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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 following 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 also 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.
The possible field attributes are:
| [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) |
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 |
The swath attributes section also contains (all character strings):
| ID_SITE | (CIRA) |
| ID_CENTER | (CloudSat DPC) |
| ID_URL | (http://cloudsat.cira.colostate.edu) |
| ID_MACHINE | machine that created the file |
| 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 |
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