This low-cost, portable, and simplified system overcomes facility restrictions and can improve calibration quality of accelerometer-based instruments.
NASA Website
... SOUNDING, FALLING BODIES), (*UPPER ATMOSPHERE, DENSITY), (*ACCELEROMETERS, *METEOROLOGICAL INSTRUMENTS), SPHERES ...
DTIC Science & Technology
determined by the use of accelerometers. ... The resulting accelerometer record was suiciently pure ... Two 1/io-g accelerometers were mounted on the top of ...
MINIATURIZED THERMISTORS, ACCELEROMETERS AND PRESSURE TRANSDUCERS. James K. Luersc .... An acceleration profile, measured by an accelerometer, may be ...
... ACCELEROMETERS, *AVIATION MEDICINE), HELICOPTERS, INSTRUMENTATION, PILOTS, PROPRIOCEPTION, VESTIBULAR APPARATUS ...
Two schemes are proposed for constructing trajectory measurement systems on the basis of six-pendulum accelerographs which make possible separate determination of translational and rotational movement of the soil, excluding the influence of the transverse component of oscillations. These methods are similar to those developed for inertial navigation. It would be possible to employ three ...
NASA Astrophysics Data System (ADS)
This book contains papers presented at a conference of the International Society for Optical Engineering. The topics covered include: automated dimensional analysis using a light-sectioning microscope; laser interferometer based accelerometer calibrator; and automated single mode fiber alignment system.
Energy Citations Database
The GOCE gradiometer is based on ultrasensitive space accelerometers, last issues of the three-axes electrostatic accelerometers specifically developed in our laboratory for the geodesy missions CHAMP, GRACE and GOCE. After more than one year of in orbit operation, performance of these six sensors is analysed with respect to the ...
... from four satellite accelerometer systems ... re-entry data and contractual ... ACCELEROMETERS, *ARTIFICIAL SATELLITES, DATA BASES, REENTRY ...
When the spacecraft carries an accelerometer, these measured accelerations can be ... These are calculated by combining the mean value of the accelerometer ...
... for a mobile autonomous robot is presented. ... A new robot world modeling and path ... ACCELEROMETERS, *COMPUTERS, *ROBOTS, *NAVIGATION ...
... Abstract : A fiber-optic accelerometer concept based on the radial displacement of a hollow cylinder subject to acceleration is experimentally ...
The rotation rate is provided by a Fiber Optic Gyro (FOG) sensor, while the accelerations are provided by silicon accelerometers. ...
... Descriptors : *DATA PROCESSING, *ACCELEROMETERS, *ELECTRONIC RECORDING SYSTEMS, VIBRATION, AIRBORNE, POWER SPECTRA ...
... Descriptors : *ACCELEROMETERS, *ANALOG SYSTEMS, *LOADING, *SEISMIC WAVES, *STRUCTURES, *VIBRATION. ...
... ACCELEROMETERS, AIR, EXCITATION, HEATERS, HYDROPHONES, INSTRUMENTATION, MANOMETERS, MEASUREMENT, OSCILLATION ...
... The final results are dependent on the geometric location of ths accelerometers so it is recommended that the locations of the instrumentation ...
... Located at these sites are; strainmeters, tiltmeters, seismometers, accelerometers and other instrumentation. These instruments are capable of ... ...
NBII National Biological Information Infrastructure
All accelerometers have a 'proof mass' and it is the tendency of the proof ... The principal accelerometer used in the aerobraking analysis is the z-axis ...
6 days ago ... The ASI/MET consisted of an accelerometer and temperature, pressure and wind sensors. The accelerometer is a redundant set of x-, y-, ...
MICROSCOPE is a space mission, scheduled for a launch in 2010, which aims to verify the equivalence principle (EP) with an accuracy of 10, over a hundred times better than what has been realized on Earth today. The EP test is based on the measurement of the electrostatic forces to be applied on each test mass of two concentric inertial sensors, in order to maintain these two ...
The six accelerometers of the ESA GOCE mission have been developed by ONERA under contract with ThalesAleniaSpace France as Prime Contractor of the Gradiometer. These instruments are based on a principle similar to the ones flying from several years on board the CHAMP and the twin GRACE satellites but with some technological evolution ...
