• “DATA DIGITIZING UNIT” ELIMINATES THE NEED FOR ANALOG RECORDERS

      Bougan, Timothy B.; Science Applications International Corporation (International Foundation for Telemetering, 1996-10)
      Today’s telemetry environment is becoming increasingly digital. Highly reliable and relatively inexpensive digital recorders readily available, and most telemetry facilities are migrating away from the older analog recorders which are difficult to calibrate and expensive to maintain. Unfortunately, most site managers find they still have one or more “legacy” signals (such as FM-FM, PAM, and pre-detect PCM) that still require analog recording. To exclusively use digital recorders the TM site must integrate some device to convert the analog signals to digital format before recording. Until recently, the TM site managers had very few options short of building custom equipment to convert and capture the legacy signals. One solution available from Racal (for their Storeplex digital recorder) is to purchase their Analog Record/Play Signal Module. Unfortunately, their module uses a 16-bit Sigma-Delta converter and has a maximum bandwidth of 45.5 KHz, which is woefully inadequate for many analog signals. Other manufacturers offer similar solutions with similar bandwidth restrictions. Another solution is to purchase a multiplexor “front-end” which is capable of mixing multiple signal types (both digital and analog) on to the recorder’s serial-digital data stream. This option can provide higher analog bandwidths, but represents a significant investment (greater than $100K and often more than the recorder itself). This paper discusses the conceptualization, design, and performance of a unit to fill the gap between the low-bandwidth analog channel module and the high-end signal multiplexors. We will discuss how high-speed field-programmable gate arrays (FPGAs) can be configured to provide a low-cost interface between the digital recorder and the analog-to-digital converters (ADCs) and digital-to-analog converters (DACs) to capture and playback the analog signals. Our design focuses on achieving the maximum possible bandwidth for each analog signal while ensuring that IRIG-A or IRIG-B timecode are recorded simultaneously (so the analog signals can be later synchronized with their digital counterparts). We have found that such a solution permits multiple analog signals from 400 KHz up to 3 MHz to be easily and inexpensively recorded on the current generation of digital recorders. Our conclusions show that such a device can permit most telemetry sites to transition completely to more reliable, cheaper, and easier-to-maintain digital recorders.
    • SAINT-EX Système d'Analyse INteractif de Tracé et d'EXploitation A Test Data Analysis Tool Based on FX+

      Pureur, Michel; DASSAULT-AVIATION (International Foundation for Telemetering, 1996-10)
      A sophisticated human interface can be developed for Post flight analysis with the technology of UNIX-MOTIF. Tests and measurements demand performance and reliability. SAINT-EX can meet these requirements. This paper describes the results of an appraoch in the development of DASSAULT AVIATION’s SAINT-EX software.
    • DESIGNING AN ANTENNA/PEDESTAL FOR TRACKING LEO AND MEO IMAGING SATELLITES

      Turner, W. C.; Electro-Magnetic Processes, Inc. (International Foundation for Telemetering, 1996-10)
      This paper takes one through the processes followed by a designer when responding to a specification for an earth terminal. The orbital parameters of Low-Earth Orbiting and Medium-Earth Orbiting (LEO and MEO) satellites that affect autotracking and pointing of an antenna are presented. The do’s and don’ts of specifying (or over specifying) the antenna feed and pedestal size are discussed. The axis velocity and acceleration rates required of a Y over X and El over AZ type pedestal are developed as a function of satellite altitude, radio frequency of operation, and ground antenna terminal diameter. Decision criteria are presented leading to requiring a tilt mechanism or a third axis to cover direct and near overhead passes using an El over Az pedestal. Finally, the expressions transforming Y over X configuration position angles to azimuth and elevation axis position angles are presented.
    • ANTENNA PATTERN EVALUATION FOR LINK ANALYSIS

      Pedroza, Moises; White Sands Missile Range (International Foundation for Telemetering, 1996-10)
      The use of high bit rates in the missile testing environment requires that the receiving telemetry system(s) have the correct signal margin for no PCM bit errors. This requirement plus the fact that the use of “redundant systems” are no longer considered optimum support scenarios has made it necessary to select the minimum number of tracking sites that will gather the data with the required signal margin. A very basic link analysis can be made by using the maximum and minimum gain values from the transmitting antenna pattern. Another way of evaluating the transmitting antenna gain is to base the gain on the highest percentile appearance of the highest gain value. This paper discusses the mathematical analysis the WSMR Telemetry Branch uses to determine the signal margin resulting from a radiating source along a nominal trajectory. The mathematical analysis calculates the missile aspect angles (Theta, Phi, and Alpha) to the telemetry tracking system that yields the transmitting antenna gain. The gain is obtained from the Antenna Radiation Distribution Table (ARDT) that is stored in a computer file. An entire trajectory can be evaluated for signal margin before an actual flight. The expected signal strength level can be compared to the actual signal strength level from the flight. This information can be used to evaluate any plume effects.
    • TRACKING RECEIVER NOISE BANDWIDTH SELECTION

