Search NASA⌕ Search

SEARCH · Search NASA

Results for “laser ranging”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 559 records · Page 31
All sourcesNASA NTRSDOE OSTI
NASA NTRS2014

NASA Tech Briefs, January 2014

Topics include: Multi-Source Autonomous Response for Targeting and Monitoring of Volcanic Activity; Software Suite to Support In-Flight Characterization of Remote Sensing Systems; Visual Image Sensor Organ Replacement; Ultra-Wideband, Dual-Polarized, Beam-Steering P-Band Array Antenna; Centering a DDR Strobe in the Middle of a Data Packet; Using a Commercial Ethernet PHY Device in a Radiation Environment; Submerged AUV Charging Station; Habitat Demonstration Unit (HDU) Vertical Cylinder Habitat; Origami-Inspired Folding of Thick, Rigid Panels; A Novel Protocol for Decoating and Permeabilizing Bacterial Spores for Epifluorescent Microscopy; Method and Apparatus for Automated Isolation of Nucleic Acids from Small Cell Samples; Enabling Microliquid Chromatography by Microbead Packing of Microchannels; On-Command Force and Torque Impeding Devices (OC-FTID) Using ERF; Deployable Fresnel Rings; Transition-Edge Hot-Electron Microbolometers for Millimeter and Submillimeter Astrophysics; Spacecraft Trajectory Analysis and Mission Planning Simulation (STAMPS) Software; Cross Support Transfer Service (CSTS) Framework Library; Arbitrary Shape Deformation in CFD Design; Range Safety Flight Elevation Limit Calculation Software; Frequency-Modulated, Continuous-Wave Laser Ranging Using Photon-Counting Detectors; Calculation of Operations Efficiency Factors for Mars Surface Missions; GPU Lossless Hyperspectral Data Compression System; Robust, Optimal Subsonic Airfoil Shapes; Protograph-Based Raptor-Like Codes; Fuzzy Neuron: Method and Hardware Realization; Kalman Filter Input Processor for Boresight Calibration; Organizing Compression of Hyperspectral Imagery to Allow Efficient Parallel Decompression; and Temperature Dependences of Mechanisms Responsible for the Water-Vapor Continuum Absorption.

Source record↗
NASA NTRS1993

The new MTLRS transmitting system

This paper presents a detailed description about the new transmitting system of the Modular Transportable Laser Ranging Systems MTLRS-1/2. A simplified theory of the Self Filtering Unstable Resonator (SFUR) is explained. Laser design details are discussed concerning the extreme environmental conditions in which these mobile systems are operating. Details are given concerning the new avalanche START detector. The new SFUR laser and START detector are necessary parts in order to bring both mobile systems towards 1 cm ranging accuracy.

Sperber, Peter↗
NASA NTRS1966

Satellite tracking with a laser

Satellite tracking with laser - range equation, detection at night and in daylight, noncooperative satellites, and comparison of of laser and radar systems

LASER↗
NASA NTRS1979

Is lunar ranging a viable component in a next-generation earth rotation service

The present actuality of the application of lunar laser ranging to the problem of the experimental determination of earth's rotation is discussed. The current status of the 'Earth Rotation from Lunar Distances' (EROLD) program is briefly summarized. Some results obtained up to 1978 for UT0 determinations are noted, and the situation regarding stations in Australia, France, West Germany, Japan, the United States, and the USSR is reviewed.

Mulholland, J. D.↗
NASA NTRS1985

A global geodetic reference frame from Lageos ranging (SL5.1AP)

A summary of the results obtained for a new comprehensive geodetic parameter solution from the analysis of Lageos laser ranging data for the period May 1976 to the end of 1982 is presented. Estimates of each component of the polar motion and earth rotation, the station coordinates, the value of the earth's gravitational constant GM, and the elements of the Lageos orbit comprise this SL5.1AP solution. The results differ from previously published values primarily through incorporation of more rigorous dynamic models for the ocean and solid earth tides. The precision of the geodetic parameters are on average 5-marc sec polar motion, 0.2-ms length of day, better than 5-cm center-of-mass geodetic positioning, 3-cm global baselines, and 2-cm regional baselines. An assessment of the contribution of systematic errors in the interstation distance determination is presented.

