The Experts below are selected from a list of 3576 Experts worldwide ranked by ideXlab platform
Maria T Zuber - One of the best experts on this subject based on the ideXlab platform.
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summary of the results from the Lunar Orbiter laser altimeter after seven years in Lunar orbit
Icarus, 2017Co-Authors: D. E. Smith, Erwan Mazarico, M S Robinson, F G Lemoine, Gregory A Neumann, Maria T Zuber, J.w. Head, Paul G Lucey, O Aharonson, Xiaoli SunAbstract:In June 2009 the Lunar Reconnaissance Orbiter (LRO) spacecraft was launched to the Moon. The payload consists of 7 science instruments selected to characterize sites for future robotic and human missions. Among them, the Lunar Orbiter Laser Altimeter (LOLA) was designed to obtain altimetry, surface roughness, and reflectance measurements. The primary phase of Lunar exploration lasted one year, following a 3-month commissioning phase. On completion of its exploration objectives, the LRO mission transitioned to a science mission. After 7 years in Lunar orbit, the LOLA instrument continues to map the Lunar surface. The LOLA dataset is one of the foundational datasets acquired by the various LRO instruments. LOLA provided a high-accuracy global geodetic reference frame to which past, present and future Lunar observations can be referenced. It also obtained high-resolution and accurate global topography that were used to determine regions in permanent shadow at the Lunar poles. LOLA further contributed to the study of polar volatiles through its unique measurement of surface brightness at zero phase, which revealed anomalies in several polar craters that may indicate the presence of water ice. In this paper, we describe the many LOLA accomplishments to date and its contribution to Lunar and planetary science.
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a new Lunar digital elevation model from the Lunar Orbiter laser altimeter and selene terrain camera
Icarus, 2016Co-Authors: M K Barker, Erwan Mazarico, Gregory A Neumann, Maria T Zuber, Junichi Haruyama, David E SmithAbstract:Abstract We present an improved Lunar digital elevation model (DEM) covering latitudes within ±60°, at a horizontal resolution of 512 pixels per degree (∼60 m at the equator) and a typical vertical accuracy ∼3 to 4 m. This DEM is constructed from ∼ 4.5 × 10 9 geodetically-accurate topographic heights from the Lunar Orbiter Laser Altimeter (LOLA) onboard the Lunar Reconnaissance Orbiter, to which we co-registered 43,200 stereo-derived DEMs (each 1 ° × 1 ° ) from the SELENE Terrain Camera (TC) (∼1010 pixels total). After co-registration, approximately 90% of the TC DEMs show root-mean-square vertical residuals with the LOLA data of
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Lunar phase function at 1064 nm from Lunar Orbiter laser altimeter passive and active radiometry
Icarus, 2016Co-Authors: M K Barker, Erwan Mazarico, Gregory A Neumann, Maria T Zuber, Xiaoli Sun, David E SmithAbstract:Abstract We present initial calibration and results of passive radiometry collected by the Lunar Orbiter Laser Altimeter onboard the Lunar Reconnaissance Orbiter over the course of 12 months. After correcting for time- and temperature-dependent dark noise and detector responsivity variations, the LOLA passive radiometry measurements are brought onto the absolute radiance scale of the SELENE Spectral Profiler. The resulting photometric precision is estimated to be ∼5%. We leverage the unique ability of LOLA to measure normal albedo to explore the 1064 nm phase function’s dependence on various geologic parameters. On a global scale, we find that iron abundance and optical maturity (quantified by FeO and OMAT) are the dominant controlling parameters. Titanium abundance (TiO 2 ), surface roughness on decimeter to decameter scales, and soil thermophysical properties have a smaller effect, but the latter two are correlated with OMAT, indicating that exposure age is the driving force behind their effects in a globally-averaged sense. The phase function also exhibits a dependence on surface slope at ∼300 m baselines, possibly the result of mass wasting exposing immature material and/or less space weathering due to reduced sky visibility. Modeling the photometric function in the Hapke framework, we find that, relative to the highlands, the maria exhibit decreased backscattering, a smaller opposition effect (OE) width, and a smaller OE amplitude. Immature highlands regolith has a higher backscattering fraction and a larger OE width compared to mature highlands regolith. Within the maria, the backscattering fraction and OE width show little dependence on TiO 2 and OMAT. Variations in the phase function shape at large phase angles are observed in and around the Copernican-aged Jackson crater, including its dark halo, a putative impact melt deposit. Finally, the phase function of the Reiner Gamma Formation behaves more optically immature than is typical for its composition and OMAT, suggesting the visible-to-near-infrared spectrum and phase function respond differently to the unusual regolith evolution and properties at this location.
