def test_6s_example1(self):
# Implements Example_In_1.txt from the 6S distribution in Py6S
# Tests against manual run of that file
s = SixS()
s.geometry = Geometry.User()
s.geometry.solar_z = 40
s.geometry.solar_a = 100
s.geometry.view_z = 45
s.geometry.view_a = 50
s.geometry.month = 7
s.geometry.day = 23
s.atmos_profile = AtmosProfile.UserWaterAndOzone(3.0, 3.5)
s.aero_profile = AeroProfile.User(dust=0.25,
water=0.25,
oceanic=0.25,
soot=0.25)
s.aot550 = 0.5
s.altitudes.set_target_custom_altitude(0.2)
s.altitudes.set_sensor_custom_altitude(3.3, aot=0.25)
s.wavelength = Wavelength(PredefinedWavelengths.AVHRR_NOAA9_B1)
s.ground_reflectance = GroundReflectance.HeterogeneousLambertian(
0.5, GroundReflectance.ClearWater,
GroundReflectance.GreenVegetation)
s.atmos_corr = AtmosCorr.AtmosCorrBRDFFromReflectance(0.1)
s.run()
self.assertAlmostEqual(s.outputs.apparent_radiance,
12.749,
delta=0.002)
def __init__(self,
bandnums,
wavelengths,
geometry,
date_time,
sensor=None):
""" Run SixS atmospheric model using Py6S """
start = datetime.datetime.now()
VerboseOut('Running atmospheric model (6S)', 2)
s = SixS()
# Geometry
s.geometry = Geometry.User()
s.geometry.from_time_and_location(geometry['lat'], geometry['lon'],
str(date_time), geometry['zenith'],
geometry['azimuth'])
s.altitudes = Altitudes()
s.altitudes.set_target_sea_level()
s.altitudes.set_sensor_satellite_level()
doy = (date_time - datetime.datetime(date_time.year, 1, 1)).days + 1
# Atmospheric profile
s.atmos_profile = atmospheric_model(doy, geometry['lat'])
# Aerosols
# TODO - dynamically adjust AeroProfile?
s.aero_profile = AeroProfile.PredefinedType(AeroProfile.Continental)
self.aod = aodData.get_aod(geometry['lat'], geometry['lon'],
date_time.date())
s.aot550 = self.aod[1]
# Other settings
s.ground_reflectance = GroundReflectance.HomogeneousLambertian(
GroundReflectance.GreenVegetation)
s.atmos_corr = AtmosCorr.AtmosCorrLambertianFromRadiance(1.0)
# Used for testing
try:
stdout = sys.stdout
funcs = {
'LT5': SixSHelpers.Wavelengths.run_landsat_tm,
'LT7': SixSHelpers.Wavelengths.run_landsat_etm,
# LC8 doesn't seem to work
#'LC8': SixSHelpers.Wavelengths.run_landsat_oli
}
if sensor in funcs.keys():
sys.stdout = open(os.devnull, 'w')
wvlens, outputs = funcs[sensor](s)
sys.stdout = stdout
else:
# Use wavelengths
outputs = []
for wv in wavelengths:
s.wavelength = Wavelength(wv[0], wv[1])
s.run()
outputs.append(s.outputs)
except Exception, e:
sys.stdout = stdout
raise AtmCorrException("Error running 6S: %s" % e)
def __init__(self, bandnums, wavelengths, geometry, date_time, sensor=None):
""" Run SixS atmospheric model using Py6S """
start = datetime.datetime.now()
verbose_out('Running atmospheric model (6S)', 2)
s = SixS()
# Geometry
s.geometry = Geometry.User()
s.geometry.from_time_and_location(geometry['lat'], geometry['lon'], str(date_time),
geometry['zenith'], geometry['azimuth'])
s.altitudes = Altitudes()
s.altitudes.set_target_sea_level()
s.altitudes.set_sensor_satellite_level()
doy = (date_time - datetime.datetime(date_time.year, 1, 1)).days + 1
# Atmospheric profile
s.atmos_profile = atmospheric_model(doy, geometry['lat'])
# Aerosols
# TODO - dynamically adjust AeroProfile?
s.aero_profile = AeroProfile.PredefinedType(AeroProfile.Continental)
self.aod = aodData.get_aod(
geometry['lat'], geometry['lon'], date_time.date()
)
