• Acquisition and Near Real-Time Display of Multispectral Test Data from Widely Separated Test Sites

      Donlan, Brian; Sabo, Frank; Science Applications International Corporation (International Foundation for Telemetering, 1994-10)
      As modern weapons grow more sophisticated and capable of operating autonomously, the challenge of testing these weapons has also grown more complex. Seekers may be multispectral and must be able to overcome threat countermeasures. To effectively analyze the performance of these weapons, time-correlated test data must be efficiently, simultaneously acquired from both the weapons' internal busses and from the threat countermeasures' internal communication busses, often in a "live fire" environment. The test data must be transmitted to a central processing station where test personnel may immediately analyze the performance of the weapon with the assistance of scientific visualization techniques. In addition, the data must be captured on permanent media for future playback and more detailed analysis. One solution is to link the test article, threat countermeasures and other test support resources through an Integrated Telemetry System (ITS). Instrumentation to acquire high-speed test data is installed in data collection vans that are remotely located in the vicinity of the article under test or in the vicinity of the threat countermeasures systems or test support resources. The remote vans will be interconnected and linked to a control van which provides a centralized test control and monitoring point. Remote Data Formatter (RDF) instrumentation units, located in the remote vans, can acquire data from and control seekers, sensors, emission sources or other equipment located in or near the remote vans. The RDF units can also format the data for transmission to the control van via either fiber optic or microwave radio links. The data transmitted from multiple remote vans is received by Real-time Data Processing System (RTPS) units located in the control van for merging, processing and recording. Some of the processed data can be transferred to a Host Processing System (HPS) where it can be displayed on color graphic workstations. The control van's HPS workstations provide user-friendly displays and menus for test setup and control. Both the remote and control vans are equipped with secure digital communication systems capable of supporting compressed digital video, audio, high-speed instrumentation data and an Ethernet computer network.

      Baca, Dawnielle C. (International Foundation for Telemetering, 1994-10)
      The Data Acquisition, Analysis, and Simulation System (DAAS) is a computer system designed to allow data sources on spacecraft in the Flight System Testbed (FST) to be monitored, analyzed, and simulated. This system will be used primarily by personnel in the Flight System Testbed, flight project designers, and test engineers to investigate new technology that may prove useful across many flight projects. Furthermore, it will be used to test various spacecraft design possibilities during prototyping. The basic capabilities of the DAAS involve unobtrusively monitoring various information sources on a developing spacecraft. This system also provides the capability to generate simulated data in appropriate formats at a given data rate, and to inject this data onto the communication line or bus, using the necessary communication protocol. The DAAS involves Serial RS232/RS422, Ethernet, and MIL-STD-1553 communication protocols, as well as LabVIEW software, VME hardware, and SunOS/UNIX operating systems.

      Barringer, Bruce O.; Fairchild Space and Defense Company (International Foundation for Telemetering, 1994-10)
      Fairchild is presently developing a high-rate telemetry collection and formatting component for one of NASA’s Mission to Planet Earth’s key missions. Because of the complexity and new technology involved, discrete event simulation tools have played a key role in the development process. This paper serves as a brief introduction to this component and to the model developed with the simulation tools.

      Martin, Fredric W. (International Foundation for Telemetering, 1994-10)
      Use of top-down design principles and standard interface techniques provides the basis for a global telemetry data collection, analysis, and satellite control network with a high degree of survivability via use of distributed architecture. Use of Commercial Off-The-Shelf (COTS) hardware and software minimizes costs and provides for easy expansion and adaption to new satellite constellations. Adaptive techniques and low cost multiplexers provide for graceful system wide degradation and flexible data distribution.

