The Experts below are selected from a list of 260517 Experts worldwide ranked by ideXlab platform
Michael T Mellon - One of the best experts on this subject based on the ideXlab platform.
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high resolution thermal Inertia mapping of mars sites of exobiological interest
Journal of Geophysical Research, 2001Co-Authors: Bruce M. Jakosky, Michael T MellonAbstract:We have mapped thermal Inertia at high resolution for selected regions of Mars that are of potential biological relevance, using observations made by the Mars Global Surveyor Thermal Emission Spectrometer. Thermal Inertia is a direct indicator of physical properties of the surface at the decimeter-to-meter scale. Our goal is to understand the geological processes by which the sites formed and their subsequent evolution, their current state, and their safety and science potential as landing sites for future lander, rover, and sample-return spacecraft missions. The thermal Inertia values at ∼3-km scale for the sites considered span the entire range of values measured at Mars; thermal Inertias range from low values indicative of substantial aeolian mantling up to high values suggesting surfaces covered predominantly with bedrock, exposed rocks or blocks, or well-indurated crusts. The highest thermal Inertias correlate strongly with local morphology, while areas with intermediate and low thermal Inertias generally show no such correlation. This suggests that selection of future landing sites will be plagued by a choice of a well-mantled site that is safe but less interesting scientifically versus an unmantled site that is more interesting scientifically but less safe.
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High‐resolution thermal Inertia mapping of Mars: Sites of exobiological interest
Journal of Geophysical Research, 2001Co-Authors: Bruce M. Jakosky, Michael T MellonAbstract:We have mapped thermal Inertia at high resolution for selected regions of Mars that are of potential biological relevance, using observations made by the Mars Global Surveyor Thermal Emission Spectrometer. Thermal Inertia is a direct indicator of physical properties of the surface at the decimeter-to-meter scale. Our goal is to understand the geological processes by which the sites formed and their subsequent evolution, their current state, and their safety and science potential as landing sites for future lander, rover, and sample-return spacecraft missions. The thermal Inertia values at ∼3-km scale for the sites considered span the entire range of values measured at Mars; thermal Inertias range from low values indicative of substantial aeolian mantling up to high values suggesting surfaces covered predominantly with bedrock, exposed rocks or blocks, or well-indurated crusts. The highest thermal Inertias correlate strongly with local morphology, while areas with intermediate and low thermal Inertias generally show no such correlation. This suggests that selection of future landing sites will be plagued by a choice of a well-mantled site that is safe but less interesting scientifically versus an unmantled site that is more interesting scientifically but less safe.
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High-Resolution Thermal Inertia Mapping from the Mars Global Surveyor Thermal Emission Spectrometer
Icarus, 2000Co-Authors: Michael T Mellon, Hugh H Kieffer, Bruce M. Jakosky, Philip R ChristensenAbstract:Abstract High-resolution thermal Inertia mapping results are presented, derived from Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES) observations of the surface temperature of Mars obtained during the early portion of the MGS mapping mission. Thermal Inertia is the key property controlling the diurnal surface temperature variations, and is dependent on the physical character of the top few centimeters of the surface. It represents a complex combination of particle size, rock abundance, exposures of bedrock, and degree of induration. In this work we describe the derivation of thermal Inertia from TES data, present global scale analysis, and place these results into context with earlier work. A global map of nighttime thermal-bolometer-based thermal Inertia is presented at 1 4 ° per pixel resolution, with approximately 63% coverage between 50°S and 70°N latitude. Global analysis shows a similar pattern of high and low thermal Inertia as seen in previous Viking low-resolution mapping. Significantly more detail is present in the high-resolution TES thermal Inertia. This detail represents horizontal small-scale variability in the nature of the surface. Correlation with albedo indicates the presence of a previously undiscovered surface unit of moderate-to-high thermal Inertia and intermediate albedo. This new unit has a modal peak thermal Inertia of 180–250 J m−2 K−1 s− 1 2 and a narrow range of albedo near 0.24. The unit, covering a significant fraction of the surface, typically surrounds the low thermal Inertia regions and may comprise a deposit of indurated fine material. Local 3-km-resolution maps are also presented as examples of eolian, fluvial, and volcanic geology. Some impact crater rims and intracrater dunes show higher thermal Inertias than the surrounding terrain; thermal Inertia of aeolian deposits such as intracrater dunes may be related to average particle size. Outflow channels and valleys consistently show higher thermal Inertias than the surrounding terrain. Generally, correlations between spatial variations in thermal Inertia and geologic features suggest a relationship between the hundred-meter-scale morphology and the centimeter-scale surface layer.
