Google earth engine对Landsat8辐射定标

• 辐射定标的本质是波段运算，y = ax+b
• 以第10波段为例，首先从元数据文件找到RADIANCE_MULT_BAND_10和RADIANCE_ADD_BAND_10，第一个是乘项 3.3420E-04，第二个是加项0.1。在gee中进行波段运算

var rad10 = image.select('B10').multiply(3.3420*0.0001).add(0.1)

• 以下是一个Landsat8影像自带的元数据文件。

GROUP = L1_METADATA_FILE
  GROUP = METADATA_FILE_INFO
    ORIGIN = "Image courtesy of the U.S. Geological Survey"
    REQUEST_ID = "0702003135965_00029"
    LANDSAT_SCENE_ID = "LC81220352020065LGN00"
    LANDSAT_PRODUCT_ID = "LC08_L1TP_122035_20200305_20200314_01_T1"
    COLLECTION_NUMBER = 01
    FILE_DATE = 2020-03-14T05:18:46Z
    STATION_ID = "LGN"
    PROCESSING_SOFTWARE_VERSION = "LPGS_13.1.0"
  END_GROUP = METADATA_FILE_INFO
  GROUP = PRODUCT_METADATA
    DATA_TYPE = "L1TP"
    COLLECTION_CATEGORY = "T1"
    ELEVATION_SOURCE = "GLS2000"
    OUTPUT_FORMAT = "GEOTIFF"
    SPACECRAFT_ID = "LANDSAT_8"
    SENSOR_ID = "OLI_TIRS"
    WRS_PATH = 122
    WRS_ROW = 35
    NADIR_OFFNADIR = "NADIR"
    TARGET_WRS_PATH = 122
    TARGET_WRS_ROW = 35
    DATE_ACQUIRED = 2020-03-05
    SCENE_CENTER_TIME = "02:48:28.1796780Z"
    CORNER_UL_LAT_PRODUCT = 37.09079
    CORNER_UL_LON_PRODUCT = 115.64750
    CORNER_UR_LAT_PRODUCT = 37.09195
    CORNER_UR_LON_PRODUCT = 118.24675
    CORNER_LL_LAT_PRODUCT = 34.97083
    CORNER_LL_LON_PRODUCT = 115.68327
    CORNER_LR_LAT_PRODUCT = 34.97190
    CORNER_LR_LON_PRODUCT = 118.21378
    CORNER_UL_PROJECTION_X_PRODUCT = 379800.000
    CORNER_UL_PROJECTION_Y_PRODUCT = 4105800.000
    CORNER_UR_PROJECTION_X_PRODUCT = 610800.000
    CORNER_UR_PROJECTION_Y_PRODUCT = 4105800.000
    CORNER_LL_PROJECTION_X_PRODUCT = 379800.000
    CORNER_LL_PROJECTION_Y_PRODUCT = 3870600.000
    CORNER_LR_PROJECTION_X_PRODUCT = 610800.000
    CORNER_LR_PROJECTION_Y_PRODUCT = 3870600.000
    PANCHROMATIC_LINES = 15681
    PANCHROMATIC_SAMPLES = 15401
    REFLECTIVE_LINES = 7841
    REFLECTIVE_SAMPLES = 7701
    THERMAL_LINES = 7841
    THERMAL_SAMPLES = 7701
    FILE_NAME_BAND_1 = "LC08_L1TP_122035_20200305_20200314_01_T1_B1.TIF"
    FILE_NAME_BAND_2 = "LC08_L1TP_122035_20200305_20200314_01_T1_B2.TIF"
    FILE_NAME_BAND_3 = "LC08_L1TP_122035_20200305_20200314_01_T1_B3.TIF"
    FILE_NAME_BAND_4 = "LC08_L1TP_122035_20200305_20200314_01_T1_B4.TIF"