Smith, D. E.↗
NASA NTRS1978

Structural Alignment Sensor Feasibility Demonstration

A structural alignment sensor (SAS) was developed for use with large deployable antenna systems for contour measurement and/or active control. The SAS is a laser ranging system using frequency modulation and accurate phase measurement to determine distance. Work was done with a CO2 and HeNe laser. The capability of the SAS to measure antenna rib contours was studied over ranges of 50 meters to a resolution of 100 microns. Initial resolution data was taken with the CO2 system. This data shows that it will indeed meet the SAS requirements. The development of the HeNe system was initiated because it offers substantial improvement in size, weight, and power over the CO2 system. The final demonstration was made with the HeNe system and it too showed that the SAS requirements could be met with this alternate approach. The projection of these results to a conceptual design for a flight system and its application are described.

Anderson, R. H.↗
NASA NTRS1994

Design of an unmanned Martian polar exploration system

The design of an unmanned Martian polar exploration system is presented. The system elements include subsystems for transportation of material from earth to Mars, study of the Martian north pole, power generation, and communications. Early next century, three Atlas 2AS launch vehicles will be used to insert three Earth-Mars transfer vehicles, or buses, into a low-energy transfer orbit. Capture at Mars will be accomplished by aerobraking into a circular orbit. Each bus contains four landers and a communications satellite. Six of the twelve total landers will be deployed at 60 deg intervals along 80 deg N, and the remaining six landers at 5 deg intervals along 30 deg E from 65 deg N to 90 deg N by a combination of retrorockets and parachutes. The three communications satellites will be deployed at altitudes of 500 km in circular polar orbits that are 120 deg out of phase. These placements maximize the polar coverage of the science and communications subsystems. Each lander contains scientific equipment, two microrovers, power supplies, communications equipment, and a science computer. The lander scientific equipment includes a microweather station, seismometer, thermal probe, x-ray spectrometer, camera, and sounding rockets. One rover, designed for short-range (less than 2 km) excursions from the lander, includes a mass spectrometer for mineral analysis, an auger/borescope system for depth profiling, a deployable thermal probe, and charge coupled device cameras for terrain visualization/navigation. The second rover, designed for longer-range (2-5 km) excursions from the lander, includes radar sounding/mapping equipment, a seismometer, and laser ranging devices. Power for all subsystems is supplied by a combination of solar cells, Ni-H batteries, and radioisotope thermoelectric generators. Communications are sequenced from rovers, sounding rockets, and remote sensors to the lander, then to the satellites, through the Deep Space Network to and from earth.

Baldwin, Curt↗
NASA NTRS1989

An improved model for the Earth's gravity field

An improved model for the Earth's gravity field, TEG-1, was determined using data sets from fourteen satellites, spanning the inclination ranges from 15 to 115 deg, and global surface gravity anomaly data. The satellite measurements include laser ranging data, Doppler range-rate data, and satellite-to-ocean radar altimeter data measurements, which include the direct height measurement and the differenced measurements at ground track crossings (crossover measurements). Also determined was another gravity field model, TEG-1S, which included all the data sets in TEG-1 with the exception of direct altimeter data. The effort has included an intense scrutiny of the gravity field solution methodology. The estimated parameters included geopotential coefficients complete to degree and order 50 with selected higher order coefficients, ocean and solid Earth tide parameters, Doppler tracking station coordinates and the quasi-stationary sea surface topography. Extensive error analysis and calibration of the formal covariance matrix indicate that the gravity field model is a significant improvement over previous models and can be used for general applications in geodesy.

Tapley, B. D.↗
NASA NTRS2011

Laser Frequency Stabilization

Laser ranging and interferometry are essential technologies allowing for many astounding new spacebased missions such as the Laser Interferometer Space Antenna (LISA) to measure gravitational radiation emitted from distant super massive black hole mergers or distributed aperture telescopes with unprecedented angular resolution in the NIR or visible regime. The requirements on laser frequency noise depend on the residual motion and the distances between the spacecraft forming the interferometer. The intrinsic frequency stability of commercial lasers is several orders of magnitude above these requirements. Therefore, it is necessary for lasers to be stabilized to an ultrastable frequency reference so that they can be used to sense and control distances between spacecraft. Various optical frequency references and frequency stabilization schemes are considered and investigated for the applicability and usefulness for space-based interferometry missions.

Donelan, Darsa↗
NASA NTRS2007

NASA Goddard's Application of Lasers in Space

Researchers at NASA Goddard have been applying lasers for space measurements for over 4 decades, starting with satellite laser ranging in the mid 1960s. This talk will briefly review the history of Goddard's application to lasers to the scientific exploration of space, provide an overview of its ongoing laser-related programs, and give some possibilities for the future.