A triaxial-accelerometer system will be included in each of the Atmosphere Explorer (AE) payloads, The instrument consists of three uniaxial miniature-electrostatic-accelerometer units mounted mutually at right angles. This paper provides a description of...
National Technical Information Service (NTIS)
An overview is given of methodology and test results pertaining to the characterization of ultra sensitive accelerometers. Two issues are of primary concern. The terminology ultra sensitive accelerometer is used to imply instruments whose noise floors and...
Radio tracking of interplanetary probes is an important tool for navigation purposes as well as for testing the laws of physics or exploring planetary environments. The addition of an accelerometer on board a spacecraft provides orbit determination specialists and physicists with an additional observable of great interest: it measures the value of the non-gravitational ...
of the instrument is sensed by a new magnetometer-aided all- accelerometer inertial measurement unit (IMU). The sensing system consists of three dual-axis miniature accelerometers and a three-axis magnetometer.1.3 Conventional vs All-Accelerometer Inertial Measurement Unit.............. 14 2.2 Magnetometer-Aided ...
E-print Network
... do so through a variety of output devices. ... a wireless accelerometer-based input device and classified by ... incorporation of a tactile display, an output ...
... Accession Number : ADA072851. Title : Atmosphere Explorer MESA Accelerometer Density Data Base. Descriptive Note : Final rept. ...
... angles .by means of a special pinion ... instrument to indicate heading, bank attitude, angle ... gravity since when the accelerometer leaves the original ...
...accelerometer is mounted on the rear wall of the instrumentation cavity of the pelvis (SID-087 revision H, dated May 18, 1994...for the spine, rib and pelvis accelerometers shall have no resonance frequency within a range of 3 times the frequency range...
Code of Federal Regulations, 2010
... the development of high-precision gyroscopes and accelerometers, the Instrumentation Laboratory has had to provide Clean Rooms and develop ...
... Particular attention is given to the data obtained from phase 3. The shock phenomena are shown which could not have been obtained with ...
... plots. Telemeter, SAL, Accelerometer, Hand rammer, Hydraulic rammer, Acceleration, Telemetry, Velocity, Extraction force. ...
... Descriptors : *Hulls(Structures), *Dynamics, *Strain gages, Pressure gages, Accelerometers, Preamplifiers, Oscilloscopes, Instrumentation. ...
The use of FBG based sensors for the monitoring of the pantograph-catenary interaction is very attractive due to the insensitivity of fiber optic sensors to the electromagnetic disturbances and due to their ability to be electrically insulated. In fact, the monitoring of pantograph-catenary interaction with traditional sensors needs a complicated set-up to electrically ...
The Modal Group at Sandia National Laboratories performs a variety of tests on structures ranging from weapons systems to wind turbines. The desired number of data channels for these tests has increased significantly over the past several years. Tests requiring large numbers of data channels makes roving, accelerometers impractical and inefficient. The Modal Lab has ...
This paper describes the innovative control of an accelerometer to support the needs of the scientists operating science experiments that are on-board Space ...
Microgravity applications; Accelerometers; Vibration meters; Interactive control . NUMBER OF PAGES: 15. PDF marked as available not found on server. ...
The materials and technology now exist to construct miniaturized, light weight, robust, highly multiplexed, fiber optic-based, micromachined accelerometers ...
Two candidate accelerometer mount adhesives were tested for vibration transmissibility using the same fixture and procedures described previously. The transmissibility is normalized relative to the base-case threaded stud accelerometer mount, and these two adhesives are ranked with the four previously tested adhesives according to ...
Two candidate accelerometer mount adhesives were tested for vibration transmissibility using the same fixture and procedures described previously. The transmissibility is normalized relative to the base-case threaded stud accelerometer mount, and these tw...
This paper describes the innovative control of an accelerometer to support the needs of the scientists operating science experiments that are on-board Space Station Freedom (SSF). Accelerometers in support of science experiments on the shuttle have typica...