      Pedroza, Moises; White Sands Missile Range (International Foundation for Telemetering, 1996-10)
      The selection of the Intermediate Frequency (IF) bandwidth filter for a data receiver for processing PCM data is based on using a peak deviation of 0.35 times the bit rate. The optimum IF bandwidth filter is equal to the bit rate. An IF bandwidth filter of 1.5 times the bit rate degrades the data by approximately 0.7 dB. The selection of the IF bandwidth filter for tracking receivers is based on the narrowest “noise bandwidth” that will yield the best system sensitivity. In some cases the noise bandwidth of the tracking receiver is the same as the IF bandwidth of the data receiver because it is the same receiver. If this is the case, the PCM bit rate determines the IF bandwidth and establishes the system sensitivity. With increasing bit rates and increased transmitter stability characteristics, the IF bandwidth filter selection criteria for a tracking receiver must include system sensitivity considerations. The tracking receiver IF bandwidth filter selection criteria should also be based on the narrowest IF bandwidth that will not cause the tracking errors to be masked by high bit rates and alter the pedestal dynamic response. This paper describes a selection criteria for a tracking receiver IF bandwidth filter based on measurements of the tracking error signals versus antenna pedestal dynamic response. Different IF bandwidth filters for low and high bit rates were used.
    • Midcourse Space Experiment Spacecraft and Ground Segment Telemetry Design and Implementation

      DeBoy, Christopher C.; Schwartz, Paul D.; Huebschman, Richard K.; The Johns Hopkins University (International Foundation for Telemetering, 1996-10)
      This paper reviews the performance requirements that provided the baseline for development of the onboard data system, RF transmission system, and ground segment receiving system of the Midcourse Space Experiment (MSX) spacecraft. The onboard Command and Data Handling (C&DH) System was designed to support the high data outputs of the three imaging sensor systems onboard the spacecraft and the requirement for large volumes of data storage. Because of the high data rates, it was necessary to construct a dedicated X-band ground receiver system at The Johns Hopkins University Applied Physics Laboratory (APL) and implement a tape recorder system for recording and downlinking sensor and spacecraft data. The system uses two onboard tape recorders to provide redundancy and backup capabilities. The storage capability of each tape recorder is 54 gigabits. The MSX C&DH System can record data at 25 Mbps or 5 Mbps. To meet the redundancy requirements of the high-priority experiments, the data can also be recorded in parallel on both tape recorders. To provide longer onboard recording, the data can also be recorded serially on the two recorders. The reproduce (playback) mode is at 25 Mbps. A unique requirement of the C&DH System is to multiplex and commutate the different output rates of the sensors and housekeeping signals into a common data stream for recording. The system also supports 1-Mbps real-time sensor data and 16-kbps real-time housekeeping data transmission to the dedicated ground site and through the U.S. Air Force Satellite Control Network ground stations. The primary ground receiving site for the telemetry is the MSX Tracking System (MTS) at APL. A dedicated 10-m X-band antenna is used to track the satellite during overhead passes and acquire the 25-Mbps telemetry downlinks, along with the 1-Mbps and 16-kbps real-time transmissions. This paper discusses some of the key technology trade-offs that were made in the design of the system to meet requirements for reliability, performance, and development schedule. It also presents some of the lessons learned during development and the impact these lessons will have on development of future systems.
    • DIFFERENTIAL GPS ENHANCES TEST CAPABILITIES OF DOMESTIC AND INTERNATIONAL PROGRAMS

