Detection and Countermeasures: Magnetic & Electric Fld Detection & Detectors

Comparison of Aircraft Maneuver Compensators for Antisubmarine Warfare Magnetometers

02 MAR 81

56 pages

Authors: Walter L. Harriman; Paul H. Palosky; NAVAL AIR DEVELOPMENT CENTER WARMINSTER PA SENSORS AND AVIONICS TECHNOLOGY DI RECTORATE

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Submarines can be detected from the perturbations they cause in the earth's magnetic field. Aircraft mounted magnetometers are used to detect these perturbations. Magnetic compensators are used to minimize the aircraft's effect upon the magnetometer signal. The Naval Air Development Center has compared the performance of two advanced magnetic compensators, the Integrated Digital Magnetometer (IDM), and the Compensator Group Adaptor (CGA), developed for ASW aircraft. Data for the comparison were ...

Magnetostrictive Optical Fiber Cable and Magnetic Field Detector, and Method thereof.

12 JAN 1981

Authors: Ammon Nariv; Harry V. Winsor; DEPARTMENT OF THE NAVY WASHINGTON DC

The full text of this report is not available and therefore is not for sale. This information is provided for reference purposes only.

An optical fiber cable and magnetic field detector magnetostrictively reactive to the presence of an external magnetic field is presented. The optical fiber cable comprises a elongated optically transparent core sheathed by a magnetostrictively responsive jacket disposed about the periphery of the core. The jacket responds to magnetic fields present and strains the core effecting the light transmission of the core. The effect upon the light transmission by the jacket ...

Port Everglades Shallow Water Range As-Built Documentation

JAN 81

Authors: NAVAL FACILITIES ENGINEERING COMMAND WASHINGTON DC CHESAPEAKE DIV

The Chesapeake Div., Naval Facilities Engineering Command (CHESNAVFACENGCOM) was tasked to construct an array of sensors at the Naval Surface Weapons Center (NSWC) Facility, Ft. Lauderdale, Florida. This installation is a part of the Linear Chair Program. CHESNAVFACENGCOM's responsibilities included the design, procurement, and installation of all system hardware except sensors and associated electronics. This Command, with major participation by Civil Engineering Lab., designed and procured pressure vessels for housing ...

First Motion Detector.

22 DEC 1980

Authors: Jeffrey A. Lienau; DEPARTMENT OF THE ARMY WASHINGTON DC

The first motion detector includes a missile which is mounted in a conventional manner in a launch tube or relative to a launch rail and has magnetic means for producing a magnetic field that is projected outwardly from the missile into the detection range of a detector that detects when the field moves axially and thereby produces an output signal which indicates the exact time that the missile moves in ...

Materials Research for Advanced Inertial Instrumentation. Task 1. Dimensional Stability of Gyroscope Structural Materials.

DEC 1980

Authors: K. Kumar; J. McCarthy; F. Petri; J. Wollam; CHARLES STARK DRAPER LAB INC CAMBRIDGE MA

Additional microyield measurements on HIP-50 beryllium samples, subjected to a variety of selected heat treatments, were performed. It was determined that of the several treatments that were employed the most significant increase in the value of the microyield strength occurred from a 100 hour exposure to 600 C. A microyield value of about 26.5 klb/sq in. was measured after this treatment compared to an as-received value of 17.2 klb/sq in. ...

Materials Research for Advanced Inertial Instrumentation. Task 2. Gas Bearing Material Development.

DEC 1980

Authors: D. Das; K. Kumar; E. Wettstein; J. Wollam; CHARLES STARK DRAPER LAB INC CAMBRIDGE MA

Progress is reported on three fronts: Boron deposition on beryllium by chemical vapor deposition (CVD) and subsequent reactive diffusion of the deposited boron film, ion implantation of boron into beryllium, and beryllium-ceramic composite materials. CVD coatings of boron, from B2H6 on beryllium at 700 C showed less tendency to crack and spall at a 5 micron thickness than did previous coatings 1 micron thick which had been deposited at 900 ...

