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At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS2007

Wireless Channel Characterization in the 5 GHz Microwave Landing System Extension Band for Airport Surface Areas

In this project final report, entitled "Wireless Channel Characterization in the 5 GHz Microwave Landing System Extension Band for Airport Surface Areas," we provide a detailed description and model representation for the wireless channel in the airport surface environment in this band. In this executive summary, we review report contents, describe the achieved objectives and major findings, and highlight significant conclusions and recommendations.

Matolak, David W.↗
NASA NTRS2004

Wireless event-recording device with identification codes

A wireless recording device can be interrogated to determine its identity and its state. The state indicates whether a particular physical or chemical event has taken place. In effect, the physical or chemical event is recorded by the device. The identity of the device allows it to be distinguished from a number of similar devices. Thus the sensor device may be used in an array of devices that can be probed by a wireless interrogation unit. The device tells the interrogator who it is and what state it is in. The interrogator can thus easily identify particular items in an array that have reached a particular condition.

Watters, David G.↗
NASA NTRS2006

Wireless augmented reality communication system

The system of the present invention is a highly integrated radio communication system with a multimedia co-processor which allows true two-way multimedia (video, audio, data) access as well as real-time biomedical monitoring in a pager-sized portable access unit. The system is integrated in a network structure including one or more general purpose nodes for providing a wireless-to-wired interface. The network architecture allows video, audio and data (including biomedical data) streams to be connected directly to external users and devices. The portable access units may also be mated to various non-personal devices such as cameras or environmental sensors for providing a method for setting up wireless sensor nets from which reported data may be accessed through the portable access unit. The reported data may alternatively be automatically logged at a remote computer for access and viewing through a portable access unit, including the user's own.

Devereaux, Ann↗
NASA NTRS2007

Wireless Instrumentation System and Power Management Scheme Therefore

A wireless instrumentation system enables a plurality of low power wireless transceivers to transmit measurement data from a plurality of remote station sensors to a central data station accurately and reliably. The system employs a relay based communications scheme where remote stations that cannot communicate directly with the central station due to interference, poor signal strength, etc., are instructed to communicate with other of the remote stations that act as relays to the central station. A unique power management scheme is also employed to minimize power usage at each remote station and thereby maximize battery life. Each of the remote stations prefembly employs a modular design to facilitate easy reconfiguration of the stations as required.

Perotti, Jose↗
NASA NTRS2008

Passive Wireless SAW Sensors for IVHM

NASA aeronautical programs require integrated vehicle health monitoring (IVHM) to ensure the safety of the crew and the vehicles. Future IVHM sensors need to be small, light weight, inexpensive, and wireless. Surface acoustic wave (SAW) technology meets all of these constraints. In addition it operates in harsh environments and over wide temperature ranges, and it is inherently radiation hardened. This paper presents a survey of research opportunities for universities and industry to develop new sensors that address anticipated IVHM needs for aerospace vehicles. Potential applications of passive wireless SAW sensors from ground testing to high altitude aircraft operations are presented, along with some of the challenges and issues of the technology.

Wilson, William C.↗
NASA NTRS2008

Wearable Wireless Telemetry System for Implantable BioMEMS Sensors

Telemetry systems of a type that have been proposed for the monitoring of physiological functions in humans would include the following subsystems: Surgically implanted or ingested units that would comprise combinations of microelectromechanical systems (MEMS)- based sensors [bioMEMS sensors] and passive radio-frequency (RF) readout circuits that would include miniature loop antennas. Compact radio transceiver units integrated into external garments for wirelessly powering and interrogating the implanted or ingested units. The basic principles of operation of these systems are the same as those of the bioMEMS-sensor-unit/external-RFpowering- and-interrogating-unit systems described in "Printed Multi-Turn Loop Antennas for Biotelemetry" (LEW-17879-1) NASA Tech Briefs, Vol. 31, No. 6 (June 2007), page 48, and in the immediately preceding article, "Hand-Held Units for Short-Range Wireless Biotelemetry" (LEW-17483-1). The differences between what is reported here and what was reported in the cited prior articles lie in proposed design features and a proposed mode of operation. In a specific system of the type now proposed, the sensor unit would comprise mainly a capacitive MEMS pressure sensor located in the annular region of a loop antenna (more specifically, a square spiral inductor/ antenna), all fabricated as an integral unit on a high-resistivity silicon chip. The capacitor electrodes, the spiral inductor/antenna, and the conductor lines interconnecting them would all be made of gold. The dimensions of the sensor unit have been estimated to be about 110.4 mm. The external garment-mounted powering/ interrogating unit would include a multi-turn loop antenna and signal-processing circuits. During operation, this external unit would be positioned in proximity to the implanted or ingested unit to provide for near-field, inductive coupling between the loop antennas, which we have as the primary and secondary windings of an electrical transformer.