      Wallace, Keith; McCleaf, Tim; Pham, Tri; Veda Incorporated; Wright-Patterson Air Force Base (International Foundation for Telemetering, 1996-10)
      A system was developed using capabilities from the Range Applications Joint Program Office (RAJPO) GPS tracking system and the ACMI Interface System (ACINTS) to provide tracking data and visual cues to experimenters. The Mobile Advanced Range Data System (ARDS) Control System (MACS) outputs are used to provide research data in support of advanced project studies. Enhanced from a previous system, the MACS expands system capabilities to allow researchers to locate where Digital Terrain Elevation Data (DTED) is available for incorporation into a reference data base. The System Integration Group at Veda Incorporated has been supporting Wright Laboratories in the ground-based tracking and targeting arena since 1989 with the design, development, and integration of four generations of real-time, telemetry-based tracking aids. Commencing in Q3 1995, Veda began developing a mobile, transportable system based on the RAJPO GPS tracking system. The resulting system architecture takes advantage of the front end processor (FEP) used in the three previous generations of interface systems built for Wright Laboratories, thus maximizing hardware and software reuse. The FEP provides a computational interface between the GPS tracking system and the display (operator) system. The end product is a powerful, flexible, fully mobile testbed supporting RDT&E requirements for Wright Laboratories, as well as to other U.S. and foreign research organizations. The system is rapidly reconfigurable to accommodate ground-based tracking systems as well as GPS-based systems, and its capabilities can be extended to include support for mission planning tools, insertion of virtual participants such as DIS entities, and detailed post-mission analysis.
    • APPLICATIONS FOR A PORTABLE PC/104 BASED INSTRUMENTATION CONTROLLER

      Schumacher, Gary A.; Terametrix Systems International, Inc. (International Foundation for Telemetering, 1996-10)
      PC based instrumentation and telemetry processing systems are attractive because of their ease of use, familiarity, and affordability. The evolution of PC computing power has resulted in a telemetry processing system easily up to most tasks, even for control of and processing of data from a very complex system such as the Common Airborne Instrumentation System (CAIS) used on the new Lockheed-Martin F-22. A complete system including decommutators, bit synchronizers, IRIG time code readers, simulators, DACs, live video, and tape units for logging can be installed in a rackmount, desktop, or even portable enclosure. The PC/104 standard represents another step forward in the PC industry evolution towards the goals of lower power consumption, smaller size, and greater capacity. The advent of this standard and the availability of processors and peripherals in this form factor has made possible the development of a new generation of portable low cost test equipment. This paper will outline the advantages and applications offered by a full-function, standalone, rugged, and portable instrumentation controller. Applications of this small (5.25"H x 8.0"W x 9.5"L) unit could include: flight line instrumentation check-out, onboard aircraft data monitoring, automotive testing, small craft testing, helicopter testing, and just about any other application where small-size, affordability, and capability are required.
    • LOW-COST MISSION SUPPORT CONCEPT

      Lam, Barbara; Jet Propulsion Laboratory (International Foundation for Telemetering, 1996-10)
      This paper presents a new architecture of the end-to-end ground system to reduce overall mission support costs. The present ground system of the Jet Propulsion Laboratory (JPL) is costly to operate, maintain, deploy, reproduce, and document. In the present climate of shrinking NASA budgets, this proposed architecture takes on added importance as it will dramatically reduce all of the above costs. Currently, the ground support functions (i.e., receiver, tracking, ranging, telemetry, command, monitor and control) are distributed among several subsystems that are housed in individual rack-mounted chassis. These subsystems can be integrated into one portable laptop system using established MultiChip Module (MCM) packaging technology. The large scale integration of subsystems into a small portable system will greatly reduce operations, maintenance and reproduction costs. Several of the subsystems can be implemented using Commercial Off-The-Shelf (COTS) products further decreasing non-recurring engineering costs. The inherent portability of the system will open up new ways for using the ground system at the “point-of-use” site as opposed to maintaining several large centralized stations. This eliminates the propagation delay of the data to the Principal Investigator (PI), enabling the capture of data in real-time and performing multiple tasks concurrently from any location in the world. Sample applications are to use the portable ground system in remote areas or mobile vessels for real-time correlation of satellite data with earth-bound instruments; thus, allowing near real-time feedback and control of scientific instruments. This end-to-end portable ground system will undoubtedly create opportunities for better scientific observation and data acquisition.
    • “CAIS GROUND SUPPORT EQUIPMENT USING A LOW COST, PC-BASED PLATFORM”

      Knoebel, Robert; Berdugo, Albert; Aydin Vector Division (International Foundation for Telemetering, 1996-10)
      The Common Airborne Instrumentation System (CAIS) was developed under the auspices of the Department of Defense to promote standardization, commonality, and interoperability among flight test instrumentation. The central characteristic of CAIS is a common suite of equipment used across service boundaries and in many airframe and weapon systems. The CAIS system has many advanced capabilities which must be tested during ground support and system test. There is a need for a common set of low cost, highly capable ground support hardware and software tools to facilitate these tasks. The ground support system should combine commonly available PC-based telemetry tools with unique devices needed for CAIS applications (such as CAIS Bus Emulator, CAIS Hardware Simulator, etc.). An integrated software suite is imperative to support this equipment. A CAIS Ground Support Unit (GSU) has been developed to promote these CAIS goals. This paper presents the capabilities and features of a PC-based CAIS GSU, emphasizing those features that are unique to CAIS. Hardware tools developed to provide CAIS Bus Emulation and CAIS Hardware Simulation are also described.
    • Group Telemetry Analysis Using the World Wide Web

