Output Format

Data organization

The data are organized in a gridded data structure, i.e. data cubes. The tiles manifest as directories in the file system, and the images are stored within. For mosaicking, use force-mosaic.

Data Cube definition

The spatial data cube definition is appended to each data cube, i.e. to each directory containing tiled datasets, see Data Cube definition.

Naming convention

Following 41-digit naming convention is applied to all output files:

Example filename: 2000-2010_001-365-03_HL_CSO_LNDLG_NUM.tif

There are several product types available, all are optional. The Number of Observations (NUM) product contains the number of clear sky observations for each pixel and bin. The other products are statistical summaries of the temporal difference (dt) between consecutive observations within these bins.

Table 1: Naming convention

Digits	Description
Digits	Description
1–9	Temporal range for the years as YYYY–YYYY
1–9	Temporal range for the years as YYYY–YYYY
11-17	Temporal range for the DOY as DDD–DDD
11-17	Temporal range for the DOY as DDD–DDD
19-20	Temporal binning in months
19-20	Temporal binning in months
22-23	Product Level
22-23	Product Level
25-27	Submodule
25-27	Submodule
29-33	Sensor ID
	Sensor ID
	LNDLG	Landsat legacy bands
	LNDLG	Landsat legacy bands
	SEN2L	Sentinel-2 land bands
	SEN2L	Sentinel-2 land bands
	SEN2H	Sentinel-2 high-res bands
	SEN2H	Sentinel-2 high-res bands
	R-G-B	Visible bands
	R-G-B	Visible bands
	VVVHP	VV/VH Dual Polarized
	VVVHP	VV/VH Dual Polarized
35-37	Product Type
	Product Type
	NUM	Number of Observations
	NUM	Number of Observations
	AVG	Average of days between observations (dt)
	AVG	Average of days between observations (dt)
	STD	Standard Deviation of dt
	STD	Standard Deviation of dt
	MIN	Minimum of dt
	MIN	Minimum of dt
	MAX	Maximum of dt
	MAX	Maximum of dt
	RNG	Range of dt
	RNG	Range of dt
	SKW	Skewness of dt
	SKW	Skewness of dt
	KRT	Kurtosis of dt
	KRT	Kurtosis of dt
	QXX	Quantile of dt (e.g. 0.25 quantile = Q25)
	QXX	Quantile of dt (e.g. 0.25 quantile = Q25)
	IQR	Interquartile Range of dt
	IQR	Interquartile Range of dt
39-41	File extension
	File extension
	tif	image data in compressed GeoTiff format
	tif	image data in compressed GeoTiff format
	dat	image data in flat binary ENVI format
	dat	image data in flat binary ENVI format
	hdr	metadata for ENVI format
	hdr	metadata for ENVI format

File format

The images are provided with signed 16bit datatype and band sequential (BSQ) interleaving in one of the following formats:

GeoTiff

This is the recommended output option. Images are compressed GeoTiff images using LZW compression with horizontal differencing. The images are generated with internal blocks for partial image access. These blocks are strips that are as wide as the TILE_SIZE and as high as the BLOCK_SIZE.
ENVI Standard format

This produces flat binary images without any compression. This option might seem tempting as there is no overhead in cracking the compression when reading these data. However, the transfer of the larger data volume from disc to CPU often takes longer than cracking the compression. Therefore, we recommend to use the GeoTiff option.

Metadata

Metadata are written to all output products. For ENVI format, the metadata are written to the ENVI header (.hdr extension). For GeoTiff format, the metadata are written into the GeoTiff file. If the metadata is larger than allowed by the GeoTiff driver, the excess metadata will be written to an “auxiliary metadata” file with .aux.xml extension. FORCE-specific metadata will be written to the FORCE domain, and thus are probably not visible unless the FORCE domain (or all domains) are specifically printed:

gdalinfo -mdd all 20160823_LEVEL2_SEN2A_BOA.tif

Product type

Clear Sky Observation Statistcs

Currently available statistics are the number of observations, and aggregate statistics of the temporal difference between observations (available are average, standard deviation, minimum, maximum, range, skewness, kurtosis, any quantile from 1-99%, and interquartile range.