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Henrik Kahanpää - One of the best experts on this subject based on the ideXlab platform.
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diurnal variations of energetic particle radiation at the surface of Mars as observed by the Mars Science Laboratory radiation assessment detector
Journal of Geophysical Research, 2014Co-Authors: Scot C R Rafkin, Ari-matti Harri, J Gomezelvira, Cary Zeitlin, Donald M. Hassler, Bent Ehresmann, Jingnan Guo, J Kohler, R F Wimmerschweingruber, Henrik KahanpääAbstract:The Radiation Assessment Detector onboard the Mars Science Laboratory rover Curiosity is detecting the energetic particle radiation at the surface of Mars. Data collected over the first 350 Martian days of the nominal surface mission show a pronounced diurnal cycle in both the total dose rate and the neutral particle count rate. The diurnal variations detected by the Radiation Assessment Detector were neither anticipated nor previously considered in the literature. These cyclic variations in dose rate and count rate are shown to be the result of changes in atmospheric column mass driven by the atmospheric thermal tide that is characterized through pressure measurements obtained by the Rover Environmental Monitoring Station, also onboard the rover. In addition to bulk changes in the radiation environment, changes in atmospheric shielding forced by the thermal tide are shown to disproportionately affect heavy ions compared to H and He nuclei.
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REMS: The environmental sensor suite for the Mars Science Laboratory rover
Space Science Reviews, 2012Co-Authors: J. Gómez-elvira, C. Armiens, Robert Haberle, Ari-matti Harri, M. Dominguez, Luis Castañer, F. Gomez, V. Jimenez, M. Genzer, Henrik KahanpääAbstract:The Rover Environmental Monitoring Station (REMS) will investigate environ-mental factors directly tied to current habitability at the Martian surface during the Mars Sci-ence Laboratory (MSL) mission. Three major habitability factors are addressed by REMS: the thermal environment, ultraviolet irradiation, and water cycling. The thermal environment is determined by a mixture of processes, chief amongst these being the meteorological. Ac-cordingly, the REMS sensors have been designed to record air and ground temperatures, pressure, relative humidity, wind speed in the horizontal and vertical directions, as well as ultraviolet radiation in different bands. These sensors are distributed over the rover in four places: two booms located on the MSL Remote Sensing Mast, the ultraviolet sensor on the rover deck, and the pressure sensor inside the rover body. Typical daily REMS observa-tions will collect 180 minutes of data from all sensors simultaneously (arranged in 5 minute hourly samples plus 60 additional minutes taken at times to be decided during the course of the mission). REMS will add significantly to the environmental record collected by prior missions through the range of simultaneous observations including water vapor; the ability to take measurements routinely through the night; the intended minimum of one Martian year of observations; and the first measurement of surface UV irradiation. In this paper, we describe the scientific potential of REMS measurements and describe in detail the sensors that constitute REMS and the calibration procedures.
J Gomezelvira - One of the best experts on this subject based on the ideXlab platform.
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gale surface wind characterization based on the Mars Science Laboratory rems dataset part ii wind probability distributions
Icarus, 2019Co-Authors: D Viudezmoreiras, J Gomezelvira, C E Newman, Sara Navarro, M Marin, J Torres, M De La TorrejuarezAbstract:Abstract The characterization of Martian surface wind speed as a function of time of day and season at one location can increase our knowledge of Mars surface conditions and assist in planning for future unmanned and manned missions, since the probability of the wind speed exceeding a given value is often required for both engineering and geophysical applications. Wind speeds are also useful for assessing the aeolian impact of the circulation. The Rover Environmental Monitoring Station (REMS) instrument on the Mars Science Laboratory (MSL) rover has been measuring Martian winds since 2012, thus has provided more than two Mars years of wind data in the first Martian landing site with significant topography. Unfortunately, dust debris during the MSL landing stage damaged the sensor, making difficult to extract useful wind data. This paper complements the characterization performed in the companion paper, by producing a wind speed characterization based on probability distribution models. Significant diurnal and seasonal wind speed variability is found, due to complex interactions between the synoptic flow, the regional and local slope winds and microscale flow around MSL. The highest wind speed probabilities are found in general during the midday period, particularly around the equinoxes. In addition, the REMS data suggest strong flows during the summer nighttime, which could be related to the increased aeolian activity detected then by MSL.
