Products

Description

The main variable of this product is a features categorisation mask, with :

  • a vertical resolution of 60m between [ -1.02 km , 25.08 km ]
  • colocated with the CLOUDSAT footprints ( ~1.1 km )

It also contains many variables extracted from the CALIPSO and CLOUDSAT products, sampled or interpolated to the DARDAR resolution.

Browse of the DARDAR-MASK simplified categorisation – Orbit subset

Naming convention

DARDAR-MASK_v<Version>_<Timestamp>_<Granule>.hdf

<Version>A 3 digits dot separated version number as X.X.X
<Timestamp>The timestamp of the orbit, using the CLOUDSAT format YYYYJJJHHMMSS, Year, Julian day, hour, minute, second of the first data contained in the file (UTC)
<Granule>The granule number, on 5 digits

Examples

ProductParametresDownload
DARDAR-MASK – Cloud and Aerosols advanced Feature Mask
– Simplified categorisation
DARDAR-MASK_v1.1.4_2009001021530_14253.hdf
DARDAR-MASK Browse The full orbit quick-look of the simplified categorisation DARDAR-MASK_v1.1.4_2009001021530_14253 Simplified_Categorization.png

Variables

Description

NameDescriptionUnitTypeFillComments
CS_TRACK_HeightHeight of range binkmfloat32Height of range bin above reference surface (~ mean sea level)
CLOUDSAT_UTC_TimeRadar Footprint UTC timesfloat32Seconds since the start of the granule UTC
Layer_NumberIndice of the layer, for layer integrated variablesNoneint8
CLOUDSAT_TAI_TimeRadar Footprint TAI timesfloat64Seconds since the start of the granule TAI
CLOUDSAT_LatitudeLatitude of the colocated productdegreesfloat32
CLOUDSAT_LongitudeLongitude of the colocated productdegreesfloat32
CLOUDSAT_Radar_FrequencyRadar FrequencyGHzfloat32Frequency of the CloudSat Radar
CLOUDSAT_2B_GEOPROF_Radar_ReflectivityRadar Reflectivity at 94GHz (must be divided by 100)dBZint16-8888Radar Reflectivity at 94GHz (must be divided by 100)
CLOUDSAT_2B_GEOPROF_CPR_Gaseous_AttenuationGaseous Attenuation must be divided by 100dBZint16-9999Gaseous Attenuation must be divided by 100
CLOUDSAT_2B_GEOPROF_CPR_Cloud_MaskCloudSat cloud maskNoneint8-9Each CPR resolution volume is assigned 1 bit mask value
0=No cloud detected
1=likely bad data
5=likely ground clutter
5-10=week detection found using along track integration
20 to 40=Cloud detected .. increasing values represents clouds with lower chance of a being a false detection
CLOUDSAT_1B_CPR_Sigma-ZeroThe Sigma-Zero is the normalized surface cross section (must be divided by 100)Noneint16-9999The Sigma-Zero is the normalized surface cross section (not corrected for attenuation) from CloudSat
CLOUDSAT_Random_Measurement_ErrorRandom Measurement Error in Radar Reflectivity at 94GHzdBZfloat32-9999.0
CALIOP_Profile_TimeProfile time of the first and the last LIDAR shot averaged in the RADAR footprintsecsfloat64-infTAI93 time convention
CALIOP_Lidar_WavelengthLidar wavelengthnmfloat32Wavelength of the Calipso lidar
CALIOP_Lidar_Telescope_Field_Of_ViewLidar telescope field of viewmicroradfloat32Field of view of the Calipso lidar
CALIOP_Lidar_Beam_DivergenceLidar beam divergencemicroradfloat32Lidar beam divergence of the Calipso lidar
CALIPSO_Spacecraft_AltitudeAltitude of the CALIPSO satellite above reference surface (~ mean sea level)Nonefloat32km
CLOUDSAT_CALIOP_Colocation_DistanceDistance between radar and lidar footprintskmfloat32-9999.0
CALIOP_Total_Attenuated_Backscatter_532CALIOP Total Attenuated backscatter at 532nmm-1 sr-1float32-9999.0New height resolution (60m)
CALIOP_Parallel_Attenuated_Backscatter_532CALIOP Parallel Attenuated backscatter at 532nmm-1 sr-1float32-9999.0New height resolution (60m)