Simons, Rainee N.↗
NASA NTRS2009

Standards-Based Wireless Sensor Networking Protocols for Spaceflight Applications

Wireless sensor networks (WSNs) have the capacity to revolutionize data gathering in both spaceflight and terrestrial applications. WSNs provide a huge advantage over traditional, wired instrumentation since they do not require wiring trunks to connect sensors to a central hub. This allows for easy sensor installation in hard to reach locations, easy expansion of the number of sensors or sensing modalities, and reduction in both system cost and weight. While this technology offers unprecedented flexibility and adaptability, implementing it in practice is not without its difficulties. Any practical WSN deployment must contend with a number of difficulties in its radio frequency (RF) environment. Multi-path reflections can distort signals, limit data rates, and cause signal fades that prevent nodes from having clear access to channels, especially in a closed environment such as a spacecraft. Other RF signal sources, such as wireless internet, voice, and data systems may contend with the sensor nodes for bandwidth. Finally, RF noise from electrical systems and periodic scattering from moving objects such as crew members will all combine to give an incredibly unpredictable, time-varying communication environment.

Barton, Richard J.↗
NASA NTRS2009

Wireless Avionics Packet to Support Fault Tolerance for Flight Applications

In this protocol and packet format, data traffic is monitored by all network interfaces to determine the health of transmitter and subsystems. When failures are detected, the network inter face applies its recover y policies to provide continued service despite the presence of faults. The protocol, packet format, and inter face are independent of the data link technology used. The current demonstration system supports both commercial off-the-shelf wireless connections and wired Ethernet connections. Other technologies such as 1553 or serial data links can be used for the network backbone. The Wireless Avionics packet is divided into three parts: a header, a data payload, and a checksum. The header has the following components: magic number, version, quality of service, time to live, sending transceiver, function code, payload length, source Application Data Interface (ADI) address, destination ADI address, sending node address, target node address, and a sequence number. The magic number is used to identify WAV packets, and allows the packet format to be updated in the future. The quality of service field allows routing decisions to be made based on this value and can be used to route critical management data over a dedicated channel. The time to live value is used to discard misrouted packets while the source transceiver is updated at each hop. This information is used to monitor the health of each transceiver in the network. To identify the packet type, the function code is used. Besides having a regular data packet, the system supports diagnostic packets for fault detection and isolation. The payload length specifies the number of data bytes in the payload, and this supports variable-length packets in the network. The source ADI is the address of the originating interface. This can be used by the destination application to identify the originating source of the packet where the address consists of a subnet, subsystem class within the subnet, a subsystem unit, and the local ADI number. The destination ADI is used to route the packet to its ultimate destination. At each hop, the sending interface uses the destination address to determine the next node for the data. The sending node is the node address of the interface that is broadcasting the packet. This field is used to determine the health of the subsystem that is sending the packet. In the case of a packet that traverses several intermediate nodes, it may be the node address of the intermediate node. The target node is the node address of the next hop for the packet. It may be an intermediate node, or the final destination for the packet. The sequence number is used to identify duplicate packets. Because each interface has multiple transceivers, the same packet will appear at both receivers. The sequence number allows the interface to correlate the reception and forward a single, unique packet for additional processing. The subnet field allows data traffic to be partitioned into segregated local networks to support large networks while keeping each subnet at a manageable size. This also keeps the routing table small enough so routing can be done by a simple table lookup in an FPGA device. The subsystem class identifies members of a set of redundant subsystems, and, in a hot standby configuration, all members of the subsystem class will receive the data packets. Only the active subsystem will generate data traffic. Specific units in a class of redundant units can be identified and, if the hot standby configuration is not used, packets will be directed to a specific subsystem unit.

