Robin Fergason Philip Christensen MSL Landing Site Selection Workshop May 31, 2006

  • Published on
    23-Jan-2016

  • View
    38

  • Download
    0

Embed Size (px)

DESCRIPTION

Determining surface characteristics at candidate MSL landing sites using THEMIS high-resolution orbital thermal inertia data. Robin Fergason Philip Christensen MSL Landing Site Selection Workshop May 31, 2006. Thermal Inertia Background. Used to infer a particle size of the surface layer - PowerPoint PPT Presentation

Transcript

  • Determining surface characteristics at candidate MSL landing sites using THEMIS high-resolution orbital thermal inertia data

    Robin FergasonPhilip Christensen

    MSL Landing Site Selection WorkshopMay 31, 2006

  • Thermal Inertia BackgroundUsed to infer a particle size of the surface layer

    Helps to identify features, their location and extent on the surface, and their particle size

    Detect exposed bedrock and dust

  • Exposed Bedrock80026067.6 ENili Patera66.9 E8.7 N9.5 NAres VallesRogers et al., 2005Christensen et al., 2003a; 2005950190341.6 E341.3 E5.9 N6.4 N3.4 km3.5 kmTHEMIS-derived thermal inertia overlain onto THEMIS visible

  • Hebes Chasma Interior Layered DepositsV10052001800 mTI: 190-245TI: 275-360TI: 290-420TI: 125-145125615Fergason et al., submitted

  • Thermal Inertia BackgroundI = (kc)1/2 bulk density k conductivity c specific heatThermal inertia measures a materials resistance to change in temperature

  • THEMIS-derived thermal inertiaUse thermal model developed by H. H. KiefferLs, latitude, local time from spacecraft ephemerisTES-derived albedo (8ppd)MOLA-derived elevations (128 epd)TES-derived dust opacity (2 ppd) every 30 LsRadiance at 12.57 m (Band 9) is converted to brightness temperature, correcting for drift and wobble of the spacecraftInterpolate upon a 7-D look-up table

  • THEMIS-derived Thermal Inertia UncertaintiesUncertainties are primarily due to: (1) instrument calibration (2) uncertainties in model input parameters (3) thermal model uncertainties

    Variations in thermal inertia within a single image are accurate and represent differences in the physical properties of the surface

  • Comparison with TES25600180 E40 S40 N180 E180 E40 S40 N180 ETHEMISTES Fergason et al., submitted

  • Comparison of Mini-TES and THEMISThermal InertiaFergason et al., 2006250430

    Chart2

    168.16280

    157.09300

    192.93330

    150.12305

    197.5175290

    136.43225315

    216.638350

    487.788390

    668.1165

    1206.98

    436.476

    336.216

    351.142

    205.595

    196.736

    363.331

    235.513

    257.435

    227.187

    220.189

    164.327

    294.06

    275.998

    284.769

    759.402

    352.24

    178.753

    240.203

    276.633

    338.538

    176.183

    Mini-TES Thermal Inertia

    THEMIS Thermal Inertia

    Spirit - Gusev Landing Site Number

    Thermal Inertia

    THEMIS and Mini-TES Thermal Inertia

    Sheet1

    Gusev Plains Traverse

    Comparing THEMIS and Mini-TES thermal inertia data results

    THEMIS Thermal InertiaMini-TES Thermal InertiaMini-TESTHEMIS

    SolAvg SolAve SiteFeatureAvg THEMIS thermal inertiaAvg Mini-TES thermal inertiaAlbedo - 0.25Albedo - 0.22Albedo - 0.22 - minus the outlying high values to calculate an appropriate standard deviation

    Albedo 0.25Alb 0.22siteSolinertiainertia

    1-50254plains280140173325133.71168.16280168.16

    51-615612transition between plains and Bonneville crater300190134437124.62157.09284157.09

    61-897520Bonneville ejecta330380774744161.49192.93288192.93

    90-1009526transition between plains and Bonneville crater305300301946125.952150.12292150.12

    101-12311236Lahonton Crater2901852441050146.677197.5175296173.1635197.5175

    124-13312848plains315195196115282.13136.43225300136.43225

    138-15014456plains3503103071261185.56216.638310133.845216.638

    150-15815464near Colombia hills3902402641362419.42487.788320487.788

    1565697.01668.1165330436.476

    RMS between THEMIS and MT24891206.981206.98321.7263.8658055556774.47336.216

    2590315436.476313.4358.177225351.142

    2691286.22336.216305205.595

    2799304.56351.142302.5301.9266666667196.736

    28101176.25205.595300363.331

    29102167.465196.736297.5235.513

    31106313.82363.331295257.435

    33109202.17235.513292.5227.187

    36112217.12257.435290220.189

    39118183.54227.187295164.327

    42122186.25220.189300243.7122857143294.06

    44124129.42164.327305275.998

    46125294.06294.06310284.769

    48128239.5275.998315352.24

    50130121.94284.769326.6196.23178.753

    55143567.46759.402338.2240.203

    57145300.95352.24350276.633

    59147152.72178.753363.3338.538

    61149207.967240.203376.6307.27425176.183

    64153239.112276.633390

    71189293.93338.538

    73191147.75176.183293.8536190476263.7846666667

    6170.926

    314.6031693548313.3551724138

    218.72087890789.0118269262

    RSS

    Bonneville to CH RSS:319.5983309972Mini-TESBonneville to CH RSS:

    331.9487912314THEMIS

    12.3504602342

    Sheet1

    Mini-TES Thermal Inertia

    THEMIS Thermal Inertia

    Spirit - Gusev Landing Site Sol Number

    Thermal Inertia

    THEMIS and Mini-TES Thermal Inertia

    Sheet2

    Mini-TES Thermal Inertia

    THEMIS Thermal Inertia

    Spirit - Gusev Landing Site Number

    Thermal Inertia

    THEMIS and Mini-TES Thermal Inertia

    Sheet3

  • Landing Site CharacterizationIdentify regions of very high or very low thermal inertiaTI > 400 likely has rocky surface [Nowicki, 2006]TI < 100 is likely dusty and not drivableEvaluate surface properties of the candidate landing sitesPredicted surface temperature for the primary missionRover design temperature limits: 145 - 310 KMaximum diurnal temperature range: 145 K

  • Opportunity THEMIS Temperature Mosaic - 2003

  • Opportunity THEMIS Temperature Mosaic - 2006

  • 63.2 E57017526.8 N26.3 N62.6 EFergason et al., submitted

  • THEMIS Day and Night IR

  • Predicting Surface TemperatureThermal inertia is derived from THEMIS imageThe derived thermal inertia value is then used to calculate the surface temperature for a given local time and season

    Can predict the minimum surface kinetic temperature during the primary mission

  • ASU Will ProvideInterpretations of THEMIS and TES thermal inertia data for all candidate landing sites

    Thermal inertia mosaics of candidate landing site regions (100 m)Relative thermal inertia values

  • ASU Will ProvideIndividual thermal inertia images of specific areas of interest (100 m)Thermal inertia values of specific morphologies

    Predicted temperature maps of candidate landing site regions (100 m)Predict range of temperaturesDerive maximum diurnal temperature range