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high resolution thermal Inertia mapping from the mars global surveyor thermal emission spectrometer
Lunar and Planetary Science Conference, 2000Co-Authors: Michael T Mellon, Hugh H Kieffer, Bruce M. Jakosky, Philip R ChristensenAbstract:High-resolution thermal Inertia mapping results are presented, derived from Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES) observations of the surface temperature of Mars obtained during the early portion of the MGS mapping mission. Thermal Inertia is the key property controlling the diurnal surface temperature variations, and is dependent on the physical character of the top few centimeters of the surface. It represents a complex combination of particle size, rock abundance, exposures of bedrock, and degree of induration. In this work we describe the derivation of thermal Inertia from TES data, present global scale analysis, and place these results into context with earlier work. A global map of nighttime thermal-bolometer-based thermal Inertia is presented at 1 ‐ per pixel resolution, with approximately 63% coverage between 50 ‐ S and 70 ‐ N latitude. Global analysis shows a similar pattern of high and low thermal Inertia as seen in previous Viking low-resolution mapping. Significantly more detail is present in the high-resolution TES thermal Inertia. This detail represents horizontal small-scale variability in the nature of the surface. Correlation with albedo indicates the presence of a previously undiscovered surface unit of moderate-to-high thermal Inertia and intermediate albedo. This new unit has a modal peak thermal Inertia of 180‐ 250 Jm i 2 K i 1 s i 1 2 and a narrow range of albedo near 0.24. The unit, covering a significant fraction of the surface, typically surrounds the low thermal Inertia regions and may comprise a deposit of indurated fine material. Local 3-km-resolution maps are also presented as examples of eolian, fluvial, and volcanic geology. Some impact crater rims and intracrater dunes show higher thermal Inertias than the surrounding terrain; thermal Inertia of aeolian deposits such as intracrater dunes may be related to average particle size. Outflow channels and valleys consistently show higher thermal Inertias than the surrounding terrain. Generally, correlations between spatial variations in thermal Inertia and geologic features suggest a relationship between the hundred-meter-scale morphology and the centimeter-scale surface layer. c ∞ 2000 Academic Press
Francisco Manuel Gonzalez-longatt - One of the best experts on this subject based on the ideXlab platform.
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Impact of emulated Inertia from wind power on under-frequency protection schemes of future power systems
Journal of Modern Power Systems and Clean Energy, 2015Co-Authors: Francisco Manuel Gonzalez-longattAbstract:Future power systems face several challenges. One of them is the use of high power converters that decouple new energy sources from the AC power grid. This situation decreases the total system Inertia affecting its ability to overcome system frequency disturbances. The wind power industry has created several controllers to enable Inertial response on wind turbines generators: artificial, emulated, simulated, or synthetic Inertial. This paper deals with the issues related to the emulated Inertia of wind turbines based on full-converters and their effect on the under-frequency protection schemes during the recovery period after system frequency disturbances happen. The main contribution of this paper is to demonstrate the recovery period of under-frequency transients in future power systems which integrate wind turbines with emulated Inertia capability does not completely avoid the worse scenarios in terms of under-frequency load shedding. The extra power delivered from a wind turbine during frequency disturbances can substantially reduce the rate of frequency change. Thus it provides time for the active governors to respond.
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Frequency Control and Inertial Response Schemes for the Future Power Networks
Large Scale Renewable Power Generation, 2014Co-Authors: Francisco Manuel Gonzalez-longattAbstract:Future power systems face several challenges: (i) the high penetration level of renewable energy from highly variable generators connected over power converters, (ii) several technologies for energy storage with very different time constants, some of them using power converters as an interface to the grid, and (iii) a pan-European transmission network facilitating the integration of large-scale renewable energy sources and the balancing and transportation of electricity based on underwater multi-terminal high voltage direct current (MTDC) transmission. All of them have an element in common, high power converters that decouple the new energy sources from the pre-existent AC power systems. During a system frequency disturbance, the generation/demand power balance is lost, the system frequency will change at a rate initially determined by the total system Inertia. However, future power systems will increase the installed power capacity (MVA) but the effective system Inertial response will stay the same nowadays, because the new generation units based on power converters creates a decoupling effect of the real Inertia and the AC grid. The result is deeper frequency excursions of system disturbances. A considerable reduction in the ability to overcome system frequency disturbances is expected, the Inertia response may be decreased. The aim of this chapter is to present the fundamental aspects of system frequency control and Inertial response schemes for the future power networks.