Block, Gary L.↗
NASA NTRS2009

Biomedical Wireless Ambulatory Crew Monitor

A compact, ambulatory biometric data acquisition system has been developed for space and commercial terrestrial use. BioWATCH (Bio medical Wireless and Ambulatory Telemetry for Crew Health) acquires signals from biomedical sensors using acquisition modules attached to a common data and power bus. Several slots allow the user to configure the unit by inserting sensor-specific modules. The data are then sent real-time from the unit over any commercially implemented wireless network including 802.11b/g, WCDMA, 3G. This system has a distributed computing hierarchy and has a common data controller on each sensor module. This allows for the modularity of the device along with the tailored ability to control the cards using a relatively small master processor. The distributed nature of this system affords the modularity, size, and power consumption that betters the current state of the art in medical ambulatory data acquisition. A new company was created to market this technology.

Chmiel, Alan↗
NASA NTRS2009

"Fly-by-Wireless" Vehicles and Evaluations of ISA 100 Applications to Space-Flight

"Fly-by-Wireless" (What is it?) Vision: To minimize cables and connectors and increase functionality across the aerospace industry by providing reliable, lower cost, modular, and higher performance alternatives to wired data connectivity to benefit the entire vehicle/program life-cycle. Focus Areas: 1. System Engineering and Integration to reduce cables and connectors. 2. Provisions for modularity and accessibility in the vehicle architecture. 3. Develop Alternatives to wired connectivity (the "tool box").NASA and Aerospace depend more and more on cost-effective solutions that can meet our requirements. ISA-100.11 a is a promising new standard and NASA wants to evaluate it. NASA should be involved in understanding and contributing to other ISA-100 efforts that contribute to "Fly-by-Wireless" and it's objectives. ISA can engage other aerospace groups that are working on similar goals and obtain more aerospace industry perspective.

Studor, George F.↗
NASA NTRS2009

CxP Wireless DFI Summary Presentation for OTI Flight Test Working Group

This slide presentation reviews the wireless instrumentation architecture needed for the Alatir Lunar Lander, Ares I, Ares V, and the Block II Orion Crew Exploration Vehicle (CEV). It includes information about the Wireless DFI system, mission planning, and the technology roadmap.

Arteaga, Ricardo A.↗
NASA NTRS2010

A Safe, Self-Calibrating, Wireless System for Measuring Volume of Any Fuel at Non-Horizontal Orientation

A system for wirelessly measuring the volume of fluid in tanks at non-horizontal orientation is predicated upon two technologies developed at Langley Research Center. The first is a magnetic field response recorder that powers and interrogates magnetic field response sensors [ Magnetic Field Response Measurement Acquisition System, (LAR-16908), NASA Tech Briefs, Vol. 30, No. 6 (June 2006), page 28]. Magnetic field response sensors are a class of sensors that are powered via oscillating magnetic fields and when electrically active respond with their own magnetic fields whose attributes are dependent upon the magnitude of the physical quantity being measured. The response recorder facilitates the use of the second technology, which is a magnetic field response fluid-level sensor ["Wireless Fluid- Level Sensors for Harsh Environments," (LAR-17155), NASA Tech Briefs, Vol. 33, No. 4 (April 2009), page 30]. The method for powering and interrogating the sensors allows them to be completely encased in materials (Fig. 1) that are chemically resilient to the fluid being measured, thereby facilitating measurement of substances (e.g., acids, petroleum, cryogenic, caustic, and the like) that would normally destroy electronic circuitry. When the sensors are encapsulated, no fluid (or fluid vapor) is exposed to any electrical component of the measurement system. There is no direct electrical line from the vehicle or plant power into a fuel container. The means of interrogating and powering the sensors can be completely physically and electrically isolated from the fuel and vapors by placing the sensor on the other side of an electrically non-conductive bulkhead (Fig. 2). These features prevent the interrogation system and its electrical components from becoming an ignition source.