CALIOP_Perpendicular_Attenuated_Backscatter_532CALIOP Perpendicular Attenuated backscatter at 532nmm-1 sr-1float32-9999.0New height resolution (60m)
CALIOP_Total_Backscatter_532_Random_ErrorRandom measurement error in Total Attenuated backscatterm-1 sr-1float32-9999.0
CALIOP_Land_Water_MaskLand Water Mask from Calipso filesNoneint8-9Land Water Mask from Calipso files, indicating the surface type at the laser footprint
0=shallow ocean
1=land
2=coastlines
3=shallow inland water
4=intermittent water
5=deep inland water
6=continental ocean
7=deep ocean
CALIOP_IGBP_Surface_TypeIGBP Surface Type from Calipso filesNoneint8-9International Geosphere Biosphere Programme Global Land Cover types at the laser footprint
http://www-surf.larc.nasa.gov/surf/pages/sce_type.html
1=Evergreen Needleleaf Forest
2=Evergreen Broadleaf Forest
3=Deciduous Needleleaf Forest
4=Deciduous Broadleaf Forest
5=Mixed Deciduous Forest
6=Closed Shrubland
7=Open Shrubland
8=Woody Savanna
9=Savanna
10=Grassland
11=Permenant Wetland
12=Cropland
13=Urban
14=Crop/Natural Veg. Mosaic
15=Permanent Snow/Ice
16=Barren/Desert
17=Water Bodies
18=Tundra
19=Fresh Snow
20=Sea Ice
CALIOP_Day_Night_FlagDay Night Flag for lidar Night (1) Day (0)Noneint8
Surface_pressureSurface Pressure from ECMWF modelPafloat32-999.0
Skin_temperatureSkin Temperature from ECMWF modelKfloat32-999.0
Temperature_2mTwo-meter temperature from ECMWF modelKfloat32-999.0
Tropopause_HeightTropopause Height from CAL_LID_L1, averaged in the RADAR spotkmfloat32
CLOUDSAT_Cloud_ScenarioCLOUDSAT 2B-CLDCLASS Cloud ScenarioNoneint8-99Bits [0,1,2,3] of the CLOUDSAT 2B-CLDCLASS Cloud Scenario
No cloud 0
Cirrus 1
Altostratus 2
Altocumulus 3
St 4
Sc 5
Cumulus 6
Deep Convection 7
Ns 8
CLOUDSAT_Precipitation_FlagCLOUDSAT 2B-CLDCLASS Precipitation FlagNoneint8-99Bits [13,14] of the CLOUDSAT 2B-CLDCLASS Cloud Scenario
no precipitation 0
liquid precipitation 1
solid precipitation 2
possible drizzle 3
TemperatureTemperature from ECMWF modelKfloat32-999.0Temperature from ECMWF model interpolated on DARDAR heights
PressurePressure from ECMWF modelPafloat32-999.0Pressure from ECMWF model interpolated on DARDAR heights
Specific_humiditySpecific humidity from ECMWF modelNonefloat32-999.0Specific humidity from ECMWF model interpolated on DARDAR heights
OzoneOzone mixing ratio from ECMWF modelNonefloat32-999.0Ozone mixing ratio from ECMWF model interpolated on DARDAR heights
CALIPSO_MaskNew mask from calipso L2 vertical feature maskNoneint8-99sub surface m=-1
surfarce m=0
no signal m=1
molecular m=2
cloud good m=3
cloud med m=4
cloud bad m=5
cloud none m=6
aerosol good m=7
aerosol med m=8
aerosol bad m=9
aerosol none m=10
stratospheric feature m=11
MODIS_ChannelMODIS Radiances Channel indexNoneint8
MODIS_WavelengthMODIS Radiances Channel wavelengthNonefloat32microns
MODIS_RadianceRadiances at the top of the Atmosphere from ModisW m-2 um-1 sr-1float32-999.0Radiances (29-31-32) at the top of the Atmosphere from Modis
MODIS_Radiance_UncertUncertainties Indexes from Modis%float32-999.0Uncertainties Indexes from Modis
MODIS_Solar_zenithSolar zenith angle for MODIS pixel ( must be divided by 100 )degreesint16-32767Solar zenith angle for MODIS central pixel ( must be divided by 100 )
MODIS_Solar_azimuthSolar azimuth angle for MODIS pixel ( must be divided by 100 )degreesint16-32767Solar azimuth angle for MODIS central pixel ( must be divided by 100 )
MODIS_Sensor_zenithSensor zenith angle for MODIS pixel ( must be divided by 100 )degreesint16-32767Sensor zenith angle for MODIS central pixel ( must be divided by 100 )
MODIS_Sensor_azimuthSensor azimuth angle for MODIS pixel ( must be divided by 100 )degreesint16-32767Sensor azimuth angle for MODIS central pixel ( must be divided by 100 )