Abshire, James B.↗
NASA NTRS2011

Spectrally Tailored Pulsed Thulium Fiber Laser System for Broadband Lidar CO2 Sensing

Thulium doped pulsed fiber lasers are capable of meeting the spectral, temporal, efficiency, size and weight demands of defense and civil applications for pulsed lasers in the eye-safe spectral regime due to inherent mechanical stability, compact "all-fiber" master oscillator power amplifier (MOPA) architectures, high beam quality and efficiency. Thulium fiber's longer operating wavelength allows use of larger fiber cores without compromising beam quality, increasing potential single aperture pulse energies. Applications of these lasers include eye-safe laser ranging, frequency conversion to longer or shorter wavelengths for IR countermeasures and sensing applications with otherwise tough to achieve wavelengths and detection of atmospheric species including CO2 and water vapor. Performance of a portable thulium fiber laser system developed for CO2 sensing via a broadband lidar technique with an etalon based sensor will be discussed. The fielded laser operates with approximately 280 J pulse energy in 90-150ns pulses over a tunable 110nm spectral range and has a uniquely tailored broadband spectral output allowing the sensing of multiple CO2 lines simultaneously, simplifying future potentially space based CO2 sensing instruments by reducing the number and complexity of lasers required to carry out high precision sensing missions. Power scaling and future "all fiber" system configurations for a number of ranging, sensing, countermeasures and other yet to be defined applications by use of flexible spectral and temporal performance master oscillators will be discussed. The compact, low mass, robust, efficient and readily power scalable nature of "all-fiber" thulium lasers makes them ideal candidates for use in future space based sensing applications.

Heaps, William S.↗
NASA NTRS2008

Range-Gated Metrology with Compact Optical Head

This work represents a radical simplification in the design of the optical head needed for high-precision laser ranging applications. The optical head is now a single fiber-optic collimator with dimensions of order of 1 1 2 cm, which can be easily integrated into the system being measured with minimal footprint.

Dubovitsky, Serge↗
NASA NTRS1972

Calculation of retroreflector array transfer functions

Computer programs have been developed for calculating the transfer function of a retroreflector array. The transfer functions provide range corrections and effective reflecting areas for the retroreflector arrays carried by satellites now in orbit. This information can be used to estimate laser echo signal strengths and to correct laser range measurements in order to obtain the range to the center of mass of the satellite. The values are tabulated for various angles of incidence of the laser beam with respect to the symmetry axis of the satellite. Transfer functions have been computed for the following satellites: BE-B, BE-C, Geos 1, D1C, D1D, Geos 2, Peole, and Geos C.

Arnold, D. A.↗
NASA NTRS1992

Coherent summation of spatially distorted laser Doppler signals by using a two-dimensional heterodyne detector array

Phase-sensitive coherent summation of individual heterodyne detector array signals was demonstrated for the enhanced detection of spatially distorted laser Doppler returns. With the use of a 2 x 2 heterodyne detector array, the phase and amplitude of a time-varying speckle pattern was detected, and the signal-to-noise ratio of the Doppler shift estimate was shown to be improved by a factor of 2, depending on the extent of spatial coherence loss. These results are shown to agree with a first-order analysis and indicate the advantage of coherent summation for both short-range laser Doppler velocimetry and long-range atmospheric coherent lidar.

Chan, Kin P.↗
NASA NTRS2006

Robonaut Mobile Autonomy: Initial Experiments

A mobile version of the NASA/DARPA Robonaut humanoid recently completed initial autonomy trials working directly with humans in cluttered environments. This compact robot combines the upper body of the Robonaut system with a Segway Robotic Mobility Platform yielding a dexterous, maneuverable humanoid ideal for interacting with human co-workers in a range of environments. This system uses stereovision to locate human teammates and tools and a navigation system that uses laser range and vision data to follow humans while avoiding obstacles. Tactile sensors provide information to grasping algorithms for efficient tool exchanges. The autonomous architecture utilizes these pre-programmed skills to form complex behaviors. The initial behavior demonstrates a robust capability to assist a human by acquiring a tool from a remotely located individual and then following the human in a cluttered environment with the tool for future use.

