289 research outputs found

    Apollo 17 mission. Mapping camera extension mechanism operated erratically

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    The erratic operation of the mapping camera assemblies on board Apollo 15, 16, 17 is investigated. The exact causes of the problems with the scientific equipment module deployment mechanisms are not identified. However, the possibility of increased friction in hard vacuum is implied. It is suggested that since hard vacuum conditions are not attainable in large chambers, realistically loaded components could be tested in small chambers capable of vacuums to 10 to the minus 14th power torr. It is concluded that this technique carries with it the greatest promise for future investigations

    1:3M Geological Mapping of the Derain (H-10) Quadrangle of Mercury

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    We are making a high resolution geological map of the Derain quadrangle of Mercury. This is part of a coordinated project to create a global set of geological maps for BepiColombo

    Magellan

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    The Magellan Mission consists of a single spacecraft to be placed in an elliptical orbit around Venus. The main objective of the mission is to perform radar imaging, altimetry, and reflectivity of 90 percent of the planet for one Venusian year (243 days). A flight profile is given, and information is presented in tabular form on the following topics: Deep Space Network support, frequency assignments, telemetry, command, and tracking support responsibilities

    Verification of Photometric Parallaxes with Gaia DR2 Data

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    Results of comparison of Gaia DR2 parallaxes with data derived from a combined analysis of 2MASS (Two Micron All-Sky Survey), SDSS (Sloan Digital Sky Survey), GALEX (Galaxy Evolution Explorer), and UKIDSS (UKIRT Infrared Deep Sky Survey) surveys in four selected high-latitude b>48|b|>48^{\circ} sky areas are presented. It is shown that multicolor photometric data from large modern surveys can be used for parameterization of stars closer than 4400 pc and brighter than gSDSS=19.m6g_{SDSS} = 19.^m6, including estimation of parallax and interstellar extinction value. However, the stellar luminosity class should be properly determined.Comment: 11 pages, 5 figure

    Assessing Mission Performance for Technology Reliant Missions

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    Operators today increasingly rely on technology to accomplish objectives. Although technology can increase mission success and efficiency in a majority of operations, it can simultaneously increase vulnerability prevalence, resulting in a higher exploitation likelihood. Defense methods have been proposed and evaluated based on their ability to ensure network security. However, these evaluation metrics do not fully quantify how network exploitation impacts mission task completion. Our mission performance model links cyber devices to mission tasks utilizing a mission’s mission map and evaluates a mission’s performance as the proportion of completed mission tasks in an agent based simulation. Our model allows for mission mappings with varying degrees of completion to enable a generic and adaptable model. We investigate the impact differing levels of mission map completion have on the mission performance metric for the same mission. Experiments serve to provide quantitative assessment for mission performance in cyber-network mission systems

    Lensing of 21cm Absorption "Halos" of zz\sim20-30 First Galaxies

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    Extended 21cm absorption regions (dubbed ``21cm absorption halos'') around first galaxies at z30z\sim 30 are likely the first distinctive structures accessible to radio observations. Though the radio array capable of detecting and resolving them must have 200\sim 200 km2^2 total collecting area, given the great impact of such detections to the understanding of the reionization process and cosmology, such radio survey would be extremely profitable. As an example, we point out a potentially useful byproduct of such survey. The resolved 21cm absorption ``halos'', likely close to spherical, can serve as (almost) ideal sources for measuring the {\it cosmic shear} and mapping the matter distribution to z30z\sim 30. We investigate the expected lensing signal and consider a variety of noise contributions on the shear measurement. We find that S/N 1\sim 1 can be achieved for individual ``halos''. Given millions of 21cm absorption ``halos'' across the sky, the total S/N will be comparable to traditional shear measurement of \sim10910^9 galaxies at z1z\sim 1.Comment: Minor revisions and expanded discussions. Accepted to MNRA