Various tests were performed to determine the capabilities and limits of piezoresistive accelerometers. Macroscopic, static, and dynamic tests were conducted on all accelerometers before and after the environmental tests (electrical, humidity, and temperature). The accelerometers were overranged to check their overrange performance ...
Design of All-Accelerometer Inertial Measurement Unit for Tremor Sensing in Hand-held Microsurgical University Pittsburgh, PA 15213 USA Abstract � We present the design of an all-accelerometer inertial-time the erroneous motion. The new IMU design consists of three miniature dual-axis accelerometers, two of which
Three test instruments are being evaluated to determine the feasibility of using photoacoustic technology for measuring unburned carbon in fly ash. The first test instrument is a single microwave frequency system previously constructed to measure photoacoustic signals in an off-line configuration. A second off-line instrument was ...
ACCELEROMETER-BASED GESTURE RECOGNITION VIA DYNAMIC� TIME WARPING, AFFINITY PROPAGATION system based primarily on a single 3-axis accelerometer. The system employs dynamic time warping of training samples and with the other accelerometer-based gesture recognition systems available in literature
Page 1. I , AD-784 944 AGARD FLIGHT TEST INSTRUMENTATION SERIES. VOLUME 6. OPEN AND CLOSED LOOP ACCELEROMETERS ...
... Accession Number : AD0784944. Title : AGARD Flight Test Instrumentation Series. Volume 6. Open and Closed Loop Accelerometers. ...
A low-cost highly sensitive optical accelerometer is developed based on the pick-up head of a commercially available DVD. The proposed accelerometer detects the focus error signal (FES) generated by a moving object using a built-in four-quadrant photodiode. The linear range of the FES curve is employed to indicate the displacement of ...
Accelerometer-based Tilt Estimation of a Rigid Body with only Rotational Degrees of Freedom pitch and roll angles (tilt) of a rigid body fixed at a pivot using multiple accelerometers. As an extension, the accelerometer-based estimate is fused with rate gyro data in order to further reduce
The GG1012AB01 Electrically Suspended Accelerometer (ESA) is a three-axis accelerometer designed for space applications. The dynamic range of this instrument covers four decades and can be set anywhere in the 0.002 to 10 to the -11g range. The instrument ...
GesText: Accelerometer-Based Gestural Text-Entry Systems Eleanor Jones1 , Jason Alexander1@cs.manitoba.ca ABSTRACT Accelerometers are common on many devices, including those required for text-entry. We investigate with accelerometers. Prelimi- nary studies provide insight into two potential text-entry designs that purely use
Accelerometer-based Tilt Estimation of a Rigid Body with only Rotational Degrees of Freedom pitch and roll angles (tilt) of a rigid body fixed at a pivot point using multiple accelerometers. Accelerometers are used to estimate the pitch and roll components of attitude in many applications.1
) based on accelerometer sensor data. Using this system, a robot actively "knocks" on a surface with an accelerometer-equipped device (e.g., hand or leg), collects the accelerometer data in real approach based on accelerometers to characterize and classify the physical ...
A compressive strain wave traveling in a Hopkinson's Bar is used as a pulse to calibrate accelerometers at a level of 100,000 G's acceleration. An instrumentation package was built to automatically display the calibration constant on a digital voltmeter a...
The Aristoteles gravity mission is achieved in part by performing gradiometry measurements using an instrument called GRADIO. Its principle is based on the simultaneous measurement of acceleration on several locations of a very stable plate (the GRADIO plate) equipped with high accuracy three axes accelerometers. To correct ...
Epoch Engineering, Incorporated (EEI) has completed a series of vibration measurements comparing their newly-developed Robust Laser Interferometer (RLI) with accelerometer-based instrumentation systems. EEI has successfully demonstrated, on several pieces of commonplace machinery, that non-contact, line-of-sight measurements are practical and yield results ...
This report describes the development of an extensive neutral atmospheric density data base generated from MESA accelerometer experiments. This data base represents the most extensive set of neutral density measurements in existence. Studies by AFGL scien...