Experimental Demonstration of Weaver's Model of Magnetic Fields from Ocean Waves

12 NOV 80

24 pages

Authors: Andrew R. Ochadlick Jr; NAVAL AIR DEVELOPMENT CENTER WARMINSTER PA SENSORS AND AVIONICS TECHNOLOGY DI RECTORATE

Magnetic measurements have been made above ocean waves from a stable platform at sea. The results are consistent with the theory of magnetic fields associated with ocean waves. The theory offers the potential to reduce or eliminate ocean wave noise in MAD (Magnetic Anomaly Detection).

Feature Recognition System.

14 OCT 1980

Authors: George J. Dusheck Jr.; Phillips B. Scott; DEPARTMENT OF THE NAVY WASHINGTON DC

An airborne system for automatically and electronically recognizing and detecting the relative presence of invariant features of a transient submarine signal occurring in the presence of signal-like noise. A plurality of comb filters receive MAD signal information in the amplitude-time domain and filter it to provide amplitude-time-frequency domain information. The primary features (positive and negative slopes) of this latter information are then abstracted, the abstracted information being utilized in a ...

Magnetically Undetectable Electronic Circuit Assemblies

03 OCT 1980

Authors: Hayden Morris; NAVAL SURFACE WEAPONS CENTER SILVER SPRING MD

This report describes the results of work concerned with fabricating, electronic circuit assemblies which are undetectable magnetically, and contains recommendations concerning further development work. (Author)

Some Features of Deep Structure and Origin of Lomonosov Ridge According to Aeromagnetic Data,

22 AUG 1980

Authors: A. M. Karasik; N. I. Gurevich; V. N. Masolov; V. G. Shchelovanov; FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OH

Magnetic Sensor Feasibility Test for Coast Guard Vessel Traffic Services.

AUG 1980

Authors: T. M. Drown; COAST GUARD WASHINGTON DC OFFICE OF RESEARCH AND DEVELOPMENT

The Coast Guard Office of R & D has an on-going project to test the feasibility of using various sensors in the monitoring of vessel traffic in existing Vessel Traffic Service (VTS) operating areas. This report describes the effort involved in testing magnetic sensors. The report contains a description of both the sensor system configuration and the results of feasibility tests that were performed in Houston, Texas and Sault Ste ...

MILES Pressure/Seismic Response Engineering Development of MILES Test Fixture.

AUG 1980

Authors: Kerry J. Sutherland; Thom R. Cavanagh; HONEYWELL INC ST PETERSBURG FL

This report describes the development, configuration, operation, and evaluation of Transducer Test Set TS-3753/U. The test set is a fixture designed to measure the physical parameters plus seismic and magnetic response characteristics of Motional Pickup Transducer TR-29916 commonly called the MILES transducer. The measurements can be performed in a factory environment to permit the data to be used to monitor the manufactured quality of the MILES transducer. (Author)

Transmission and Orbital Constraints in Space Related Programs: Project Description.

AUG 1980

Authors: A. L. Hiebert; A. F. Brewer; RAND CORP SANTA MONICA CA

Future growth in commercial and military space systems is constrained by technical problems associated with the frequency spectrum, by orbital congestion, and by costs stemming from proliferated terminals. The authors outline an Air Force sponsored research project to design and develop a capability for predicting and analyzing the spectrum/orbital geometry requirements of current and projected U.S. and international space-related systems. The two essential components of the project are a comprehensive ...

Forecast of Remote Underwater Sensing Technology.

JUL 1980

Authors: Vincent A. Del Grosso; Perry B. Alers; NAVAL RESEARCH LAB WASHINGTON DC

A report has been prepared for the United States Coast Guard which develops 10-year and 25-year forecasts of the evolution of underwater remote sensing system technologies. Included is a delineation of the status of those technologies identified as having present or potential utility to current and projected Coast Guard missions. A modified Delphi technique was utilized to develop the forecasts wherein 131 questionnaires dealing with 9 specific technologies were sent ...

Concepts of Signal Acquisition and Processing for Use with a Passive Space Communication Array.

