Sample records for gyrocompasses

  1. 46 CFR 108.715 - Magnetic compass and gyrocompass.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Magnetic compass and gyrocompass. 108.715 Section 108... DESIGN AND EQUIPMENT Miscellaneous Equipment § 108.715 Magnetic compass and gyrocompass. (a) Each self-propelled unit in ocean or coastwise service must have a magnetic compass. (b) Each self-propelled unit of 1...

  2. 46 CFR 167.40-45 - Magnetic compass and gyrocompass.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Magnetic compass and gyrocompass. 167.40-45 Section 167... NAUTICAL SCHOOL SHIPS Certain Equipment Requirements § 167.40-45 Magnetic compass and gyrocompass. (a) All mechanically propelled vessels in ocean or coastwise service must be fitted with a magnetic compass. (b) All...

  3. 46 CFR 108.715 - Magnetic compass and gyrocompass.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Magnetic compass and gyrocompass. 108.715 Section 108... DESIGN AND EQUIPMENT Miscellaneous Equipment § 108.715 Magnetic compass and gyrocompass. (a) Each self-propelled unit in ocean or coastwise service must have a magnetic compass. (b) Each self-propelled unit of 1...

  4. 46 CFR 167.40-45 - Magnetic compass and gyrocompass.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Magnetic compass and gyrocompass. 167.40-45 Section 167... NAUTICAL SCHOOL SHIPS Certain Equipment Requirements § 167.40-45 Magnetic compass and gyrocompass. (a) All mechanically propelled vessels in ocean or coastwise service must be fitted with a magnetic compass. (b) All...

  5. Dynamics of the surveying gyrocompass

    NASA Astrophysics Data System (ADS)

    Petrenko, V. E.; Zakharenko, S. A.; Ponomarenko, A. E.

    The dynamics of the surveying gyrocompass is investigated analytically for the case of perturbations due to ball bearing imperfections. Approximate analytical expressions are obtained for calculating the natural frequencies of the compass in the presence of parametric perturbations of this kind. An example of natural frequency calculations is presented.

  6. 46 CFR 77.11-1 - When required.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SYSTEMS AND EQUIPMENT Magnetic Compass and Gyrocompass § 77.11-1 When required. (a) All mechanically propelled vessels in ocean, coastwise or Great Lakes service must be fitted with a magnetic compass. (b) All... gyrocompass in addition to the magnetic compass. (c) Each vessel must have an illuminated repeater for the...

  7. 46 CFR 96.17-1 - When required.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... MISCELLANEOUS SYSTEMS AND EQUIPMENT Magnetic Compass and Gyrocompass § 96.17-1 When required. (a) All mechanically propelled vessels in ocean or coastwise service must be fitted with a magnetic compass. (b) All... gyrocompass in addition to the magnetic compass. (c) Each vessel must have an illuminated repeater for the...

  8. 46 CFR 77.11-1 - When required.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SYSTEMS AND EQUIPMENT Magnetic Compass and Gyrocompass § 77.11-1 When required. (a) All mechanically propelled vessels in ocean, coastwise or Great Lakes service must be fitted with a magnetic compass. (b) All... gyrocompass in addition to the magnetic compass. (c) Each vessel must have an illuminated repeater for the...

  9. 46 CFR 195.19-1 - When required.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... MISCELLANEOUS SYSTEMS AND EQUIPMENT Magnetic Compass and Gyrocompass § 195.19-1 When required. (a) All mechanically propelled vessels in ocean or coastwise service must be fitted with a magnetic compass. (b) All... gyrocompass in addition to the magnetic compass. (c) Each vessel must have an illuminated repeater for the...

  10. 46 CFR 195.19-1 - When required.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... MISCELLANEOUS SYSTEMS AND EQUIPMENT Magnetic Compass and Gyrocompass § 195.19-1 When required. (a) All mechanically propelled vessels in ocean or coastwise service must be fitted with a magnetic compass. (b) All... gyrocompass in addition to the magnetic compass. (c) Each vessel must have an illuminated repeater for the...

