International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / Since June of 1993, an experimental GPS receiver system has been orbiting the earth aboard a small, low-altitude, polar-orbiting satellite called RADCAL. The purpose of the experiment was to prove the concept of using GPS for satellite navigation. If successful, the system would also provide a backup to the satellite's primary navigation beacon. The goal: provide position and velocity data to an accuracy of three to five meters, and provide attitude data to within a degree. The configuration of the RADCAL GPS experiment precluded realtime feedback loops for navigation; the data was stored and downloaded after a designated collection period. On the ground, a lengthy process was used to yield the position and attitude data days after the collection event. The GPS receivers and ground equipment were configured in several modes; they ultimately yielded a position accuracy of five meters, and attitude of two degrees. This was the original goal, and the experiment was considered successful. However, one of the receivers failed in November 1993, and the other failed in January 1995. The GPS receivers were commercially available and not spaceflight proven; they were suspected of being vulnerable to single-event upsets and latchups. This turned out to be the cause of the failure of both receivers. The interface between the GPS receivers and RADCAL's other subsystems proved to be the area which could not tolerate corrupt data. The single-event latchups problems would ultimately lead to the failure of the receivers. These difficulties, as well as other lesser obstacles, provide a host of lessons learned for future satellite navigation systems.

International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / The Modular Range Interface (ModRI) is a reliable networked data acquisition system used to acquire and disseminate dissimilar data. ModRI’s purpose is to connect TSPI systems to a central computer network. The modular hardware design consists of an SBC, COTS network interfaces, and other COTS interfaces in a VME form factor. The modular software design uses C++ and OO patterns running under an RTOS. Current capabilities of ModRI include acquisition of Ethernet, PCM data, RS-422/232 serial data, and IRIG-B time. Future strategies might include stand-alone data acquisition, acquisition of digital video, and migration to other architectures and operating systems.

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The loss of radio frequency (RF) spectrum for use in testing has steadily increased the likelihood that users of the few remaining frequencies available to test ranges will experience scheduling conflicts and interference with nontest users. A gradual increase in the base of test customers engaged in scientific, military, and commercial R&D, point toward a near term situation in which more test customers will be competing for fewer frequencies. The test ranges, often operating in close geographical proximity with other communications-intensive functions as well as with each other, will also encounter increasing out-of-band and adjacent-channel interference. This projected growth of R&Drelated testing constrained to operate in a diminished RF spectrum (and a more confined test space), will undoubtedly stimulate the development of new products that make more efficient use of the RF spectrum. This paper describes one such innovative approach to spectrum sharing. The authors assess the operational need for an affordable miniaturized avionics instrument package based on a C-band radar transponder integrated with a Global Positioning System/Inertial Measurement Unit (GPS/IMU). The proposed approach would make use of frequencies already allocated for use by existing C-band aeronautical transponders. It would augment the format of the transponder output data to include the vehicle position obtained from an onboard GPS/IMU. Existing range instrumentation radars, such as the venerable AN/FPS-16, could be modified with lowcost upgrade kits to provide uniformly higher accuracy over the entire transponder coverage range.

International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / In the last few years there has been a proliferation of GPS receivers and receiver manufacturers. Couple this with a growing number of DoD test programs requiring high accuracy Time-Space-Position-Information (TSPI) with diminishing test support funds and/or needing a wide area, low altitude or surface tracking capability. The Air Force Development Test Center (AFDTC) recognized the growing requirements for using GPS in test programs and the need for a low cost, portable TSPI processing capability which sparked the development of the Desktop GPS Analyst. The Desktop GPS Analyst is a personal computer (PC) based software application for the generation of GPS-based TSPI.

International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The Edwards Digital Switch (EDS) provides mission critical voice and time-spaceposition information (TSPI) communication switching capability to the Edwards Test Range. The present system has been in operation for about 10 years. The core of this system is based on widely used commercial-off-the-shelf (COTS) time-slot interchange switches that were designed for a 40-year service life. The application layers of the system, comprising the command/control elements and the communications and user interfaces, were custom developed by the prime contractor to satisfy the performance requirements of the Air Force Flight Test Center (AFFTC). Problems with the current system include difficulty in obtaining replacement items for equipment developed by the prime contractor and higher than expected failure rates for this equipment. Based on experience, the service life for the equipment developed by the prime contractor appears to be about 15 years. Another problem is that lower cost packet switches are taking market share from the more traditional time-slot interchange switches. This factor tends to accelerate the obsolescence of the existing COTS equipment. Solutions are being investigated to update or replace the EDS. One solution is to reuse the existing COTS core equipment and replace the present application layers, preferably with COTS. Another solution is to replace the entire system with COTS or vendormodified COTS hardware and software.