    Superflux I, II, and III experiment design: Remote sensing aspects

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    The Chesapeake Bay plume study called Superflux is described. The study was initiated to incorporate the disciplines of both resources management and remote sensing in accomplishing the following objectives: (1) process oriented research to understand the impact of estuarine outflows on continental shelf ecosystems; (2) monitoring and assessment to delineate the role of remote sensing in future monitoring and assessment programs; and (3) remote sensing research: to advance the state of the art in remote sensing systems as applied to sensing of the marine environment, thereby hastening the day when remote sensing can be used operationally for monitoring and assessment and for process oriented research

    Potential of ALOS2 and NDVI to estimate forest above-ground biomass, and comparison with lidar-derived estimates

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    Remote sensing supports carbon estimation, allowing the upscaling of field measurements to large extents. Lidar is considered the premier instrument to estimate above ground biomass, but data are expensive and collected on-demand, with limited spatial and temporal coverage. The previous JERS and ALOS SAR satellites data were extensively employed to model forest biomass, with literature suggesting signal saturation at low-moderate biomass values, and an influence of plot size on estimates accuracy. The ALOS2 continuity mission since May 2014 produces data with improved features with respect to the former ALOS, such as increased spatial resolution and reduced revisit time. We used ALOS2 backscatter data, testing also the integration with additional features (SAR textures and NDVI from Landsat 8 data) together with ground truth, to model and map above ground biomass in two mixed forest sites: Tahoe (California) and Asiago (Alps). While texture was useful to improve the model performance, the best model was obtained using joined SAR and NDVI (R2 equal to 0.66). In this model, only a slight saturation was observed, at higher levels than what usually reported in literature for SAR; the trend requires further investigation but the model confirmed the complementarity of optical and SAR datatypes. For comparison purposes, we also generated a biomass map for Asiago using lidar data, and considered a previous lidar-based study for Tahoe; in these areas, the observed R2 were 0.92 for Tahoe and 0.75 for Asiago, respectively. The quantitative comparison of the carbon stocks obtained with the two methods allows discussion of sensor suitability. The range of local variation captured by lidar is higher than those by SAR and NDVI, with the latter showing overestimation. However, this overestimation is very limited for one of the study areas, suggesting that when the purpose is the overall quantification of the stored carbon, especially in areas with high carbon density, satellite data with lower cost and broad coverage can be as effective as lidar

    Protecting the Protector: Mapping the Key Terrain that Supports the Continuous Monitoring Mission of a Cloud Cybersecurity Service Provider

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    Key terrain is a concept that is relevant to warfare, military strategy, and tactics. A good general maps out terrain to identify key areas to protect in support of a mission (i.e., a bridge allowing for mobility of supplies and reinforcements). Effective ways to map terrain in Cyberspace (KT-C) has been an area of interest for researchers in Cybersecurity ever since the Department of Defense designated Cyberspace as a warfighting domain. The mapping of KT-C for a mission is accomplished by putting forth efforts to understand and document a mission\u27s dependence on Cyberspace and cyber assets. A cloud Cybersecurity Service Provider (CSSP) continuously monitors the network infrastructure of an information system in the cloud ensuring its security posture is within acceptable risk. This research is focused on mapping the key terrain that supports the continuous monitoring mission of a cloud CSSP. Traditional methods to map KT-C have been broad. Success has been difficult to achieve due to the unique nature of the Cyberspace domain when compared to traditional warfighting domains. This work focuses on a specific objective or mission within cyberspace. It is a contextual approach to identify and map key terrain in cyberspace. Mapping is accomplished through empirical surveys conducted on Cybersecurity professionals with various years of experience working in a cloud or CSSP environment. The background of the Cybersecurity professionals participating in the survey will include United States Government personnel/contractors, and other Cybersecurity practitioners in the private sector. This process provided an approach to identify and map key terrain in a contextual manner specific to the mission of a typical cloud CSSP. Practitioners can use it as a template for their specific cloud CSSP mission
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