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Effects of the synthetic Inertia from wind power on the total system Inertia: simulation study
2012 2nd International Symposium On Environment Friendly Energies And Applications, 2012Co-Authors: Francisco Manuel Gonzalez-longattAbstract:The future power systems face several challenges; one of them is the use of high power converters that virtually decouple primary energy source from the AC power grid. An important consequence of this modified the total system Inertia and affecting its ability to overcome system frequency's disturbances. The wind power industry has created a controller to enable Inertial response on wind turbines generators: Synthetic Inertial. This paper evaluates the effects of the synthetic Inertia provided by wind turbines on the total system Inertia after a system frequency disturbance. The main contribution of this paper is to demonstrate that during an under-frequency transients on future power systems, the synthetic Inertia not completely avoid worse scenarios in terms of under-frequency load shedding. The extra power delivered from a wind turbine during frequency disturbances can increase “momentary” the total system Inertia and substantially reduce the rate of change of frequency providing time for the active governors to respond. However, synthetic Inertia might not completely avoid under-frequency load shedding.
Hugh H Kieffer - One of the best experts on this subject based on the ideXlab platform.
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physical properties of the mars exploration rover landing sites as inferred from mini tes derived thermal Inertia
Journal of Geophysical Research, 2006Co-Authors: R L Fergason, Philip R Christensen, J F Bell, Matthew P Golombek, Kenneth E Herkenhoff, Hugh H KiefferAbstract:[1] The Miniature Thermal Emission Spectrometer (Mini-TES) on board the two Mars Exploration Rovers provides the first opportunity to observe thermal properties from the Martian surface, relate these properties to orbital data, and perform soil conductivity experiments under Martian conditions. The thermal Inertias of soils, bedforms, and rock at each landing site were derived to quantify the physical properties of these features and understand geologic processes occurring at these localities. The thermal Inertia for the Gusev plains rock target Bonneville Beacon (∼1200 J m−2 K−1 s−1/2) is consistent with a dense, basaltic rock, but the rocks at the Columbia Hills have a lower thermal Inertia (∼620 J m−2 K−1 s−1/2), suggesting that they have a volcaniclasic origin. Bedforms on the floors of craters at both landing sites have thermal Inertias of 200 J m−2 K−1 s−1/2, consistent with a particle diameter of ∼160 μm. This diameter is comparable to the most easily moved grain size in the current atmosphere on Mars, suggesting that these bedforms may have formed under current atmospheric conditions. Along the Meridiani plains, the thermal Inertia is lower than that derived from TES and Thermal Emission Imaging System (THEMIS) orbital data. This discrepancy is not well understood. Mini-TES–derived thermal Inertias at Gusev along a ∼2.5 km traverse follow trends in thermal Inertia measured from orbit with TES and THEMIS. However, along the traverse, there are variability and mixing of particle sizes that are not resolved in the orbital thermal Inertia data due to meter-scale processes that are not identifiable at larger scales.
