Telemetry synchronizer
A telemetry data synchronizer is reported for achieving phase lock and synchronization of an input signal having a pseudorandom sequence.
Pardoe, C. T.↗
SEARCH · Search NASA
Results for “telemetry data”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Experimental development of processes to produce homogenized alloys of immiscible metals, phase 3
An experimental drop tower package was designed and built for use in a drop tower. This effort consisted of a thermal analysis, container/heater fabrication, and assembly of an expulsion device for rapid quenching of heated specimens during low gravity conditions. Six gallium bismuth specimens with compositions in the immiscibility region (50 a/o of each element) were processed in the experimental package: four during low gravity conditions and two under a one gravity environment. One of the one gravity processed specimens did not have telemetry data and was subsequently deleted for analysis since the processing conditions were not known. Metallurgical, Hall effect, resistivity, and superconductivity examinations were performed on the five specimens. Examination of the specimens showed that the gallium was dispersed in the bismuth. The low gravity processed specimens showed a relatively uniform distribution of gallium, with particle sizes of 1 micrometer or less, in contrast to the one gravity control specimen. Comparison of the cooling rates of the dropped specimens versus microstructure indicated that low cooling rates are more desirable.
Reger, J. L.↗
Viking mission support
Deep Space Network support is summarized for the two Viking missions to Mars and the Mars orbit insertions of Vikings 1 and 2 and the landing of Viking 1. Special procedures were employed during these critical events to minimize interruptions to the telemetry data return due to spacecraft data mode and attitude changes.
Amorose, R. J.↗
OSO-1 final program report
The performance of the OSO-I control subsystem is described. On orbit telemetry data was compared with the system specifications and the results were tabulated. Wherever possible, the GMT time of the occurrence of the data used to describe the performance is given for cross reference purposes. Extensive comments are also included to assist in the interpretation of the data.
Source record↗
Viking mission support
Deep Space Network support for the four Viking spacecraft during October and November 1976 is summarized. The period covers the last portion of the prime mission which officially terminated on 15 November 1976 and the start of the Viking extended mission on that date. November also covered the Mars-Sun-Earth superior conjunction period with the rapid degradation of RF link performance resulting in the tapering off and termination of telemetry data coincident with a rapid increase in radio science experiment activity. The various radio science experiments are described in detail and the computer aided countdown program utilized by the tracking stations during the Viking mission is also described.
Johnston, D. W. H.↗
Hybrid temperature-monitoring circuit
Hybrid circuit developed for use in hand-held vital signs monitor converts resistance of thermistor probe to 3 1/2 digit BCD (binary-coded-decimal) temperature readout. If used alone circuit can form 'stand alone' temperature monitor or can transmit temperature data via telemetry to data acquisition systems.
Rinard, G. A.↗
Modification of simulation conversion assembly for support of Voyager project and Pioneer-Venus 1978 project
The simulation conversion assembly was upgraded to provide the additional capabilities of simulating Voyager and Pioneer-Venus 1978 telemetry data streams for verifying the integrity of the deep space stations while continuing to fulfill the DSN test and training support requirements. The requirements and the implementations are summarized.
Yee, S. H.↗
Reliable dual-redundant sensor failure detection and identification for the NASA F-8 DFBW aircraft
A technique was developed which provides reliable failure detection and identification (FDI) for a dual redundant subset of the flight control sensors onboard the NASA F-8 digital fly by wire (DFBW) aircraft. The technique was successfully applied to simulated sensor failures on the real time F-8 digital simulator and to sensor failures injected on telemetry data from a test flight of the F-8 DFBW aircraft. For failure identification the technique utilized the analytic redundancy which exists as functional and kinematic relationships among the various quantities being measured by the different control sensor types. The technique can be used not only in a dual redundant sensor system, but also in a more highly redundant system after FDI by conventional voting techniques reduced to two the number of unfailed sensors of a particular type. In addition the technique can be easily extended to the case in which only one sensor of a particular type is available.
Deckert, J. C.↗
Test and development of inflatable spheres instrumented with miniaturized thermistors, accelerometers and pressure transducers
Instrumentation was developed for the high altitude inflatable sphere to measure its skin temperature, acceleration and internal pressure. The sphere without instrumentation has routinely been used over the past 10 years to provide measurements of winds, density, temperature and pressure between 100 Km and 30 Km altitude. With the miniaturized instrumentation package onboard, the system offers the potential for providing meteorological information as well as a better understanding of sphere performance and dynamics during its descent. Of the six launches of instrumented spheres only one provided telemetry data. However, many of the objectives of the program were achieved.
Luers, J. K.↗
The High Energy Astronomy Observatory X-ray Telescope
The High Energy Astronomy Observatory-Mission B (HEAO-B) is a satellite observatory for the purpose of performing a detailed X-ray survey of the celestial sphere. Measurements will be made of stellar radiation in the range 0.2 through 20 keV. The primary viewing requirement is to provide final aspect solution and internal alignment information to correlate an observed X-ray image with the celestial sphere to within one-and-one-half arc seconds. The Observatory consists of the HEAO Spacecraft together with the X-ray Telescope. The Spacecraft provides the required attitude control and determination system, data telemetry system, space solar power system, and interface with the launch vehicle. The X-ray Telescope includes a high resolution mirror assembly, optical bench metering structure, X-ray detectors, detector positioning system, detector electronics and aspect sensing system.