The paper will review the different on-going applications and future projects in Space Geodesy, Gravimetry and Gradiometry, or Solar System exploration based on ultrasensitive accelerometer developed at ONERA. Providing a precise measurement of the non gravitational accelerations of the satellite, the STAR and SuperSTAR models have contributed to the ...
This report summarizes results of the W-87/Mk21 Deployment Separation Shock Tests conducted at the Survivability and Vulnerability Integration Center (SVIC) Hill Air Force Base in Ogden, Utah, from 10/5/98 to 10/8/98. Specific details regarding the test plan and procedures can be found in the Master Test Plan listed in the references. Test Objectives: (1) Evaluate the ...
Transducers represent a key component of medical instrumentation systems. In this paper, sensors that perform the task of measuring the physical quantity of acceleration are discussed. These sensors are of special significance since, by integrating their output signal, accelerometers can additionally provide a measure of velocity and position. Applications ...
PubMed
PURPOSE:: Sitting at work is an emerging occupational health risk. Few instruments designed for use in population-based research measure occupational sitting and standing as distinct behaviours. This study aimed to develop and validate a brief measure of occupational sitting and physical activity. METHODS:: A convenience sample (N=99, 61% female) was ...
-up data re- trieval. A triaxial EpiSensor accelerometer was also installed on the ninth floor SCSN station, recording eight channels of EpiSensor accelerometer data. Three tri- axial instruments (GSA) GSA is a 24-bit SCSN station with a triaxial EpiSensor accelerometer located in the basement
A novel fiber-optic tip accelerometer based on Fabry-Perot (F-P) interferometer is proposed and demonstrated, with potential to operate under high temperature, in this paper. Such a tip accelerometer is directed fabricated on a large cladding fiber end by using the 157nm laser-micromachining technology. With the calibration of a micro ...
We present reference noise models for high-quality strong motion accelerometer installations. We use continuous accelerometer data acquired by the Swiss Seismological Service (SED) since 2006 and other international high-quality accelerometer network data to derive very broadband (50Hz-100s) high and low noise models. The proposed ...
The use of spaceborne accelerometers for gravity gradiometry is described. The tensor of the second derivatives of the gravitational potential is measured by arranging the accelerometers so that they form a simple geometric figure centered at point 0 (which is not necessarily identical to the center of mass of the satellite). With four ...
A navigation system for a mobile autonomous robot is presented. The navigation system is based upon a directional gyroscope and a single axis accelerometer which enables a robot to navigate independent of wheel optical shaft encoders and other commonly us...
BackgroundThe number of days of pedometer or accelerometer data needed to reliably assess physical activity (PA) is important for research that examines the relationship with health. While this important research has been completed in young to middle-aged adults, data is lacking in older adults. Further, data determining the number of days of self-reports PA data is also void. ...
PubMed Central
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, ...
The structural instrumentation consisted of strain gages, pressure and temperature transducers, accelerometers, microphones, and angle-of-attack ...
The springs are for use in accelerometers, vibration isolation mounts, and high temperature instruments where force, pressure, or acceleration is measured by employing the stiffness of a spring. Temperature variations which effect the Young's modulus of r...
Jul 1, 2005 ... Measuring instruments called accelerometers are positioned all over the vehicle to read the effects of the vibrations to check the ...
Jul 1, 2005 ... Measuring instruments called accelerometers are positioned all over the vehicle to read the effects of the vibrations, in order to check the ...
Introduction: Pascal is a Mars Climate Network Mission that is being developed for ... Pascal's instrument suite combines entry data from accelerometers and ...
(MSFC) conducted modal tests on seven large elements of .... and aid in post- test instrumentation removal. Due to the large number of accelerometers ...
High speed photography equipment and specialized accelerometers was purchased to obtain measurements related to blast mitigation and damage evolution in concrete systems and large scale buildings.
Wind-vane data were also corrected for upwash, sidewash, and boom-bending effects. Linear accelerometer data were corrected for instrument offsets from the ...
... Corporate Author : AIR FORCE WEAPONS LAB KIRTLAND AFB N MEX. Personal Author(s) : Patel,Mahendra Kumar ; Chazen,David G. ...