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High-Resolution Thermal Inertia Mapping from the Mars Global Surveyor Thermal Emission Spectrometer
Icarus, 2000Co-Authors: Michael T Mellon, Hugh H Kieffer, Bruce M. Jakosky, Philip R ChristensenAbstract:Abstract High-resolution thermal Inertia mapping results are presented, derived from Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES) observations of the surface temperature of Mars obtained during the early portion of the MGS mapping mission. Thermal Inertia is the key property controlling the diurnal surface temperature variations, and is dependent on the physical character of the top few centimeters of the surface. It represents a complex combination of particle size, rock abundance, exposures of bedrock, and degree of induration. In this work we describe the derivation of thermal Inertia from TES data, present global scale analysis, and place these results into context with earlier work. A global map of nighttime thermal-bolometer-based thermal Inertia is presented at 1 4 ° per pixel resolution, with approximately 63% coverage between 50°S and 70°N latitude. Global analysis shows a similar pattern of high and low thermal Inertia as seen in previous Viking low-resolution mapping. Significantly more detail is present in the high-resolution TES thermal Inertia. This detail represents horizontal small-scale variability in the nature of the surface. Correlation with albedo indicates the presence of a previously undiscovered surface unit of moderate-to-high thermal Inertia and intermediate albedo. This new unit has a modal peak thermal Inertia of 180–250 J m−2 K−1 s− 1 2 and a narrow range of albedo near 0.24. The unit, covering a significant fraction of the surface, typically surrounds the low thermal Inertia regions and may comprise a deposit of indurated fine material. Local 3-km-resolution maps are also presented as examples of eolian, fluvial, and volcanic geology. Some impact crater rims and intracrater dunes show higher thermal Inertias than the surrounding terrain; thermal Inertia of aeolian deposits such as intracrater dunes may be related to average particle size. Outflow channels and valleys consistently show higher thermal Inertias than the surrounding terrain. Generally, correlations between spatial variations in thermal Inertia and geologic features suggest a relationship between the hundred-meter-scale morphology and the centimeter-scale surface layer.
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high resolution thermal Inertia mapping from the mars global surveyor thermal emission spectrometer
Lunar and Planetary Science Conference, 2000Co-Authors: Michael T Mellon, Hugh H Kieffer, Bruce M. Jakosky, Philip R ChristensenAbstract:High-resolution thermal Inertia mapping results are presented, derived from Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES) observations of the surface temperature of Mars obtained during the early portion of the MGS mapping mission. Thermal Inertia is the key property controlling the diurnal surface temperature variations, and is dependent on the physical character of the top few centimeters of the surface. It represents a complex combination of particle size, rock abundance, exposures of bedrock, and degree of induration. In this work we describe the derivation of thermal Inertia from TES data, present global scale analysis, and place these results into context with earlier work. A global map of nighttime thermal-bolometer-based thermal Inertia is presented at 1 ‐ per pixel resolution, with approximately 63% coverage between 50 ‐ S and 70 ‐ N latitude. Global analysis shows a similar pattern of high and low thermal Inertia as seen in previous Viking low-resolution mapping. Significantly more detail is present in the high-resolution TES thermal Inertia. This detail represents horizontal small-scale variability in the nature of the surface. Correlation with albedo indicates the presence of a previously undiscovered surface unit of moderate-to-high thermal Inertia and intermediate albedo. This new unit has a modal peak thermal Inertia of 180‐ 250 Jm i 2 K i 1 s i 1 2 and a narrow range of albedo near 0.24. The unit, covering a significant fraction of the surface, typically surrounds the low thermal Inertia regions and may comprise a deposit of indurated fine material. Local 3-km-resolution maps are also presented as examples of eolian, fluvial, and volcanic geology. Some impact crater rims and intracrater dunes show higher thermal Inertias than the surrounding terrain; thermal Inertia of aeolian deposits such as intracrater dunes may be related to average particle size. Outflow channels and valleys consistently show higher thermal Inertias than the surrounding terrain. Generally, correlations between spatial variations in thermal Inertia and geologic features suggest a relationship between the hundred-meter-scale morphology and the centimeter-scale surface layer. c ∞ 2000 Academic Press
Bruce M. Jakosky - One of the best experts on this subject based on the ideXlab platform.
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high resolution thermal Inertia mapping of mars sites of exobiological interest
Journal of Geophysical Research, 2001Co-Authors: Bruce M. Jakosky, Michael T MellonAbstract:We have mapped thermal Inertia at high resolution for selected regions of Mars that are of potential biological relevance, using observations made by the Mars Global Surveyor Thermal Emission Spectrometer. Thermal Inertia is a direct indicator of physical properties of the surface at the decimeter-to-meter scale. Our goal is to understand the geological processes by which the sites formed and their subsequent evolution, their current state, and their safety and science potential as landing sites for future lander, rover, and sample-return spacecraft missions. The thermal Inertia values at ∼3-km scale for the sites considered span the entire range of values measured at Mars; thermal Inertias range from low values indicative of substantial aeolian mantling up to high values suggesting surfaces covered predominantly with bedrock, exposed rocks or blocks, or well-indurated crusts. The highest thermal Inertias correlate strongly with local morphology, while areas with intermediate and low thermal Inertias generally show no such correlation. This suggests that selection of future landing sites will be plagued by a choice of a well-mantled site that is safe but less interesting scientifically versus an unmantled site that is more interesting scientifically but less safe.