JUL 1980

Authors: James C. Springett; RAND CORP SANTA MONICA CA

A passive communication satellite is attractive for relaying strategic messages between distant points under conditions where active communication satellite and other terrestrial links have been negated. This note addresses two problems associated with efficient passive communication satellite use: (1) signal acquisition and (2) correction for array near-field signal degradation. A signal transfer model is developed for the satellite array, from which various fundamental properties are derived and used to assess ...

A Proton Magnetometer Survey of Borrow Areas Along Cut-Off Lake: L-246

MAY 1980

Authors: Larry Grantham; Earl W. McMurry; NORTHEAST MISSOURI STATE UNIV KIRKSVILLE

A proton magnetometer survey of borrow areas along the north shore of Cut-Off Lake was performed using a GEOMETRICS proton precession magnetometer. The area was surveyed using a twenty-feet grid spacing with five-feet grid spacings in areas of interest. Magnetic anomalies were discovered, but most of these were associated with modern artifacts at the surface. Two anomalies at the eastern end of the borrow areas were investigated in greater detail ...

Method and Apparatus for Reducing Magnetometer Errors.

18 MAR 1980

Authors: Arthur W. Obenschain; DEPARTMENT OF THE NAVY WASHINGTON DC

This invention relates to magnetometers and more particularly to a method and apparatus for reducing errors as a result of turnover and block misparabolism during the manufacture of a total field magnetometer. A total field magnetometer of the type contemplated by the present invention consists of three pairs of magnetometer elements arranged in three mutually perpendicular planes. Each of these magnetometer elements consists of a coil centered on a low ...

Mine Proximity Fuse.

26 FEB 1980

Authors: John M. Shaull; Godfrey R. Gauld; Lawson E. Richtmyer; DEPARTMENT OF THE ARMY WASHINGTON DC

Claim 1 (of 4) is for a proximity fuze for a stationary mine comprising: (a) a power supply; (b) a vibration sensitive switch having a stationary contact and a vibratory contact, one of said contacts being connected to said power supply: (c) an LC ringing circuit connected to the other of said contacts, said vibration sensitive switch intermittently conducting current from said power supply to said LC ringing circuit when ...

Method and Apparatus for Calibrating Gyroscopically-Stabilized, Magnetically-Slaved Heading Reference System.

19 FEB 1980

Authors: Matthew J. Fisher; William J. Gregory Jr; DEPARTMENT OF THE ARMY WASHINGTON DC

A heading reference system mounted in a vehicle, e.g. an aircraft or a tank, includes a magnetic compass and a gyroscope. The magnetic compass is subject to deviation in the magnetic field, hence the system must be calibrated. If the vehicle is oriented in a starting direction, and the output of the magnetic compass compared to the output of the gyroscope, an error signal is developed. This error signal is ...

Adaptive Cancellation of Magnetic Noise Generated by Ocean Surface Waves

15 FEB 1980

20 pages

Authors: G. A. Garcia; NAVAL OCEAN SYSTEMS CENTER SAN DIEGO CA

A method of suppressing ocean surface wave-generated magnetic noise from near surface-mounted total field magnetometer signals is presented. This technique uses reference data furnished by a measurement of the ocean surface displacement at a single point in the vicinity of the magnetometer to cancel adaptively the magnetic noise generated by the surface wave field. A transfer function is derived which relates the ocean surface displacement measurement to the associated magnetic ...

Angular Rate Sensor.

12 FEB 1980

Authors: Paul L. Jacobs; DEPARTMENT OF THE ARMY WASHINGTON DC

An angular rate sensor is conceived which operates by utilizing electrically conducting fluid flowing in a transverse magnetic field. The electric field induced in the flow direction due to rotation will produce a signal that is proportional to angular rate. (Author)

An Improved Self-Powered Vehicle Detection System.