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a new Lunar digital elevation model from the Lunar Orbiter laser altimeter and selene terrain camera
Elsevier, 2015Co-Authors: M K Barker, Erwan Mazarico, Gregory A Neumann, Maria T Zuber, Junichi Haruyama, David E SmithAbstract:United States. National Aeronautics and Space Administration. Lunar Reconnaissance Orbiter Project and Planetary Geology and Geophysics Program
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detection of the Lunar body tide by the Lunar Orbiter laser altimeter
Geophysical Research Letters, 2014Co-Authors: Erwan Mazarico, Gregory A Neumann, Maria T Zuber, M K Barker, David E SmithAbstract:The Lunar Orbiter Laser Altimeter instrument onboard the Lunar Reconnaissance Orbiter spacecraft collected more than 5 billion measurements in the nominal 50 km orbit over ~10,000 orbits. The data precision, geodetic accuracy, and spatial distribution enable two-dimensional crossovers to be used to infer relative radial position corrections between tracks to better than ~1 m. We use nearly 500,000 altimetric crossovers to separate remaining high-frequency spacecraft trajectory errors from the periodic radial surface tidal deformation. The unusual sampling of the Lunar body tide from polar Lunar orbit limits the size of the typical differential signal expected at ground track intersections to ~10 cm. Nevertheless, we reliably detect the topographic tidal signal and estimate the associated Love number h2 to be 0.0371 ± 0.0033, which is consistent with but lower than recent results from Lunar laser ranging.
David E Smith - One of the best experts on this subject based on the ideXlab platform.
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optical characterization of laser retroreflector arrays for Lunar landers
Applied Optics, 2020Co-Authors: Daniel R Cremons, Erwan Mazarico, Xiaoli Sun, Zachary Denny, Shane Wake, E D Hoffman, Edward C Aaron, David E SmithAbstract:The Laser Retroreflector Array for Lunar Landers (LRALL) is a small optical instrument designed to provide a target for precision laser ranging from a spacecraft in Lunar orbit, enabling geolocation of the lander and its instrument suite and establishing a fiducial maker on the Lunar surface. Here we describe the optical performance of LRALL at visible and near-infrared wavelengths. Individual corner cube reflectors (CCRs) within LRALL were tested for surface flatness and dihedral angle values. We also imaged the far-field diffraction patterns of individual CCRs as well as the entire retroreflector array over the range of possible incident angles to extract the optical cross section as a function of viewing angle. We also measured the optical properties of one of the CCRs over the Lunar temperature range (100–380 K) and found no significant temperature-dependent variance. The test results show LRALL meets the design criteria and can be ranged to elevation angles above 30° with respect to the instrument base from an orbital laser altimeter such as the Lunar Orbiter Laser Altimeter on the Lunar Reconnaissance Orbiter. This work summarizes the test data and serves as a guide for future laser ranging to these retroreflector arrays.