    FILE_NAME_BAND_5 = "LC08_L1TP_122035_20200305_20200314_01_T1_B5.TIF"
    FILE_NAME_BAND_6 = "LC08_L1TP_122035_20200305_20200314_01_T1_B6.TIF"
    FILE_NAME_BAND_7 = "LC08_L1TP_122035_20200305_20200314_01_T1_B7.TIF"
    FILE_NAME_BAND_8 = "LC08_L1TP_122035_20200305_20200314_01_T1_B8.TIF"
    FILE_NAME_BAND_9 = "LC08_L1TP_122035_20200305_20200314_01_T1_B9.TIF"
    FILE_NAME_BAND_10 = "LC08_L1TP_122035_20200305_20200314_01_T1_B10.TIF"
    FILE_NAME_BAND_11 = "LC08_L1TP_122035_20200305_20200314_01_T1_B11.TIF"
    FILE_NAME_BAND_QUALITY = "LC08_L1TP_122035_20200305_20200314_01_T1_BQA.TIF"
    ANGLE_COEFFICIENT_FILE_NAME = "LC08_L1TP_122035_20200305_20200314_01_T1_ANG.txt"
    METADATA_FILE_NAME = "LC08_L1TP_122035_20200305_20200314_01_T1_MTL.txt"
    CPF_NAME = "LC08CPF_20200101_20200331_01.04"
    BPF_NAME_OLI = "LO8BPF20200305023553_20200305041534.01"
    BPF_NAME_TIRS = "LT8BPF20200223110021_20200310034739.01"
    RLUT_FILE_NAME = "LC08RLUT_20150303_20431231_01_12.h5"
  END_GROUP = PRODUCT_METADATA
  GROUP = IMAGE_ATTRIBUTES
    CLOUD_COVER = 0.11
    CLOUD_COVER_LAND = 0.11
    IMAGE_QUALITY_OLI = 9
    IMAGE_QUALITY_TIRS = 9
    TIRS_SSM_MODEL = "FINAL"
    TIRS_SSM_POSITION_STATUS = "ESTIMATED"
    TIRS_STRAY_LIGHT_CORRECTION_SOURCE = "TIRS"
    ROLL_ANGLE = -0.001
    SUN_AZIMUTH = 147.02536051
    SUN_ELEVATION = 42.47324638
    EARTH_SUN_DISTANCE = 0.9918391
    SATURATION_BAND_1 = "N"
    SATURATION_BAND_2 = "N"
    SATURATION_BAND_3 = "Y"
    SATURATION_BAND_4 = "Y"
    SATURATION_BAND_5 = "Y"
    SATURATION_BAND_6 = "Y"
    SATURATION_BAND_7 = "Y"
    SATURATION_BAND_8 = "N"
    SATURATION_BAND_9 = "N"
    GROUND_CONTROL_POINTS_VERSION = 4
    GROUND_CONTROL_POINTS_MODEL = 322
    GEOMETRIC_RMSE_MODEL = 8.037
    GEOMETRIC_RMSE_MODEL_Y = 6.031
    GEOMETRIC_RMSE_MODEL_X = 5.312
    GROUND_CONTROL_POINTS_VERIFY = 142
    GEOMETRIC_RMSE_VERIFY = 4.786
    TRUNCATION_OLI = "UPPER"
  END_GROUP = IMAGE_ATTRIBUTES
  GROUP = MIN_MAX_RADIANCE
    RADIANCE_MAXIMUM_BAND_1 = 772.62183
    RADIANCE_MINIMUM_BAND_1 = -63.80336
    RADIANCE_MAXIMUM_BAND_2 = 791.17413
    RADIANCE_MINIMUM_BAND_2 = -65.33542
    RADIANCE_MAXIMUM_BAND_3 = 729.06024
    RADIANCE_MINIMUM_BAND_3 = -60.20603
