Documentation

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.

DARDAR-MASK categorisation browse - orbit subset
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

Product Parametres Download
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

Name Description Unit Type Fill Comments
CS_TRACK_Height Height of range bin km float32 Height of range bin above reference surface (~ mean sea level)
CLOUDSAT_UTC_Time Radar Footprint UTC time s float32 Seconds since the start of the granule UTC
Layer_Number Indice of the layer, for layer integrated variables None int8
CLOUDSAT_TAI_Time Radar Footprint TAI time s float64 Seconds since the start of the granule TAI
CLOUDSAT_Latitude Latitude of the colocated product degrees float32
CLOUDSAT_Longitude Longitude of the colocated product degrees float32
CLOUDSAT_Radar_Frequency Radar Frequency GHz float32 Frequency of the CloudSat Radar
CLOUDSAT_2B_GEOPROF_Radar_Reflectivity Radar Reflectivity at 94GHz (must be divided by 100) dBZ int16 -8888 Radar Reflectivity at 94GHz (must be divided by 100)
CLOUDSAT_2B_GEOPROF_CPR_Gaseous_Attenuation Gaseous Attenuation must be divided by 100 dBZ int16 -9999 Gaseous Attenuation must be divided by 100
CLOUDSAT_2B_GEOPROF_CPR_Cloud_Mask CloudSat cloud mask None int8 -9 Each 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-Zero The Sigma-Zero is the normalized surface cross section (must be divided by 100) None int16 -9999 The Sigma-Zero is the normalized surface cross section (not corrected for attenuation) from CloudSat
CLOUDSAT_Random_Measurement_Error Random Measurement Error in Radar Reflectivity at 94GHz dBZ float32 -9999.0
CALIOP_Profile_Time Profile time of the first and the last LIDAR shot averaged in the RADAR footprint secs float64 -inf TAI93 time convention
CALIOP_Lidar_Wavelength Lidar wavelength nm float32 Wavelength of the Calipso lidar
CALIOP_Lidar_Telescope_Field_Of_View Lidar telescope field of view microrad float32 Field of view of the Calipso lidar
CALIOP_Lidar_Beam_Divergence Lidar beam divergence microrad float32 Lidar beam divergence of the Calipso lidar
CALIPSO_Spacecraft_Altitude Altitude of the CALIPSO satellite above reference surface (~ mean sea level) None float32 km
CLOUDSAT_CALIOP_Colocation_Distance Distance between radar and lidar footprints km float32 -9999.0
CALIOP_Total_Attenuated_Backscatter_532 CALIOP Total Attenuated backscatter at 532nm m-1 sr-1 float32 -9999.0 New height resolution (60m)
CALIOP_Parallel_Attenuated_Backscatter_532 CALIOP Parallel Attenuated backscatter at 532nm m-1 sr-1 float32 -9999.0 New height resolution (60m)
CALIOP_Perpendicular_Attenuated_Backscatter_532 CALIOP Perpendicular Attenuated backscatter at 532nm m-1 sr-1 float32 -9999.0 New height resolution (60m)
CALIOP_Total_Backscatter_532_Random_Error Random measurement error in Total Attenuated backscatter m-1 sr-1 float32 -9999.0
CALIOP_Land_Water_Mask Land Water Mask from Calipso files None int8 -9 Land 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_Type IGBP Surface Type from Calipso files None int8 -9 International 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_Flag Day Night Flag for lidar Night (1) Day (0) None int8
Surface_pressure Surface Pressure from ECMWF model Pa float32 -999.0
Skin_temperature Skin Temperature from ECMWF model K float32 -999.0
Temperature_2m Two-meter temperature from ECMWF model K float32 -999.0
Tropopause_Height Tropopause Height from CAL_LID_L1, averaged in the RADAR spot km float32
CLOUDSAT_Cloud_Scenario CLOUDSAT 2B-CLDCLASS Cloud Scenario None int8 -99 Bits [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_Flag CLOUDSAT 2B-CLDCLASS Precipitation Flag None int8 -99 Bits [13,14] of the CLOUDSAT 2B-CLDCLASS Cloud Scenario
no precipitation 0
liquid precipitation 1
solid precipitation 2
possible drizzle 3
Temperature Temperature from ECMWF model K float32 -999.0 Temperature from ECMWF model interpolated on DARDAR heights
Pressure Pressure from ECMWF model Pa float32 -999.0 Pressure from ECMWF model interpolated on DARDAR heights
Specific_humidity Specific humidity from ECMWF model None float32 -999.0 Specific humidity from ECMWF model interpolated on DARDAR heights
Ozone Ozone mixing ratio from ECMWF model None float32 -999.0 Ozone mixing ratio from ECMWF model interpolated on DARDAR heights