IIR_Channel_WavelengthCALIPSO IIR Channels Wavelengthmicronsfloat32
IIR_RadianceIIR calibrated radiances for each channelWatts per square meter per steradian per micronint16-9999
IIR_Viewing_Zenith_AngleIIR viewing zenith angle for each channeldegreesint16-9999
IIR_Viewing_Azimuth_AngleIIR viewing azimuth angle for each channeldegreesint16-9999
CALIOP_Mask_RefinedNew feature mask derived from the RADAR and the LIDAR signalsNoneint8-99ground=-1
no signal=0
molecular=1
nuage=2
aerosol=3
strato=4
unsel=5
Warm_Cold_PixelWarm/Cold Pixels IndicesNoneint8-1Flag identifying the phase of the cloudy bin – Intermediate Variable
-1 -> Invalid
0 -> Water
1 -> Ice
Lidar_GatesProfiles Mask that identifies the cloud layersNoneint8-1Vertical resolution : 60m
Warm_Layer_MaskProfiles Mask that identifies the Warm cloud binsNoneint8-1Vertical resolution : 60m
Layer_TemperatureTemperature integrated layer by layerKfloat32-9999
Layer_Radar_ReflectivityCLOUDSAT Radar Reflectivity integrated layer by layerdBZefloat32-9999
Layer_Perpendicular_Attenuated_Backscatter_532Total Perpendicular LIDAR Backscatter 532 integrated layer by layersr-1float32-9999.0
Layer_Parallel_Attenuated_Backscatter_532Total Parallel LIDAR Backscatter 532 integrated layer by layersr-1float32-9999.0
Layer_Total_Attenuated_Backscatter_532Total Total LIDAR Backscatter 532 integrated layer by layersr-1float32-9999.0
Layer_Lidar_RatioLidar Ratio (Beta Perp / Beta Para) integrated layer by layerNonefloat32-9999.0
CLOUDSAT_Ground_MaskMask issued of the RADAR signal that identifies the groundNoneint8-1-1 -> Invalid
0 -> No Ground
1 -> Ground
CLOUDSAT_No_Data_MaskMask issued of a combination of the RADAR and LIDAR signals that identifies the profiles that have no dataNoneint8-1-1 -> Invalid
0 -> Data
1 -> No Data
CLOUDSAT_Unknown_Lidar_MaskMask that flags the bins where the feature can’t be retrieved by the LIDARNoneint8-1
CLOUDSAT_Target_Radar_MaskRADAR instrument flagsNoneint8-1-1 -> Unknown
0 -> Background Noise
1 -> Good Signal
-2 -> Clutter
-9 -> Ground
CLOUDSAT_Target_Lidar_MaskLIDAR instrument flagsNoneint8-1-1 -> Unknown
0 -> Molecular
1 -> Cloud, Aerosol or Stratospheric Feature
-9 -> Ground
DARMASK_IceDARMASK Ice Feature FlagsNoneint8-1-9 -> ground
-1 -> don’t know
0 -> no
1 -> yes
2 -> Stratospheric Feature
DARMASK_RainDARMASK Rain Feature FlagsNoneint8-1-9 -> ground
-2 -> clutter
-1 -> don’t know
0 -> none
1 -> yes
DARMASK_LiquidDARMASK Liquid Feature FlagsNoneint8-1-9 -> ground
-1 -> don’t know
0 -> no
1 -> warmed
2 -> supercooled
3 -> warm in RADAR clutter and ice above
DARMASK_AerosolDARMASK Aerosol Feature Flags, directly read from LIDAR maskNoneint8-1-9 -> ground
-1 -> don’t know
0 -> none
1 -> yes
DARMASK_InsectDARMASK Insect Feature FlagsNoneint8-1-9 -> ground
-1 -> don’t know
0 -> none
1 -> Maybe
DARMASK_Simplified_CategorizationSimplified DARMASK Categorization FlagsNoneint8-1-9 -> ground
-1 -> don’t know
0 -> clear
1 -> ice
2 -> ice + supercooled
3 -> liquid warm
4 -> supercooled
5 -> reain
6 -> aerosol
7 -> maybe insects
8 stratospheric feature

Calibration

Some of the variables are stored as integers for saving disk space. For each variable, the user will find 2 standard SDS attributes called « scale_factor » and « add_offset ». Most of time, the standard HDF formula for scaling raw file values to physical ones is used :

science_value = ( raw_value – add_offset ) * scale_factor

Nevertheless, when a non standard scaling equation is used, this will be specified in a SDS attribute called « scaling_equation ».

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