    RADIANCE_MAXIMUM_BAND_4 = 614.78467
    RADIANCE_MINIMUM_BAND_4 = -50.76912
    RADIANCE_MAXIMUM_BAND_5 = 376.21756
    RADIANCE_MINIMUM_BAND_5 = -31.06817
    RADIANCE_MAXIMUM_BAND_6 = 93.56188
    RADIANCE_MINIMUM_BAND_6 = -7.72637
    RADIANCE_MAXIMUM_BAND_7 = 31.53536
    RADIANCE_MINIMUM_BAND_7 = -2.60420
    RADIANCE_MAXIMUM_BAND_8 = 695.76703
    RADIANCE_MINIMUM_BAND_8 = -57.45667
    RADIANCE_MAXIMUM_BAND_9 = 147.03435
    RADIANCE_MINIMUM_BAND_9 = -12.14214
    RADIANCE_MAXIMUM_BAND_10 = 22.00180
    RADIANCE_MINIMUM_BAND_10 = 0.10033
    RADIANCE_MAXIMUM_BAND_11 = 22.00180
    RADIANCE_MINIMUM_BAND_11 = 0.10033
  END_GROUP = MIN_MAX_RADIANCE
  GROUP = MIN_MAX_REFLECTANCE
    REFLECTANCE_MAXIMUM_BAND_1 = 1.210700
    REFLECTANCE_MINIMUM_BAND_1 = -0.099980
    REFLECTANCE_MAXIMUM_BAND_2 = 1.210700
    REFLECTANCE_MINIMUM_BAND_2 = -0.099980
    REFLECTANCE_MAXIMUM_BAND_3 = 1.210700
    REFLECTANCE_MINIMUM_BAND_3 = -0.099980
    REFLECTANCE_MAXIMUM_BAND_4 = 1.210700
    REFLECTANCE_MINIMUM_BAND_4 = -0.099980
    REFLECTANCE_MAXIMUM_BAND_5 = 1.210700
    REFLECTANCE_MINIMUM_BAND_5 = -0.099980
    REFLECTANCE_MAXIMUM_BAND_6 = 1.210700
    REFLECTANCE_MINIMUM_BAND_6 = -0.099980
    REFLECTANCE_MAXIMUM_BAND_7 = 1.210700
    REFLECTANCE_MINIMUM_BAND_7 = -0.099980
    REFLECTANCE_MAXIMUM_BAND_8 = 1.210700
    REFLECTANCE_MINIMUM_BAND_8 = -0.099980
    REFLECTANCE_MAXIMUM_BAND_9 = 1.210700
    REFLECTANCE_MINIMUM_BAND_9 = -0.099980
  END_GROUP = MIN_MAX_REFLECTANCE
  GROUP = MIN_MAX_PIXEL_VALUE
    QUANTIZE_CAL_MAX_BAND_1 = 65535
    QUANTIZE_CAL_MIN_BAND_1 = 1
    QUANTIZE_CAL_MAX_BAND_2 = 65535
    QUANTIZE_CAL_MIN_BAND_2 = 1
    QUANTIZE_CAL_MAX_BAND_3 = 65535
    QUANTIZE_CAL_MIN_BAND_3 = 1
    QUANTIZE_CAL_MAX_BAND_4 = 65535
    QUANTIZE_CAL_MIN_BAND_4 = 1
    QUANTIZE_CAL_MAX_BAND_5 = 65535
    QUANTIZE_CAL_MIN_BAND_5 = 1
    QUANTIZE_CAL_MAX_BAND_6 = 65535
    QUANTIZE_CAL_MIN_BAND_6 = 1
    QUANTIZE_CAL_MAX_BAND_7 = 65535
    QUANTIZE_CAL_MIN_BAND_7 = 1
    QUANTIZE_CAL_MAX_BAND_8 = 65535
    QUANTIZE_CAL_MIN_BAND_8 = 1
    QUANTIZE_CAL_MAX_BAND_9 = 65535
    QUANTIZE_CAL_MIN_BAND_9 = 1
    QUANTIZE_CAL_MAX_BAND_10 = 65535
    QUANTIZE_CAL_MIN_BAND_10 = 1
    QUANTIZE_CAL_MAX_BAND_11 = 65535