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gale surface wind characterization based on the Mars Science Laboratory rems dataset part i wind retrieval and gale s wind speeds and directions
Icarus, 2019Co-Authors: D Viudezmoreiras, J Gomezelvira, C E Newman, Sara Navarro, M Marin, J Torres, M De La TorrejuarezAbstract:Abstract The characterization of Martian surface winds as a function of time of day and season at one location can increase our knowledge of Mars surface conditions and assist in planning for future unmanned and manned missions. Martian surface winds vary greatly with location, and even at a particular landing site show a high degree of diurnal, seasonal, and interannual variability. Thus characterizing surface wind speeds and directions requires a long time series, which is rarely obtained on Mars. The Rover Environmental Monitoring Station (REMS) instrument on the Mars Science Laboratory (MSL) rover has been measuring Martian winds since 2012, thus has provided more than two Martian years of wind data at the first Martian landing site to have significant topography, in the trench of Gale Crater. Unfortunately, likely debris impacts during landing damaged the wind sensor, making it difficult to extract useful wind data. The first part of this paper presents a new retrieval that allows “good” wind measurements to be extracted from the raw dataset obtained under such conditions. In addition, a characterization of wind speeds and directions in Gale Crater is presented, after processing the full dataset of wind data in order to obtain the representative winds for different diurnal timeslots and seasons. Results suggest complex wind patterns and great variability depending on local time and season. Also, a significant influence by the synoptic scale circulation in the wind patterns is observed, although the local-scale circulation is suggested to be the major contributor to the observed surface winds in Gale Crater.
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Mars Science Laboratory relative humidity observations initial results
Journal of Geophysical Research, 2014Co-Authors: Ari-matti Harri, Osku Kemppinen, J Polkko, Hannu Savijarvi, N O Renno, J Gomezelvira, J A Rodriguezmanfredi, Robert M. Haberle, M. Genzer, W. SchmidtAbstract:The Mars Science Laboratory (MSL) made a successful landing at Gale crater early August 2012. MSL has an environmental instrument package called the Rover Environmental Monitoring Station (REMS) as ...
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diurnal variations of energetic particle radiation at the surface of Mars as observed by the Mars Science Laboratory radiation assessment detector
Journal of Geophysical Research, 2014Co-Authors: Scot C R Rafkin, Ari-matti Harri, J Gomezelvira, Cary Zeitlin, Donald M. Hassler, Bent Ehresmann, Jingnan Guo, J Kohler, R F Wimmerschweingruber, Henrik KahanpääAbstract:The Radiation Assessment Detector onboard the Mars Science Laboratory rover Curiosity is detecting the energetic particle radiation at the surface of Mars. Data collected over the first 350 Martian days of the nominal surface mission show a pronounced diurnal cycle in both the total dose rate and the neutral particle count rate. The diurnal variations detected by the Radiation Assessment Detector were neither anticipated nor previously considered in the literature. These cyclic variations in dose rate and count rate are shown to be the result of changes in atmospheric column mass driven by the atmospheric thermal tide that is characterized through pressure measurements obtained by the Rover Environmental Monitoring Station, also onboard the rover. In addition to bulk changes in the radiation environment, changes in atmospheric shielding forced by the thermal tide are shown to disproportionately affect heavy ions compared to H and He nuclei.
A Cousin - One of the best experts on this subject based on the ideXlab platform.