  11. 46 CFR 96.17-1 - When required.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... MISCELLANEOUS SYSTEMS AND EQUIPMENT Magnetic Compass and Gyrocompass § 96.17-1 When required. (a) All mechanically propelled vessels in ocean or coastwise service must be fitted with a magnetic compass. (b) All... gyrocompass in addition to the magnetic compass. (c) Each vessel must have an illuminated repeater for the...

  12. 46 CFR 32.15-35 - Magnetic Compass and Gyrocompass-T/OC.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., MACHINERY, AND HULL REQUIREMENTS Navigation Equipment § 32.15-35 Magnetic Compass and Gyrocompass—T/OC. (a) All tankships in ocean or coastwise service must be fitted with a magnetic compass. (b) All tankships... 46 Shipping 1 2012-10-01 2012-10-01 false Magnetic Compass and Gyrocompass-T/OC. 32.15-35 Section...

  13. 46 CFR 32.15-35 - Magnetic Compass and Gyrocompass-T/OC.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Magnetic Compass and Gyrocompass-T/OC. 32.15-35 Section..., MACHINERY, AND HULL REQUIREMENTS Navigation Equipment § 32.15-35 Magnetic Compass and Gyrocompass—T/OC. (a) All tankships in ocean or coastwise service must be fitted with a magnetic compass. (b) All tankships...

  14. 46 CFR 32.15-35 - Magnetic Compass and Gyrocompass-T/OC.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Magnetic Compass and Gyrocompass-T/OC. 32.15-35 Section..., MACHINERY, AND HULL REQUIREMENTS Navigation Equipment § 32.15-35 Magnetic Compass and Gyrocompass—T/OC. (a) All tankships in ocean or coastwise service must be fitted with a magnetic compass. (b) All tankships...

  15. 46 CFR 185.220 - Records of a voyage resulting in a marine casualty.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., navigation charts, navigation work books, compass deviation cards, gyrocompass records, stowage plans... passenger lists and counts, articles of shipment, official logs, and other material that might be of...

  16. 46 CFR 122.220 - Records of a voyage resulting in a marine casualty.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., compass deviation cards, gyrocompass records, stowage plans, records of draft, aids to mariners, night order books, radiograms sent and received, radio logs, crew and passenger lists and counts, articles of...

  17. Technologies for Positioning and Placement of Underwater Structures

    DTIC Science & Technology

    2000-03-01

    for imaging the bottom immediately before placement of the structure. c. Use passive sensors (such as tiltmeters , inclinometers, and gyrocompasses...4 Acoustic Sensors .................................................................... 5 Multibeamn and Side-Scan Sonar Transducers...11.I Video Camera....................................................................11. Passive Sensors

  18. Active Control of a Pneumatic Isolation System,

    DTIC Science & Technology

    A pneumatically isolated test platform has been modified to provide active control to the local gravity vector. A combination of sensors , including... tiltmeters , angular accelerometers, seismometers, and a gyrocompass measure total platform motion between 0 and 100 Hz. Electrical-to-pressure

  19. 46 CFR 169.807 - Notice of casualty.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... the vessel's seaworthiness or fitness for service or route, including but not limited to fire... of the vessel involved, the name of the vessel's owner or agent, nature, location and circumstances..., navigation charts, navigation work books, compass deviation cards, gyrocompass records, record of draft, aids...

  20. 46 CFR 169.807 - Notice of casualty.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... the vessel's seaworthiness or fitness for service or route, including but not limited to fire... of the vessel involved, the name of the vessel's owner or agent, nature, location and circumstances..., navigation charts, navigation work books, compass deviation cards, gyrocompass records, record of draft, aids...

  1. 46 CFR 169.807 - Notice of casualty.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... the vessel's seaworthiness or fitness for service or route, including but not limited to fire... of the vessel involved, the name of the vessel's owner or agent, nature, location and circumstances..., navigation charts, navigation work books, compass deviation cards, gyrocompass records, record of draft, aids...

  2. Quartermaster 1 and C, Rate Training Manual.

    ERIC Educational Resources Information Center

    Naval Personnel Program Support Activity, Washington, DC.