      Hoefener, Carl E.; Interstate Electronics Corporation (International Foundation for Telemetering, 1994-10)
      With the decline in military budgets worldwide, the need for ever more effective training is becoming apparent. The size of the armed forces is being reduced, so the remaining members have to be trained to be more effective and efficient in doing their jobs. To improve effectiveness and efficiency of performance, military training needs will be increased. Our largest training costs will be in pilot training because of the high cost of keeping aircraft in the air. When we look at the cost of training a pilot to operate in a multiplayer scenario against a large number of unfriendly aircraft and a large number of ground threats, the cost of training is tremendous. It requires a large number of personnel, aircraft and ground equipment to train a limited number of pilots. Our current Red Flag exercises can require as many as 75 aircraft in the air simultaneously plus a large number of ground threats and a large number of support personnel. This can amount to a prohibitive cost to train a limited number of pilots.
    • Voice Encode/Decode System for PCM Insertion and Extraction

      Laird, Daniel T.; Edwards Air Force Base (International Foundation for Telemetering, 1994-10)
      In the field of aircraft testing the need to efficiently record the cockpit voice communication without consuming a significant amount of the acquisition frame bandwidth has been an issue for years. There are methods, based on commercially available products, that allow for voice placement into PCM streams that will satisfy the requirement of relatively low bandwidth consumption. In this paper I will discuss a design that makes minimal demand on bandwidth, with the freedom to vary the placement of the voice within the minor acquisition frame.
    • Planned Evolution of Range Telemetry and Communications into the Public Data Network

      Erdahl, Mike; Loral Test & Information Systems (International Foundation for Telemetering, 1994-10)
      The area of range telemetry and communications has been under budget constraints and interoperability enhancement requirements for some time. The near-term onslaught of multimedia communications offerings by telephony and communications companies is certain to cause range engineering personnel to conduct extensive research and possibly make numerous decisions on procurements and technologies before standards are finalized. This paper will address a low-risk migration path for range telemetry to the new multimedia communications for ranges based on current capabilities. This migration path has an end goal of positioning the ranges to take advantage of future multimedia communications as they become available, while leveraging off of current products and procurements, without a major investment.
    • Optimum Symbol Synchronization

      James, Calvin L.; AlliedSignal Technical Services Corporation (International Foundation for Telemetering, 1994-10)
      Although most closed-loop synchronizers employ maximum likelihood estimators for symbol value decisions, in general, their symbol timing estimates are not optimum. It would seem only natural that an optimum timing estimator would choose interval partitions based on maximizing the observed sample signal-to-noise ratio. The symbol synchronizer described below achieves optimum performance when decisions on present symbol values are based on current and previously-received symbol samples. This procedure attempts to reestablish the interval independence criterion, thereby reducing timing estimator variance. The realization presented is motivated by an open-loop maximum a posteriori (MAP) structure analysis.
    • Variable Polarization Ferrite Antenna

      Dunn, Daniel S.; Telep, Matthew S.; Augustin, Eugene P.; Technical Systems Associates, Inc (International Foundation for Telemetering, 1994-10)
      This paper describes a ferrite antenna that can produce any polarization on the Poincaré sphere over the frequency range of 9.0 to 11.4 GHz by utilizing Faraday rotation and a quarter-wavelength phase shifter. All possible polarizations of the electromagnetic wave are achievable with this antenna which includes linear, circular and elliptical polarizations. Any tilt angle of elliptical polarization and any orientation of the linear polarization can be achieved as well. The polarization of the ferrite antenna can be electronically switched to a different polarization instantly without the use of moving parts. An automatic data acquisition system was designed and built to fully analyze the antenna' s characteristics.
    • A Telemetry System with Fibre Transmission

      Qishan, Zhang; Xianliang, LI; Jun, Zhang; Beijing University of Aeronautics and Astronautics (International Foundation for Telemetering, 1994-10)
      It is known that a PCM telemetry system features with good accuracy, great dynamic range, and low noise. And when more than fourteen data channels are required, the PCM is generally the best choice. The paper describes the general ideas involved in developing a PCM telemetry system with fibre transmission.