01 FEB 1980

Authors: John F. Scarzello; Daniel S. Lenko; Albert D. Krall; Wayne R. Grine; Robert E. Brown; DEPARTMENT OF THE NAVY WASHINGTON DC

An improved self-powered vehicle detector (SPVD) uses a two-axis magnetometer in conjunction with digital nulling loops to sense a vehicle's magnetic signature and then telemeter vehicle presence information to a roadside receiver. The SPVD system includes a tone code transmitter and an omnidirectional microstrip antenna to simplify installation and maintenance of the SPVD. (Author)

Mine Search Coil Simulator.

01 JAN 1980

Authors: Gaylon L. West; John M. Boyle; DEPARTMENT OF THE NAVY WASHINGTON DC

A passive inductor and associated circuitry which enables a compact search coil to simulate the response characteristics of a service mine search coil having different electrical properties. Output from the passive inductor is amplified and modified to duplicate frequency response characteristics at ship frequency, magnetic sensitivity, and output impedance of a larger search coil. Provision is made for disengagement of magnetic surveillance by the inductor. (Author)

Use of a Parallel Plate Transmission Line to Calibrate a Fiber-Optic Coupled Magnetic Field Sensor.

JAN 1980

Authors: Andrew A. Cuneo Jr.; James L. Loftus; HARRY DIAMOND LABS ADELPHI MD

It is vitally important to accurately measure the field components of a simulated electromagnetic pulse (EMP), to determine both the waveshape and the amplitude of the electromagnetic test environment. A parallel plate transmission line is used to calibrate a magnetic field sensor as well as to determine the field enhancement factor when the sensor is mounted on the compact transmitter of an optical electronic data-link system. The transmitter is coupled ...

Final Report

1980

Authors: Stuart Schwartz; PRINCETON UNIV NJ DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE

Activity under this contract has centered on two general problem areas related to the airborne detection of underwater targets. The first utilizes anomalies in the earth's magnetic field to detect the presence of a target, while the second is a detection problem associated with returns from an optical radar. Two models and approaches for the detection of targets by means of measuring magnetic anomilies have been studied. In the first, ...

Method of Manufacturing a Magnetic Field Sensitivity Indicator Apparatus for Evaluating Magnetic Fields in Parts During Magnetic Particle Inspection.

30 OCT 1979

Authors: Gilbert L. Marsh; DEPARTMENT OF THE AIR FORCE WASHINGTON DC

The method of manufacture and use of a magnetic field sensitivity indicator apparatus for evaluating magnetic fields applied to ferromagnetic material parts during magnetic particle inspection utilizing known defect indicators to establish the strength and direction of magnetic fields in the parts under test. (Author)

2.06 Micron-Laser Rangefinder Technology.

SEP 1979

Authors: B. E. Hendrickson; L. S. O'hara; RCA GOVERNMENT SYSTEMS DIV BURLINGTON MA

A laser rangefinder receiver using a photoconductive, thermoelectrically cooled HgCdTe detector was developed for detection of the 2.06 micron wavelength Holmium laser. The HgCdTe receiver was tested with an RCA developed Ho:YLF laser as a laser rangefinder. Quantitative ranging tests were conducted and compared to predicted results utilizing the measured Noise Equivalent Power (NEP) of (5 - 10) (10 to the minue 10th power/square root of (Hz)) of the detector ...

Proceedings of the Air Force Geophysics Laboratory Workshop on Geomagnetism: April 6-7, 1979.

20 AUG 1979

Authors: Rita C. Sagalyn; Robert O. Hutchinson; Susan Gussenhoven; AIR FORCE GEOPHYSICS LAB HANSCOM AFB MA

On 6-7 April 1979 a two-day workshop on geomagnetism was held at the Air Force Geophysics Laboratory (AFGL). Proceedings of the workshop presented here include: reports on tutorial sessions concerning magnetospheric and geomagnetic pulsations, summaries of contributed papers, descriptions of active magnetometer networks, conclusions of workshop-discussion groups. Special emphasis is given to the use and future potential of the AFGL midlatitude magnetometer chain. (Author)

Preliminary Evaluation of an Algorithm for Analysis of Stationary Random Data from a Multiple-Input Linear System.