    The subject matter of this training manual is prepared for regular navy and naval reserve personnel. Operations of gyrocompasses and magnetic and magnesyn compasses are discussed with a background of error determination, compass adjustments, and degaussing applications. Navigation techniques are analyzed in terms of piloting, dead reckoning,…

  3. Quartermaster 1 and C, Rate Training Manual.

    ERIC Educational Resources Information Center

    Naval Personnel Program Support Activity, Washington, DC.

    The technical subject matter of the Quartermaster rating is presented in this training manual written to prepare men of the Navy and Naval Reserve for advancement examinations. The manual includes eleven chapters. Discussed are commonly used methods and procedures of operating magnetic compasses and gyrocompasses, determining a ship's position,…

  4. 33 CFR 164.82 - Maintenance, failure, and reporting.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... safety, such as propulsion machinery, steering gear, radar, gyrocompass, echo depth-sounding or other... repair within 96 hours an inoperative marine radar required by § 164.72(a) shall so notify the Captain of... navigational-safety equipment, including but not limited to failure of one of two installed radars, where each...

  5. 33 CFR 164.82 - Maintenance, failure, and reporting.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... safety, such as propulsion machinery, steering gear, radar, gyrocompass, echo depth-sounding or other... repair within 96 hours an inoperative marine radar required by § 164.72(a) shall so notify the Captain of... navigational-safety equipment, including but not limited to failure of one of two installed radars, where each...

  6. 33 CFR 164.82 - Maintenance, failure, and reporting.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... safety, such as propulsion machinery, steering gear, radar, gyrocompass, echo depth-sounding or other... repair within 96 hours an inoperative marine radar required by § 164.72(a) shall so notify the Captain of... navigational-safety equipment, including but not limited to failure of one of two installed radars, where each...

  7. 33 CFR 164.82 - Maintenance, failure, and reporting.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... safety, such as propulsion machinery, steering gear, radar, gyrocompass, echo depth-sounding or other... repair within 96 hours an inoperative marine radar required by § 164.72(a) shall so notify the Captain of... navigational-safety equipment, including but not limited to failure of one of two installed radars, where each...

  8. 46 CFR 109.415 - Retention of records after casualty.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... casualty. (a) The owner, agent, master, or person in charge of a unit for which a report of casualty is... of casualty. (6) Navigation work books. (7) Compass deviation cards. (8) Gyrocompass records. (9...) The radio log. (14) Personnel list. (15) Crane record book. (c) The owner, agent, master, or person in...

  9. The Development of the Gyrocompass - Inventors as Navigators

    NASA Astrophysics Data System (ADS)

    Broelmann, J.

    1998-09-01

    Most reference books or monographs about the history of the gyrocompass portray individual inventors, each as an inventive genius, respected as a national hero and probably depicted creating novelties in 'brooding meditation'. This seems to be an accepted, rather comfortable point of view, as the subject covers the invention of a 'black-box'-type too. But the invention, development and the adaption of this gyro instrument in a complex technological and social system was not achieved on the basis of a 'single-handed' venture.If emerging technologies are not only scientific, but also involve social or cultural requirements, then communication along the networks of knowledge between inventor, mechanic and mathematician, the code of patent lawyers and financiers and - last but not least - navigation officers and the red tape of a navy must play an influential role. I would thus like to sketch out the subject of invention as communication and present the inventor as a navigator, someone who leads his crew through all currents, shallows and drifts and, while keeping ahead of other competitors, arrives at some still uncertain location.

  10. Worldwide Radionavigation Systems

    DTIC Science & Technology

    1993-09-01

    apparent pole star changes over time. In 3,000 BC the pole star was a Draconis, the brightest star in the constellation Draco (the Dragon), located...the yet-to-be-completed Global Positioning System (GPS), have added a new dimension to the science of navigation. The gyrocompass and inertial platforms...funded as an IDA Central Research Project, is a collection of technical descriptions of worldwide radionavigation systems written by the author over a

