.. _l2c_definition:

File Naming Convention & L2C Product Definition
================================================

This section defines the Level-2C (L2C) product generated by ``topsocnww3sp``.

Product Definition
------------------

The L2C product is a NetCDF file that co-localizes Sentinel-1 Ocean Waves (OSW) data with WaveWatch III (WW3) spectral data. The goal is to provide a dataset where SAR observations and model spectra are aligned in time and space for easier comparison and analysis.

L2C Output Structure
---------------------


The output files use NetCDF groups to separate different types of information:

* **SAR Groups**: Contain the original OSW data (e.g., ``SAR_intraburst``, ``SAR_interburst``).
* **WW3 Group**: Contains the associated WW3 spectra. The group name depends on the mode:
    * In ``lasso`` mode, it is simply named ``WW3``.
    * In other modes, it is often prefixed by the SAR group (e.g., ``WW3_intraburst``).
* **MATCH_MAP Groups**: (Used in 1to1, unique, and many modes) Contains mapping information such as distances and pointers from SAR tiles to WW3 spectra.

File Naming Convention
----------------------

The output files are named following this pattern:

``<original_osw_stem>_<product_version>.nc``

Example: ``s1a-iw1-osw-vv-20220107t062429-20220107t062500-041351-04ea80-001_v0.1.nc``

The files are organized in a hierarchical directory structure:
``<output_dir>/<year>/<month>/<day>/<safe_name>/<filename>.nc``

Metadata
--------

Every L2C file contains comprehensive global attributes following CF-1.8 conventions, including the processor version, source SAR product, and the co-localization mode used.