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Frequency divider provides sixteen output states free of spurious pulses from four input circuits. The input is binary coded, and a change of one in the input only changes the number of output states by one.
Circuitry simultaneously inserts message framing information and detects noise errors in binary code data transmissions. Separate message groups are framed without requiring both framing bits and error-checking bits, and predetermined message sequence are separated from other message sequences without being hampered by intervening noise.
Algorithm for assigning binary codes to inputs, internal states and outputs for sequential machines by threshold logic
Semiautomatic 35-mm photographic slide checkout console optically and electronically verifies registration of slides at a minimum rate of 250/hr. The console compares slide registration with a registration standard within the console. It verifies a binary code number on the bottom of the slide and visually displays its equivalent.
Circuit handles data, regardless of polarity and amplitude, in 10-line decimal form or in any form of binary coded decimal. When measuring instruments have common chassis grounds, Zener diodes prevent low-leak circulating currents from unbalancing the circuit.
System consists of digital voltmeter with binary coded decimal output, programmer, multiplexer, and two to six gated digital displays. Maximum number of circuits monitored is determined by digital voltmeter, rate of change of parameter being measured and complexity of multiplexer design.
Film density data that have been digitalized and recorded in binary coded decimal (BCD) format are converted into a number representing the film density difference between the unexposed film border and any point on a photograph by program CONVERT. The difference AVERAGE, the BCD number representing the unexposed film area and the BCD number of a specific data point is calculated and then multiplied by three constants to produce the desired film density difference. The angle off the principal axis of the lens is computed for each data point in order that a correction factor be applied to compensate for atmospheric backscattering differences and light intensity fall-off, inherent in the camera lens system in use. The program is capable of plotting the calculated density differences. The percentage of points in specific density ranges can also be computed.
Binary-coded-decimal microdensitometer output is converted into number representing film-density difference between unexposed film border and any data point on photograph, while also correcting for atmospheric backscattering and lens vignetting.
Converter inputs multiple precision binary words, converts data to multiple precision binary-coded decimal, and routes data back to computer. Converter base can be readily changed without need for new gate structure for each base changeover.
The Crew System Vidar Data Reduction (CSVIDR) program was written to process selected portions of data acquired from long term tests of space shuttle crew equipment. Data are recorded on a seven track computer compatible tape using the Vidar autodata eight processing system. The input tape is in a six bit binary coded decimal format. The 1110 hardware conversion option is used to convert all data from a BCD format to Fieldata since the majority of the data is output without further conversion. Data is retrieved from a character string, calibrated, tabulated, printed, and output on a fixed sample rate tape for use as input to a general purpose plot program.
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.
Efforts to freely exchange all types of NASTRAN datablocks between the internalized forms in any of three makes of NASTRAN-class computers and that of any other such make are described. The medium used is magnetic tape formatted in BCD (Binary Coded Decimal) character and numerical fields. The method used involves a FORTRAN-coded post-processor and a pre-processor, mostly portable but with a small assembly-coded component peculiar to each make of machine. Snags in a method reported in an earlier NASTRAN colloquium have been overcome and functional requirements upgraded as well.
A simple interface has been designed for the automatic control and data collection from a Grubb Parsons Mark III cube interferometer. A computer is used to automatically step the movable mirror on the interferometer. Data may be directly input into the computer for immediate transformation or stored for later analysis via a fast Fourier transformation. The interface is based on a commercial analog-to-digital converter having a parallel-to-serial data converter. The device can also display ASCII characters sent from the computer in parallel binary code. The system is applicable to recording interferograms having long time durations and to measuring multiple interferograms for statistical averaging.
The conceptual design of a spacecraft clock that will provide a standard time scale for experimenters in future spacecraft., and can be sychronized to a time scale without the need for additional calibration and validation is described. The time distribution to the users is handled through onboard computers, without human intervention for extended periods. A group parallel binary code, under consideration for onboard use, is discussed. Each group in the code can easily be truncated. The autonomously operated clock not only achieves simpler procedures and shorter lead times for data processing, but also contributes to spacecraft autonomy for onboard navigation and data packetization. The clock can be used to control the sensor in a spacecraft, compare another time signal such as that from the global positioning system, and, if the cost is not a consideration, can be used on the ground in remote sites for timekeeping and control.
Power-limited communication links may be susceptible to significant degradation if intentional or unintentional pulsed high level radio frequency interference (RFI) is present. Pulsed RFI is, in fact, of current interest to NASA in studies relating to its Tracking and Data Relay Satellite System (TDRSS). The present paper examines the impact of pulsed RFI on the error probability performance of a power-limited satellite communication link: the assumed modulation scheme is PN coded binary PSK. The composite effects of thermal noise, pulsed CW and pulsed Gaussian noise are analyzed, where RFI arrivals are assumed to follow Poisson statistics. Under the assumption that the satellite repeater is ideal and that integrate and dump filtering is employed at the ground receiver, an exact error probability expression and associated approximations are derived. Computed results are generated using an arbitrarily specified RFI model.
Sensitivity decreases by 10 at beginning of each input decade. Method conceived to convert binary-coded data to suitable linear form for stripchart recording. Strip-chart recordings obtained from typical pressure readings in a vacuum system during pumpdown. In reading curve, BCD digital vacuum-gage output processed by analog-to-digital converter in such way that only reading digits (but not range) appear in output. In range and reading, range also converted to analog and placed as most significant digit.
Prototype digital controller intended for use in 406-MHz emergency beacon. Undergoing development according to international specifications, 406-MHz emergency beacon system includes satellites providing worldwide monitoring of beacons, with Doppler tracking to locate each beacon within 5 km. Controller turns beacon on and off and generates binary codes identifying source (e.g., ship, aircraft, person, or vehicle on land). Codes transmitted by phase modulation. Knowing code, monitor attempts to communicate with user, monitor uses code information to dispatch rescue team appropriate to type and locations of carrier.
For all the data gathered by the space shuttle while in orbit, NASA engineers are just as concerned about the information it generates on the ground. From the moment the shuttle s wheels touch the runway to the break of its electrical umbilical cord at 0.4 seconds before its next launch, sensors feed streams of data about the status of the vehicle and its various systems to Kennedy Space Center s shuttle crews. Even while the shuttle orbiter is refitted in Kennedy s orbiter processing facility, engineers constantly monitor everything from power levels to the testing of the mechanical arm in the orbiter s payload bay. On the launch pad and up until liftoff, the Launch Control Center, attached to the large Vehicle Assembly Building, screens all of the shuttle s vital data. (Once the shuttle clears its launch tower, this responsibility shifts to Mission Control at Johnson Space Center, with Kennedy in a backup role.) Ground systems for satellite launches also generate significant amounts of data. At Cape Canaveral Air Force Station, across the Banana River from Kennedy s location on Merritt Island, Florida, NASA rockets carrying precious satellite payloads into space flood the Launch Vehicle Data Center with sensor information on temperature, speed, trajectory, and vibration. The remote measurement and transmission of systems data called telemetry is essential to ensuring the safe and successful launch of the Agency s space missions. When a launch is unsuccessful, as it was for this year s Orbiting Carbon Observatory satellite, telemetry data also provides valuable clues as to what went wrong and how to remedy any problems for future attempts. All of this information is streamed from sensors in the form of binary code: strings of ones and zeros. One small company has partnered with NASA to provide technology that renders raw telemetry data intelligible not only for Agency engineers, but also for those in the private sector.