  11. Seismic Motion Stability, Measurement and Precision Control.

    DTIC Science & Technology

    1979-12-01

    tiltmeter . Tilt was corrected by changing air pressure in one bank of isolators to maintain the reference tiltmeter at null well within the 0.1 arcsecond...frequency rotations (0-0.1 Hz), a high quality, two-axis tiltmeter is used. The azimuth orientation angle could be measured with a four-position gyro...compassing system with considerably less accuracy than the tiltmeters . However, it would provide a continuous automatic azimuth determination update every

  12. Description and Applications for an Automated Inertial Azimuth Measuring System,

    DTIC Science & Technology

    specialized field environment. The present system consists of two integrated inertial sensors , an angle transfer system, a tiltmeter array and a...optical path. Highly sensitive tiltmeters are used to measure and correct for errors due to base motions of the inertial sensors . Data handling and...microprocessor. The inertial sensors use gimbal-mounted rate gyrocompasses to indicate the azimuths of two transfer mirrors with respect to true North. The

  13. North Seeking Gyrocompass.

    DTIC Science & Technology

    1981-01-01

    ENVIRONMENTAL TEST SPECIFICATION FOR GIMBAL MOUNT 67 2 LIST OF ILLUSTRATIONS Figure Title Page 1 NFM Mounted on NSG Gimbals 6 2 NSG Family Tree 9 3 NFM...has a rating of .45 ampere-hours and can provide up to 30 northings on one charge. The NSG is designed to operate either on the vehicle batery or the BB...is included in Appendix B. The acceptance test requirements for the NFM are presented in Appendix C. The environmental test specification for the NSG

  14. Low Cost Gyrocompass.

    DTIC Science & Technology

    1984-06-01

    consists of a pair of LVDT’s amplifiers and electro- magnetic forcers. The current through the forcers provide a mea- sure of tilt angle since it measures...suspension system which exhibits the astatic property (zero friction and infinite comnliance). There are no ",rey" or questionable areas in the design since...due to relative bCase translation is achieved by uifirga earailelogra:n trip)od K- nife -edgle arrangement of floxure uoonoe in contras:t to a sirn;Ue

  15. Seasat-A attitude control system

    NASA Technical Reports Server (NTRS)

    Weiss, R.; Rodden, J. J.; Hendricks, R. J.

    1977-01-01

    The Seasat-A attitude control system controls the attitude of the satellite system during injection into final circular orbit after Atlas boost, during orbit adjust and trim phases, and throughout the 3-year mission. Ascent and injection guidance and attitude control are provided by the Agena spacecraft with a gyrocompassed mass expulsion system. On-orbit attitude control functions are performed by a system that has its functional roots in the gravity-gradient momentum bias technology. The paper discusses hardware, control laws, and simulation results.

  16. Multiple IMU system test plan, volume 4. [subroutines for space shuttle requirements

    NASA Technical Reports Server (NTRS)

    Landey, M.; Vincent, K. T., Jr.; Whittredge, R. S.

    1974-01-01

    Operating procedures for this redundant system are described. A test plan is developed with two objectives. First, performance of the hardware and software delivered is demonstrated. Second, applicability of multiple IMU systems to the space shuttle mission is shown through detailed experiments with FDI algorithms and other multiple IMU software: gyrocompassing, calibration, and navigation. Gimbal flip is examined in light of its possible detrimental effects on FDI and navigation. For Vol. 3, see N74-10296.

  17. The Coriolis field

    NASA Astrophysics Data System (ADS)

    Costa, L. Filipe; Natário, José

    2016-05-01

    We present a pedagogical discussion of the Coriolis field, emphasizing its not-so-well-understood aspects. We show that this field satisfies the field equations of the so-called Newton-Cartan theory, a generalization of Newtonian gravity that is covariant under changes of arbitrarily rotating and accelerated frames. Examples of solutions of this theory are given, including the Newtonian analogue of the Gödel universe. We discuss how to detect the Coriolis field by its effect on gyroscopes, of which the gyrocompass is an example. Finally, using a similar framework, we discuss the Coriolis field generated by mass currents in general relativity, and its measurement by the gravity probe B and LAGEOS/LARES experiments.