      Kalibjian, Jeffrey R.; Lawrence Livermore National Laboratory (International Foundation for Telemetering, 1996-10)
      Today it is not uncommon to have large contractor teams involved in the design and deployment of even small satellite systems. The larger (and more geographically remote) the team members, the more difficult it becomes to efficiently manage the disbursement of telemetry data for evaluation and analysis. Further complications are introduced if some of the telemetry data is sensitive. An application is described which can facilitate telemetry data sharing utilizing the National Information Infrastructure (Internet).
    • THE S-BAND COAXIAL WAVEGUIDE TRACKING FEED FOR ARIA

      Mahon, John P. (International Foundation for Telemetering, 1996-10)
      This paper contains a description of a new technology tracking feed and a discussion of the features which make this feed unique and allow it to perform better than any other comparable feed. Also included in this report are measured primary antenna patterns, measured and estimated phase tracking performance and estimated aperture efficiency. The latter two items were calculated by integrating the measured primary patterns.
    • HARDENED SUBMINIATURE TELEMETRY AND SENSOR SYSTEM

      Faulstich, Raymond J.; Burke, Lawrence W. Jr; D’Amico, William P. (International Foundation for Telemetering, 1996-10)
      The Army development and test community must demonstrate the functionality and reliability of gun-launched projectiles and munitions systems, especially newer smart munitions. The best method to satisfy this requirement is to combine existing optical and tracking systems data with internal data measured with on-board instrumentation (i.e. spin, pitch, and yaw measurements for standard items and terminal sensor, signal processor, and guidance/navigation system monitoring for smart munitions). Acquisition of internal data is usually limited by available space, harsh launch environments, and high associated costs. A technology development and demonstration effort is underway to provide a new generation of products for use in this high-g arena. This paper describes the goals, objectives, and progress of the Hardened Subminiature Telemetry and Sensor System (HSTSS) program.
    • THE SPACE IMAGING OPERATIONS CENTER

      Clemons, Robert R. (International Foundation for Telemetering, 1996-10)
      The next-generation commercial imaging satellites will generate data at several times the rate of current systems. To be commercially successful, these systems must have earth stations as sophisticated as the satellites themselves. Space Imaging has worked with E-Systems to exploit technologies developed over four generations of image processing, analysis and application systems to create a modular, standards-based, earth station for commercial use. A Space Imaging Operations Center can be configured in a variety of ways to provide complete, end-to-end, capabilities, from task generation to receipt of downlink, image processing, and product generation. While it is intended primarily for use with imagery from Space Imaging and other commercial satellites, an Operations Center can also accept, process and manage data from land-based, airborne or seaborne collectors. A sophisticated data management product, Mission Server™, handles and routes all data from signal receipt through final product generation. A unique family of data processing applications permit simultaneous manipulation and analysis of integrated map, image, graphic and text data. Online data storage and archiving are provided by the EMASS® family of products. An Operations Center of any size can accept, process and manage data streams of several hundred megabits per second in real time.
    • TDRSS COMPATIBLE TELEMETRY TRANSMITTER

      Rupp, Greg; Cincinnati Electronics (International Foundation for Telemetering, 1996-10)
      An S-band telemetry transmitter has been developed for Expendable Launch Vehicles (ELV's) that can downlink data through NASA's Tracking and Data Relay Satellite System (TDRSS). The transmitter operates in the 2200 to 2300 MHz range and provides a number of unique features to achieve optimum performance in the launch vehicle environment: · Commandable QPSK or BPSK modulation format. · Data rates up to 10 Mbps. · Commandable concatenated coding provides superior link performance. · Premodulation filtering produces excellent spectral containment characteristics. · Phase noise of less than 3 degrees rms is maintained through launch and ascent vibration profiles. · A 30 watt nominal RF output power provides a robust RF link. · Two RF antenna output ports with commandable selection of all power out to either port or power split evenly between ports. · Operating modes and conditions of the unit can be monitored through a number of bilevel and analog outputs. · A ruggedized mechanical design provides a reliable communications link for launch vehicle environments.
    • DESIGN AND USE OF MODERN OPTIMAL RATIO COMBINERS

