International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / In space applications, telemetry systems are traditionally used to provide a front end for processing Control Center data. Control Center operations dictate the content and processing requirements of the telemetry data to enable the control center personnel to make proper decisions concerning the operation of their space vehicle. Unfortunately many anomalous operational scenarios do not arise during control center checkout procedures which are designed to test the functionality of the Control Center equipment. However, an interactive telemetry simulation, which involves producing telemetry data using real-world formats and data rates, can create many of the situations control center personnel may encounter. A host computer is used to drive a telemetry system which in turn produces simulated vehicle data. As a result, a telemetry simulation can not only verify the functionality of the Control Center hardware and software, but also validate Control Center procedures and train Control Center personnel in the process.

International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / The advantages of using visual programming to create, modify, test and display a telemetry stream are presented. The failure to fully deploy the high-gain antenna of the Galileo spacecraft has resulted in a software redesign of the computer systems onboard the spacecraft to support the low-gain antenna mission. Visual programming software is being used to test new algorithms as part of the ground support for the spacecraft Test Bed. It is very important that any new software algorithms be thoroughly tested on the ground before any modifications are made to the spacecraft. The advantage of using a visual programming language (LabVIEW, National Instruments) is that it provides easy visibility into the decommutation process that is being modified by the Galileo programming support team. In addition, utilities were written using visual programming to allow real-time data display and error detection. A data acquisition board is used to clock in the actual synchronous telemetry signal from the Test Bed at rates below 10 kHz. The time to write and modify the code using visual programming is significantly less (by a factor of 4 to 10) than using text-based code. The gains in productivity are attributed to the communication among the customer, developer, and computer that are facilitated by the visual syntax of the language.

International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / Over the last 3 years the Naval Air Warfare Center Aircraft Division (NAWCAD), Patuxent River, MD, has been in the process of developing a link between its secure Manned Flight Simulator (MFS) and Real Time Processing System (RTPS) facilities. The MFS hosts a wide variety of high fidelity fixed and rotary wing aircraft simulation models. The RTPS is used as a telemetry ground station for conduct of Navy flight testing at Patuxent River MD. The ability to integrate simulation with flight testing in a real time environment provides new potential for increased flight safety, enhanced engineering training, optimized flight test planning, real time simulation fidelity assessments, improved engineering analysis and other applications for enhanced flight testing, data analysis and data processing. A prototype system has been successfully designed and operated at NAWCAD in support of an F/A-18C flight test project which required simultaneous merging and display of real time and simulation data to reduce the risk of departure from controlled flight. As currently designed the link (encryption and decryption gear in the loop) can be operated in three modes: (1) Simulation sending data to RTPS (e.g. pilot-engineer pre-first flight preparation/training scenario, (2) simulation is driven by real aircraft control surface inputs and response is compared with that of the real aircraft for simulation fidelity assessments and (3) simulation "rides along" with the real aircraft and data are extracted from the simulation which are otherwise unavailable from the aircraft (e.g. flight control law interconnect signals, control law feedback signals, aerodynamic data, propulsion model data, avionics model data, other model data etc.). This paper discusses, design and implementation aspects of the RTPS-Simulator link, and includes a description of how the link was used to support a real time flight test program by providing critical safety of flight data. Other potential uses for the link will also be highlighted.

International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / With the increased concerns for reducing cost and improving reliability in today's telemetry systems, many users are employing simulation and automation to guarantee reliable telemetry systems operation. Pre-Mission simulation of the telemetry system will reduce the cost associated with a loss of mission data. In order to guarantee the integrity of the receive system, the user must be able to simulate several conditions of the transmitted signal. These include Doppler shift and dynamic fade simulation. Additionally, the simulator should be capable of transmitting industry standard PCM data streams to allow pre-mission bit error rate testing of the receive system. Furthermore, the simulator should provide sufficient output power to allow use as a boresite transmitter to check all aspects of the receive link. Finally, the simulator must be able to operate at several frequency bands and modulation modes to keep cost to a minimum.