      Lundberg, L. L.; Naval Air Warfare Center (International Foundation for Telemetering, 1994-10)
    • Data Acquisition System Central Multiplexer

      Anderson, William; Carro, Eduardo; Loral Test & Information Systems (International Foundation for Telemetering, 1994-10)
      The Central Multiplexer is a versatile data multiplexer designed to address emerging test requirements for recording data from many sources on digital rotary head recorders at high data rates. A modular design allows easy reconfiguration for airborne or laboratory use; simultaneous data input from 63 sources of data in any combination of PCM commutators, ARINC 429 buses, ARINC 629 buses, MIL- STD-1553 buses, and general-purpose high-speed serial data packets; simultaneous, independent programmable outputs to high-speed digital data recorders, quick-look displays, and engineering monitor and analysis systems; and setup and control from a remote panel, a dumb terminal, a laptop personal computer, a standalone test system, or a large control computer.

      Hazra, Tushar K.; Stephenson, Richard A.; Troendly, Gregory M.; Martin Marietta Services, Inc. (International Foundation for Telemetering, 1994-10)
      During the recent years of small satellite space access missions, the trend has been towards designing low-cost ground control centers to maintain the space/ground cost ratio. The use of personal computers (PC) in combination with high speed transputer modules as embedded parallel processors, provides a relatively affordable, highly versatile, and reliable desktop workstation upon which satellite telemetry systems can be built to meet the ever-growing challenge of the space missions today and of the future. This paper presents the feasibility of cost effective, high performance ground systems and a quantitative analysis and study in terms of performance, speedup, efficiency, and the compatibility of the architecture to commercial off the shelf (COTS) tools, and finally, introduces an operational high performance, low cost ground system to strengthen the insight of the concept.

      Finegan, Brian H.; Singer, Gary; Harris Computer Systems Corporation; Harris Corporation (International Foundation for Telemetering, 1994-10)
      The Advanced Telemetry Processing System (ATPS) is the result of a joint development project between Harris Corporation and Veda Systems, Incorporated. The mission of the development team was to produce a high-performance, cost-effective, supportable telemetry system; one that would utilize commercial-off-the-shelf (COTS) hardware and software, thereby eliminating costly customization typically required for range and telemetry applications. A critical element in the 'cost-effective, supportable' equation was the ability to easily incorporate system performance upgrades as well as future hardware and software technology advancements. The ATPS combines advanced hardware and software technology that includes a high-speed, top-down data management environment; a mature man-machine interface; a B1-level Trusted operating system and network; and stringent real-time multiprocessing capabilities into a single, fully integrated, 'open' platform. In addition, the system incorporates a unique direct memory transfer feature that allows incoming data to pass directly into local memory space where it can be displayed and analyzed, thereby reducing I/O bottleneck and freeing processors for other specialized tasks.
    • Recovery of Telemetered Data by Vertical Merging Algorithms

      Hoag, Joseph E.; Kalibjian, Jeffrey R.; Shih, Dwight; Toy, Edward J.; Lawrence Livermore National Laboratory; EL and Associates, Inc. (International Foundation for Telemetering, 1994-10)
      A long standing problem in telemetry applications is the recovery of data which has been damaged during downlink. Data recovery can be significantly improved by telemetering information in a packet format which employs redundant mechanisms for data encapsulation. A simple statistical algorithm (known as a "merge" algorithm) can be run on the captured data to derive a "least damaged" data set.