Diftler, M. A.↗
NASA NTRSDate not supplied

NASA’s Moon Trek Portal: New Capabilities Supporting Mission Planning and Engagement

Introduction: NASA’s Moon Trek (https://trek.nasa.gov/moon/) is one of a growing number of interactive, browser-based, online portals for planetary data visualization and analysis produced by NASA’s Solar System Treks Project (SSTP). Moon Trek continues to be enhanced with new data and new capabilities enabling it to facilitate the planning and conducting of upcoming lunar missions by NASA, its commercial partners, and its international partners, as well as advancing its role as a valuable outreach tool. A Comprehensive Online Web Portal: Developed at NASA’s Jet Propulsion Laboratory (JPL) and managed as a project of NASA’s Solar System Exploration Research Virtual Institute (SSERVI) at NASA Ames Research Center, Moon Trek is a browser-based web portal. The portal provides easy-to-use tools for browsing, data layering, data product blending, and feature search among thousands of data products covering topography, mineralogy, elemental abundance, geology, and much more. Visualizations are provided in var-ious map projections, interactive 3D viewing, and in virtual reality. Using an in-house stereo workflow, SSTP is able to produce new NAC-based high-resolution mosaics and DEMs. Diverse Applications for Lunar Exploration: Baseline analytic tools available to all users include dis-tance measurement, elevation profiling, sun angle calculation, and 3D print file generation. More advanced account-level tools allow users to perform more computationally intensive analyses. These include ray-traced lighting analysis for user-specified areas over user-specified time/date ranges and time intervals, electro-static surface potential analysis, subsetting of large data products, slope analysis, and Lunar Laser Ranging geometry calculation. Artificial intelligence (AI) and ma-chine learning (ML) based tools have been implemented for crater detection and hazard analysis, boulder detection and hazard analysis, and rockfall detection. New Tools Facilitating Exploration: Additional, new tools have recently been added and others are in development, offering even greater functionality in con-ducting analyses of potential landing sites and areas of surface operations. The new Line-of-Sight tool facilitates communications planning between locations on the lunar surface, between any given site on the lunar surface and a specified ground station on the Earth, and between a site on the lunar surface and a relay asset in lunar orbit, all taking into account local lunar topography. The new Data Plotter tool provides both tabular and graphical representations of pixel values along a user specified path for a growing number of data products. The new NAC Finder tool will identify and pro-vide access to NAC images that intersect a user-defined path or bounded area. The SSTP development team is looking to leverage the capabilities of its existing AI and ML crater, boulder, and rockfall detection and analysis tools, and extend that technology to a generalized feature detector that can be trained on instances of specific types of landforms and then search the lunar surface for more examples of such features. New traverse planning tools are being developed with use cases in generalized concept studies and specific mission planning in mind. These will facilitate finding optimal traverse paths based on constraints such as slope, lighting, hazard avoidance, and communications. These will be complemented by new traverse visualization capabilities. Users will be able to interactively ride along with a rover, examining 3D views of the terrain while adjusting camera height and viewing angle along with selecting different data layer overlays to drape across the terrain. Engaging the Public: The capabilities being developed for mission planning are being leveraged to further enhance Moon Trek’s proven utility as a valuable public outreach resource. This includes providing multiple lev-els of engagement with different points of entry. At its simplest level, promoting understanding through visualization, media and the public will be able to easily visualize and conduct their own exploration of lunar sites targeted by NASA and its partners. For a more in-depth experience, we are working with our stakeholders to promote understanding through interaction by extend-ing our current landing site and traverse analysis capabilities, making simplified access to these tools available to those who want to explore more deeply key factors in planning a mission through interactive and possibly even gamified experiences. The highest degree of public outreach, focusing on engagement through scientific participation, could be achieved through our work with missions and the NASA Office of the Chief Scientist on Moon Trek’s extension as a tool with specialized capabilities for facilitating citizen science. In such scenarios, participants become members of extended mis-sion science teams, using dedicated and integrated interfaces to analyze mission data to help answer questions key to lunar science and exploration. We are work-ing with NASA’s Office of Communications, museums, planetariums, and the media to help them easily integrate accurate, detailed visualizations of NASA’s lunar destinations and exploration into their content/productions and to engage diverse audiences in diverse venues.