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recalibration of the Mars Science Laboratory chemcam instrument with an expanded geochemical database
Spectrochimica Acta Part B: Atomic Spectroscopy, 2017Co-Authors: S M Clegg, O. Forni, R C Wiens, A Cousin, R B Anderson, J Frydenvang, J Lasue, V Payre, T Boucher, Darby M DyarAbstract:Abstract The ChemCam Laser-Induced Breakdown Spectroscopy (LIBS) instrument onboard the Mars Science Laboratory (MSL) rover Curiosity has obtained > 300,000 spectra of rock and soil analysis targets since landing at Gale Crater in 2012, and the spectra represent perhaps the largest publicly-available LIBS datasets. The compositions of the major elements, reported as oxides (SiO2, TiO2, Al2O3, FeOT, MgO, CaO, Na2O, K2O), have been re-calibrated using a Laboratory LIBS instrument, Mars-like atmospheric conditions, and a much larger set of standards (408) that span a wider compositional range than previously employed. The new calibration uses a combination of partial least squares (PLS1) and Independent Component Analysis (ICA) algorithms, together with a calibration transfer matrix to minimize differences between the conditions under which the standards were analyzed in the Laboratory and the conditions on Mars. While the previous model provided good results in the compositional range near the average Mars surface composition, the new model fits the extreme compositions far better. Examples are given for plagioclase feldspars, where silicon was significantly over-estimated by the previous model, and for calcium-sulfate veins, where silicon compositions near zero were inaccurate. The uncertainties of major element abundances are described as a function of the abundances, and are overall significantly lower than the previous model, enabling important new geochemical interpretations of the data.
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pre flight calibration and initial data processing for the chemcam laser induced breakdown spectroscopy instrument on the Mars Science Laboratory rover
Spectrochimica Acta Part B: Atomic Spectroscopy, 2013Co-Authors: R C Wiens, S. Maurice, O. Forni, S M Clegg, R B Anderson, J Lasue, S Bender, D L Blaney, B L Barraclough, A CousinAbstract:Abstract The ChemCam instrument package on the Mars Science Laboratory rover, Curiosity, is the first planetary Science instrument to employ laser-induced breakdown spectroscopy (LIBS) to determine the compositions of geological samples on another planet. Pre-processing of the spectra involves subtracting the ambient light background, removing noise, removing the electron continuum, calibrating for the wavelength, correcting for the variable distance to the target, and applying a wavelength-dependent correction for the instrument response. Further processing of the data uses multivariate and univariate comparisons with a LIBS spectral library developed prior to launch as well as comparisons with several on-board standards post-landing. The level-2 data products include semi-quantitative abundances derived from partial least squares regression. A LIBS spectral library was developed using 69 rock standards in the form of pressed powder disks, glasses, and ceramics to minimize heterogeneity on the scale of the observation (350–550 μm dia.). The standards covered typical compositional ranges of igneous materials and also included sulfates, carbonates, and phyllosilicates. The provenance and elemental and mineralogical compositions of these standards are described. Spectral characteristics of this data set are presented, including the size distribution and integrated irradiances of the plasmas, and a proxy for plasma temperature as a function of distance from the instrument. Two Laboratory-based clones of ChemCam reside in Los Alamos and Toulouse for the purpose of adding new spectra to the database as the need arises. Sensitivity to differences in wavelength correlation to spectral channels and spectral resolution has been investigated, indicating that spectral registration needs to be within half a pixel and resolution needs to match within 1.5 to 2.6 pixels. Absolute errors are tabulated for derived compositions of each major element in each standard using PLS regression. Sources of errors are investigated and discussed, and methods for improving the analytical accuracy of compositions derived from ChemCam spectra are discussed.