      Lennox, William M.; Microdyne Corporation (International Foundation for Telemetering, 1996-10)
      This paper will discuss the design and use of Optimal Ratio Combiners in modern telemetry applications. This will include basic design theory, operational setups, and various types of combiner configurations. The paper will discuss the advantages of pre-detection vs. post-detection combining. Finally, the paper will discuss modern design techniques.
    • AN APPLICATION OF THE VIDEO MATCHED FILTERS IN PULSE TELEMETERING RECEIVER

      Wentai, Feng; Biao, Li; Xinan Electronic Engineering Institute (International Foundation for Telemetering, 1996-10)
      It is well known that the pulse telemetering system whose system equipment is simple is superior to the continuous one in ultilizing signal power. But in designing a pulse telemetering receiver the frequency shift problem is often encountered, the shift often greatly wider than the signal bandwidth is very unfavorable for improving receiver working sensitivity. Either to limit transmitter frequency stability strictly or to adapt AFC system in receiver for tracking carrier wave can solve the problem above, the AFC system method could improve the receiver’s performance, but the equipment is complicated. To what extent the receiver working sensitivity will be effected and how to judge the effection in case of adapting VF matched filter and RF being wideband in receiver are this paper’s emphasis. In this paper the power density spectrum distribution of the white noise which has passed through the non-linear system-the linear detector is analysed theoretically, and the improved working sensitivity of the receiver with video matched filter and its difference sensitivity value to that of the optimal receiver are derived. The tested working sensitivity data of two kind pulse receivers with different RF bands are given and the theoretical calculation results conform well with these data, thus it is proven that adapting video matched filter in pulse receiver is a effective approach for compensating the receiver working sensitivity dropping from RF bandwidth increase.
    • Digital Video Telemetry System

      Thom, Gary A.; Snyder, Edwin; Delta Information Systems; Aydin Vector (International Foundation for Telemetering, 1996-10)
      The ability to acquire real-time video from flight test platforms is becoming an important requirement in many test programs. Video is often required to give the flight test engineers a view of critical events during a test such as instrumentation performance or weapons separation. Digital video systems are required because they allow encryption of the video information during transmission. This paper describes a Digital Video Telemetry System that uses improved video compression techniques which typically offer at least a 10:1 improvement in image quality over currently used techniques. This improvement is the result of inter-frame coding and motion compensation which other systems do not use. Better quality video at the same bit rate, or the same quality video at a lower bit rate is achieved. The Digital Video Telemetry System also provides for multiplexing the video information with other telemetered data prior to encryption.
    • SPIRIT III Data Verification Processing

      Garlick, Dean; Wada, Glen; Krull, Pete (International Foundation for Telemetering, 1996-10)
      This paper will discuss the functions performed by the Spatial Infrared Imaging Telescope (SPIRIT) III Data Processing Center (DPC) at Utah State University (USU). The SPIRIT III sensor is the primary instrument on the Midcourse Space Experiment (MSX) satellite; and as builder of this sensor system, USU is responsible for developing and operating the associated DPC. The SPIRIT III sensor consists of a six-color long-wave infrared (LWIR) radiometer system, an LWIR spectrographic interferometer, contamination sensors, and housekeeping monitoring systems. The MSX spacecraft recorders can capture up to 8+ gigabytes of data a day from this sensor. The DPC is subsequently required to provide a 24-hour turnaround to verify and qualify these data by implementing a complex set of sensor and data verification and quality checks. This paper addresses the computing architecture, distributed processing software, and automated data verification processes implemented to meet these requirements.
    • PC-BASED TELEMETRY AND COMMAND FRONT-END FOR A DISTRIBUTED SATELLITE CONTROL SYSTEM

      Orsino, Mary Ellen; Williams, Michael; Avtec Systems, Inc. (International Foundation for Telemetering, 1996-10)
      Satellite Control Systems require a front-end component which performs real-time telemetry acquisition and command output. This paper will describe a fully networked, PC-based telemetry and command front-end which supports multiple streams and is based on Commercial Off The Shelf (COTS) technology. The front-end system is a gateway that accepts multiple telemetry streams and outputs time-tagged frame or packet data over a network to workstations in a distributed satellite control and analysis system. The system also includes a command gateway that accepts input from a command processor and outputs serial commands to the uplink. The front-end can be controlled locally or remotely via the network using Simple Network Management Protocol. Key elements of the front-end system are the Avtec MONARCH-E™ PCI-based CCSDS/TDM Telemetry Processor/Simulator board, a network-based, distributed computing architecture, and the Windows NT operating system. The PC-based telemetry and command gateway is useful throughout the lifecycle of a satellite system. During development, integration, and test, the front-end system can be used as a test tool in a distributed test environment. During operations, the system is installed at remote ground stations, with network links back to operations center(s) for telemetry and command processing and analysis.