    QUANTIZE_CAL_MIN_BAND_11 = 1
  END_GROUP = MIN_MAX_PIXEL_VALUE
  GROUP = RADIOMETRIC_RESCALING
    RADIANCE_MULT_BAND_1 = 1.2763E-02
    RADIANCE_MULT_BAND_2 = 1.3070E-02
    RADIANCE_MULT_BAND_3 = 1.2044E-02
    RADIANCE_MULT_BAND_4 = 1.0156E-02
    RADIANCE_MULT_BAND_5 = 6.2149E-03
    RADIANCE_MULT_BAND_6 = 1.5456E-03
    RADIANCE_MULT_BAND_7 = 5.2094E-04
    RADIANCE_MULT_BAND_8 = 1.1494E-02
    RADIANCE_MULT_BAND_9 = 2.4289E-03
    RADIANCE_MULT_BAND_10 = 3.3420E-04
    RADIANCE_MULT_BAND_11 = 3.3420E-04
    RADIANCE_ADD_BAND_1 = -63.81612
    RADIANCE_ADD_BAND_2 = -65.34849
    RADIANCE_ADD_BAND_3 = -60.21807
    RADIANCE_ADD_BAND_4 = -50.77927
    RADIANCE_ADD_BAND_5 = -31.07438
    RADIANCE_ADD_BAND_6 = -7.72792
    RADIANCE_ADD_BAND_7 = -2.60472
    RADIANCE_ADD_BAND_8 = -57.46816
    RADIANCE_ADD_BAND_9 = -12.14457
    RADIANCE_ADD_BAND_10 = 0.10000
    RADIANCE_ADD_BAND_11 = 0.10000
    REFLECTANCE_MULT_BAND_1 = 2.0000E-05
    REFLECTANCE_MULT_BAND_2 = 2.0000E-05
    REFLECTANCE_MULT_BAND_3 = 2.0000E-05
    REFLECTANCE_MULT_BAND_4 = 2.0000E-05
    REFLECTANCE_MULT_BAND_5 = 2.0000E-05
    REFLECTANCE_MULT_BAND_6 = 2.0000E-05
    REFLECTANCE_MULT_BAND_7 = 2.0000E-05
    REFLECTANCE_MULT_BAND_8 = 2.0000E-05
    REFLECTANCE_MULT_BAND_9 = 2.0000E-05
    REFLECTANCE_ADD_BAND_1 = -0.100000
    REFLECTANCE_ADD_BAND_2 = -0.100000
    REFLECTANCE_ADD_BAND_3 = -0.100000
    REFLECTANCE_ADD_BAND_4 = -0.100000
    REFLECTANCE_ADD_BAND_5 = -0.100000
    REFLECTANCE_ADD_BAND_6 = -0.100000
    REFLECTANCE_ADD_BAND_7 = -0.100000
    REFLECTANCE_ADD_BAND_8 = -0.100000
    REFLECTANCE_ADD_BAND_9 = -0.100000
  END_GROUP = RADIOMETRIC_RESCALING
  GROUP = TIRS_THERMAL_CONSTANTS
    K1_CONSTANT_BAND_10 = 774.8853
    K2_CONSTANT_BAND_10 = 1321.0789
    K1_CONSTANT_BAND_11 = 480.8883
    K2_CONSTANT_BAND_11 = 1201.1442
  END_GROUP = TIRS_THERMAL_CONSTANTS
  GROUP = PROJECTION_PARAMETERS
    MAP_PROJECTION = "UTM"
    DATUM = "WGS84"
    ELLIPSOID = "WGS84"
    UTM_ZONE = 50
    GRID_CELL_SIZE_PANCHROMATIC = 15.00
    GRID_CELL_SIZE_REFLECTIVE = 30.00
    GRID_CELL_SIZE_THERMAL = 30.00
    ORIENTATION = "NORTH_UP"
    RESAMPLING_OPTION = "CUBIC_CONVOLUTION"
  END_GROUP = PROJECTION_PARAMETERS
END_GROUP = L1_METADATA_FILE
END