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a new Lunar digital elevation model from the Lunar Orbiter laser altimeter and selene terrain camera
Icarus, 2016Co-Authors: M K Barker, Erwan Mazarico, Gregory A Neumann, Maria T Zuber, Junichi Haruyama, David E SmithAbstract:Abstract We present an improved Lunar digital elevation model (DEM) covering latitudes within ±60°, at a horizontal resolution of 512 pixels per degree (∼60 m at the equator) and a typical vertical accuracy ∼3 to 4 m. This DEM is constructed from ∼ 4.5 × 10 9 geodetically-accurate topographic heights from the Lunar Orbiter Laser Altimeter (LOLA) onboard the Lunar Reconnaissance Orbiter, to which we co-registered 43,200 stereo-derived DEMs (each 1 ° × 1 ° ) from the SELENE Terrain Camera (TC) (∼1010 pixels total). After co-registration, approximately 90% of the TC DEMs show root-mean-square vertical residuals with the LOLA data of
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Lunar phase function at 1064 nm from Lunar Orbiter laser altimeter passive and active radiometry
Icarus, 2016Co-Authors: M K Barker, Erwan Mazarico, Gregory A Neumann, Maria T Zuber, Xiaoli Sun, David E SmithAbstract:Abstract We present initial calibration and results of passive radiometry collected by the Lunar Orbiter Laser Altimeter onboard the Lunar Reconnaissance Orbiter over the course of 12 months. After correcting for time- and temperature-dependent dark noise and detector responsivity variations, the LOLA passive radiometry measurements are brought onto the absolute radiance scale of the SELENE Spectral Profiler. The resulting photometric precision is estimated to be ∼5%. We leverage the unique ability of LOLA to measure normal albedo to explore the 1064 nm phase function’s dependence on various geologic parameters. On a global scale, we find that iron abundance and optical maturity (quantified by FeO and OMAT) are the dominant controlling parameters. Titanium abundance (TiO 2 ), surface roughness on decimeter to decameter scales, and soil thermophysical properties have a smaller effect, but the latter two are correlated with OMAT, indicating that exposure age is the driving force behind their effects in a globally-averaged sense. The phase function also exhibits a dependence on surface slope at ∼300 m baselines, possibly the result of mass wasting exposing immature material and/or less space weathering due to reduced sky visibility. Modeling the photometric function in the Hapke framework, we find that, relative to the highlands, the maria exhibit decreased backscattering, a smaller opposition effect (OE) width, and a smaller OE amplitude. Immature highlands regolith has a higher backscattering fraction and a larger OE width compared to mature highlands regolith. Within the maria, the backscattering fraction and OE width show little dependence on TiO 2 and OMAT. Variations in the phase function shape at large phase angles are observed in and around the Copernican-aged Jackson crater, including its dark halo, a putative impact melt deposit. Finally, the phase function of the Reiner Gamma Formation behaves more optically immature than is typical for its composition and OMAT, suggesting the visible-to-near-infrared spectrum and phase function respond differently to the unusual regolith evolution and properties at this location.
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a new Lunar digital elevation model from the Lunar Orbiter laser altimeter and selene terrain camera
Elsevier, 2015Co-Authors: M K Barker, Erwan Mazarico, Gregory A Neumann, Maria T Zuber, Junichi Haruyama, David E SmithAbstract:United States. National Aeronautics and Space Administration. Lunar Reconnaissance Orbiter Project and Planetary Geology and Geophysics Program
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detection of the Lunar body tide by the Lunar Orbiter laser altimeter
Geophysical Research Letters, 2014Co-Authors: Erwan Mazarico, Gregory A Neumann, Maria T Zuber, M K Barker, David E SmithAbstract:The Lunar Orbiter Laser Altimeter instrument onboard the Lunar Reconnaissance Orbiter spacecraft collected more than 5 billion measurements in the nominal 50 km orbit over ~10,000 orbits. The data precision, geodetic accuracy, and spatial distribution enable two-dimensional crossovers to be used to infer relative radial position corrections between tracks to better than ~1 m. We use nearly 500,000 altimetric crossovers to separate remaining high-frequency spacecraft trajectory errors from the periodic radial surface tidal deformation. The unusual sampling of the Lunar body tide from polar Lunar orbit limits the size of the typical differential signal expected at ground track intersections to ~10 cm. Nevertheless, we reliably detect the topographic tidal signal and estimate the associated Love number h2 to be 0.0371 ± 0.0033, which is consistent with but lower than recent results from Lunar laser ranging.
