• GPS Imbedded Telemetry

      Ciasulli, Lou; Aydin Vector Division (International Foundation for Telemetering, 1992-10)
      The Global Positioning System has achieved a maturity whereby a large marketplace of users have developed. This marketplace has been flooded with many types of receivers from a large number of manufacturers. The broad acceptance of the system among military as well as commercial users has created this market, and receiver availability due to planned mass production has precipitated substantial price reduction for GPS receivers. OEM receivers are presently available on the market at such a low cost that their incorporation into flight test systems should be seriously considered. The data produced by the system has a reasonable and usable accuracy for platform position, flight vectors and time. These are suitable in most range applications and can either augment or replace present tracking methods such as multilateration or triangulation for vehicle position. The advantages of eliminating the need for tracking functions in ground control stations are obvious especially in multi-vehicle operations such as in air-to-air weaponry testing and range training missions. The simplification of operation in position determination becomes especially desirable for over-the-horizon platforms. In this case, ground or airborne relays must be employed which complicates the location task by orders of magnitude.

      Ricker, William; Kolb, John Jr; Aydin Vector Division (International Foundation for Telemetering, 1992-10)
      Due to the vast amount of data required to be collected for design/performance analysis of operational and development systems, there has evolved a real requirement for a high-speed, large capacity, data collection/record system in a small Flight/Ruggedized package. This need is realized by several user communities and factors which include the evolution of small operational vehicles (airborne, land and UAV’s), the desire of weapons manufacturers/integrators to be independent from the vehicle during vehicle integration, and a general need for a field/airborne, reliable portable data collection system for intelligence gathering, operational performance verification and on-board data processing. In the Air Defence community, the need for a ruggedized record system was highlighted after Desert Storm, in which the operational performance of the Patriot Missile was questioned and data collection was not performed to support the performance. The Aydin Vector Division in conjunction with the prime contractor, has come up with a solution to this problem which utilizes a commercially available helical scan 8mm data storage unit. This solution provides a highly reliable record system, ruggedized for airborne and field environments and a low price in comparison with the more traditional approaches currently offered. This paper will describe the design implementation of this small ruggedized, flight worthy Data collection system deemed the ATD-800. It will also discuss the performance and limitations of implementing such a system, as well as provide several applications and solutions to different operational environments to be encountered. Additionally, the paper will conclude with several product enhancements which may benefit the flight test, operational and intelligence communities in the future.
    • A Rotor Mounted Data Acquisition System

      Piazza, Anthony; Radmand, Mansour; NASA Ames Research Center; Aydin Vector Division (International Foundation for Telemetering, 1992-10)
      Research and development testing of rotating machinery has always been limited in the number of measurements because slip ring assemblies have a limited number of conductors available for signals to pass from rotating to non rotating sections. Such testing has been impeded because relatively long wires are needed to pass low level analog signals. Because of the line resistance and capacitance and their susceptibility to stray fields, much effort is dedicated to the investigation of line loss and protection from EMI. The solution in recent years is to use current drivers or to digitize these signals as close to the transducers as possible or to employ painstaking procedures for correction of data in software. At NASA's Ames Research Center, recent research requirements have approached the limit of practical slip ring assemblies. Line lengths needed for wind tunnel tests can be 300 feet. The solution provides for an increase of channels by an order of magnitude, improved data quality, elimination of all efforts to correct data for line loss, a simple and quick installation, real time monitoring with extensive graphics capability and a manageable method for data storage. The system is called the Rotor Mounted Data Acquisition System (RMDAS) and has been acquired through a U.S. Government contract with Aydin Vector Division in Newtown, Pennsylvania. This is a high density, high speed, signal conditioning and multiplexing system which mounts on the rotating hub of full scale rotorcraft and transmits PCM, NRZ-L bit streams to a fixed end data system. The system is 512 channel capable at 20 KSPS/channel when configured for maximum channel capacity. The channel sampling capability for a single channel or for a group of channels is 177 KSPS. The individual channel sample rate can be changed by reprogramming the number of channels per segment. Various other configurations exist but always with an aggregate rate of 17 Mbps, including overhead words, per serial bit stream. This system utilizes 12-bit digitizers to provide high accuracy over the operating temperature range.