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High‐resolution thermal Inertia mapping of Mars: Sites of exobiological interest
Journal of Geophysical Research, 2001Co-Authors: Bruce M. Jakosky, Michael T MellonAbstract:We have mapped thermal Inertia at high resolution for selected regions of Mars that are of potential biological relevance, using observations made by the Mars Global Surveyor Thermal Emission Spectrometer. Thermal Inertia is a direct indicator of physical properties of the surface at the decimeter-to-meter scale. Our goal is to understand the geological processes by which the sites formed and their subsequent evolution, their current state, and their safety and science potential as landing sites for future lander, rover, and sample-return spacecraft missions. The thermal Inertia values at ∼3-km scale for the sites considered span the entire range of values measured at Mars; thermal Inertias range from low values indicative of substantial aeolian mantling up to high values suggesting surfaces covered predominantly with bedrock, exposed rocks or blocks, or well-indurated crusts. The highest thermal Inertias correlate strongly with local morphology, while areas with intermediate and low thermal Inertias generally show no such correlation. This suggests that selection of future landing sites will be plagued by a choice of a well-mantled site that is safe but less interesting scientifically versus an unmantled site that is more interesting scientifically but less safe.
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High-Resolution Thermal Inertia Mapping from the Mars Global Surveyor Thermal Emission Spectrometer
Icarus, 2000Co-Authors: Michael T Mellon, Hugh H Kieffer, Bruce M. Jakosky, Philip R ChristensenAbstract:Abstract High-resolution thermal Inertia mapping results are presented, derived from Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES) observations of the surface temperature of Mars obtained during the early portion of the MGS mapping mission. Thermal Inertia is the key property controlling the diurnal surface temperature variations, and is dependent on the physical character of the top few centimeters of the surface. It represents a complex combination of particle size, rock abundance, exposures of bedrock, and degree of induration. In this work we describe the derivation of thermal Inertia from TES data, present global scale analysis, and place these results into context with earlier work. A global map of nighttime thermal-bolometer-based thermal Inertia is presented at 1 4 ° per pixel resolution, with approximately 63% coverage between 50°S and 70°N latitude. Global analysis shows a similar pattern of high and low thermal Inertia as seen in previous Viking low-resolution mapping. Significantly more detail is present in the high-resolution TES thermal Inertia. This detail represents horizontal small-scale variability in the nature of the surface. Correlation with albedo indicates the presence of a previously undiscovered surface unit of moderate-to-high thermal Inertia and intermediate albedo. This new unit has a modal peak thermal Inertia of 180–250 J m−2 K−1 s− 1 2 and a narrow range of albedo near 0.24. The unit, covering a significant fraction of the surface, typically surrounds the low thermal Inertia regions and may comprise a deposit of indurated fine material. Local 3-km-resolution maps are also presented as examples of eolian, fluvial, and volcanic geology. Some impact crater rims and intracrater dunes show higher thermal Inertias than the surrounding terrain; thermal Inertia of aeolian deposits such as intracrater dunes may be related to average particle size. Outflow channels and valleys consistently show higher thermal Inertias than the surrounding terrain. Generally, correlations between spatial variations in thermal Inertia and geologic features suggest a relationship between the hundred-meter-scale morphology and the centimeter-scale surface layer.