JUL 1979

Authors: Henry Hidalgo; Wasyl Wasylkiwskyj; INSTITUTE FOR DEFENSE ANALYSES ARLINGTON VA SCIENCE AND TECHNOLOGY DIV

This paper deals with a preliminary evaluation of a mean-squared estimated algorithm for the extraction of a signal that is embedded in superposed stationary noise processes. The motivation for this study is the processing and interpretation of data obtained in recent experiments to measure gradients of magnetic fields induced by internal waves in a shallow ocean. The approach used is simulation of the signal and noise processes through construction of ...

Electromagnetic Fields Induced by Ocean Currents

JUL 1979

297 pages

Authors: Wasyl Wasylkiwskyj; INSTITUTE FOR DEFENSE ANALYSES ALEXANDRIA VA SCIENCE AND TECHNOLOGY DIV

This paper provides a comprehensive account of analytical results for computing electromagnetic fields that are induced by ocean sea water as a result of its motion relative to the geomagnetic field. The emphasis is on the characterization of magnetic field and magnetic field gradient spectra induced by internal waves and surface waves in a deep ocean environment. The theoretical results are formulated so as to be directly applicable to the ...

Radiative Transmission Line Analysis.

JUN 1979

Authors: R. J. Garbacz; J. Richmond; B. Tran; M. Kuznetsov; F. McQuillin; OHIO STATE UNIV COLUMBUS ELECTROSCIENCE LAB

This Final Report summarizes the results of work accomplished on the theoretical analysis of two types of transmission lines for use as intruder sensors. One type is the Yagi line consisting of uniformly spaced, imperfectly conducting thin rods of identical length which are suspended a uniform height above and perpendicular to a lossy flat earth. A second type of line investigated theoretically is the single coaxial cable whose outer shield ...

Subterranean Anomalies Detection System.

20 APR 1979

Authors: Peder M. Hansen; John G. Hoffman; Edwin W. Seeley; Wesley A. Andrew; DEPARTMENT OF THE NAVY WASHINGTON DC

This patent application describes a method and apparatus for detecting anomalies beneath an area of the earth's surface wherein an oscillator couples a current into two conductors laid parallel to each other to generate two magnetic fields in the earth beneath the area. The magnetic field is measured along a line midway between the two horizontal conductors to detect for an increase in the measured field which is an indication ...

A Feasibility Study of the Use of SQUIDS for Scalar Field Magnetometry.

04 JAN 1979

Authors: J. H. Claassen; NAVAL RESEARCH LAB WASHINGTON D C

A single SQUID mounted on a platform subject to random motions in the earth's field will have large spurious components in its output. In order to recover the information of interest (changes in magnitude of the total magnetic field), it is necessary to combine the outputs of three mutually orthogonal sensors in an appropriate way. The coefficients characterizing this combination depend on the initial orientation of the platform relative to ...

Quarterly Bulletin of the Division of Mechanical Engineering and the National Aeronautical Establishment, Ottawa, 1 October to 31 December 1979.

1979

Authors: NATIONAL RESEARCH COUNCIL OF CANADA OTTAWA (ONTARIO) DIV OF MECHANICAL ENGINEERING

Contents: NAE Convair 580 Aeromagnetics Program; Urban Traffic Signal Control for Fuel Economy; and Current Projects of the Division of Mechanical Engineering and the National Aeronautical Establishment.

Electronic Intruder Detection System.

26 DEC 1978

Authors: Otto E. Rittenbach; Reinhard G. Olesch; DEPARTMENT OF THE ARMY WASHINGTON DC

An electronic detection system for detecting intruders employs a transmission line as a sensing element. In one embodiment the transmission line is a modified surface-wave transmission line, for example, a Goubau line, which is positioned about the perimeter of the area to be protected. An intruder in the field of the line causes an RF reflection back toward the source, which reflection may be detected by Doppler range-gating techniques. In ...

