International Telemetering Conference Proceedings / October 17-20, 1988 / Riviera Hotel, Las Vegas, Nevada / This paper describes the design, test and the analysis of the test results of a new type S-band FM telemetry transmitter. Compared with the modulator adopting conventional fundamental crystal direct modulation, the transmitter which adopts UHF fundamental crystal direct modulation has a comparatively better modulation characteristics and a higher center frequency stability. The test results show that the deviation sensitivity of the transmitter is up to 400KHz/Vrms, frequency response is DC~200 KHz, total harmonic distortion is 3% and the center frequency stability is ten to the minus fifth power within the range of - 30~+70°c. Because of the high operating frequency of the modulator, the complicacy of the frequency multiplier has been requced, design of circuitry simplified and harmonic and spurious outputs has been improved to a great extent.

International Telemetering Conference Proceedings / October 26-29, 1987 / Town and Country Hotel, San Diego, California / Spacecraft telemetry systems have evolved from simple hardware devices to complex computer applications performing data acquisition and formatting tasks. This paper reviews the role of spacecraft computers in performing telemetry functions and examines computer based telemetry systems being considered for use on the NASA Space Station.

International Telemetering Conference Proceedings / October 17-20, 1988 / Riviera Hotel, Las Vegas, Nevada / With the acceptance of Mil-Std-1553B by vehicle and weapons industries a wealth of new information is available for vehicle testing. In the past, selected data was extracted and included in a standard PCM telemetry stream. But only the selected data was made available. In EA6B and in the proposed IRIG Standard, multiple Mil-Std-1553B data busses are combined with identifying control bits in a single PCM telemetry stream. All of the information traveling each bus is available to the ground station. These formats share a number of features. One is that for each Bus the Mil-Std-1553B word appears in the same order in the telemetry stream. Another is that individual data words do not depend on their position in the telemetry stream for identification, but they do depend on the control information associated with the current message to give meaning to the data words. An efficient approach is outlined for identifying, selecting and routing individual measurements, messages, and/or all Mil-Std-1553B bus information to processes and I/O devices in a data flow environment.

International Telemetering Conference Proceedings / October 17-20, 1988 / Riviera Hotel, Las Vegas, Nevada / In this paper, a programming parallel real-time process data flow telemetry system is presented. What we developed recently is a advanced telemetry system which can process multi-data-flow of multi-target for mulit-user at the same time. It can be used in RPV, missile and others. Its main characteristics are as follows: Input radio frequency is S wave band (multi-dot frequencies). In telemetry front-end, the chip microprocessor is used to make demodulation and decode. Telemetry preprocessor consists of parallel distributed chip microprocessor mould plates (bus link). There are menu shope man-computer dialogue, figure display, intelligence display and intelligence self-diagnosis in this system. Now, we have developed data compress mould plate, floating-point arithmetic mould plate, derive calculation mould plate and signal process mould plate etc. The main computer is VAX-II.

International Telemetering Conference Proceedings / October 17-20, 1988 / Riviera Hotel, Las Vegas, Nevada / Digital-based linear-array chart recorders are replacing conventional stylus recorders in telemetry data stations everywhere. They offer advantages in virtually all respects, and are becoming indispensable. But because of the completely different writing method and technology employed, it is difficult to make completely analogous performance comparisons between analog and digital chart recorders. This has led to some confusion when replacing aging stylus recorders is contemplated. Objectives: Establish a set of universal, standardized performance characteristics for digital chart recorders. Introduce appropriate terminology, allowing valid, repeatable comparison of old and new systems.

International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper describes the design considerations and methodology applied to solve the practical problems posed in the creation of a high bit rate telemetry relay system and specifically the techniques implemented to enhance signal to noise performance under adverse operational conditions.

International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / New techniques for using Ethernet in real time systems are applicable to the typical requirements of high performance Telemetry installations. Most TM installations around the world today are currently implemented using specialized, high speed, point-to-point data paths which have reached their limits in performance. By using Ethernet in real time as a “Data Highway” path, system performance is optimized, and the effective life of a Telemetry system can be significantly extended. Additionally, by integrating a Local Area Network into the system, further advantages are realized. New graphics display hardware and software may be used to provide virtually an “offthe-shelf”, and very cost-effective major system upgrade. Meanwhile, little modification to the host processor hardware or software system is required. This paper examines these premises, and discusses several examples of major Telemetry systems which have made this upgrade.

International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Based on the theory of orthogonality, two orthogonal multiplex systems called frequency division multiplexing(FDM) and time division multiplexing(TDM) have long been developed. Therefore, many people tend to think that these two systems represent the ONLY two multiplexing methods that satisfy the orthogonal condition. However, after years of research, we've discovered a new kind of orthogonal functions called Bridge functions. The Bridge functions have the every promise of being the basis for constructing an entirely new kind of telemetry system, which has been named as sequency division multiplexing(SDM). Since the Bridge functions are the mathematical basis of the new telemetry system, we will give a summary of the Bridge functions at first. We have successfully constructed an experimental prototype called BAM-FM system in our laboratory. The main ideas, block diagram, operational principles, and technical problems are discussed in this paper. All our work has proved that SDM has not only research interests, but also practical value.

International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Methods to improve reception during multipath fading of telemetry data received aboard ships participating in missile exercises include various diversity techniques. Among these techniques are polarization, angle, height, and frequency diversity. In this paper, a two-ray multipath model is used to investigate the various techniques and determine the merits of each. Possible ways of implementing the promising ones are discussed.

International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The Telemetry Test Station has been developed at the Digital Systems Division, ISRO Satellite Centre, to test the housekeeping telemetry packages which will be flown onboard satellites. The heart of the test procedure is the decommutation, display and processing of the telemetry output format. The decommutation has been achieved by designing a simple plug in card to an IBM PC/XT compatible computer and writing the related assembly language software. The card and the software have been extensively tested and found to work satisfactorily upto 60 Kbps PCM data rate. To make the hardware and software flexible and truly general purpose, the acquisition should be independent of the modes of operation and data formats. All the parameters which define acquisition display and processing are therefore programmable and can be changed at any time. The parameters which influence acquisition are bit rate, word rate, frame rate, length of word, length of frame and frame synchronous code. The bit rate is transparent, i.e., need not be set by the user. The word length is assumed to be 8 bits or multiples of 8 bits. The other parameters are programmable at any time during the test session. Similarly, the parameters which affect display are the display rate, and positioning of the format including highlighting, alarm signals, related information etc. This gives a user the facility to tailor the display to his liking. The storage is also flexible and independent of display. All these modes are in real time and have therefore been coded in assembly. It has been found that a large part of the software is needed for user interface alone and user requirement is far more changeable than expected. The software is therefore designed for change. The problems and solutions in achieving these features are discussed in this paper.