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onboard calibration igneous targets for the Mars Science Laboratory curiosity rover and the chemistry camera laser induced breakdown spectroscopy instrument
Spectrochimica Acta Part B: Atomic Spectroscopy, 2011Co-Authors: C Fabre, S. Maurice, O. Forni, R C Wiens, A Cousin, V Sautter, Damien GuillaumeAbstract:article i nfo Accurate characterization of the Chemistry Camera (ChemCam) laser-induced breakdown spectroscopy (LIBS) on-board composition targets is of prime importance for the ChemCam instrument. The Mars Science Laboratory (MSL) Science and operations teams expect ChemCam to provide the first compositional results at remote distances (1.5-7 m) during the in situ analyses of the Martian surface starting in 2012. Thus, establishing LIBS reference spectra from appropriate calibration standards must be undertaken diligently. Considering the global mineralogy of the Martian surface, and the possible landing sites, three specific compositions of igneous targets have been determined. Picritic, noritic, and shergottic glasses have been produced, along with a Macusanite natural glass. A sample of each target will fly on the MSL Curiosity rover deck, 1.56 m from the ChemCam instrument, and duplicates are available on the ground. Duplicates are considered to be identical, as the relative standard deviation (RSD) of the composition dispersion is around 8%. Electronic microprobe and laser ablation inductively coupled plasma mass spectrometry (LA ICP-MS) analyses give evidence that the chemical composition of the four silicate targets is very homogeneous at microscopic scales larger than the instrument spot size, with RSD b5% for concentration variations N0.1 wt.% using electronic microprobe, and b10% for concentration variations N0.01 wt.% using LA ICP-MS. The LIBS campaign on the igneous targets performed under flight-like Mars conditions establishes reference spectra for the entire mission. The LIBS spectra between 240 and 900 nm are extremely rich, hundreds of lines with high signal-to-noise, and a dynamical range sufficient to identify unambiguously major, minor and trace elements. For instance, a first LIBS calibration curve has been established for strontium from (Sr)=284 ppm to (Sr)=1480 ppm, showing the potential for the future calibrations for other major or minor elements.
M De La Torrejuarez - One of the best experts on this subject based on the ideXlab platform.
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gale surface wind characterization based on the Mars Science Laboratory rems dataset part ii wind probability distributions
Icarus, 2019Co-Authors: D Viudezmoreiras, J Gomezelvira, C E Newman, Sara Navarro, M Marin, J Torres, M De La TorrejuarezAbstract:Abstract The characterization of Martian surface wind speed as a function of time of day and season at one location can increase our knowledge of Mars surface conditions and assist in planning for future unmanned and manned missions, since the probability of the wind speed exceeding a given value is often required for both engineering and geophysical applications. Wind speeds are also useful for assessing the aeolian impact of the circulation. The Rover Environmental Monitoring Station (REMS) instrument on the Mars Science Laboratory (MSL) rover has been measuring Martian winds since 2012, thus has provided more than two Mars years of wind data in the first Martian landing site with significant topography. Unfortunately, dust debris during the MSL landing stage damaged the sensor, making difficult to extract useful wind data. This paper complements the characterization performed in the companion paper, by producing a wind speed characterization based on probability distribution models. Significant diurnal and seasonal wind speed variability is found, due to complex interactions between the synoptic flow, the regional and local slope winds and microscale flow around MSL. The highest wind speed probabilities are found in general during the midday period, particularly around the equinoxes. In addition, the REMS data suggest strong flows during the summer nighttime, which could be related to the increased aeolian activity detected then by MSL.
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gale surface wind characterization based on the Mars Science Laboratory rems dataset part i wind retrieval and gale s wind speeds and directions
Icarus, 2019Co-Authors: D Viudezmoreiras, J Gomezelvira, C E Newman, Sara Navarro, M Marin, J Torres, M De La TorrejuarezAbstract:Abstract The characterization of Martian surface winds as a function of time of day and season at one location can increase our knowledge of Mars surface conditions and assist in planning for future unmanned and manned missions. Martian surface winds vary greatly with location, and even at a particular landing site show a high degree of diurnal, seasonal, and interannual variability. Thus characterizing surface wind speeds and directions requires a long time series, which is rarely obtained on Mars. The Rover Environmental Monitoring Station (REMS) instrument on the Mars Science Laboratory (MSL) rover has been measuring Martian winds since 2012, thus has provided more than two Martian years of wind data at the first Martian landing site to have significant topography, in the trench of Gale Crater. Unfortunately, likely debris impacts during landing damaged the wind sensor, making it difficult to extract useful wind data. The first part of this paper presents a new retrieval that allows “good” wind measurements to be extracted from the raw dataset obtained under such conditions. In addition, a characterization of wind speeds and directions in Gale Crater is presented, after processing the full dataset of wind data in order to obtain the representative winds for different diurnal timeslots and seasons. Results suggest complex wind patterns and great variability depending on local time and season. Also, a significant influence by the synoptic scale circulation in the wind patterns is observed, although the local-scale circulation is suggested to be the major contributor to the observed surface winds in Gale Crater.