# sixs throws IEEE_UNDERFLOW_FLAG IEEE_DENORMAL for small aod.
# and if using a predefined AeroProfile, visible or aot550 must be
# specified. Small here was determined emprically on my laptop, and
# visible = 1000 km is essentially setting the visibility to infinite.
if self.aod[1] < 0.0103:
s.visible = 1000
else:
s.aot550 = self.aod[1]
# Other settings
s.ground_reflectance = GroundReflectance.HomogeneousLambertian(GroundReflectance.GreenVegetation)
s.atmos_corr = AtmosCorr.AtmosCorrLambertianFromRadiance(1.0)
# Used for testing
funcs = {
'LT5': SixSHelpers.Wavelengths.run_landsat_tm,
'LT7': SixSHelpers.Wavelengths.run_landsat_etm,
# LC8 doesn't seem to work
#'LC8': SixSHelpers.Wavelengths.run_landsat_oli
}
if sensor in funcs.keys():
saved_stdout = sys.stdout
try:
sys.stdout = open(os.devnull, 'w')
wvlens, outputs = funcs[sensor](s)
finally:
sys.stdout = saved_stdout
else:
# Use wavelengths
outputs = []
for wv in wavelengths:
s.wavelength = Wavelength(wv[0], wv[1])
s.run()
outputs.append(s.outputs)
self.results = {}
verbose_out("{:>6} {:>8}{:>8}{:>8}".format('Band', 'T', 'Lu', 'Ld'), 4)
for b, out in enumerate(outputs):
t = out.trans['global_gas'].upward
Lu = out.atmospheric_intrinsic_radiance
Ld = (out.direct_solar_irradiance + out.diffuse_solar_irradiance + out.environmental_irradiance) / numpy.pi
self.results[bandnums[b]] = [t, Lu, Ld]
verbose_out("{:>6}: {:>8.3f}{:>8.2f}{:>8.2f}".format(bandnums[b], t, Lu, Ld), 4)
verbose_out('Ran atmospheric model in %s' % str(datetime.datetime.now() - start), 2)
def __init__(self, bandnums, wavelengths, geometry, date_time, sensor=None):
""" Run SixS atmospheric model using Py6S """
start = datetime.datetime.now()
VerboseOut('Running atmospheric model (6S)', 2)
s = SixS()
# Geometry
s.geometry = Geometry.User()
s.geometry.from_time_and_location(geometry['lat'], geometry['lon'], str(date_time),
geometry['zenith'], geometry['azimuth'])
s.altitudes = Altitudes()
s.altitudes.set_target_sea_level()
s.altitudes.set_sensor_satellite_level()
doy = (date_time - datetime.datetime(date_time.year, 1, 1)).days + 1
# Atmospheric profile
s.atmos_profile = atmospheric_model(doy, geometry['lat'])
# Aerosols
# TODO - dynamically adjust AeroProfile?
s.aero_profile = AeroProfile.PredefinedType(AeroProfile.Continental)
self.aod = aodData.get_aod(geometry['lat'], geometry['lon'], date_time.date())
s.aot550 = self.aod[1]
# Other settings
s.ground_reflectance = GroundReflectance.HomogeneousLambertian(GroundReflectance.GreenVegetation)
s.atmos_corr = AtmosCorr.AtmosCorrLambertianFromRadiance(1.0)
# Used for testing
try:
stdout = sys.stdout
funcs = {
'LT5': SixSHelpers.Wavelengths.run_landsat_tm,
'LT7': SixSHelpers.Wavelengths.run_landsat_etm,
# LC8 doesn't seem to work
#'LC8': SixSHelpers.Wavelengths.run_landsat_oli
}
if sensor in funcs.keys():
sys.stdout = open(os.devnull, 'w')
wvlens, outputs = funcs[sensor](s)
sys.stdout = stdout
else:
# Use wavelengths
outputs = []
for wv in wavelengths:
s.wavelength = Wavelength(wv[0], wv[1])
s.run()
outputs.append(s.outputs)
except Exception, e:
sys.stdout = stdout
raise AtmCorrException("Error running 6S: %s" % e)
def test_6s_example2(self):
# Implements Example_In_2.txt from the 6S distribution in Py6S
# Tests against manual run of that file
s = SixS()
s.geometry = Geometry.User()
s.geometry.solar_z = 0