... Mar 65-Feb 66,. Corporate Author : LEAR SIEGLER INC GRAND RAPIDS MI INSTRUMENT DIV. Personal Author(s) : Conroy, John F. ...
... rept. Mar-Sep 64. Corporate Author : LEAR SIEGLER INC GRAND RAPIDS MI INSTRUMENT DIV. Report Date : MAR 1965. ...
ASI/MET data were collected during different phases of the mission by accelerometers and wind, temperature, and pressure sensors mounted in various places ...
Table of contents: Some instrumental errors of gyroscopes, On the theory of the compensating gyroazimuth, Dynamic balancing of rotors, Error influence of a real accelerometer on the measuring accuracy of angular velocity, Calculation of the aerodynamic dr...
A method is proposed for obtaining the in-track wind component by exploiting the different ways in which two satellite-borne instruments interact with the airstream. It makes possible the completion of the three-dimensional wind vector from measurements which yield at most two components. This is especially important during geomagnetic storms when winds can cause serious ...
An executive summary is presented based upon the scientific and engineering studies and developments performed or directed by a Study Team composed of various Federal and University activities involved with the development of a three-axis Superconducting Gravity Gradiometer integrated with a six-axis superconducting accelerometer. This ...
... determinant of the filter performance. ... VALIDATION, ACCELEROMETERS, WATER, RATES, KALMAN FILTERING, ACCURACY, THESES ...
... Data bases for on-board experiments such as photometers, spectrometers, accelerometers, particle detectors, and magnetometers have been ...
This report describes the use of noise analysis to investigate in-core instrument tube vibrations in BWR-4 reactors. Neutron noise signals from in-core fission chambers and acoustic noise signals from externally mounted accelerometers were used in these studies. The results show that neutron noise can be used to detect vibration and, more importantly, ...
DOE Information Bridge
BackgroundPhysical activity instruments can be subjective or objective. There is a need to assess the reliability of these instruments, especially for researches in children. The aim of this study was to determine the validity of the Netherlands Physical Activity Questionnaire (NPAQ).MethodsPopulation under study were Brazilian children aged 4 to 11 years ...
Seismic cone penetration testing (SCPT), a relatively new in situ technique, records the arrival of seismic waves generated at the surface using velocity or acceleration transducers installed in an electric piezocone. To distinguish the different seismic arrivals, instruments with fast response times are required, i.e., accelerometers. The fast response ...
A new thermospheric wind measurement technique is reported, which is based on a satellite electrostatic triaxial accelerometer (SETA) system capable of accurately measuring accelerations in the satellite's in-track, cross-track, ad radial directions. Cros...
A piezoelectric triaxial accelerometer system has been evolved for use in satellite based neutral air density measurements. Piezoelectric bimorphs are heavily loaded with masses that are clamped at sealevel and are released in orbit by the use of pyrodevi...
A digital quartz accelerometer includes a pair of spaced double-ended tuning forks fastened at one end to a base and at the other end through a spacer mass. Transverse movement of the resonator members stresses one and compresses the other, providing a differential frequency output which is indicative of acceleration.
An accelerometer based on a spring-suspended reference mass and its precise relative motion measurement by means of 3 two-dimensional position sensitive detectors (PSD) is described. A breadboard model achieves a resolution (longterm linearity) of 25 nm i...
Five accelerometers mounted near the adapter base of the Titan 3-C launch vehicle and three on the hub of the ATS-F spacecraft provided (1) data for verifying basic spacecraft mode shapes and frequencies during powered flight while attached to the launch ...
This report describes the Hanford Seismic Network. The network consists of two instrument arrays: seismometers and strong motion accelerometers. The seismometers determine the location and magnitude of earthquakes, and the strong motion accelerometers determine ground motion. Together these instruments arrays ...
A high sensitivity piezoelectric accelerometer has been developed by replacing the conventional piezoelectric rings with a cymbal transducer. The sensitivity of the cymbal-based accelerometers containing cymbal transducers with different endcap thicknesses and different seismic masses has been measured as a function of driving ...