Ari-matti Harri - One of the best experts on this subject based on the ideXlab platform.
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Mars Science Laboratory relative humidity observations initial results
Journal of Geophysical Research, 2014Co-Authors: Ari-matti Harri, Osku Kemppinen, J Polkko, Hannu Savijarvi, N O Renno, J Gomezelvira, J A Rodriguezmanfredi, Robert M. Haberle, M. Genzer, W. SchmidtAbstract:The Mars Science Laboratory (MSL) made a successful landing at Gale crater early August 2012. MSL has an environmental instrument package called the Rover Environmental Monitoring Station (REMS) as ...
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diurnal variations of energetic particle radiation at the surface of Mars as observed by the Mars Science Laboratory radiation assessment detector
Journal of Geophysical Research, 2014Co-Authors: Scot C R Rafkin, Ari-matti Harri, J Gomezelvira, Cary Zeitlin, Donald M. Hassler, Bent Ehresmann, Jingnan Guo, J Kohler, R F Wimmerschweingruber, Henrik KahanpääAbstract:The Radiation Assessment Detector onboard the Mars Science Laboratory rover Curiosity is detecting the energetic particle radiation at the surface of Mars. Data collected over the first 350 Martian days of the nominal surface mission show a pronounced diurnal cycle in both the total dose rate and the neutral particle count rate. The diurnal variations detected by the Radiation Assessment Detector were neither anticipated nor previously considered in the literature. These cyclic variations in dose rate and count rate are shown to be the result of changes in atmospheric column mass driven by the atmospheric thermal tide that is characterized through pressure measurements obtained by the Rover Environmental Monitoring Station, also onboard the rover. In addition to bulk changes in the radiation environment, changes in atmospheric shielding forced by the thermal tide are shown to disproportionately affect heavy ions compared to H and He nuclei.
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REMS: The environmental sensor suite for the Mars Science Laboratory rover
Space Science Reviews, 2012Co-Authors: J. Gómez-elvira, C. Armiens, Robert Haberle, Ari-matti Harri, M. Dominguez, Luis Castañer, F. Gomez, V. Jimenez, M. Genzer, Henrik KahanpääAbstract:The Rover Environmental Monitoring Station (REMS) will investigate environ-mental factors directly tied to current habitability at the Martian surface during the Mars Sci-ence Laboratory (MSL) mission. Three major habitability factors are addressed by REMS: the thermal environment, ultraviolet irradiation, and water cycling. The thermal environment is determined by a mixture of processes, chief amongst these being the meteorological. Ac-cordingly, the REMS sensors have been designed to record air and ground temperatures, pressure, relative humidity, wind speed in the horizontal and vertical directions, as well as ultraviolet radiation in different bands. These sensors are distributed over the rover in four places: two booms located on the MSL Remote Sensing Mast, the ultraviolet sensor on the rover deck, and the pressure sensor inside the rover body. Typical daily REMS observa-tions will collect 180 minutes of data from all sensors simultaneously (arranged in 5 minute hourly samples plus 60 additional minutes taken at times to be decided during the course of the mission). REMS will add significantly to the environmental record collected by prior missions through the range of simultaneous observations including water vapor; the ability to take measurements routinely through the night; the intended minimum of one Martian year of observations; and the first measurement of surface UV irradiation. In this paper, we describe the scientific potential of REMS measurements and describe in detail the sensors that constitute REMS and the calibration procedures.