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high resolution thermal Inertia mapping from the mars global surveyor thermal emission spectrometer
Lunar and Planetary Science Conference, 2000Co-Authors: Michael T Mellon, Hugh H Kieffer, Bruce M. Jakosky, Philip R ChristensenAbstract:High-resolution thermal Inertia mapping results are presented, derived from Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES) observations of the surface temperature of Mars obtained during the early portion of the MGS mapping mission. Thermal Inertia is the key property controlling the diurnal surface temperature variations, and is dependent on the physical character of the top few centimeters of the surface. It represents a complex combination of particle size, rock abundance, exposures of bedrock, and degree of induration. In this work we describe the derivation of thermal Inertia from TES data, present global scale analysis, and place these results into context with earlier work. A global map of nighttime thermal-bolometer-based thermal Inertia is presented at 1 ‐ per pixel resolution, with approximately 63% coverage between 50 ‐ S and 70 ‐ N latitude. Global analysis shows a similar pattern of high and low thermal Inertia as seen in previous Viking low-resolution mapping. Significantly more detail is present in the high-resolution TES thermal Inertia. This detail represents horizontal small-scale variability in the nature of the surface. Correlation with albedo indicates the presence of a previously undiscovered surface unit of moderate-to-high thermal Inertia and intermediate albedo. This new unit has a modal peak thermal Inertia of 180‐ 250 Jm i 2 K i 1 s i 1 2 and a narrow range of albedo near 0.24. The unit, covering a significant fraction of the surface, typically surrounds the low thermal Inertia regions and may comprise a deposit of indurated fine material. Local 3-km-resolution maps are also presented as examples of eolian, fluvial, and volcanic geology. Some impact crater rims and intracrater dunes show higher thermal Inertias than the surrounding terrain; thermal Inertia of aeolian deposits such as intracrater dunes may be related to average particle size. Outflow channels and valleys consistently show higher thermal Inertias than the surrounding terrain. Generally, correlations between spatial variations in thermal Inertia and geologic features suggest a relationship between the hundred-meter-scale morphology and the centimeter-scale surface layer. c ∞ 2000 Academic Press
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Atmospheric effects on the mapping of Martian thermal Inertia and thermally derived albedo
Journal of Geophysical Research, 1995Co-Authors: Joan N. Hayashi, Bruce M. Jakosky, Robert M. HaberleAbstract:We examine the effects of a dusty CO2 atmosphere on the thermal Inertia and thermally derived albedo of Mars and we present a new map of thermal Inertias. This new map was produced using a coupled surface atmosphere (CSA) model, dust opacities from Viking infrared thermal mapper (IRTM) data, and CO2 columns based on topography. The CSA model thermal Inertias are smaller than the 2% model thermal Inertias, with the difference largest at large thermal Inertia. Although the difference between the thermal Inertias obtained with the two models is moderate for much of the region studied, it is largest in regions of either high dust opacity or of topographic lows, including the Viking Lander 1 site and some geologically interesting regions. The CSA model thermally derived albedos do not accurately predict the IRTM measured albedos and are very similar to the thermally derived albedos obtained with models making the 2% assumption.
Philip R Christensen - One of the best experts on this subject based on the ideXlab platform.
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physical properties of the mars exploration rover landing sites as inferred from mini tes derived thermal Inertia
Journal of Geophysical Research, 2006Co-Authors: R L Fergason, Philip R Christensen, J F Bell, Matthew P Golombek, Kenneth E Herkenhoff, Hugh H KiefferAbstract:[1] The Miniature Thermal Emission Spectrometer (Mini-TES) on board the two Mars Exploration Rovers provides the first opportunity to observe thermal properties from the Martian surface, relate these properties to orbital data, and perform soil conductivity experiments under Martian conditions. The thermal Inertias of soils, bedforms, and rock at each landing site were derived to quantify the physical properties of these features and understand geologic processes occurring at these localities. The thermal Inertia for the Gusev plains rock target Bonneville Beacon (∼1200 J m−2 K−1 s−1/2) is consistent with a dense, basaltic rock, but the rocks at the Columbia Hills have a lower thermal Inertia (∼620 J m−2 K−1 s−1/2), suggesting that they have a volcaniclasic origin. Bedforms on the floors of craters at both landing sites have thermal Inertias of 200 J m−2 K−1 s−1/2, consistent with a particle diameter of ∼160 μm. This diameter is comparable to the most easily moved grain size in the current atmosphere on Mars, suggesting that these bedforms may have formed under current atmospheric conditions. Along the Meridiani plains, the thermal Inertia is lower than that derived from TES and Thermal Emission Imaging System (THEMIS) orbital data. This discrepancy is not well understood. Mini-TES–derived thermal Inertias at Gusev along a ∼2.5 km traverse follow trends in thermal Inertia measured from orbit with TES and THEMIS. However, along the traverse, there are variability and mixing of particle sizes that are not resolved in the orbital thermal Inertia data due to meter-scale processes that are not identifiable at larger scales.