Investigation of Stress-Strain History Modeling at Stress Risers

DEC 1978

261 pages

Authors: James R. Carroll; R. L. Brugh; W. Wilkinson; LOCKHEED-GEORGIA CO MARIETTA

An analytical and experimental study of the stress and strain history at stress risers was conducted to evaluate the effects of time- and cycle- dependent changes on the fatigue life of aluminum alloy structures. This report covers Phase II of a two-phase program . Both creep and stress relaxation were modeled and measured. An elastic-plastic finite element code simulation was utilized to model the nonlinear stress-strain field around the stress ...

Investigation of Micropulsation Activity.

NOV 1978

Authors: William F. Bellew; M. Patricia Hagan; Robert L. Vesprini; EMMANUEL COLL BOSTON MASS

Programs, functions, and subroutines were designed to collect, archive, and provide user access to date received from the MAGAF data collection network. Subroutines were written to unpack a data frame from received data orer to instrument order, and also to repack data into received order. A series of plotting routines were added to the system to enable plot files in Varian Dataplot format and to produce magnetograms from the magnetometer ...

Development of a Self Powered Vehicle Detector

OCT 1978

235 pages

Authors: J. F. Scarzello; D. S. Lenko; A. D. Krall; R. E. Brown; NAVAL SURFACE WEAPONS CENTER WHITE OAK LAB SILVER SPRING MD

A battery operated motor vehicle detection system has been developed which detects a vehicle's magnetic signature, processes it and then transmits vehicle presence information from its roadway position to a nearby receiver control unit. The Self Powered Vehicle Detector (SPVD) is an advanced vehicle detector concept which requires minimum installation time and cost, little maintenance, and is capable of detecting vehicles on any standard roadway surface. The SPVD system consists ...

Variable Temperature Multimode Magnetometer.

SEP 1978

Authors: J. J. Winter; F. Rothwarf; H. A. Leupold; J. T. Breslin; ARMY ELECTRONICS RESEARCH AND DEVELOPMENT COMMAND FORT MONMOUTH NJ ELECTRONICS TECHNOLOGY/DEVICES LAB

Preinstallation Survey Guide for MAID-MILES System.

JUN 1978

Authors: Charles A. Miller; ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS

The study was conducted to investigate various field techniques to be used to identify the seismic response of the MAID-MILES system at a site. This report also presents a description of the steps needed to perform a preinstallation seismic survey for the MAID-MILES system. The general purpose of this survey is to determine the suitability of an installation for the deployment of the MAID-MILES system. This survey is designed to ...

The Effects of Work/Rest, Target Activity, Background Noise, and String Size on Operator Interpretation of Unattended Ground Sensor Records.

JUN 1978

Authors: Harold Martinek; Sterling Pilette; Billy Biggs; HRB-SINGER INC STATE COLLEGE PA

It was required to investigate the relationships between unattended ground sensor (UGS) operator performance and work/rest cycles, sensor string size, target activity levels, and noisy/quiet environments and to identify sources of operator error that can be eliminated through the use of new interpretation techniques, procedures, and training. The procedure was: Operators monitored UGS records for 8 hours of worktime under four different work/rest conditions: 2 hours works, 1 hour rest; ...

Method and Apparatus for Normalizing the Outputs of Sequentially Scanned Magnetic Flaw Detectors.

02 MAY 1978

Authors: Ray G. McCormack; DEPARTMENT OF THE ARMY WASHINGTON D C

A method and apparatus for detecting flaws in conduits or the like which comprises positioning an annular array of Hall-effect devices transversely around the conduit, applying an electric current to the conduit to flow longitudinally therethrough so as to create a magnetic field around the conduit, sequentially scanning the Hall-effect devices to produce a series of output signals corresponding to the portions of the magnetic field sensed respectively by them, ...

A Dynamic Magnetic Technique for Sensing Block Motion.

30 APR 1978

Authors: P. Coleman; SYSTEMS SCIENCE AND SOFTWARE LA JOLLA CALIF

We report the development of a technique for dynamically sensing relative displacements; the intended application is for the measurement of block motion due to an underground explosion. The technique utilizes a permanent bar magnet and a magnetometer system located about a meter from the magnet. Relative motoin between the magnet and magnetometer system leads to a time-varying magnetometer signal. The well-known properties of a magnetic dipole allows the magnet's relative ...