Gregory A Neumann - One of the best experts on this subject based on the ideXlab platform.
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summary of the results from the Lunar Orbiter laser altimeter after seven years in Lunar orbit
Icarus, 2017Co-Authors: D. E. Smith, Erwan Mazarico, M S Robinson, F G Lemoine, Gregory A Neumann, Maria T Zuber, J.w. Head, Paul G Lucey, O Aharonson, Xiaoli SunAbstract:In June 2009 the Lunar Reconnaissance Orbiter (LRO) spacecraft was launched to the Moon. The payload consists of 7 science instruments selected to characterize sites for future robotic and human missions. Among them, the Lunar Orbiter Laser Altimeter (LOLA) was designed to obtain altimetry, surface roughness, and reflectance measurements. The primary phase of Lunar exploration lasted one year, following a 3-month commissioning phase. On completion of its exploration objectives, the LRO mission transitioned to a science mission. After 7 years in Lunar orbit, the LOLA instrument continues to map the Lunar surface. The LOLA dataset is one of the foundational datasets acquired by the various LRO instruments. LOLA provided a high-accuracy global geodetic reference frame to which past, present and future Lunar observations can be referenced. It also obtained high-resolution and accurate global topography that were used to determine regions in permanent shadow at the Lunar poles. LOLA further contributed to the study of polar volatiles through its unique measurement of surface brightness at zero phase, which revealed anomalies in several polar craters that may indicate the presence of water ice. In this paper, we describe the many LOLA accomplishments to date and its contribution to Lunar and planetary science.
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a new Lunar digital elevation model from the Lunar Orbiter laser altimeter and selene terrain camera
Icarus, 2016Co-Authors: M K Barker, Erwan Mazarico, Gregory A Neumann, Maria T Zuber, Junichi Haruyama, David E SmithAbstract:Abstract We present an improved Lunar digital elevation model (DEM) covering latitudes within ±60°, at a horizontal resolution of 512 pixels per degree (∼60 m at the equator) and a typical vertical accuracy ∼3 to 4 m. This DEM is constructed from ∼ 4.5 × 10 9 geodetically-accurate topographic heights from the Lunar Orbiter Laser Altimeter (LOLA) onboard the Lunar Reconnaissance Orbiter, to which we co-registered 43,200 stereo-derived DEMs (each 1 ° × 1 ° ) from the SELENE Terrain Camera (TC) (∼1010 pixels total). After co-registration, approximately 90% of the TC DEMs show root-mean-square vertical residuals with the LOLA data of
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Lunar phase function at 1064 nm from Lunar Orbiter laser altimeter passive and active radiometry
Icarus, 2016Co-Authors: M K Barker, Erwan Mazarico, Gregory A Neumann, Maria T Zuber, Xiaoli Sun, David E SmithAbstract:Abstract We present initial calibration and results of passive radiometry collected by the Lunar Orbiter Laser Altimeter onboard the Lunar Reconnaissance Orbiter over the course of 12 months. After correcting for time- and temperature-dependent dark noise and detector responsivity variations, the LOLA passive radiometry measurements are brought onto the absolute radiance scale of the SELENE Spectral Profiler. The resulting photometric precision is estimated to be ∼5%. We leverage the unique ability of LOLA to measure normal albedo to explore the 1064 nm phase function’s dependence on various geologic parameters. On a global scale, we find that iron abundance and optical maturity (quantified by FeO and OMAT) are the dominant controlling parameters. Titanium abundance (TiO 2 ), surface roughness on decimeter to decameter scales, and soil thermophysical properties have a smaller effect, but the latter two are correlated with OMAT, indicating that exposure age is the driving force behind their effects in a globally-averaged sense. The phase function also exhibits a dependence on surface slope at ∼300 m baselines, possibly the result of mass wasting exposing immature material and/or less space weathering due to reduced sky visibility. Modeling the photometric function in the Hapke framework, we find that, relative to the highlands, the maria exhibit decreased backscattering, a smaller opposition effect (OE) width, and a smaller OE amplitude. Immature highlands regolith has a higher backscattering fraction and a larger OE width compared to mature highlands regolith. Within the maria, the backscattering fraction and OE width show little dependence on TiO 2 and OMAT. Variations in the phase function shape at large phase angles are observed in and around the Copernican-aged Jackson crater, including its dark halo, a putative impact melt deposit. Finally, the phase function of the Reiner Gamma Formation behaves more optically immature than is typical for its composition and OMAT, suggesting the visible-to-near-infrared spectrum and phase function respond differently to the unusual regolith evolution and properties at this location.