Miller, R.↗
A recommended entry reconstruction process for the Pioneer Venus multi-probe mission
A method for determining the entry trajectories for the Pioneer Venus multi-probe mission is presented that utilizes earth based Doppler and onboard accelerometry as observables to provide updates for the spacecraft state and atmospheric parameters. The evolution of this method, based on error analyses and actual simulation results, is discussed. A derivative of the Viking radio science orbit determination software is recommended for the reconstruction. Telemetry data pre-processing requirements were defined. A cubic spline derivative routine is recommended to extract accelerations from the accumulated velocity decrements.
Findlay, J. T.↗
The Space Shuttle Ground Terminal Delta Modulation System
Shuttle voice processing uses a Variable Slope Delta Modulation scheme which is a variant of the ABATE algorithm. This paper summarizes the ground terminal subsystem which processes the multiplexed voice and telemetry data digital sequence in the downlink processing and digitizes the voice signal in the uplink processing. The Delta Modulation System (DMS) performance characteristics are given in terms of an intelligibility test score and in terms of time and frequency responses measured on a production system developed for NASA Goddard Space Flight Center. Implementation details of the encoder and decoder algorithms are given in terms of the circuit logic used to implement them.
Auger, R. L.↗
A versatile microprocessor-controlled hybrid receiver
A hybrid receiver has been designed for the Galileo Project. The receiver, located on the Galileo Orbiter, will autonomously acquire and track signals from the first atmospheric probe of Jupiter as well as demodulate, bit-synchronize, and buffer the telemetry data. The receiver has a conventional RF and LF front end but performs multiple functions digitally under firmware control. It will be a self-acquiring receiver that operates under a large frequency uncertainty; it can accommodate different modulation types, bit rates, and other parameter changes via reprogramming. A breadboard receiver and test set demonstrate a preliminary version of the sequential detection process and verify the hypothesis that a fading channel does not reduce the probability of detection.
Grant, T. L.↗
Efficient telemetry format
Format would simplify ground processing of telemetry data. Also, missing minor frame would create error in only one set of source data instead of disrupting all sets. Format organizes data from various sources into autonomous blocks. Data are pre-processed, in effect, so main computer only needs to determine block type and process data set as batch.
Greenberg, E.↗
Inertial Upper Stage/Shuttle Orbiter communications
The Inertial Upper Stage (IUS) system is intended for DOD and NASA space vehicle (S/V) launches from the Shuttle Orbiter. Prior to and during the IUS launch, commands must be transmitted to the S/V and IUS and the telemetry data must be communicated to the Orbiter. This paper describes the communication links between the IUS and the Orbiter, with particular emphasis on the RF link equipment and performance. The transponder equipment carried on board the IUS system is also described.
Huth, G. K.↗
Preliminary interface revision notice SD-152C update of section 8.3 of ICD 2-19001 for detached payloads
The payload interrogator provides full duplex communication between the orbiter and detached payloads. This capability includes transmission of commands to and the reception of telemetry data from such payloads. Both NASA (STDN and DSN) and DOD (SGLS) transmit/receive frequency pairs are available. In addition to two way RF communication, Ku band rendezvous radar is also available. The radar skin-tracks targets in the passive mode or actively tracks transponder equipped payloads. Characteristics referring to those orbiter avionics characteristics of which the payloads must be cognizant and requirements referring to specifications placed upon payload communication equipment are discussed.
Source record↗
Performance of unbalanced QPSK in the presence of noisy reference and crosstalk
The problem of transmitting two telemetry data streams having different rates and different powers using unbalanced quadriphase shift keying (UQPSK) signaling is considered. It is noted that the presence of a noisy carrier phase reference causes a degradation in detection performance in coherent communications systems and that imperfect carrier synchronization not only attenuates the main demodulated signal voltage in UQPSK but also produces interchannel interference (crosstalk) which degrades the performance still further. Exact analytical expressions for symbol error probability of UQPSK in the presence of noise phase reference are derived.
Divsalar, D.↗
Heart rate, multiple body temperature, long-range and long-life telemetry system for free-ranging animals
The design details and rationale for a versatile, long-range, long-life telemetry data acquisition system for heart rates and body temperatures at multiple locations from free-ranging animals are presented. The design comprises an implantable transmitter for short to medium range transmission, a receiver retransmitter collar to be worn for long-range transmission, and a signal conditioner interface circuit to assist in signal discrimination and demodulation of receiver or tape-recorded audio outputs. Implanted electrodes are used to obtain an ECG, from which R-wave characteristics are selected to trigger a short RF pulse. Pulses carrying heart rate information are interrupted periodically by a series of pulse interval modulated RF pulses conveying temperature information sensed at desired locations by thermistors. Pulse duration and pulse sequencing are used to discriminate between heart rate and temperature pulses as well as radio frequency interference. The implanted transmitter may be used alone for medium and short-range tracking, or with a receiver-transmitter collar that employs commercial tracking equipment for transmissions of up to 12 km. A system prototype has been tested on a dog.
Lund, G. F.↗