  18. In-flight angular alignment of inertial navigation systems by means of radio aids

    NASA Technical Reports Server (NTRS)

    Tanner, W.

    1972-01-01

    The principles involved in the angular alignment of the inertial reference by nondirectional data from radio aids are developed and compared with conventional methods of alignment such as gyro-compassing and pendulous vertical determination. The specific problem is considered of the space shuttle reentry and a proposed technique for the alignment of the inertial reference system some time before landing. A description is given of the digital simulation of a transponder interrogation system and of its interaction with the inertial navigation system. Data from reentry simulations are used to demonstrate the effectiveness of in-flight inertial system alignment. Concluding remarks refer to other potential applications such as space shuttle orbit insertion and air navigation of conventional aircraft.

  19. Quantum imaging for underwater arctic navigation

    NASA Astrophysics Data System (ADS)

    Lanzagorta, Marco

    2017-05-01

    The precise navigation of underwater vehicles is a difficult task due to the challenges imposed by the variable oceanic environment. It is particularly difficult if the underwater vehicle is trying to navigate under the Arctic ice shelf. Indeed, in this scenario traditional navigation devices such as GPS, compasses and gyrocompasses are unavailable or unreliable. In addition, the shape and thickness of the ice shelf is variable throughout the year. Current Arctic underwater navigation systems include sonar arrays to detect the proximity to the ice. However, these systems are undesirable in a wartime environment, as the sound gives away the position of the underwater vehicle. In this paper we briefly describe the theoretical design of a quantum imaging system that could allow the safe and stealthy navigation of underwater Arctic vehicles.

  20. Development of a Self-Calibrated MEMS Gyrocompass for North-Finding and Tracking

    NASA Astrophysics Data System (ADS)

    Prikhodko, Igor P.

    This Ph.D. dissertation presents development of a microelectromechanical (MEMS) gyrocompass for north-finding and north-tracking applications. The central part of this work enabling these applications is control and self-calibration architectures for drift mitigation over thermal environments, validated using a MEMS quadruple mass gyroscope. The thesis contributions are the following: • Adapted and implemented bias and scale-factor drifts compensation algorithm relying on temperature self-sensing for MEMS gyroscopes with high quality factors. The real-time self-compensation reduced a total bias error to 2 °/hr and a scale-factor error to 500 ppm over temperature range of 25 °C to 55 °C (on par with the state-of-the-art). • Adapted and implemented a scale-factor self-calibration algorithm previously employed for macroscale hemispherical resonator gyroscope to MEMS Coriolis vibratory gyroscopes. An accuracy of 100 ppm was demonstrated by simultaneously measuring the true and estimated scale-factors over temperature variations (on par with the state-of-the art). • Demonstrated north-finding accuracy satisfying a typical mission requirement of 4 meter target location error at 1 kilometer stand-off distance (on par with a GPS accuracy). Analyzed north-finding mechanizations trade-offs for MEMS vibratory gyroscopes and demonstrated measurements of the Earth's rotation (15 °/hr). • Demonstrated, for the first time, an angle measuring MEMS gyroscope operation for north-tracking applications in a +/-500 °/s rate range and 100 Hz bandwidth, eliminating both bandwidth and range constraints of conventional open-loop Coriolis vibratory gyroscopes. • Investigated hypothesis that surface-tension driven glass-blowing microfabrication can create highly spherical shells for 3-D MEMS. Without any trimming or tuning of the natural frequencies, a 1 MHz glass-blown 3-D microshell resonator demonstrated a 0.63 % frequency mismatch between two degenerate 4-node wineglass modes. • Multi-axis rotation detection for nuclear magnetic resonance (NMR) gyroscope was proposed and developed. The analysis of cross-axis sensitivities for NMR gyroscope was performed. The framework for the analysis of NMR gyroscope dynamics for both open loop and closed loop modes of operation was developed.