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Baseline Design and Performance Analysis of Laser Altimeter for Korean Lunar Orbiter
Korean Space Science Society (KSSS), 2016Co-Authors: Hyung-chul Lim, Gregory A Neumann, Myeong-hwan Choi, Seong-cheol Bang, Jong-uk Park, Man-soo Choi, Eunseo ParkAbstract:Korea’s Lunar exploration project includes the launching of an Orbiter, a lander (including a rover), and an experimental Orbiter (referred to as a Lunar pathfinder). Laser altimeters have played an important scientific role in Lunar, planetary, and asteroid exploration missions since their first use in 1971 onboard the Apollo 15 mission to the Moon. In this study, a laser altimeter was proposed as a scientific instrument for the Korean Lunar Orbiter, which will be launched by 2020, to study the global topography of the surface of the Moon and its gravitational field and to support other payloads such as a terrain mapping camera or spectral imager. This study presents the baseline design and performance model for the proposed laser altimeter. Additionally, the study discusses the expected performance based on numerical simulation results. The simulation results indicate that the design of system parameters satisfies performance requirements with respect to detection probability and range error even under unfavorable conditions
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a new Lunar digital elevation model from the Lunar Orbiter laser altimeter and selene terrain camera
Elsevier, 2015Co-Authors: M K Barker, Erwan Mazarico, Gregory A Neumann, Maria T Zuber, Junichi Haruyama, David E SmithAbstract:United States. National Aeronautics and Space Administration. Lunar Reconnaissance Orbiter Project and Planetary Geology and Geophysics Program
Erwan Mazarico - One of the best experts on this subject based on the ideXlab platform.
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optical characterization of laser retroreflector arrays for Lunar landers
Applied Optics, 2020Co-Authors: Daniel R Cremons, Erwan Mazarico, Xiaoli Sun, Zachary Denny, Shane Wake, E D Hoffman, Edward C Aaron, David E SmithAbstract:The Laser Retroreflector Array for Lunar Landers (LRALL) is a small optical instrument designed to provide a target for precision laser ranging from a spacecraft in Lunar orbit, enabling geolocation of the lander and its instrument suite and establishing a fiducial maker on the Lunar surface. Here we describe the optical performance of LRALL at visible and near-infrared wavelengths. Individual corner cube reflectors (CCRs) within LRALL were tested for surface flatness and dihedral angle values. We also imaged the far-field diffraction patterns of individual CCRs as well as the entire retroreflector array over the range of possible incident angles to extract the optical cross section as a function of viewing angle. We also measured the optical properties of one of the CCRs over the Lunar temperature range (100–380 K) and found no significant temperature-dependent variance. The test results show LRALL meets the design criteria and can be ranged to elevation angles above 30° with respect to the instrument base from an orbital laser altimeter such as the Lunar Orbiter Laser Altimeter on the Lunar Reconnaissance Orbiter. This work summarizes the test data and serves as a guide for future laser ranging to these retroreflector arrays.
