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Telemetry data from the 'Copernicus' experiment stored on magnetic tape on the Ural-IX computer are transcribed to the internal memory of the IBM 360 computer. Operations involved in this process are described.
This paper discusses very specifically the mode of the Mariner Venus/Mercury 1973 (MVM'73) telecommunications system in the interplexed dual channel 117.6 kilobits per second (kbps) and 2.45 kbps telemetry. This mode, originally designed for only Venus encounter, was also used at Mercury despite significantly less performance margin. Detailed analysis and careful measurement of system performance before and during flight operations allowed critical operational decisions, which made maximum use of the system capabilities.
The present work reviews technological progress over the past five years in the field of long-term telemetric monitoring of physiological parameters during space flight. Emphasis is placed on those developments that have direct application to animal or human use on earth. An effort was made in these recent developments to free subjects from encumbering wires: a swallowable telemetry capsule for monitoring body temperature and a wristwatch transmitter connected to EKG leads were two of the devices developed.
The design, principles of operation, and performance of an implantable miniaturized (48 cu cm in volume) multiplex telemetry system for simultaneous measurement of up to eight physiological parameters (including cardiovascular data) are described. Integrated circuits are used to reduce the size, complexity, and cost of fabrication. Power consumption is reduced using recently developed complementary MOS devices. PWM technique is selected as it is relatively easy to implement, lends itself to ICs, and provides an accurate means of transmitting data. The system is totally implantable within the chest of a test animal, with no wire penetrating through the skin. It is shown that the described system permits repeated measurement of the physiological effects of a variety of interventions in awake unanesthetized animals.
The results of a design study of a spread spectrum transponder for use on the HEAO-C satellite were given. The transponder performs the functions of code turn-around for ground range and range-rate determination, ground command receiver, and telemetry data transmitter. The spacecraft transponder and associated communication system components will allow the HEAO-C satellite to utilize the Tracking and Data Relay Satellite System (TDRSS) subnet of the post 1978 STDN. The following areas were discussed in the report: TDRSS Subnet Description, TDRSS-HEAO-C System Configuration, Gold Code Generator, Convolutional Encoder Design and Decoder Algorithm, High Speed Sequence Generators, Statistical Evaluation of Candidate Code Sequences using Amplitude and Phase Moments, Code and Carrier Phase Lock Loops, Total Spread Spectrum Transponder System, and Reference Literature Search.
A telemetry data synchronizer is reported for achieving phase lock and synchronization of an input signal having a pseudorandom sequence.
DSN telemetry system performance is analyzed based on convolutionally coded data for the short constraint length 7:1/2 codes at low bit rates, 8 to 2,048 bits per second, obtained from CTA 21 for the S-band configuration. The results indicate that a loss of one or more decibels in the system performance may be expected due to system degradation. Also, burst error lengths up to 100 bits may not be unusual in actual operational situations.
DSN telemetry system performance in decoding convolutionally coded data by both sequential and maximum likelihood techniques is being determined by testing at various deep space stations. This article describes corrections and refinements to the sequential decoding tests.
An accelerometer telemetry system incorporated in a finger ring is used for monitoring the motor responses of a subject. The system includes an accelerometer, battery, and transmitter and provides information to a remote receiver regarding hand movements of a subject wearing the ring, without the constraints of wires. Possible applications include the detection of fatigue from the hand movements of the wearer.
Correlation criteria have previously been established for identifying whether a given binary sequence would be a good frame sync word for phase-shift keyed telemetry. In the past, the search for a good K-bit sync word has involved the application of these criteria to the entire set of 2 exponent K binary K-tuples. It is shown that restricting this search to a much smaller subset consisting of K-bit prefixes of pseudonoise sequences results in sync words of comparable quality, with greatly reduced computer search times for larger values of K. As an example, this procedure is used to find good sync words of length 16-63; from a storage viewpoint, each of these sequences can be generated by a 5- or 6-bit linear feedback shift register.
A multichannel personal-type telemetry system is described that utilizes PCM encoding for the most effective range with minimum RF bandwidth and noise interference. Recent IC developments (COS MOS) make it possible to implement a sophisticated encoding system (PCM) within the low power and size constraints necessary for a personal biotelemetry system. This system includes low-level high-impedance preamplifiers to make the system suitable for EEG recording.
Report presents very thorough and rigorous analysis of bandwidths and filters required to achieve a specific error. Included is an investigation of contribution to error of 3- and 6-pole Chebyschev, Butterworth, and Bessel filters. Also included is methodology for designing DSB/FM telemetry system to make optimum use of available bandwidth while reducing error toward its theoretical minimum.
The DSN telemetry system performance with convolutionally coded data using the operational maximum-likelihood convolutional decoder (MCD) being implemented in the Network is described. Data rates from 80 bps to 115.2 kbps and both S- and X-band receivers are reported. The results of both one- and two-way radio losses are included.
Previously and currently planned methods of transferring or relaying telemetered information from a remote receiving station to the Mission Control Center, at the National Aeronautics and Space Administration Lyndon B. Johnson Space Center, are discussed. The data flow techniques of the Apollo Program (fixed formats), the Skylab Program (data compression), and the Space Shuttle Program (data throughput) are defined and analyzed according to their advantages and deficiencies from an operations viewpoint. Excluded from the data flow technique discussions are command data, tracking data, television data, and Teletype and Datafax messages. Voice transmissions are addressed in the Space Shuttle Program discussion because they form a part of the telemetry data stream. The tradeoffs between actual data flow requirements and existing communications limitations are addressed for each of these programs. Finally, a short discussion of current problem areas in the planned ground data transmission system for the Space Shuttle Program is presented.
Miniature, individual crystal-controlled RF transmitters located in EMG pressure sensors simplifies multichannel EMG telemetry for electronic gait monitoring. Transmitters which are assigned operating frequencies within 174 - 216 MHz band have linear frequency response from 20 - 2000 Hz and operate over range of 15 m.
An implant telemetry system for the simultaneous monitoring of temperature, activity, and EKG from small animals, such as rats, was designed with the feature that instead of a battery the system is energized by an inductive field. A 250 kHz resonant coil surrounds the cage (30 x 30 x 20 cm) and provides the approximately 100 microns of power required to operate the implant transmitter while allowing the animal unrestrained movement in the cage. The implant can also be battery operated if desired. RF transmission is in the 8-10 MHz band, which allows the use of a simple, essentially single IC chip, receiver.
Results are described of telemetry system performance testing using DSN equipment and a Maximum Likelihood Convolutional Decoder (MCD) for code rates 1/2 and 1/3, constraint length 7 and special test software. The test results confirm the superiority of the rate 1/3 over that of the rate 1/2. The overall system performance losses determined at the output of the Symbol Synchronizer Assembly are less than 0.5 db for both code rates. Comparison of the performance is also made with existing mathematical models. Error statistics of the decoded data are examined. The MCD operational threshold is found to be about 1.96 db.
Prediction telemetry recording and playback capability was implemented in the DSN to meet PV-78 mission requirements. Test data, along with theoretical considerations, gives assurance that the data degradation commitment of 1.5 db will be met, and it is anticipated that in actual performance the design goal of 1.0 db will be met. The major technical problems requiring solution were elimination of image in the OLR and the reduction of analog recorder instabilities. These were solved through the use of single-sideband mixing techniques and the use of newer generation analog recorders.