  1. Integration and flight test of a biomimetic heading sensor

    NASA Astrophysics Data System (ADS)

    Chahl, Javaan; Mizutani, Akiko

    2013-04-01

    We report on the first successful development and implementation of an automatic polarisation compass as the primary heading sensor for a UAV. Polarisation compassing is the primary navigation sense of many flying and walking insects, including bees, ants and crickets. Manually operated polarisation astrolabes were fitted in some passenger airliners prior to the implementation of the global positioning system, to compensate for the overal degradation of magnetic and gyrocompass sensors in polar regions. The device we developed demonstrated accurate determination of the direction of the Sun, with repeatability of better than 0.2 degrees. These figures are comparable to any solid state magnetic compass, including flux gate based devices. Flight trials were undertaken in which the output of the polarimeter was the only heading reference used by the aircraft as it flew through GPS waypoints.

  2. Car suspension system monitoring under road conditions

    NASA Astrophysics Data System (ADS)

    Fedotov, A. I.; Kuznetsov, N. Y.; Lysenko, A. V.; Vlasov, V. G.

    2017-12-01

    The paper describes an advanced gyro-based measuring system comprising a CGV-4K central vertical gyro and a G-3M gyrocompass. The advanced system provides additional functions that help measure unsprung mass rotation angles about a vertical axis, rolling angles, trim angles and movements of the unsprung masses of the front (ap and al) and rear b axes when a car wheel hits a single obstruction. The paper also describes the operation of the system, which measures movements of unsprung masses about the body of a car when it hits a single obstruction. The paper presents the dependency diagrams ap = f(t) and al = f(t) for front and rear wheels respectively, as well as b = f(t) for a rear left wheel, which were determined experimentally. Test results for a car equipped with an advanced gyro-based measuring system moving around a circle can form a basis for developing a mathematical model of the process.

  3. Description and evaluation of the Acoustic Profiling of Ocean Currents (APOC) system used on R. V. Oceanus cruise 96 on 11-22 May 1981

    NASA Technical Reports Server (NTRS)

    Joyce, T. M.; Rintoul, S. R., Jr.; Barbour, R. L.

    1982-01-01

    The underway current profiling system which consists of a microprocessor controlled data logger that collects and formats data from a four beam Ametek-Straza 300 kHz acoustic Doppler current profiler, heading from the ship's gyrocompass, and navigation information from a Loran-C receiver and a satellite navigation unit is discussed. Data are recorded on magnetic tape and real time is calculated. Time averaging is required to remove effects of ship motion. An intercomparison is made with a moored vector measuring current meter (VMCM). The mean difference in hourly averaged APOC and VMCM currents over the four hour intercomparison is a few mm s minus including: two Gulf Stream crossings, a warm core ring survey, and shallow water in a frontal zone to the east of Nantucket Shoals.

  4. 6DOF Testing of the SLS Inertial Navigation Unit

    NASA Technical Reports Server (NTRS)

    Geohagan, Kevin W.; Bernard, William P.; Oliver, T. Emerson; Strickland, Dennis J.; Leggett, Jared O.

    2018-01-01

    The Navigation System on the NASA Space Launch System (SLS) Block 1 vehicle performs initial alignment of the Inertial Navigation System (INS) navigation frame through gyrocompass alignment (GCA). In lieu of direct testing of GCA accuracy in support of requirement verification, the SLS Navigation Team proposed and conducted an engineering test to, among other things, validate the GCA performance and overall behavior of the SLS INS model through comparison with test data. This paper will detail dynamic hardware testing of the SLS INS, conducted by the SLS Navigation Team at Marshall Space Flight Center's 6DOF Table Facility, in support of GCA performance characterization and INS model validation. A 6-DOF motion platform was used to produce 6DOF pad twist and sway dynamics while a simulated SLS flight computer communicated with the INS. Tests conducted include an evaluation of GCA algorithm robustness to increasingly dynamic pad environments, an examination of GCA algorithm stability and accuracy over long durations, and a long-duration static test to gather enough data for Allan Variance analysis. Test setup, execution, and data analysis will be discussed, including analysis performed in support of SLS INS model validation.

  5. Single-channel seismic-reflection profiles from Massachusetts coastal waters and the western part of Georges Bank

    USGS Publications Warehouse

    Eskenasy, Diane M.