Moon Trek↗
NASA NTRS1985

Nonsimultaneous coupled laser velocimeter measurement technique: Error prediction for spatially noncoincident measurements

A technique for obtaining orthogonal velocity components from nonorthogonal measurements using the NASA Ames Research Center Long-Range Laser Velocimeter (LRLV) is briefly discussed. A description is then presented of the error that occurs when these nonorthogonal measurements are spatially noncoincident because of positioning inaccuracies, and equations are developed for predicting this error. Sample data are presented and a prediction of the expected error for two typical applications is made. To cover other cases in general, a parametric study is conducted and the results are presented in a tabular format.

Reinath, M. S.↗
NASA NTRS2011

NASA Tech Briefs, January 2011

The topics include: 1) Distributed Aerodynamic Sensing and Processing Toolbox; 2) Collaborative Supervised Learning for Sensor Networks; 3) Hazard Detection Software for Lunar Landing; 4) Onboard Nonlinear Engine Sensor and Component Fault Diagnosis and Isolation Scheme; 5) Network-Capable Application Process and Wireless Intelligent Sensors for ISHM; 6) Interface Supports Multiple Broadcast Transceivers for Flight Applications; 7) FPGA Sequencer for Radar Altimeter Applications; 8) Miniature Sapphire Acoustic Resonator - MSAR; 9) Process-Hardened, Multi-Analyte Sensor for Characterizing Rocket Plume Constituents; 10) SAD5 Stereo Correlation Line-Striping in an FPGA; 11) Hybrid Composite Cryogenic Tank Structure; 12) Nanoscale Deformable Optics; 13) Reliability-Based Design Optimization of a Composite Airframe Component; 14) Zinc Oxide Nanowire Interphase for Enhanced Lightweight Polymer Fiber Composites; 15) Plasma Igniter for Reliable Ignition of Combustion in Rocket Engines; 16) Wire Test Grip Fixture; 17) A Sub-Hertz, Low-Frequency Vibration Isolation Platform; 18) Carbon Nanofibers Synthesized on Selective Substrates for Nonvolatile Memory and 3D Electronics; 19) Nanoparticle/Polymer Nanocomposite Bond Coat or Coating; 20) High-Resolution Wind Measurements for Offshore Wind Energy Development; 21) Spring Tire; 22) Marsviewer 2008; 23) Mission Services Evolution Center Message Bus; 24) Major Constituents Analysis for the Vehicle Cabin Atmosphere Monitor; 25) Astronaut Health Participant Summary Application; 26) Adaption of the AMDIS Method to Flight Status on the VCAM Instrument; 27) Natural Language Interface for Safety Certification of Safety-Critical Software; 28) Cryogenic Caging for Science Instrumentation; 29) Wide-Range Neutron Detector for Space Nuclear Applications; 30) In Situ Guided Wave Structural Health Monitoring System; 31) Multiplexed Energy Coupler for Rotating Equipment; 32) Attitude Estimation in Fractionated Spacecraft Cluster Systems; 33) Full Piezoelectric Multilayer-Stacked Hybrid Actuation/Transduction Systems; 34) Active Flow Effectors for Noise and Separation Control; 35) Method and System for Temporal Filtering in Video Compression Systems; 36) Apparatus for Measuring Total Emissivity of Small, Low-Emissivity Samples; 37) Multiple-Zone Diffractive Optic Element for Laser Ranging Applications; 38) Simplified Architecture for Precise Aiming of a Deep-Space Communication Laser Transceiver; 39) Two-Photon-Absorption Scheme for Optical Beam Tracking; 40) High-Sensitivity, Broad-Range Vacuum Gauge Using Nanotubes for Micromachined Cavities; 41) Wide-Field Optic for Autonomous Acquisition of Laser Link; 42) Extracting Zero-Gravity Surface Figure of a Mirror; 43) Modeling Electromagnetic Scattering From Complex Inhomogeneous Objects; 44) Visual Object Recognition and Tracking of Tools; 45) Method for Implementing Optical Phase Adjustment; 46) Visual SLAM Using Variance Grid Maps; 47) Rapid Calculation of Spacecraft Trajectories Using Efficient Taylor Series Integration; 48) Efficient Kriging Algorithms; 49) Predicting Spacecraft Trajectories by the WeavEncke Method; 50) An Augmentation of G-Guidance Algorithms; 51) Comparison of Aircraft Icing Growth Assessment Software; 52) Silicon-Germanium Voltage-Controlled Oscillator at 105 GHz; 53) Estimation of Coriolis Force and Torque Acting on Ares-1; 54) Null Lens Assembly for X-Ray Mirror Segments; and 55) High-Precision Pulse Generator.

Source record↗