GlobColour
Products Description

Merging methods

Format

Input data sensors

Product User Guide

GlobColour Products Description

Format

GlobColour Level-3 output data includes binned, mapped and browse products. The binned and mapped products are stored in netCDF files. The netCDF library or third-party tools including netCDF readers must be used to read the GlobColour products. The browse products are written in PNG format.

netCDF (Network Common Data Form) is a machine-independent, self-describing, binary data format standard for exchanging scientific data.

Full details about the products format and content are available in the Product User Guide.

The following rules are applied when writing the global binned (ISIN grid) and mapped products (PC grid):

• each parameter is stored in a single file including metadata and accumulated statistical data
• global metadata are stored as global attributes
• accumulated statistical data are stored as variables
• metadata related to statistical data are stored as variable attributes.

The following rules are applied when writing the DDS binned and mapped products (PC grid):

• all parameters are stored in a single file including metadata and accumulated statistical data
• global metadata are stored as global attributes
• accumulated statistical data are stored as variables
• metadata related to statistical data are stored as variable attributes.

The file naming convention of the GlobColour products (common to all products) follows the following rules :

Lzz_date_time_ROI_SR_INS_PRD_TC_nn.ext

where:

• Lzz is the product level (L3b for level 3 binned ISIN grid, L3m for level 3 mapped grid)
• date is specified in UTC format as yyyymmdd[-yyyymmdd]. The end date is optional for track and daily products.
• time is specified in UTC format as hhmmss[-duration]. The time field is needed only for track products. The duration is expressed in seconds.
• ROI is the name of the region of interest (e.g. GLOB for global coverage, site name for DDS).
• SR indicates the resolution of the grid (e.g. 4 for 1/24 ISIN grid).
• INS is the instrument acronym (MER for MERIS, MOD for MODIS, SWF for SeaWiFS or any combinations of these names for the merged products). For the merged products, the instrument acronym is prefixed with the merging method (AV for simple average, AVW for weighted average, GSM for the GSM model).
• PRD is the product type (CHL for chlorophyll...). Note that the various merging algorithms can be indicated in this field using a - delimiter (e.g. CHL1-M01, CHL1-M02).
• TC is the time coverage (TR for track-level products, DAY for daily, 8D for 8days, MO for monthly, YR for annual products).
• nn is a counter. For track products, we store in this counter the data-day in yyyymmdd format.
• ext is the file extension (nc for netCDF files, png for PNG files)

The number of field is constant. Missing information leads to two adjacent underscores.

Examples:

• L3b_20040101_072312-2363_GLOB_4_MER_L555_TR_20040101.nc
• L3m_20040401__ZON1_025_MOD_CHL1_DAY_00.nc
• L3b_20040401-20040430__GLOB_4_MER_L413_MO_00.nc
• L3b_20021001-20021031__GLOB_4_AV-MERMODSWF_T865_MO_00.nc
• L3b_20040101-20041231__NMED_9_MIX_YS_YR_00.nc

The European Service for Ocean Colour - GlobColour is an ESA Data User Element Project