Add Data to SEAScope

Add compatible samples to SEAScope¶

Download samples¶

You can download data samples from the SEAScope webpage

Linux¶

• Download your samples (*.tar.gz archive)

• Uncompress the archive

• Copy the content (the folders and files in the sample data directory) into [workspace]/seascope/data

macOS¶

• Download your samples (*.zip archive)

• Drag-n-drop the zipped or unzipped folder onto the “SEAScope” icon

• Alternatively you can copy the content (the folders and files in the data directory) into ~/SEAScope-workspace/data directory

Windows¶

• Download your samples (*.zip archive)

• Uncompress the archive

• Copy the content (the folders and files in the sample data directory) into [workspace]/seascope/data

Index¶

At startup SEAScope builds/updates an index that lists all the granules available in the data directory. If SEAScope detects a change in the data directory, it will ask you whether or not the index should be updated. When prompted, agree to rebuild the index.

Alternatively, you can delete the [workspace]/seascope/index.fb file (or ~/SEAScope-workspace/index.fb on macOS) when SEAScope is not running: the file will be regenerated automatically next time you start the application.

Data format¶

SEAScope reads netCDF-4 files. What you have to do with your own data depends on the geometry it is stored in.

Data on a regular grid¶

Data on a regular latitude / longitude grid are read natively, provided the file is netCDF-4 and compliant with the CF conventions, version 1.6 or above. Such a file can be copied into the data directory as it is.

Data in sensor geometry¶

Data in the geometry of the sensor — a swath, rather than a regular grid — have to be converted into the Intermediate Data Format (IDF). An IDF file is a netCDF-4 file in which the geolocation is stored as subsampled longitude and latitude arrays with ground control points, which is what allows SEAScope to draw the swath on the globe without reprojecting it first.

The full description of the format is given in the IDF specifications.

The IDF converter¶

The converter is published on PyPI as idf-converter, and is installed in the Python environment you use with SEAScope:

pip install idf-converter

It is driven by a set of input and output options. The ones you will meet most often are:

• path — the file to read, and the directory to write the granule to

• collection — the name of the collection the granule belongs to; the granule is then placed in the directory of that collection, under data

• downscale — produce multi-resolution files, which is worth doing for high resolution products

• variables — restrict the conversion to the variables you are interested in

Readers also take options specific to the product they handle, such as the spacing between two ground control points, or the coefficient file needed to turn brightness temperatures into sea surface temperature.

Worked examples for Sentinel-1, Sentinel-3 SLSTR L1 and SWOT L3 are given in the IDF converter notebook.