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advanced illumination modeling for data analysis and calibration application to the moon
Advances in Space Research, 2018Co-Authors: Erwan Mazarico, M K Barker, J B NicholasAbstract:Abstract We present a new illumination modeling tool, called IllumNG, developed at NASA Goddard Space Flight Center (GSFC). We describe its capabilities to enhance the analysis and calibration of science data collected by planetary missions. We highlight these with examples making use of Lunar data, particularly the topographic and radiometric measurements collected by the Lunar Orbiter Laser Altimeter (LOLA) instrument, with applications to radiometric measurements from other LRO instruments as well. The unique features of IllumNG are its accuracy and flexibility to handle multiple types of observers and light sources, and its ability to accurately model both singly- and doubly-scattered radiation to an observer.
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summary of the results from the Lunar Orbiter laser altimeter after seven years in Lunar orbit
Icarus, 2017Co-Authors: D. E. Smith, Erwan Mazarico, M S Robinson, F G Lemoine, Gregory A Neumann, Maria T Zuber, J.w. Head, Paul G Lucey, O Aharonson, Xiaoli SunAbstract:In June 2009 the Lunar Reconnaissance Orbiter (LRO) spacecraft was launched to the Moon. The payload consists of 7 science instruments selected to characterize sites for future robotic and human missions. Among them, the Lunar Orbiter Laser Altimeter (LOLA) was designed to obtain altimetry, surface roughness, and reflectance measurements. The primary phase of Lunar exploration lasted one year, following a 3-month commissioning phase. On completion of its exploration objectives, the LRO mission transitioned to a science mission. After 7 years in Lunar orbit, the LOLA instrument continues to map the Lunar surface. The LOLA dataset is one of the foundational datasets acquired by the various LRO instruments. LOLA provided a high-accuracy global geodetic reference frame to which past, present and future Lunar observations can be referenced. It also obtained high-resolution and accurate global topography that were used to determine regions in permanent shadow at the Lunar poles. LOLA further contributed to the study of polar volatiles through its unique measurement of surface brightness at zero phase, which revealed anomalies in several polar craters that may indicate the presence of water ice. In this paper, we describe the many LOLA accomplishments to date and its contribution to Lunar and planetary science.
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a new Lunar digital elevation model from the Lunar Orbiter laser altimeter and selene terrain camera
Icarus, 2016Co-Authors: M K Barker, Erwan Mazarico, Gregory A Neumann, Maria T Zuber, Junichi Haruyama, David E SmithAbstract:Abstract We present an improved Lunar digital elevation model (DEM) covering latitudes within ±60°, at a horizontal resolution of 512 pixels per degree (∼60 m at the equator) and a typical vertical accuracy ∼3 to 4 m. This DEM is constructed from ∼ 4.5 × 10 9 geodetically-accurate topographic heights from the Lunar Orbiter Laser Altimeter (LOLA) onboard the Lunar Reconnaissance Orbiter, to which we co-registered 43,200 stereo-derived DEMs (each 1 ° × 1 ° ) from the SELENE Terrain Camera (TC) (∼1010 pixels total). After co-registration, approximately 90% of the TC DEMs show root-mean-square vertical residuals with the LOLA data of
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Lunar phase function at 1064 nm from Lunar Orbiter laser altimeter passive and active radiometry
Icarus, 2016Co-Authors: M K Barker, Erwan Mazarico, Gregory A Neumann, Maria T Zuber, Xiaoli Sun, David E SmithAbstract:Abstract We present initial calibration and results of passive radiometry collected by the Lunar Orbiter Laser Altimeter onboard the Lunar Reconnaissance Orbiter over the course of 12 months. After correcting for time- and temperature-dependent dark noise and detector responsivity variations, the LOLA passive radiometry measurements are brought onto the absolute radiance scale of the SELENE Spectral Profiler. The resulting photometric precision is estimated to be ∼5%. We leverage the unique ability of LOLA to measure normal albedo to explore the 1064 nm phase function’s dependence on various geologic parameters. On a global scale, we find that iron abundance and optical maturity (quantified by FeO and OMAT) are the dominant controlling parameters. Titanium abundance (TiO 2 ), surface roughness on decimeter to decameter scales, and soil thermophysical properties have a smaller effect, but the latter two are correlated with OMAT, indicating that exposure age is the driving force behind their effects in a globally-averaged sense. The phase function also exhibits a dependence on surface slope at ∼300 m baselines, possibly the result of mass wasting exposing immature material and/or less space weathering due to reduced sky visibility. Modeling the photometric function in the Hapke framework, we find that, relative to the highlands, the maria exhibit decreased backscattering, a smaller opposition effect (OE) width, and a smaller OE amplitude. Immature highlands regolith has a higher backscattering fraction and a larger OE width compared to mature highlands regolith. Within the maria, the backscattering fraction and OE width show little dependence on TiO 2 and OMAT. Variations in the phase function shape at large phase angles are observed in and around the Copernican-aged Jackson crater, including its dark halo, a putative impact melt deposit. Finally, the phase function of the Reiner Gamma Formation behaves more optically immature than is typical for its composition and OMAT, suggesting the visible-to-near-infrared spectrum and phase function respond differently to the unusual regolith evolution and properties at this location.