s.geometry.solar_a = 20
s.geometry.view_z = 30
s.geometry.view_a = 0
s.geometry.month = 8
s.geometry.day = 22
s.atmos_profile = AtmosProfile.PredefinedType(
AtmosProfile.NoGaseousAbsorption)
s.aero_profile = AeroProfile.SunPhotometerDistribution(
[
0.050000001,
0.065604001,
0.086076997,
0.112939,
0.148184001,
0.194428995,
0.255104989,
0.334715992,
0.439173013,
0.576227009,
0.756052017,
0.99199599,
1.30157101,
1.707757,
2.24070191,
2.93996596,
3.85745192,
5.06126022,
6.64074516,
8.71314526,
11.4322901,
15,
],
[
0.001338098,
0.007492487,
0.026454749,
0.058904506,
0.082712278,
0.073251031,
0.040950641,
0.014576218,
0.003672085,
0.001576356,
0.002422644,
0.004472982,
0.007452302,
0.011037065,
0.014523974,
0.016981738,
0.017641816,
0.016284294,
0.01335547,
0.009732267,
0.006301342,
0.003625077,
],
[1.47] * 20,
[0.0093] * 20,
)
s.aot550 = 1.0
s.altitudes.set_target_sea_level()
s.altitudes.set_sensor_satellite_level()
s.wavelength = Wavelength(0.550)
s.ground_reflectance = GroundReflectance.HomogeneousRoujean(
0.037, 0.0, 0.133)
s.run()
self.assertAlmostEqual(s.outputs.apparent_radiance,
76.999,
delta=0.002)
self.assertAlmostEqual(s.outputs.background_radiance,
10.017,
delta=0.002)
def test_6s_example4(self):
s = SixS()
s.geometry = Geometry.User()
s.geometry.solar_z = 61.23
s.geometry.solar_a = 18.78
s.geometry.solar_a = 0
s.geometry.view_z = 18.78
s.geometry.view_a = 159.2
s.geometry.month = 4
s.geometry.day = 30
s.atmos_profile = AtmosProfile.UserWaterAndOzone(0.29, 0.41)
s.aero_profile = AeroProfile.PredefinedType(AeroProfile.Continental)
s.aot550 = 0.14
s.altitudes.set_target_sea_level()
s.altitudes.set_sensor_satellite_level()
s.wavelength = Wavelength(PredefinedWavelengths.AVHRR_NOAA11_B1)
s.ground_reflectance = GroundReflectance.HomogeneousLambertian([
0.827,
0.828,
0.828,
0.827,
0.827,
0.827,
0.827,
0.826,
0.826,
0.826,
0.826,
0.825,
0.826,
0.826,
0.827,
0.827,
0.827,
0.827,
0.828,
0.828,
0.828,
0.829,
0.829,
0.828,
0.826,
0.826,
0.825,
0.826,
0.826,
0.826,
0.827,
0.827,
0.827,
0.826,
0.825,
0.826,
0.828,
0.829,
0.830,
0.831,
0.833,
0.834,
0.835,
0.836,
0.836,
0.837,
0.838,
0.838,
0.837,
0.836,
0.837,
0.837,
0.837,
0.840,
0.839,
0.840,
0.840,
0.841,
0.841,
0.841,
0.841,
0.842,
0.842,
0.842,
0.842,
0.843,
0.842,
0.843,
0.843,
0.843,
0.843,
0.843,
0.843,
0.841,
0.841,
0.842,
0.842,
0.842,
0.842,
0.842,
0.841,
0.840,
0.841,
0.838,
0.839,
0.837,
0.837,
0.836,
0.832,
0.832,
0.830,
0.829,
0.826,
0.826,
0.824,
0.821,
0.821,
0.818,
0.815,
0.813,
0.812,
0.811,
0.810,
0.808,
0.807,
0.807,
0.812,
0.808,
0.806,
0.807,
0.807,
0.807,
0.807,
])
s.run()
self.assertAlmostEqual(s.outputs.apparent_radiance,
170.771,
delta=0.002)
def test_6s_example3(self):
s = SixS()
s.geometry = Geometry.Landsat_TM()
s.geometry.month = 5
s.geometry.day = 9
s.geometry.gmt_decimal_hour = 11.222
s.geometry.latitude = 40
s.geometry.longitude = 30
s.atmos_profile = AtmosProfile.PredefinedType(
AtmosProfile.MidlatitudeSummer)
s.aero_profile = AeroProfile.MultimodalLogNormalDistribution(0.001, 20)
s.aero_profile.add_component(
0.05,
2.03,
0.538,
[
1.508,
1.500,
1.500,
1.500,
1.500,
1.500,
1.500,
1.500,
1.495,
1.490,
1.490,
1.490,
1.486,
1.480,
1.470,
1.460,
1.456,
1.443,
1.430,
1.470,
],
[
3.24e-07,
3.0e-08,
2.86e-08,
2.51e-08,
2.2e-08,
2.0e-08,
1.0e-08,
1.0e-08,
1.48e-08,
2.0e-08,
6.85e-08,
1.0e-07,
1.25e-06,