International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / Modern spectrally efficient telemetry transmitters are beginning to find their way on a variety of airborne test platforms. Many of these platforms also include Global Positioning System (GPS)-based Time-Space-Position-Information (TSPI) instrumentation systems. Due to space and other limitations, many of these platforms have demanding antenna placement limitations requiring closely spaced antennas. This paper describes steps taken to identify and mitigate potential interference to GPS-based TSPI instrumentation systems by these new technology transmitters. Equipment characterization was accomplished to determine interference potential of the proposed new transmitters and susceptibility of several GPS TSPI receivers. Several filtering techniques were identified as possible solutions to the anticipated interference problems. Telemetry (TM)/GPS system mockups and laboratory tests of the same were accomplished. Open-air testing was then accomplished to validate laboratory results. Finally, on aircraft tests were accomplished prior to performing any aircraft system modifications. Results of these test efforts are presented for others to consider when planning similar modifications to other platforms.

ITC/USA 2006 Conference Proceedings / The Forty-Second Annual International Telemetering Conference and Technical Exhibition / October 23-26, 2006 / Town and Country Resort & Convention Center, San Diego, California / Last year (2005), a paper discussed the efforts of integrating Joint Advanced Missile Instrumentation (JAMI) Program components (JAMI TSPI Unit - JTU, and the Flight Termination Safe & Arm device - FTS&A), commercial off the shelf parts (Flight Termination Receivers, Telemetry Transmitter, Encryptor and Thermal Batteries) and in-house developed devices (PCM Encoder and Tri-band Antenna with integrated Limiter, Filter, & Amplifier) into a five-inch diameter Missile Telemetry (TM) Section. This retrofitted missile would be captive-carried on a F/A-18 jet. This paper is a continuation of that one presented at the 2005 International Telemetry Conference (ITC) Symposium. It annotates the latest status of the JAMI Effort, as well as the Follow-On Effort to qualify the Missile TM Section for an actual missile firing. This would include the developmental and flight qualification efforts for the Explosive Train (Detonation Cord-to-Cutter Ring Assembly) and Thermal Batteries.

ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / The Joint Advance Missile Instrumentation (JAMI) program has developed a Time Space Position Information (TSPI) unit (JTU). The JTU employs a novel use of GPS technology and inertial measurement units (IMU) to provide a real time trajectory for high dynamic missile systems. The GPS system can function during high g maneuvers that an air-to-air missile might encounter. The IMU is decoupled from the GPS sensor. The IMU data is a secondary navigation source for the JTU and will provide platform attitude. The GPS data and IMU data are sent to the ground in a telemetry packet called TUMS (TSPI Unit Message Structure). The TUMS packet is sent to a computer that hosts the JAMI Data Processing (JDP) software, which performs a Kalmam filter on the GPS and IMU data to provide a real-time TSPI solution to the range displays. This paper focuses on the equipment and software needed at a telemetry ground station to display the real time TPSI solution on the range displays. It includes an overview of the system data flow. This overview should help a potential user of the system understand what is involved in running the JAMI system. The post mission tools to provide an accurate trajectory and end-game scoring will not be discussed in this paper.

ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, Nevada / Past presented papers [1,2] have discussed the integration efforts of incorporating Central Test & Evaluation Investment Program (CTEIP) sponsored Joint Advanced Missile Instrumentation (JAMI) components (namely the JAMI TSPI Unit-JTU), Commercial off the Shelf (COTS) parts (e.g. ARTM Tier I SO-QPSK Transmitter, Encryptor and Thermal Battery), and in-house developed devices (such as PCM Encoder and Dual Band Antenna) into a five-inch diameter Missile Telemetry (TM) Section. A prototype of this TM Section has been built up and integrated into an All Up Round (AUR) Missile and twice flown as a Captive Carried Test Missile (CTM) on an F/A-18 jet with great success. This TM Section has passed all flight qualification testing (including environmental and electro-magnetic interference-EMI tests). This paper will detail the current efforts to incorporate Flight Termination System (FTS) capabilities into this TM section. In addition, the effort to upgrade some Navy and Air Force Test Ranges (with JAMI Ground Stations and Decommutators/Demodulators) to track and gather data from this Missile containing the new TM section will be discussed.

ITC/USA 2008 Conference Proceedings / The Forty-Fourth Annual International Telemetering Conference and Technical Exhibition / October 27-30, 2008 / Town and Country Resort & Convention Center, San Diego, California / Past presented papers have discussed the integration efforts of incorporating Central Test & Evaluation Investment Program (CTEIP) sponsored Joint Advanced Missile Instrumentation (JAMI) components (namely the JAMI TSPI Unit-JTU), Commercial off the Shelf (COTS) parts (e.g. ARTM Tier I SO-QPSK Transmitter, Encryptor and Thermal Battery), and in-house developed devices (such as PCM Encoder and Dual Band Antenna) into a five-inch diameter Missile Telemetry (TM) Section. A prototype of this TM Section has been built up and integrated into an All Up Round (AUR) Missile and twice flown as a Captive Carried Test Missile (CTM) on an F/A-18 jet with great success. This TM Section is in the process of undergoing flight qualification testing (including environmental and electro-magnetic interference-EMI tests). After which it will be ready for mass production. This paper will detail these current efforts. In addition, the effort to upgrade some Navy and Air Force Test Ranges (with JAMI Ground Stations and Decommutators/Demodulators) to track and gather data from this Missile containing the new TM section will be discussed. Future plans to incorporate Flight Termination System (FTS) capabilities into the TM section will be covered as well.