J.w. Head - One of the best experts on this subject based on the ideXlab platform.
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summary of the results from the Lunar Orbiter laser altimeter after seven years in Lunar orbit
Icarus, 2017Co-Authors: D. E. Smith, Erwan Mazarico, M S Robinson, F G Lemoine, Gregory A Neumann, Maria T Zuber, J.w. Head, Paul G Lucey, O Aharonson, Xiaoli SunAbstract:In June 2009 the Lunar Reconnaissance Orbiter (LRO) spacecraft was launched to the Moon. The payload consists of 7 science instruments selected to characterize sites for future robotic and human missions. Among them, the Lunar Orbiter Laser Altimeter (LOLA) was designed to obtain altimetry, surface roughness, and reflectance measurements. The primary phase of Lunar exploration lasted one year, following a 3-month commissioning phase. On completion of its exploration objectives, the LRO mission transitioned to a science mission. After 7 years in Lunar orbit, the LOLA instrument continues to map the Lunar surface. The LOLA dataset is one of the foundational datasets acquired by the various LRO instruments. LOLA provided a high-accuracy global geodetic reference frame to which past, present and future Lunar observations can be referenced. It also obtained high-resolution and accurate global topography that were used to determine regions in permanent shadow at the Lunar poles. LOLA further contributed to the study of polar volatiles through its unique measurement of surface brightness at zero phase, which revealed anomalies in several polar craters that may indicate the presence of water ice. In this paper, we describe the many LOLA accomplishments to date and its contribution to Lunar and planetary science.
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the steepest slopes on the moon from Lunar Orbiter laser altimeter lola data spatial distribution and correlation with geologic features
Icarus, 2016Co-Authors: M A Kreslavsky, J.w. HeadAbstract:Abstract We calculated topographic gradients over the surface of the Moon at a 25 m baseline using data obtained by the Lunar Orbiter Laser Altimeter (LOLA) instrument onboard the Lunar Reconnaissance Orbiter (LRO) spacecraft. The relative spatial distribution of steep slopes can be reliably obtained, although some technical characteristics of the LOLA dataset preclude statistical studies of slope orientation. The derived slope-frequency distribution revealed a steep rollover for slopes close to the angle of repose. Slopes significantly steeper than the angle of repose are almost absent on the Moon due to (1) the general absence of cohesion/strength of the fractured and fragmented megaregolith of the Lunar highlands, and (2) the absence of geological processes producing steep-slopes in the recent geological past. The majority of slopes steeper than 32°–35° are associated with relatively young large impact craters. We demonstrate that these impact craters progressively lose their steepest slopes. We also found that features of Early Imbrian and older ages have almost no slopes steeper than 35°. We interpret this to be due to removal of all steep slopes by the latest basin-forming impact (Orientale), probably by global seismic shaking. The global spatial distribution of the steepest slopes correlates moderately well with the predicted spatial distribution of impact rate; however, a significant paucity of steep slopes in the southern farside remains unexplained.