3.0e-06,
3.5e-04,
6.0e-04,
6.86e-04,
1.7e-03,
4.0e-03,
1.4e-03,
],
)
s.aero_profile.add_component(
0.0695,
2.03,
0.457,
[
1.452,
1.440,
1.438,
1.433,
1.432,
1.431,
1.431,
1.430,
1.429,
1.429,
1.429,
1.428,
1.427,
1.425,
1.411,
1.401,
1.395,
1.385,
1.364,
1.396,
],
[
1.0e-08,
1.0e-08,
1.0e-08,
1.0e-08,
1.0e-08,
1.0e-08,
1.0e-08,
1.0e-08,
1.38e-08,
1.47e-08,
1.68e-08,
1.93e-08,
4.91e-08,
1.75e-07,
9.66e-06,
1.94e-04,
3.84e-04,
1.12e-03,
2.51e-03,
1.31e-01,
],
)
s.aero_profile.add_component(
0.4,
2.03,
0.005,
[
1.508,
1.500,
1.500,
1.500,
1.500,
1.500,
1.500,
1.500,
1.495,
1.490,
1.490,
1.490,
1.486,
1.480,
1.470,
1.460,
1.456,
1.443,
1.430,
1.470,
],
[
3.24e-07,
3.0e-08,
2.86e-08,
2.51e-08,
2.2e-08,
2.0e-08,
1.0e-08,
1.0e-08,
1.48e-08,
2.0e-08,
6.85e-08,
1.0e-07,
1.25e-06,
3.0e-06,
3.5e-04,
6.0e-04,
6.86e-04,
1.7e-03,
4.0e-03,
1.4e-03,
],
)
s.aot550 = 0.8
s.altitudes.set_target_custom_altitude(2)
s.altitudes.set_sensor_satellite_level()
s.wavelength = Wavelength(PredefinedWavelengths.MODIS_B4)
s.ground_reflectance = GroundReflectance.HomogeneousOcean(
11, 30, 35, 3)
s.run()
self.assertAlmostEqual(s.outputs.apparent_reflectance,
0.1234623,
delta=0.002)
def run_py6s(self, geom, acqui_date, option=1):
"""
runs the 6S algorithm for atmospheric correction on a user-defined
geometry and date on Sentinel-2 imagery
Requires Google Earth-Engine Python API client
Parameters
----------
geom : EE-Geometry
Google EE geometry specify the geographic extent to be processed
acqui_date : String
date (YYYY-MM-dd) of the desired scene to be processed
option : Integer
for computing the cloud mask the user can decide whether the
ESA delivered quality layer should be used for cloud masking
(option=1) or an alternative approach originally developed for
Landsat TM (option=2) should be used (Def=1)
Returns
-------
s2_surf : ee.image.Image
Google EE image instance with surface reflectance values
and two additional bands containing Clouds ('CloudMask') and
detected cloud shadows ('CloudShadows')
"""
date = ee.Date(acqui_date)
# get the Sentinel-2 image at or immediately after the specified date
self.S2 = ee.Image(
ee.ImageCollection('COPERNICUS/S2')
.filterBounds(geom)
.filterDate(date,date.advance(3,'month'))
.sort('system:time_start')
.first()
)
# extract the relevant metadata for carrying out the atmospheric correction
self.info = self.S2.getInfo()['properties']
# get the solar zenith angle an the scene data
self.scene_date = datetime.datetime.utcfromtimestamp(
self.info['system:time_start']/1000)
self.solar_z = self.info['MEAN_SOLAR_ZENITH_ANGLE']
# log the identifier of the processed scene
scene_id = self.info.get('DATASTRIP_ID')
self.__logger.info("Starting Processing scene '{}' using GEE and Py6S".format(
scene_id))
# get the atmospheric constituents
# i.e water vapor (h2o), ozone (o3), aerosol optical thickness (aot)
h2o = Atmospheric.water(geom, date).getInfo()
o3 = Atmospheric.ozone(geom, date).getInfo()
aot = Atmospheric.aerosol(geom, date).getInfo()
# add this information to the info dictionary as this metadata could
# be of interest afterwards
self.info['WATER_VAPOUR'] = h2o
self.info['OZONE'] = o3
self.info['AOT'] = aot
# get the average altitude of the region to be processed
# for the Digital Elevation Model (DEM) the Shuttle Radar Topography
# Mission (SRTM) is used (Version 4) as it covers most parts of the
# Earth (90 arc-sec data is used)
SRTM = ee.Image('CGIAR/SRTM90_V4')