Exploratory Remote-Sensing Survey of the Folly-River-Stono Inlet, South Carolina, Improvement Project

APR 78

Authors: A. R. Saltus Jr; GULF SOUTH RESEARCH INST BATON ROUGE LA

The objective of the study was to perform an exploratory remote- sensing survey of the shoaled areas of the Folly River and Stono Inlet, South Carolina, an area covering approximately two miles. The survey was designed to locate, through the use of a proton precession magnetometer, any historically significant shipwreck material lying on or beneath this project area. The area of study included approximately 2.0 statute miles of the underwater ...

Exploratory Magnetic Survey of Murrell's Inlet, South Carolina, and Portions of the Main Creek Inner Channel

APR 78

13 pages

Authors: A. R. Saltus Jr; GULF SOUTH RESEARCH INST BATON ROUGE LA

The objective of the study was to perform an exploratory magnetometer survey of the underwater areas of Murrell's Inlet, South Carolina, portions of the Main Creek Inner Channel, and auxiliary channels. The survey was designed to locate historically significant shipwreck materials located beneath the project areas. A proton precession magnetometer was used to gather data on submerged artifacts. Two historically documented vessels were reported lost at or in the inlet, ...

Method for Determining Changes in Earth Resistivity by Measuring Phase Difference Between Magnetic Field Components.

14 MAR 1978

Authors: Elwin W. Seeley; DEPARTMENT OF THE NAVY WASHINGTON D C

Method and apparatus for detecting tunnels beneath an area of the earth's surface wherein an oscillator couples a current into a linear conductor at the earth's surface to generate a magnetic field in the earth beneath the area. Phase angle measuring means measures phase difference between the vertical and horizontal components of the magnetic field at selected points along a line parallel to the linear conductor to detect abrupt changes ...

Investigation of Micropulsation Activity. 1. MAGAF System Additions. 2. Data Analysis.

DEC 1977

Authors: William F. Bellew; Charles J. Cantor; M. Patricia Hagan; EMMANUEL COLL BOSTON MASS

Systems Additions to the MAGAF data processing system are described herein. In the area of data analysis, a program written to generate magnetograms from the MAGAF Network data is described and sample magnetograms are shown. (Author)

Project Linear Chair Array System FY 77 Report

DEC 77

Authors: NAVAL OCEAN RESEARCH AND DEVELOPMENT ACTIVITY NSTL STATION MS

This report describes a preliminary study of the use of a large suspended, Kevlar reinforced, instrumented array for project Linear Chair. Included in the report are candidate array structure, associated cables, mooring components and deployment scenario. Considerations are also given to repair and replacement requirements. Included and presented in graphical form is a deflection analysis of the array in a selected location. This study is based on the array requirements ...

A Modular Adaptive, Variable Function Flight Control Sensor.

OCT 1977

Authors: Roland Pittman; APPLIED DEVICES CORP KISSIMMEE FL

This development effort culminated in flight-worthy test articles of multi-function sensors, for use in 'strap-down' flight control systems. The multi-function sensor with one moving part, performs the equivalent to a two-axis rate gyro, two-axis linear accelerometer, a three-axis magnetic field sensor, a two-axis electric field sensor, and a two-axis air data probe. This development effort demonstrated the feasibility of a multi-function sensor which brings together the elements of a multi-mode ...

Magnetic Perturbation Inspection of Artillery Projectiles.

SEP 1977

Authors: Russell D. Williams; John R. Barton; SOUTHWEST RESEARCH INST SAN ANTONIO TEX

The objectives of this research were to determine feasibility for the application of magnetic perturbation inspection methods to interior and exterior surfaces of artillery projectiles casings. Inspections were performed on ten (10) projectiles. Subsequent metallurgical sectioning at seven (7) magnetically determined sites confirmed flaws at all selected locations. Feasibility of method was demonstrated. Basic conceptual design of a prototype inspection device is included. (Author)