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Lunar topographic roughness maps from Lunar Orbiter laser altimeter lola data scale dependence and correlation with geologic features and units
Icarus, 2013Co-Authors: M A Kreslavsky, Gregory A Neumann, David E Smith, J.w. Head, O Aharonson, M A Rosenburg, Maria T ZuberAbstract:We present maps of the topographic roughness of the Moon at hectometer and kilometer scales. The maps are derived from range profiles obtained by the Lunar Orbiter Laser Altimeter (LOLA) instrument onboard the Lunar Reconnaissance Orbiter (LRO) spacecraft. As roughness measures, we used the interquartile range of profile curvature at several baselines, from 115 m to 1.8 km, and plotted these in a global map format. The maps provide a synoptic overview of variations of typical topographic textures and utilize the exceptional ranging precision of the LOLA instrument. We found that hectometer-scale roughness poorly correlates with kilometer-scale roughness, because they reflect different sets of processes and time scales. Hectometer-scale roughness is controlled by regolith accumulation and modification processes and affected by the most recent events, primarily, geologically recent (1–2 Ga) meteoritic impacts. Kilometer-scale roughness reflects major geological (impact, volcanic and tectonic) events in earlier geological history. Young large impact craters are rough, and their roughness decreases with age. The global roughness maps revealed a few unusually dense clusters of hectometer- and decameter-size impact craters that differ in their morphology and settings from typical secondary crater clusters and chains; the origin of these features is enigmatic. The maps can assist in the geological mapping of the Lunar maria by revealing contacts between volcanic plain units. The global roughness maps also clearly reveal cryptomaria, old volcanic plains superposed by younger materials, primarily crater and basin ejecta.
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detecting volcanic resurfacing of heavily cratered terrain flooding simulations on the moon using Lunar Orbiter laser altimeter lola data
Planetary and Space Science, 2013Co-Authors: J L Whitten, J.w. HeadAbstract:Abstract Early extrusive volcanism from mantle melting marks the transition from primary to secondary crust formation. Detection of secondary crust is often obscured by the high impact flux early in solar system history. To recognize the relationship between heavily cratered terrain and volcanic resurfacing, this study documents how volcanic resurfacing alters the impact cratering record and models the thickness, area, and volume of volcanic flood deposits. Lunar Orbiter Laser Altimeter (LOLA) data are used to analyze three different regions of the Lunar highlands: the Hertzsprung basin; a farside heavily cratered region; and the central highlands. Lunar mare emplacement style is assumed to be similar to that of terrestrial flood basalts, involving large volumes of material extruded from dike-fed fissures over relatively short periods of time. Thus, each region was flooded at 0.5 km elevation intervals to simulate such volcanic flooding and to assess areal patterns, thickness, volumes, and emplacement history. These simulations show three primary stages of volcanic flooding: (1) Initial flooding is largely confined to individual craters and deposits are thick and localized; (2) basalt flows breach crater rim crests and are emplaced laterally between larger craters as thin widespread deposits; and (3) lateral spreading decreases in response to regional topographic variations and the deposits thicken and bury intermediate-sized and larger craters. Application of these techniques to the South Pole-Aitken basin shows that emplacement of ∼1−2 km of cryptomaria can potentially explain the paucity of craters 20–64 km in diameter on the floor of the basin relative to the distribution in the surrounding highlands.
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the transition from complex craters to multi ring basins on the moon quantitative geometric properties from Lunar reconnaissance Orbiter Lunar Orbiter laser altimeter lola data
Journal of Geophysical Research, 2012Co-Authors: David M H Baker, Gregory A Neumann, Maria T Zuber, David E Smith, J.w. HeadAbstract:United States. National Aeronautics and Space Administration (NASA Lunar Reconnaissance Orbiter Lunar Orbiter Laser Altimeter (LOLA) experiment (NNX09AM54G)