    1980-01-01

    The U.S. Geological Survey collected approximately 1,200 km each of airgun and minisparker single-channel seismic-reflection profiles during the R/V FAY cruise 023 in September 1976. The purpose of the 6-day cruise was to study the shallow sedimentary structure south and east of southern Massachusetts and to obtain magnetic and gravity data in these areas and in the vicinity of Great South Channel and Cape Ann. The survey was conducted by the U.S. Geo­logical Survey as part of the Massachusetts Cooperative Marine Geologic Program.Seismic instruments used include a 1Teledyne 600-joule minisparker system and a 20-in3 airgun system. Navigational data during the cruise were obtained by the use of an Integrated Navigation System, which included the following sub­systems:Teledyne Loran-C for both range-range and hyperbofic positions;Magnovox s'atellite receiver;Sperry Mark-29 gyrocompass; andHewlett-Packard 21 MX computer system with dual 9-track magnetic tape recording.The original records may be studied at the U.S. Geological Survey offices in Woods Hole, Mass. Copies of the records can be purchased only from the National Geophysical and Solar-Terrestrial Data Center, NOAA/EDIS/NGSDC, Code D621, 325 Broadway, Boulder CO 80303- (303-497-6338).

  6. First Gravity Traverse on the Martian Surface from the Curiosity Rover

    NASA Astrophysics Data System (ADS)

    Lewis, K. W.; Peters, S. F.; Gonter, K. A.; Vasavada, A. R.

    2016-12-01

    Orbital gravity surveys have been a key tool in understanding planetary interiors and shallow crustal structure, exemplified by recent missions such as GRAIL and Juno. However, due to the loss of spatial resolution with altitude, airborne and ground-based survey methods are typically employed on the Earth. Previously, the Lunar Traverse Gravimeter experiment on the Apollo 17 mission has been the only attempt to collect surface gravity measurements on another planetary body. We will describe the results of the first gravity survey on the Martian surface, using data from the Curiosity rover over its >10 km traverse across the floor of Gale crater and lower slopes of Mount Sharp. These results enable us to estimate bulk rock density, and to search for potential subsurface density anomalies. To measure local gravitational acceleration, we use one of the two onboard Rover Inertial Measurement Units (RIMU-A), designed for rover position and fine attitude determination. The IMU contains three-axis micro-electromechanical (MEMS) accelerometers and fiber-optic gyros, and is used for gyrocompassing by integrating data for several minutes on sols with no drive or arm motions (roughly 50% of sols to date). Raw acceleration data are calibrated for biases induced by temperature effects and rover orientation, along with rover elevation over the course of the mission using multiple regression. We use the best fit linear relationship between topographic height and gravitational acceleration to estimate a Bouguer correction for the observed change in magnitude over the mission as the rover has ascended over 100 meters up the lower slopes of Mount Sharp. We find a relatively low best-fit density of 1600 +/- 500 kg/m^3 for the rocks of Mount Sharp, consistent with rover-based measurements of thermal inertial, and potentially indicating pervasive fracturing, high porosity and/or low compaction within the original sediments at least to depths of order 100 meters. Future measurements will further refine this estimate as Curiosity continues to gain elevation. Although not originally intended as a science instrument, these results highlight the scientific potential of surface gravity and topography surveys for future planetary exploration missions.

  7. 6DOF Testing of the SLS Inertial Navigation Unit

    NASA Technical Reports Server (NTRS)

    Geohagan, Kevin; Bernard, Bill; Oliver, T. Emerson; Leggett, Jared; Strickland, Dennis

