Data model for SDSS
General description
Here we describe the SDSS data model, which is archived in the datamodel product at "$DATAMODEL_DIR/datamodel/files". One can access the data in two ways:
Data model directory structure format
In the data model path, there are files of the form:
[ENVVAR]/[..path...]/[filename].html
The ENVVAR represents the environmental variable name of the root directory for each data type. Each .html file represents the generic name of a type of file (plus .html), as well as its position in the overall directory structure. The paths contain generic names for the type of subdirectories you can expect to find in that root directory.
If an integer is appended (as in RUN6) it implies that the name will be an integer, and should be expressed in that number of digits (filled out with leading 0s).
Note: PLATE4 directories may contain plate numbers with 5 digits, but the 'PLATE4' nomenclature is retained for compatibility with other documents. Directories with the 'PLATE' nomenclature explicitly denote directories that may have plate numbers with 4 or 5 digits.
If an XX is appended, that means that the last two digits of the number are replaced by XX (so we can group files and subdirectories in batches of 100).
There is a template.html file in this directory that gives an example of how to write a description of a single file, and the sort of information that can/should be included. Note that the template is valid XHTML 1.1, & this standard will be enforced on all html files in the data model. The W3C Validator will allow you to validate html before checking it in.