Experimental tests of gravity have always shown good agreement with General Relativity. There are however drivers to continue testing General Relativity, and to do so at the largest possible scales. Theoretically, Einstein's theory of gravitation shows inconsistencies with a quantum description of Nature and unified theories predict deviations from General Relativity. From an observational point ...
This work presents the development of an intelligent microsurgical instrument to perform real-time tremor compensation within a handheld tool. The intelligent instrument senses its own motion, distinguishes between voluntary and erroneous motion, and manipulates its tip to cancel the undesired component in real-time. The on-board sensing unit is made up of ...
Contents: Materials Investigation -- Experimental Data, Stress-Optic Behavior, Molecular Basis of Photoelastic Effect, Optical Anomaly and Birefringence, Instrumentation -- Photoelastic Sensor, Digital Conversion, New Instrumentation Concepts, Intracavity...
Topics covered include: Instrument for Measuring Thermal Conductivity of Materials at Low Temperatures; Multi-Axis Accelerometer Calibration System; Pupil Alignment Measuring Technique and Alignment Reference for Instruments or Optical Systems; Autonomous...
The report describes a feasibility study which has led to the development of a first generation instrument system for measuring transient pavement deflections. Accelerometers embedded in the pavement structure are employed to sense the basic motion. Dual ...
...Instrumentation for Impact Tests.� (g) The mountings for the spine, rib and pelvis accelerometers shall have no resonance frequency within a range of 3 times the frequency range of the applicable channel class. (h) Limb joints of...
Propulsion system characteristics determine to a large extent the dynamic behavior of a spacecraft. For many future science missions technologically novel micro-propulsion systems are required. In order to support its characterization, in-orbit experiments and subsequent data processing on ground can be an appropriate add-on to ground-based laboratory measurements. In this ...
towards longterm applications, we use a reduced sensor setting based on accelerometers and magnetometers- scopes, accelerometers and magnetometers [6] � is fused to estimate full orientation of each limb and acceleration sensors together. While there exist several attempts to use power effi- cient accelerometers ...
) or inertial navigation sys� tems (gyroscopes and accelerometers). Though the tech� nique is simple it is prone a tri�axial accelerometer is used as an absolute orientation measuring device (roll and pitch. A complementary Kalman filter [6] is used in [9] to estimate the robot's attitude from the accelerometer signal
and accelerometers). Though the tech� nique is simple it is prone to error due to imprecision in modeling, noise relies on the gyros when the vehicle is in motion while a tri�axial accelerometer is used as an absolute] is used in [9] to estimate the robot's attitude from the accelerometer signal during low frequency motion
-micromachined, capacitive sensing element. CONTROL SYSTEM DESIGN STUDY FOR A MICROMACHINED ACCELEROMETER Michael Kraft: In this paper an analogue, closed loop accelerometer based upon a bulk-micromachined, capacitive sensing element hardware prototype. Keywords: Accelerometers, Microsystems, Control Theory, Closed ...
A self-mixing (SM) laser displacement sensor coupled with a microelectromechanical system (MEMS) accelerometer is presented that enables reliable displacement measurements even in the case of a nonstationary laser head. The proposed technique allows the use of SM-based sensors for embedded applications. The system resolution is currently limited to ...
Dedicated accelerometers for satellite gravity gradiometry (GRADIO project) are described. The design profits from experience acquired with the CACTUS accelerometer payload of the satellite CASTOR-D5B and studies of highly accurate accelerometers for inertial navigation. The principle of operation, based on a ...
Active physiological tremor compensation instruments have been under research and development recently. The sensing unit of the instruments provides information on three degrees-of-freedom (DOF) motion of the instrument tip using accelerations provided by accelerometers placed inside the ...
Lockheed Martin has developed and fielded multiple configurations of the rotating accelerometer gravity gradiometer instrument. Applications for both static and moving-base measurements have been demonstrated for a variety of scenarios, including vehicle navigation, hydrocarbon exploration, mineral exploration, reservoir monitoring, ...
BackgroundA large number of studies have demonstrated a positive effect of increased physical activity (PA) on various health outcomes. In all large geriatric studies, however, PA has only been assessed by interview-based instruments which are all subject to substantial bias. This may represent one reason why associations of PA with geriatric syndromes ...
