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Lee S.Y.,Stinger Ghaffarian Technologies | Lees D.,Carnegie Mellon University | Cohen T.,Stinger Ghaffarian Technologies | Allan M.,Stinger Ghaffarian Technologies | And 4 more authors.
Acta Astronautica | Year: 2013

The Exploration Ground Data Systems (xGDS) project led by the Intelligent Robotics Group (IRG) at NASA Ames Research Center creates software tools to support multiple NASA-led planetary analog field experiments. The two primary tools that fall under the xGDS umbrella are the xGDS Web Tools (xGDS-WT) and Visual Environment for Remote Virtual Exploration (VERVE). IRG has also developed a hardware and software system that is closely integrated with our xGDS tools and is used in multiple field experiments called Gigapan Voyage. xGDS-WT, VERVE, and Gigapan Voyage are examples of IRG projects that improve the ratio of science return versus development effort by creating generic and reusable tools that leverage existing technologies in both hardware and software. xGDS Web Tools provides software for gathering and organizing mission data for science and engineering operations, including tools for planning traverses, monitoring autonomous or piloted vehicles, visualization, documentation, analysis, and search. VERVE provides high performance three dimensional (3D) user interfaces used by scientists, robot operators, and mission planners to visualize robot data in real time. Gigapan Voyage is a gigapixel image capturing and processing tool that improves situational awareness and scientific exploration in human and robotic analog missions. All of these technologies emphasize software reuse and leverage open source and/or commercial-off-the-shelf tools to greatly improve the utility and reduce the development and operational cost of future similar technologies. Over the past several years these technologies have been used in many NASA-led robotic field campaigns including the Desert Research and Technology Studies (DRATS), the Pavilion Lake Research Project (PLRP), the K10 Robotic Follow-Up tests, and most recently we have become involved in the NASA Extreme Environment Mission Operations (NEEMO) field experiments. A major objective of these joint robot and crew experiments is to improve NASAs understanding of how to most effectively execute and increase science return from exploration missions. This paper focuses on an integrated suite of xGDS software and compatible hardware tools: xGDS Web Tools, VERVE, and Gigapan Voyage, how they are used, and the design decisions that were made to allow them to be easily developed, integrated, tested, and reused by multiple NASA field experiments and robotic platforms. © 2012 IAA. Published by Elsevier Ltd. All rights reserved. Source


Davis S.E.,Stinger Ghaffarian Technologies | Wright N.T.,Michigan State University
International Journal of Thermophysics | Year: 2013

Suitable positioning of temperature probes improves the accuracy of thermal-diffusivity measurements in thermo-optical tests. The optimal positions depend on the unknown diffusivity, making the positions unknown a priori. One solution is to measure the temperature field and choose the optimal positions after the experiment. D-optimality is used here to choose the best positions for temperature measurement to determine the principal components of thermal diffusivity for transversely isotropic materials in a flash-type experiment. Two D-optimality parameters are examined: one uses all available information; the other neglects nuisance parameters. The slab specimens are heated over a central region while temperatures are measured on the opposite face. Increasing the duration of the heating pulse provides more information, within the limit of the imposed boundary conditions. Experiments using a metal plate showed that measurements made near the optimal positions improve the accuracy of the estimated diffusivity. These results support using IR thermography to provide flexibility in positioning measurements. This method of optimization shows promise in optimizing measurement of specimens having transverse isotropy. © 2013 Springer Science+Business Media New York. Source


Li J.,Stinger Ghaffarian Technologies | Chen N.,NASA | Ng H.K.,University of California at Santa Cruz | Sridhar B.,NASA
15th AIAA Aviation Technology, Integration, and Operations Conference | Year: 2015

The design of arrival and departure routes from an airport has to balance the conflicting requirements of fuel efficiency, airport capacity utilization and community emission and noise considerations. The commonly used tools for aircraft noise assessment are the FAA’s Integrated Noise Model (INM) and Aviation Environmental Design Tool (AEDT). These tools are suitable to generate precise noise contours. However, they are harder to use with other tools for route design optimization involving evaluation of a large number of aircraft trajectories. A simplified aircraft noise computation tool, named AIRNOISE, is developed for preliminary aircraft noise-reduction route design in this paper. AIRNOISE computes aircraft noise based on the same SAE-AIR-1845 procedures used by INM and AEDT. AIRNOISE does not consider components related to terrain and atmosphere adjustments. As a result, it is not only computationally efficient but also flexible to use for customized aircraft profiles. The aircraft noise results are compared with the FAA’s AEDT2b and show that the level of accuracy achieved by AIRNOISE can be used to reduce the number of route design options to a small number from a large pool for subsequent accurate analysis by INM. © 2015, American Institute of Aeronautics and Astronautics Inc. Source


Smith D.E.,NASA | Zuber M.T.,Massachusetts Institute of Technology | Jackson G.B.,NASA | Cavanaugh J.F.,NASA | And 27 more authors.
Space Science Reviews | Year: 2010

The Lunar Orbiter Laser Altimeter (LOLA) is an instrument on the payload of NASA's Lunar Reconnaissance Orbiter spacecraft (LRO) (Chin et al., in Space Sci. Rev. 129:391-419, 2007). The instrument is designed to measure the shape of the Moon by measuring precisely the range from the spacecraft to the lunar surface, and incorporating precision orbit determination of LRO, referencing surface ranges to the Moon's center of mass. LOLA has 5 beams and operates at 28 Hz, with a nominal accuracy of 10 cm. Its primary objective is to produce a global geodetic grid for the Moon to which all other observations can be precisely referenced. © 2009 Springer Science+Business Media B.V. Source


Quijada M.A.,NASA | Huang W.,Stanford University | Miller K.H.,NASA | Seide L.,Stinger Ghaffarian Technologies | And 2 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2015

The current baseline for the Wide-Field Infrared Survey Telescope Astrophysics Focused Telescope Assets (WFIRST/AFTA) instrument includes a single wide-field channel instrument for both imaging and spectroscopy. The only routinely moving part during scientific observations for this wide-field channel is the element wheel (EW) assembly. This filter-wheel assembly will have 8 positions that will be populated with 6 bandpass filters, a blank position, and a grism assembly that will consist of a three-element assembly to disperse the central wavelength undeviated for galaxy redshift surveys. All elements in the EW assembly will be made out of fused silica substrates (110 mm diameter) that will have the appropriate bandpass coatings according to the filter designations (Z087, Y106, J129, H158, F184, W149 and Grism). This paper will present and discuss spectral performance (including spectral transmission and surface-figure wavefront errors ) for a subset of the bandpass filter complement that include filters such as Z087, W149, and Grism. These filter coatings have been procured from three different vendors to assess the most challenging aspects in terms of the in-band throughput (> 95 %), out of band rejection (< 10-4), spatial uniformity (< 1% transmission level) and the cut-on and cut-off slopes (≈ 3% for the filters and 0.3% for the grism coatings). © 2015 SPIE. Source

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