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Active Aircraft Pylon Noise Control System
Unmanned Aerial Systems Traffic Management
Method of Bonding Dissimilar Materials
Sonar Inspection Robot System
Applying the Dynamic Inertia Measurement Method to Full-Scale Aerospace Vehicles
Method and Apparatus for Measuring Surface Air Pressure
Fully Premixed, Low-Emission, High-Pressure, Multi-Fuel Burner
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Gigabit Ethernet Camera

JAI (San Jose, CA) offers the TM-2040GE, a high resolution, high performance Gigabit Ethernet camera. The TM-2040GE offers two-megapixel UXGA resolution of 1600 × 1200 pixels at 34 frames per second. The camera features JAI’s high fidelity front-end circuitry and low noise power supply with a typical signal-to-noise ratio of greater than 58 dB. Monochrome and Bayer CFA color models are equipped with standard GigE Vision Gigabit Ethernet digital interfaces. Uses for the TM-2040GE cameras span a wide range of machine vision, medical, and intelligent transportation system applications, where high speed and high resolution are required.

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Wireless Measurement of Contact and Motion Between Contact Surfaces

A magnetic-field-response contact sensor is used. This method uses a magnetic-fieldresponse contact sensor that is designed to identify surface contact and motion between contact locations. The sensor has three components: (1) a capacitorinductor circuit with two sets of electrical contact pads, (2) a capacitor with a set of electrical contact pads, and (3) an inductor with a set of electrical contact pads. A unique feature of this sensor is that it is inherently multifunctional. Information can be derived from analyzing such sensor response attributes as amplitude, frequency, and bandwidth. A change in one attribute can be due to a change in a physical property of a system. A change in another attribute can be due to another physical property, which has no relationship to the first one.

Posted in: Briefs, Electronics & Computers

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Wireless Measurement of Rotation and Displacement Rate

A magnetic field response sensor is used in these measurements. A magnetic field response sensor is designed to measure displacement or rotation rate without a physical connection to a power source, microprocessor, data acquisition equipment, or electrical circuitry. The sensor works with the magnetic field response recorder, which was described in “Magnetic- Field- Response Measurement- Acquisition System,” NASA Tech Briefs, Vol. 30, No. 6 (June 2006), page 28. These sensors are wirelessly powered and interrogated, and the measurement acquisition system and sensors are extremely lightweight.

Posted in: Briefs, Electronics & Computers

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Tachometers Derived From a Brushless DC Motor

Neither excitation of the motor nor mechanical brushes is necessary. The upper part of the figure illustrates the major functional blocks of a direction-sensitive analog tachometer circuit based on the use of an unexcited two-phase brushless dc motor as a rotation transducer. The primary advantages of this circuit over many older tachometer circuits include the following:

Posted in: Briefs, Electronics & Computers

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VCO PLL Frequency Synthesizers for Spacecraft Transponders

Two documents discuss a breadboard version of advanced transponders that, when fully developed, would be installed on future spacecraft to fly in deep space. These transponders will be required to be capable of operation on any deepspace- communications uplink frequency channel between 7,145 and 7,235 MHz, and any downlink frequency channel between 8,400 and 8,500 MHz. The document focuses on the design and operation of frequency synthesizers for the receiver and transmitter. Heretofore, frequency synthesizers in deep-space transponders have been based on dielectric resonator oscillators (DROs), which do not have the wide tuning bandwidth necessary to tune over all channels in the uplink or downlink frequency bands. To satisfy the requirement for tuning bandwidth, the present frequency synthesizers are based on voltage-controlled- oscillator (VCO) phase-locked loops (PLLs) implemented by use of monolithic microwave integrated circuits (MMICs) implemented using inGaP heterojunction bipolar transistor (HBT) technology. MMIC VCO PLL frequency synthesizers similar to the present ones have been used in commercial and military applications but, until now, have exhibited too much phase noise for use in deep-space transponders. The present frequency synthesizers contain advanced MMIC VCOs, which use HBT technology and have lower levels of flicker (1/f) phase noise. When these MMIC VCOs are used with high-speed MMIC frequency dividers, it becomes possible to obtain the required combination of frequency agility and low phase noise. This work was done by Scott Smith, Narayan Mysoor, James Lux, and Brian Cook of Caltech for NASA’s Jet Propulsion Laboratory. For further information, contact iaoffice@jpl.nasa.gov.

Posted in: Briefs, Electronics & Computers

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Wide Tuning Capability for Spacecraft Transponders

A document presents additional information on the means of implementing a capability for wide tuning of microwave receiver and transmitter frequencies in the development reported in the immediately preceding article, “VCO PLL Frequency Synthesizers for Spacecraft Transponders” (NPO-42909). The reference frequency for a PLL-based frequency synthesizer is derived from a numerically controlled oscillator (NCO) implemented in digital logic, such that almost any reference frequency can be derived from a fixed crystal reference oscillator with microhertz precision. The frequency of the NCO is adjusted to track the received signal, then used to create another NCO frequency used to synthesize the transmitted signal coherent with, and at a specified frequency ratio to, the received signal. The frequencies can be changed, even during operation, through suitable digital programming.

Posted in: Briefs, Electronics & Computers

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Optoelectronic System Measures Distances to Multiple Targets

This system operates at an update rate >10 Hz. An optoelectronic metrology apparatus now at the laboratory- prototype stage of development is intended to repeatedly determine distances of as much as several hundred meters, at submillimeter accuracy, to multiple targets in rapid succession. The underlying concept of optoelectronic apparatuses that can measure distances to targets is not new; such apparatuses are commonly used in general surveying and machining. However, until now such apparatuses have been, variously, constrained to (1) a single target or (2) multiple targets with a low update rate and a requirement for some a priori knowledge of target geometry. When fully developed, the present apparatus would enable measurement of distances to more than 50 targets at an update rate >10 Hz, without a requirement for a priori knowledge of target geometry.

Posted in: Briefs, TSP, Electronics & Computers

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