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High-Resolution Thermal Inertia Mapping from the Mars Global Surveyor Thermal Emission Spectrometer
Icarus, 2000Co-Authors: Michael T Mellon, Hugh H Kieffer, Bruce M. Jakosky, Philip R ChristensenAbstract:Abstract High-resolution thermal Inertia mapping results are presented, derived from Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES) observations of the surface temperature of Mars obtained during the early portion of the MGS mapping mission. Thermal Inertia is the key property controlling the diurnal surface temperature variations, and is dependent on the physical character of the top few centimeters of the surface. It represents a complex combination of particle size, rock abundance, exposures of bedrock, and degree of induration. In this work we describe the derivation of thermal Inertia from TES data, present global scale analysis, and place these results into context with earlier work. A global map of nighttime thermal-bolometer-based thermal Inertia is presented at 1 4 ° per pixel resolution, with approximately 63% coverage between 50°S and 70°N latitude. Global analysis shows a similar pattern of high and low thermal Inertia as seen in previous Viking low-resolution mapping. Significantly more detail is present in the high-resolution TES thermal Inertia. This detail represents horizontal small-scale variability in the nature of the surface. Correlation with albedo indicates the presence of a previously undiscovered surface unit of moderate-to-high thermal Inertia and intermediate albedo. This new unit has a modal peak thermal Inertia of 180–250 J m−2 K−1 s− 1 2 and a narrow range of albedo near 0.24. The unit, covering a significant fraction of the surface, typically surrounds the low thermal Inertia regions and may comprise a deposit of indurated fine material. Local 3-km-resolution maps are also presented as examples of eolian, fluvial, and volcanic geology. Some impact crater rims and intracrater dunes show higher thermal Inertias than the surrounding terrain; thermal Inertia of aeolian deposits such as intracrater dunes may be related to average particle size. Outflow channels and valleys consistently show higher thermal Inertias than the surrounding terrain. Generally, correlations between spatial variations in thermal Inertia and geologic features suggest a relationship between the hundred-meter-scale morphology and the centimeter-scale surface layer.
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high resolution thermal Inertia mapping from the mars global surveyor thermal emission spectrometer
Lunar and Planetary Science Conference, 2000Co-Authors: Michael T Mellon, Hugh H Kieffer, Bruce M. Jakosky, Philip R ChristensenAbstract:High-resolution thermal Inertia mapping results are presented, derived from Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES) observations of the surface temperature of Mars obtained during the early portion of the MGS mapping mission. Thermal Inertia is the key property controlling the diurnal surface temperature variations, and is dependent on the physical character of the top few centimeters of the surface. It represents a complex combination of particle size, rock abundance, exposures of bedrock, and degree of induration. In this work we describe the derivation of thermal Inertia from TES data, present global scale analysis, and place these results into context with earlier work. A global map of nighttime thermal-bolometer-based thermal Inertia is presented at 1 ‐ per pixel resolution, with approximately 63% coverage between 50 ‐ S and 70 ‐ N latitude. Global analysis shows a similar pattern of high and low thermal Inertia as seen in previous Viking low-resolution mapping. Significantly more detail is present in the high-resolution TES thermal Inertia. This detail represents horizontal small-scale variability in the nature of the surface. Correlation with albedo indicates the presence of a previously undiscovered surface unit of moderate-to-high thermal Inertia and intermediate albedo. This new unit has a modal peak thermal Inertia of 180‐ 250 Jm i 2 K i 1 s i 1 2 and a narrow range of albedo near 0.24. The unit, covering a significant fraction of the surface, typically surrounds the low thermal Inertia regions and may comprise a deposit of indurated fine material. Local 3-km-resolution maps are also presented as examples of eolian, fluvial, and volcanic geology. Some impact crater rims and intracrater dunes show higher thermal Inertias than the surrounding terrain; thermal Inertia of aeolian deposits such as intracrater dunes may be related to average particle size. Outflow channels and valleys consistently show higher thermal Inertias than the surrounding terrain. Generally, correlations between spatial variations in thermal Inertia and geologic features suggest a relationship between the hundred-meter-scale morphology and the centimeter-scale surface layer. c ∞ 2000 Academic Press