Woodward, Stanley E.↗
NASA NTRS2011

Wireless Orbiter Hang-Angle Inclinometer System

A document describes a system to reliably gather the hang-angle inclination of the orbiter. The system comprises a wireless handheld master station (which contains the main station software) and a wireless remote station (which contains the inclinometer sensors, the RF transceivers, and the remote station software). The remote station is designed to provide redundancy to the system. It includes two RF transceivers, two power-management boards, and four inclinometer sensors.

Lucena, Angel↗
NASA NTRS2011

Fault Tolerance in ZigBee Wireless Sensor Networks

Wireless sensor networks (WSN) based on the IEEE 802.15.4 Personal Area Network standard are finding increasing use in the home automation and emerging smart energy markets. The network and application layers, based on the ZigBee 2007 PRO Standard, provide a convenient framework for component-based software that supports customer solutions from multiple vendors. This technology is supported by System-on-a-Chip solutions, resulting in extremely small and low-power nodes. The Wireless Connections in Space Project addresses the aerospace flight domain for both flight-critical and non-critical avionics. WSNs provide the inherent fault tolerance required for aerospace applications utilizing such technology. The team from Ames Research Center has developed techniques for assessing the fault tolerance of ZigBee WSNs challenged by radio frequency (RF) interference or WSN node failure.

Alena, Richard↗
NASA NTRS2011

Wireless Power Transfer for Space Applications

This paper introduces an implementation for magnetic resonance wireless power transfer for space applications. The analysis includes an equivalent impedance study, loop material characterization, source/load resonance coupling technique, and system response behavior due to loads variability. System characterization is accomplished by executing circuit design from analytical equations and simulations using Matlab and SPICE. The theory was validated by a combination of different experiments that includes loop material consideration, resonance coupling circuits considerations, electric loads considerations and a small scale proof-of-concept prototype. Experiment results shows successful wireless power transfer for all the cases studied. The prototype provided about 4.5 W of power to the load at a separation of -5 cm from the source using a power amplifier rated for 7 W.

Ramos, Gabriel Vazquez↗
NASA NTRS2011

Performance Comparison of Wireless Sensor Network Standard Protocols in an Aerospace Environment: ISA100.11a and ZigBee Pro

Standards-based wireless sensor network (WSN) protocols are promising candidates for spacecraft avionics systems, offering unprecedented instrumentation flexibility and expandability. Ensuring reliable data transport is key, however, when migrating from wired to wireless data gathering systems. In this paper, we conduct a rigorous laboratory analysis of the relative performances of the ZigBee Pro and ISA100.11a protocols in a representative crewed aerospace environment. Since both operate in the 2.4 GHz radio frequency (RF) band shared by systems such as Wi-Fi, they are subject at times to potentially debilitating RF interference. We compare goodput (application-level throughput) achievable by both under varying levels of 802.11g Wi-Fi traffic. We conclude that while the simpler, more inexpensive ZigBee Pro protocol performs well under moderate levels of interference, the more complex and costly ISA100.11a protocol is needed to ensure reliable data delivery under heavier interference. This paper represents the first published, rigorous analysis of WSN protocols in an aerospace environment that we are aware of and the first published head-to-head comparison of ZigBee Pro and ISA100.11a.

Wagner, Raymond S.↗
NASA NTRS2012

High Temperature, Wireless Seismometer Sensor for Venus

Space agency mission plans state the need to measure the seismic activity on Venus. Because of the high temperature on Venus (462? C average surface temperature) and the difficulty in placing and wiring multiple sensors using robots, a high temperature, wireless sensor using a wide bandgap semiconductor is an attractive option. This paper presents the description and proof of concept measurements of a high temperature, wireless seismometer sensor for Venus. A variation in inductance of a coil caused by the movement of an aluminum probe held in the coil and attached to a balanced leaf-spring seismometer causes a variation of 700 Hz in the transmitted signal from the oscillator/sensor system at 426? C. This result indicates that the concept may be used on Venus.

Ponchak, George E.↗