      Porter, Jim; Meyers, Tom; SEMCO (International Foundation for Telemetering, 1994-10)
      Embedded "Card-Based" receivers are one of the latest innovations in telemetry reception. These products provide substantial power and flexibility in a small form factor (one slot, PC or VME). In many applications they are a cost effective alternative to conventional telemetry receivers. This paper analyzes currently available products with regard to their features, capabilities, and performance, as well as highlighting typical applications.
    • GPS as a Telemetry Sensor

      Qishan, Zhang; Xianliang, Li; Beijing University of Aeronautics and Astronautics (International Foundation for Telemetering, 1994-10)
      GPS is required in today's vehicle tracking and navigation applications. The Navigation Satellite Timing and Ranging (NAVSTAR GPS) is an all-weather. Radio based, satellite navigation system that enables users to accurately determine 3-dimensional position, velocity and time. So it is an intelligent sensor intended to be used as a component in a system for public service.
    • On-Board Spacecraft Time-Keeping Mission System Design and Verification

      Wickham, Mark E.; Fairchild Space & Defense (International Foundation for Telemetering, 1994-10)
      Spacecraft on-board time keeping, to an accuracy better than 1 millisecond, is a requirement for many satellite missions. Scientific satellites must precisely "time tag" their data to allow it to be correlated with data produced by a network of ground and space based observatories. Multiple vehicle satellite missions, and satellite networks, sometimes require several spacecraft to execute tasks in time phased fashion with respect to absolute time. In all cases, mission systems designed to provide a high accuracy on-board clock must necessarily include mechanisms for the determination and correction of spacecraft clock error. In addition, an approach to on-orbit verification of these mechanisms may be required. Achieving this accuracy however need not introduce significant mission cost if the task of maintaining this accuracy is appropriately distributed across both the space and ground mission segments. This paper presents the mission systems approaches taken by two spacecraft programs to provide high accuracy on-board spacecraft clocks at minimum cost. The first, NASA Goddard Space Flight Center's (GSFC) Extreme Ultraviolet Explorer (EUVE) program demonstrated the ability to use the NASA Tracking and Data Relay Satellite System (TDRSS) mission environment to maintain an on-board spacecraft clock to within 100 microseconds of Naval Observatory Standard (NOS) Time. The second approach utilizes an on-board spacecraft Global Positioning System (GPS) receiver as a time reference for spacecraft clock tracking which is facilitated through the use of Fairchild's Telemetry and Command Processor (TCP) spacecraft Command & Data Handling Subsystem Unit. This approach was designed for a future Shuttle mission requiring the precise coordination of events among multiple space-vehicles.
    • An Advanced Digital Ranging and Telecontrol Apparatus

      Hua, Zhong-Han; Beijing University of Aeronautics and Astronautics (International Foundation for Telemetering, 1994-10)
      An earth station apparatus and its technical specificities and components are described in this article. Which is used for locating and telecontrol of flying objects. The pseudo-random spread spectrum system compatible with GPS is used in measuring the distance and velocity of moving-targets. The ranging and range-rate measuring signals and telecontrol signal are included in up link. The CDMADS, GLOD code are used for ranging and range-rate measuring. The GLOD code rate varies from 1 Kbps to 2.048 Mbps in step 1 bit. The subcarrier modulation systems of telecontrol are PSK, FSK, MFSK and High alphabet modulation. The frequency of subcarrier varies from 1 KHz to 1 MHZ in step 1 Hz. The rate of instruction code varies from 50 bps to 38.4Kbps in step 1 bit. The modulation indexes varies from 0.7 to 2 in 16 steps. The polarization diversity technique of digital symmetical common mode and differential mode loops are applied in down link receiver. It is used for demodulation of back signal, ranging and range-rate measuring signal and A, E error signal used by track system. The digital technique and modularization bus technique are used throughout the apparetus. All modules in apparatus and their principle are discussed in thes article.

      Hart, Dennis L.; Smith, Marvin A.; Eglin Air Force Base (International Foundation for Telemetering, 1994-10)
      This paper describes the application software used to convert AIM-120A, Advanced Medium Range Air-to-Air Missile (AMRAAM), telemetry data to a series of color images and time-correlated engineering unit results. X Window System-based graphics facilitate visualization of the doppler radar data. These software programs were developed for the VAX/VMS and DEC Alpha environments.