    2018-01-01

    The Navigation System on the NASA Space Launch System (SLS) Block 1 vehicle performs initial alignment of the Inertial Navigation System (INS) navigation frame through gyrocompass alignment (GCA). Because the navigation architecture for the SLS Block 1 vehicle is a purely inertial system, the accuracy of the achieved orbit relative to mission requirements is very sensitive to initial alignment accuracy. The assessment of this sensitivity and many others via simulation is a part of the SLS Model-Based Design and Model-Based Requirements approach. As a part of the aforementioned, 6DOF Monte Carlo simulation is used in large part to develop and demonstrate verification of program requirements. To facilitate this and the GN&C flight software design process, an SLS-Program-controlled Design Math Model (DMM) of the SLS INS was developed by the SLS Navigation Team. The SLS INS model implements all of the key functions of the hardware-namely, GCA, inertial navigation, and FDIR (Fault Detection, Isolation, and Recovery)-in support of SLS GN&C design requirements verification. Despite the strong sensitivity to initial alignment, GCA accuracy requirements were not verified by test due to program cost and schedule constraints. Instead, the system relies upon assessments performed using the SLS INS model. In order to verify SLS program requirements by analysis, the SLS INS model is verified and validated against flight hardware. In lieu of direct testing of GCA accuracy in support of requirement verification, the SLS Navigation Team proposed and conducted an engineering test to, among other things, validate the GCA performance and overall behavior of the SLS INS model through comparison with test data. This paper will detail dynamic hardware testing of the SLS INS, conducted by the SLS Navigation Team at Marshall Space Flight Center's 6DOF Table Facility, in support of GCA performance characterization and INS model validation. A 6-DOF motion platform was used to produce 6DOF pad twist and sway dynamics while a simulated SLS flight computer communicated with the INS. Tests conducted include an evaluation of GCA algorithm robustness to increasingly dynamic pad environments, an examination of GCA algorithm stability and accuracy over long durations, and a long-duration static test to gather enough data for Allan Variance analysis. Test setup, execution, and data analysis will be discussed, including analysis performed in support of SLS INS model validation.

  8. Constraining calving front processes on W Greenland outlet glaciers using inertial-corrected laser scanning & swath-bathymetry

    NASA Astrophysics Data System (ADS)

    Bates, R.; Hubbard, A.; Neale, M.; Woodward, J.; Box, J. E.; Nick, F.

    2010-12-01

    Calving and submarine melt account for the majority of loss from the Antarctic and over 50% of that from the Greenland Ice Sheet. These ice-ocean processes are highly efficient mass-loss mechanisms, providing a rapid link between terrestrial ice (storage) and the oceanic sink (sea level/freshwater flux) which renders the ocean-outlet-ice sheet system potentially highly non-linear. Despite this, the controls on tidewater processes are poorly understood and a process based description of them is lacking from the present generation of coupled ice sheet models. We present details from an innovative study where two survey techniques are integrated to enable the construction of accurate, ~m resolution 3d digital terrain models (DTMs) of the aerial and submarine ice front of calving outlet glaciers. A 2km range terrestrial laser scanner was combined with a 416KHz swath-interferometric system and corrected via an inertial motion unit stabilized by RTK GPS and gyro-compass data. The system was mounted aboard a heavy displacement (20,000kg) yacht in addition to a light displacement (100kg) semi-autonomous boat and used to image the aerial and submarine calving fronts of two large outlet glaciers in W Greenland. Six daily surveys, each 2.5km long were repeated across Lille Glacier during which significant ice flow, melt and calving events were observed and captured from on-ice GPS stations and time-lapse sequences. A curtain of CTD and velocity casts were also conducted to constrain the fresh and oceanic mass and energy fluxes within the fjord. The residual of successive DTMs yield the spatial pattern of frontal change enabling the processes of aerial and submarine calving and melt to be quantified and constrained in unprecedented detail. These observed frontal changes are tentatively related to local dynamic, atmospheric and oceanographic processes that drive them. A partial survey of Store Glacier (~7km calving front & W Greenland 2nd largest outlet after Jakobshavn Isbrae) was conducted, indicating that the technique is successful up to ~500m from the ice front and to a similar water depth. These data sets show that it is possible to integrate and build 3d DTMs at the metre-scale both above and below the water surface. The successful acquisition from our semi-autonomous vessel supervised up to 2km away greatly eases repeat surveys and reduces the exposure of equipment and personnel to the risks posed by large, active calving glaciers. Lille Glacier and s/v Gambo surveyed & photographed from the semi-autonomous vessel. Mock-up of Lille Glacier calving front and fore-bay submarine topography imaged by interferometric swath-bathymetry.

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