Decommutator and Video Decompression Module.
    • Real-Time High Resolution Digital Video for Range and Training Applications

      Mason, Andy; Gills, Steve; AP Labs (International Foundation for Telemetering, 2001-10)
      The operator interface to a modern radar, sonar or weapons system trainer (WST) is typically one or more high-resolution video displays driven by PC’s or other workstations. The training system used to instruct and qualify operators for this type of mission critical application should be capable of recording RGB video data to a fine level of detail. Similarly, ground stations for Research, Development, Test and Evaluation (RDT&E) and Operational Test & Evaluation (OT&E) applications often utilize high-resolution workstation screens to display critical test data. And often, these workstation screens are located in mobile vans, on aircraft, or are otherwise remote from test conductors who need access to the same screen data. This paper presents a solution for the efficient digitization, storage, replay, and transmission of the data displayed on the high-resolution workstation screens commonly found in these types of training system applications.
    • MAGNETIC ROLL SENSOR FOR ROLLING AIRFRAMES

      Meyer, Steven; Naval Air Warfare Center Weapons Division (International Foundation for Telemetering, 2001-10)
      Measuring the roll rate or roll position of a rolling airframe can be difficult. Some of the smaller missiles, which have roll rates in excess of 20 revolutions per second, have the least amount of room for a roll sensor such as a laser ring gyro or a quartz rate sensor. The large roll rates coupled with the rate sensor’s resolution can cause large errors in just a few seconds. The cost for these devices can be very high. The roll problem on rolling airframes has been solved by using two magnetic sensors that are 90 degrees out of phase from each other to measure the roll. The cost of the sensor is approximately $15 and is packaged in a 20-pin-surface-mount device. This paper addresses the design and the data processing algorithm to produce roll position. The sensor and algorithm were checked for accuracy on a CARCO table.
    • USING COMMERCIAL-OFF-THE-SHELF (COTS) PRODUCTS IN THE DESIGN OF MISSILE FLIGHT-QUALIFIED HARDWARE

      Kujiraoka, Scott R.; Naval Air Warfare Center Weapons Division (International Foundation for Telemetering, 2001-10)
      During these times of acquisition reform in the federal government, various missile systems are being forced into using Commercial-off-the-Shelf (COTS) products in the design of their subsystems. However one problem that this presents is the lack of configuration management. There is a concern that the manufacturer will modify the product without informing the end user. This may have a severe effect on the performance of an already flight qualified subsystem. An example of how one program is dealing with this issue will be discussed.
    • CONCEPTUAL DESIGN OF CENTIMETER ACCURACY LOCAL POSITIONING SYSTEM

      Annamraju, Venu; Kosbar, Kurt; University of Missouri – Rolla (International Foundation for Telemetering, 2001-10)
      This project investigates the feasibility of position detection in an office or industrial setting. The objective is to design a low-cost positioning system that uses the unlicensed 5.7 GHz ISM band, with centimeter accuracy and limited range. During the conceptual design phase of the system, indoor channel models will be investigated to determine which of a variety of architectures will be useful. For triangulating the position, an array of widely spaced stationary receivers and a mobile transmitter is proposed.
    • A Technical Study on Microwave FM Locked in Phase of Telemetry Transmitters

      Banghua, Zhou; Shiwei, Xiao; Xinan Electronic Institute (International Foundation for Telemetering, 2001-10)
      This paper describes techniques on the microwave FM locked in phase of transmitters in the reentry telemetry system. A few scheme configurations on the microwave FM locked in phase, its circuit characteristics and applications are analyzed. Research results show that the two-point injection microwave FM locked in phase is suitable for the telemetry system, which code rate is higher, band of wide, and modulation response very well.
    • Multi-Gbps 16-QAM All-Digital Parallel Receiver

      Gray, Andrew; Ghuman, Parminder; Hoy, Scott; California Institute of Technology; National Aeronautics Space Adminstration (International Foundation for Telemetering, 2001-10)
      Due to rapidly increasing downlink data rates between spacecraft and ground stations, the National Aeronautics and Space Administration (NASA) has developed an all-digital variable data rate receiver. The majority of the receiver is implemented on a single complementary metal oxide semiconductor (CMOS) application specific integrated circuit (ASIC) that is capable of processing data rates in excess of 300 mega-symbols per second or 600 mega-bits per second (Mbps) using quadrature phase-shift keyed (QPSK) modulation [1-5]. Developed jointly by the Goddard Space Flight Center and the Jet Propulsion Laboratory, the high rate digital demodulator (HRDD) ASIC uses parallel processing algorithms, which combined we call the advanced parallel receiver architecture (APRX), to perform the necessary functions of a satellite communications receiver. An overview of the next generation of the advanced parallel receiver architecture (APRX) is presented here, including a new parallel adaptive equalizer currently being implemented. The next generation receiver implementing this architecture will process in excess of 600 Megasymbols per second; the ASIC will process in excess of 1.2 Gbps using quadrature amplitude modulation (QPSK) and 2.4 Gbps using 16-quadrature amplitude modulation (QAM). The majority of the functions of the receiver are performed in the next generation high rate digital demodulator ASIC. A key property of such high data rate wireless communications systems is the use bandwidth efficient modulations often achieved through the use of sophisticated pulseshaping. The next generation ASIC, like the current generation ASIC, is designed to have programmable matched filters. The detection/matched filter bank in the ASIC should be programmed to “match” the received pulse-shape. This is particularly important for good biterror- rate performance in systems employing higher order modulations, such as 16-QAM employing partial-response pulse-shaping spanning many symbols. Such bandwidth efficient pulse-shaping methods require many coefficients in the matched filter; this creates increased computation and complexity in the receiver. Often such ideal receivers are not practical or possible to implement, and sub-optimal detection filtering techniques must be used. We will demonstrate that the use of a sub-optimum or truncated matched filter in some systems introduces severe intersymbol interference (ISI) distortion that results in poor BER results. However, we demonstrate for a specific pulse-shaped 16-QAM that if the demodulated baseband symbols are processed with a relatively simple equalizer very good performance may be achieved. The overall system complexity of such a system may be much lower than implementing the true matched filter [6]. Finally we present an overview of the next generation advanced parallel receiver (APRX) capable of demodulating such pulse-shaped 16-QAM that includes a novel parallel adaptive equalizer.