Level 2a Cloudnet product:

Target classification and cloud boundaries

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Summary

Designation: classification
Level: 2a
Algorithm design/Product maintainer
Institute: University of Reading
Description: This product contains a simplified target classification and other simple parameters such as cloud top and base.
Documentation: None yet available
Relevant publication(s): None yet available
Quicklooks: http://www.met.rdg.ac.uk/radar/cloudnet/quicklooks/
Suggested acknowledgement: We acknowledge the Cloudnet project (European Union contract EVK2-2000-00611) for providing the target classification and cloud boundaries, which was produced by the University of Reading using measurements from [SITE].

Dataset contents

Sample NetCDF file: 20031012_chilbolton_classification.nc
Header of sample NetCDF file in ASCII: 20031012_chilbolton_classification.cdl

The following is a description of the variables in this product, produced automatically from the metadata in the sample file (using the nc2html unix utility):

Dataset title: Classification products from Chilbolton

Institution:

Dimensions and coordinate variables

time
Time UTC

Units:

Type:

height
Height above mean sea level

Units:

Type:

layer
(No coordinate variable)

Variables

latitude
Latitude of site

Units:

Type:

longitude
Longitude of site

Units:

Type:

altitude
Height of radar above mean sea level

Units:

Type:

target_classification(time, height)
Target classification

This variable is a simplification of the bitfield "category_bits" in the target categorization and data quality dataset. It provides the 9 main atmospheric target classifications that can be distinguished by radar and lidar. The classes are defined in the definition and long_definition attributes.

Type:

Definition:

0: Clear sky
1: Cloud liquid droplets only
2: Drizzle or rain
3: Drizzle or rain coexisting with cloud liquid droplets
4: Ice particles
5: Ice coexisting with supercooled liquid droplets
6: Melting ice particles
7: Melting ice particles coexisting with cloud liquid droplets
8: Aerosol particles, no cloud or precipitation
9: Insects, no cloud or precipitation
10: Aerosol coexisting with insects, no cloud or precipitation

detection_status(time, height)
Radar and lidar detection status

This variable is a simplification of the bitfield "quality_bits" in the target categorization and data quality dataset. It reports on the reliability of the radar and lidar data used to perform the classification. The classes are defined in the definition and long_definition attributes.

Type:

Definition:

0: Clear sky
1: Lidar echo only
2: Radar echo but reflectivity may be unreliable as attenuation by rain, melting ice or liquid cloud has not been corrected
3: Good radar and lidar echos
4: No radar echo but rain or liquid cloud beneath mean that attenuation that would be experienced is unknown
5: Good radar echo only
6: No radar echo but known attenuation
7: Radar echo corrected for liquid cloud attenuation using microwave radiometer data
8: Radar ground clutter
9: Lidar clear-air molecular scattering

cloud_base_height(time, layer)
Height of cloud base above ground

This variable was calculated from the instance of cloud in the cloud mask variable and provides cloud base height for a maximum of 1 cloud layers

Units:

Type:

cloud_top_height(time, layer)
Height of cloud top above ground

This variable was calculated from the instance of cloud in the cloud mask variable and provides cloud base top for a maximum of 1 cloud layers

Units:

Type:

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