Current Epoch: Epoch 10
Start: 16 Dec 2021 (Day 350) 14:27:41 | End: Present
Active Release: R05
R04 products will be available until all R05 products have been released.
Data Products
(For an overview of what the products themselves measure, click here)
CloudSat data products are made available in HDF-EOS format and are created with HDF-EOS 2.5 based on HDF 4.1r2. Later versions of the HDF and HDF-EOS libraries should be able to manipulate the files as long as they are in the HDF 4 series. Files delivered through the online ordering system are compressed (.zip). The file naming convention is as follows:
R04 files: YYYYDDDHHMMSS_NNNNN_CS_2B-TAU_GRANULE_S_RVV_EVV.hdf
R05 files: YYYYDDDHHMMSS_NNNNN_CS_2B-TAU_GRANULE_S_RVV_EVV_F00.hdf
- YYYYDDDHHMMSS = Year, Julian day, hour, minute, second of the first data contained in the file (UTC)
- NNNNN = Granule number
- CS = Literal "CS" indicating the CloudSat mission
- 2B-TAU = Product name
- GRANULE = Indicates the data subset ("GRANULE" if the data are not subset)
- S_RVV = Version including the processing iteration ("P", "P1", "P2", etc.) and release ("R04", "R05", etc.). For example: P_R04.
- EVV = Epoch number
- F00 = Fix number (for reprocessed files within a version - R05 only)
- .hdf = HDF-EOS file suffix
Organization of fields and attributes in the HDF-EOS files
The HDF-EOS files are organized into heirarchical groups. The file contains a swath, which for the CloudSat mission has the same name as the product. The swath contains three groups: geolocation, data, and swath metadata. The fields listed on the product pages are organized into the geolocation and data groups. If there are any product-specific metadata fields then a swath metadata group will be shown as well.
The attributes shown for each field are stored in the swath metadata group. They are stored in the format [field name].[attribute name]. For example, Radar_reflectivity.factor contains the scale factor for the 2B-GEOPROF radar reflectivity field.
Field Attributes
Name | Description |
---|---|
[fieldname].factor | scale factor (4-byte floating-point) |
[fieldname].offset | offset (4-byte floating-point) |
[fieldname].units | units (character string) |
[fieldname].long_name | field description (character string) |
[fieldname].valid_range | valid range (two element array [min,max] same type as the field) |
[fieldname].missing | missing data value (same type as the field) |
[fieldname].missop | indicates that missing data are <, <=, ==, >=, or > the missing value (character string) |
Scaling
Although most fields use 1 and 0 as the scale factor and offset, some fields are scaled to fit into a smaller type when written to the file. For example, Radar_reflectivity is a 4-byte floating-point number, but is multiplied by 100 and converted to a 2-byte integer when it is written to the file. The scaling equation is:
DATA_FILE_VALUE = (SCIENCE_VALUE * FACTOR) + OFFSET
- or -
SCIENCE_VALUE = (DATA_FILE_VALUE - OFFSET) / FACTOR
Swath Attributes
Name | Description |
---|---|
ID_SITE | (CIRA) |
ID_CENTER | (CloudSat DPC) |
ID_URL | (http://cloudsat.cira.colostate.edu) |
ID_ACCOUNT | account that created the file |
ID_CREATED | date and time the file was created |
algorithm_version | algorithm version number |
product_version | product version number |
start_time | YYYYMMDDHHmmss of the first profile in the file |
end_time | YYYYMMDDHHmmss of the last profile in the file |