alt = SRTM.reduceRegion(reducer = ee.Reducer.mean(),
geometry = geom.centroid()).get('elevation').getInfo()
message = "Atcorr-Metadata: Water-Vapor = {0}, Ozone = {1}, AOT = {2}, "\
" Average Altitude (m) = {3}".format(
h2o, o3, aot, alt)
self.__logger.info(message)
# Py6S uses units of kilometers
km = alt/1000
# mask out clouds and cirrus from the imagery using the cloud score
# optionally
# algorithm provided by Sam Murhpy under Apache 2.0 licence
# see: https://github.com/samsammurphy/cloud-masking-sentinel2/blob/master/cloud-masking-sentinel2.ipynb
# also converts the image values to top-of-atmosphere reflectance
self.__logger.info('Calculating cloud and shadow mask')
self.S2 = mask_clouds(self.S2, option=1)
self.__logger.info('Finished calculating cloud and shadow mask')
# create a 6S object from the Py6S class
# Instantiate (use the explizit path to installation directory of the
# 6S binary as otherwise there might be an error)
s = SixS()
# Atmospheric constituents
s.atmos_profile = AtmosProfile.UserWaterAndOzone(h2o,o3)
s.aero_profile = AeroProfile.Continental
s.aot550 = aot
# Earth-Sun-satellite geometry
s.geometry = Geometry.User()
s.geometry.view_z = 0 # always NADIR (simplification!)
s.geometry.solar_z = self.solar_z # solar zenith angle
s.geometry.month = self.scene_date.month # month and day used for Earth-Sun distance
s.geometry.day = self.scene_date.day # month and day used for Earth-Sun distance
s.altitudes.set_sensor_satellite_level()
s.altitudes.set_target_custom_altitude(km)
self.__logger.info('6S: Starting processing of Sentinel-2 scene!')
# now iterate over the nine relevant Sentinel-2 bands to perform the
# atmospheric correction and get the surface reflectance
# go through the spectral bands
B2_surf = self.surface_reflectance(s, 'B2')
self.__logger.info('6S: Finished processing Sentinel-2 Band 2!')
B3_surf = self.surface_reflectance(s, 'B3')
self.__logger.info('6S: Finished processing Sentinel-2 Band 3!')
B4_surf = self.surface_reflectance(s, 'B4')
self.__logger.info('6S: Finished processing Sentinel-2 Band 4!')
B5_surf = self.surface_reflectance(s, 'B5')
self.__logger.info('6S: Finished processing Sentinel-2 Band 5!')
B6_surf = self.surface_reflectance(s, 'B6')
self.__logger.info('6S: Finished processing Sentinel-2 Band 6!')
B7_surf = self.surface_reflectance(s, 'B7')
self.__logger.info('6S: Finished processing Sentinel-2 Band 7!')
B8A_surf = self.surface_reflectance(s, 'B8A')
self.__logger.info('6S: Finished processing Sentinel-2 Band 8A!')
B11_surf = self.surface_reflectance(s, 'B11')
self.__logger.info('6S: Finished processing Sentinel-2 Band 11!')
B12_surf = self.surface_reflectance(s, 'B12')
self.__logger.info('6S: Finished processing Sentinel-2 Band 12!')
self.__logger.info('6S: Finished processing of Sentinel-2 scene!')
# make a stack of the spectral bands
# also add the computed cloud and shadow mask
cm = self.S2.select('CloudMask')
sm = self.S2.select('ShadowMask')
S2_surf = B2_surf.addBands(B3_surf).addBands(B4_surf).addBands(B5_surf).addBands(B6_surf).addBands(B7_surf).addBands(B8A_surf).addBands(B11_surf).addBands(B12_surf).addBands(cm).addBands(sm)
# return the surface reflectance image
close_logger(self.__logger)
return S2_surf