The technology of the gyroscopes and accelerometers used in inertial navigation is reviewed with reference to recent advances in this field made in the United States, former USSR, Europe, and Japan. Topics discussed include gyro and accelerometer errors and their consequences, the principles of accelerometers, the principles of ...
This paper describes a relatively simple method in which planar rigid body motion can be measured and analyzed in the context of an upper division mechanical engineering laboratory course. The overall intention of this work is to help facilitate upper division level laboratory projects in dynamics. Such projects are intended to provide students with the opportunity to i) apply and reinforce their ...
NSDL National Science Digital Library
The Drag and Atmospheric Neutral Density Explorer (DANDE) is a 50 kg, 0.45 meter diameter, spherical spacecraft being developed at the University of Colorado, Boulder. The goal of the DANDE mission is to make in-situ measurements of density, composition, and winds at altitudes between 200 and 350 km. The relationship between these quantities during both disturbed and quiet atmospheric conditions ...
An underwater acoustic intensity sensor is described. This sensor derives acoustic intensity from simultaneous, co-located measurement of the acoustic pressure and one component of the acoustic particle acceleration vector. The sensor consists of a pressure transducer in the form of a hollow piezoceramic cylinder and a pair of miniature accelerometers mounted inside the ...
Most earthquake early warning systems (EEWS) developed so far are conceived as either `regional' (network-based) or `on-site' (stand-alone) systems. The recent implementation of nationwide, high dynamic range, dense accelerometer arrays makes now available, potentially in real time, unsaturated waveforms of moderate-to-large magnitude earthquakes recorded ...
A compressive strain wave traveling in a Hopkinson's Bar is used as a pulse to calibrate accelerometers at a level of 100,000 G's acceleration. An instrumentation package was built to automatically display the calibration constant on a digital voltmeter at the instant of the test. The design procedures, equations, and electronic circuits ...
The development of BepiColombo mission is proceeding, in view of the launch, foreseen for 2014. This mission will perform a thorough study of the planet Mercury and its environment. An important set of scientific objectives is constituted by the so-called Radio Science Experiments (RSE), which will study the gravitational field and rotation of the planet, and will perform very precise tests of ...
The relation between the strain in an elastic wave traveling along a slender rod and the acceleration of a free end as the wave reflects from that end is given by the equation epsilon = 1/(2c)integral adt, where a = acceleration, c = wave velocity, and epsilon = strain in the rod. An air gun and projectiles have been built to induce the strain wave in the rod. The system was designed to achieve ...
The nanosatellite UNICubeSAT is described, carrying a Broglio Drag Balance Instrument for neutral thermosphere density in situ measurements. The aim of the mission is to contribute to the development of accurate thermosphere models, achieving in situ, real time measurements of atmosphere density, that could be exploited for global atmosphere model validation and accurate short ...
The ESA GOCE mission aims to map Earth gravity field in unprecedented detail. The Gradiometer is the instrument which makes possible the high resolution restitution of the gravity field to the science communities. The tri-axes Gradiometer of the GOCE Mission is conceived around six electrostatic accelerometers developed by ONERA. The satellite was launched ...
Three orthogonal components of acceleration were measured by three canisters, one containing Kistler 303 accelerometers, one Q-Flex 1100 accelerometers, and the other Q-Flex 1200 accelerometers. Measurements were made of ground motion from six different nuclear weapons tests with the three canisters located at the same station. The ...
The National Institute for Earth Physics (NIEP) has installed two infrasound networks: a four-element seismo-acoustic array with an 1.2 km aperture (IPLOR) and a three-element array with a 400m aperture (IOANE). Both arrays are installed in Vrancea seismogenic area. Each array element of IPLOR consists of three sensors (a seismic 3C broad-band instrument with 1000V/m/s ...
The introduction and development of wireless sensor network technology has resulted in rapid growth within the field of structural health monitoring (SHM), as the dramatic cable costs associated with instrumentation of large civil structures is potentially alleviated. Traditionally, condition assessment of bridge structures is accomplished through the use of either vibration ...