CALIPSO_Mask New mask from calipso L2 vertical feature mask None int8 -99 sub 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_Channel MODIS Radiances Channel index None int8
MODIS_Wavelength MODIS Radiances Channel wavelength None float32 microns
MODIS_Radiance Radiances at the top of the Atmosphere from Modis W m-2 um-1 sr-1 float32 -999.0 Radiances (29-31-32) at the top of the Atmosphere from Modis
MODIS_Radiance_Uncert Uncertainties Indexes from Modis % float32 -999.0 Uncertainties Indexes from Modis
MODIS_Solar_zenith Solar zenith angle for MODIS pixel ( must be divided by 100 ) degrees int16 -32767 Solar zenith angle for MODIS central pixel ( must be divided by 100 )
MODIS_Solar_azimuth Solar azimuth angle for MODIS pixel ( must be divided by 100 ) degrees int16 -32767 Solar azimuth angle for MODIS central pixel ( must be divided by 100 )
MODIS_Sensor_zenith Sensor zenith angle for MODIS pixel ( must be divided by 100 ) degrees int16 -32767 Sensor zenith angle for MODIS central pixel ( must be divided by 100 )
MODIS_Sensor_azimuth Sensor azimuth angle for MODIS pixel ( must be divided by 100 ) degrees int16 -32767 Sensor azimuth angle for MODIS central pixel ( must be divided by 100 )
IIR_Channel_Wavelength CALIPSO IIR Channels Wavelength microns float32
IIR_Radiance IIR calibrated radiances for each channel Watts per square meter per steradian per micron int16 -9999
IIR_Viewing_Zenith_Angle IIR viewing zenith angle for each channel degrees int16 -9999
IIR_Viewing_Azimuth_Angle IIR viewing azimuth angle for each channel degrees int16 -9999
CALIOP_Mask_Refined New feature mask derived from the RADAR and the LIDAR signals None int8 -99 ground=-1
no signal=0
molecular=1
nuage=2
aerosol=3
strato=4
unsel=5
Warm_Cold_Pixel Warm/Cold Pixels Indices None int8 -1 Flag identifying the phase of the cloudy bin - Intermediate Variable
-1 -> Invalid
0 -> Water
1 -> Ice
Lidar_Gates Profiles Mask that identifies the cloud layers None int8 -1 Vertical resolution : 60m
Warm_Layer_Mask Profiles Mask that identifies the Warm cloud bins None int8 -1 Vertical resolution : 60m
Layer_Temperature Temperature integrated layer by layer K float32 -9999
Layer_Radar_Reflectivity CLOUDSAT Radar Reflectivity integrated layer by layer dBZe float32 -9999
Layer_Perpendicular_Attenuated_Backscatter_532 Total Perpendicular LIDAR Backscatter 532 integrated layer by layer sr-1 float32 -9999.0
Layer_Parallel_Attenuated_Backscatter_532 Total Parallel LIDAR Backscatter 532 integrated layer by layer sr-1 float32 -9999.0
Layer_Total_Attenuated_Backscatter_532 Total Total LIDAR Backscatter 532 integrated layer by layer sr-1 float32 -9999.0
Layer_Lidar_Ratio Lidar Ratio (Beta Perp / Beta Para) integrated layer by layer None float32 -9999.0
CLOUDSAT_Ground_Mask Mask issued of the RADAR signal that identifies the ground None int8 -1 -1 -> Invalid
0 -> No Ground
1 -> Ground
CLOUDSAT_No_Data_Mask Mask issued of a combination of the RADAR and LIDAR signals that identifies the profiles that have no data None int8 -1 -1 -> Invalid
0 -> Data
1 -> No Data
CLOUDSAT_Unknown_Lidar_Mask Mask that flags the bins where the feature can't be retrieved by the LIDAR None int8 -1
CLOUDSAT_Target_Radar_Mask RADAR instrument flags None int8 -1 -1 -> Unknown
0 -> Background Noise
1 -> Good Signal
-2 -> Clutter
-9 -> Ground
CLOUDSAT_Target_Lidar_Mask LIDAR instrument flags None int8 -1 -1 -> Unknown
0 -> Molecular
1 -> Cloud, Aerosol or Stratospheric Feature
-9 -> Ground
DARMASK_Ice DARMASK Ice Feature Flags None int8 -1 -9 -> ground
-1 -> don't know
0 -> no
1 -> yes
2 -> Stratospheric Feature
DARMASK_Rain DARMASK Rain Feature Flags None int8 -1 -9 -> ground
-2 -> clutter
-1 -> don't know
0 -> none
1 -> yes
DARMASK_Liquid DARMASK Liquid Feature Flags None int8 -1 -9 -> ground
-1 -> don't know
0 -> no
1 -> warmed
2 -> supercooled
3 -> warm in RADAR clutter and ice above
DARMASK_Aerosol DARMASK Aerosol Feature Flags, directly read from LIDAR mask None int8 -1 -9 -> ground
-1 -> don't know
0 -> none
1 -> yes
DARMASK_Insect DARMASK Insect Feature Flags None int8 -1 -9 -> ground
-1 -> don't know
0 -> none
1 -> Maybe
DARMASK_Simplified_Categorization Simplified DARMASK Categorization Flags None int8 -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".