Data format

Aviso distributes its data in several formats.


NetCDF (network Common Data Form) is an interface for array-oriented data access and a library that provides an implementation of the interface. The netCDF library also defines a machine-independent format for representing scientific data. Together, the interface, library, and format support the creation, access, and sharing of scientific data. The netCDF software was developed at the Unidata Program Center in Boulder, Colorado. The netCDF libraries define a machine-independent format for representing scientific data.
Please see Unidata NetCDF pages for more information, and to retreive NetCDF software package.

NetCDF data is:

  • Self-Describing. A netCDF file includes information about the data it contains.
  • Architecture-independent. A netCDF file is represented in a form that can be accessed by computers with different ways of storing integers, characters, and floating-point numbers.
  • Direct-access. A small subset of a large dataset may be accessed efficiently, without first reading through all the preceding data.
  • Appendable. Data can be appended to a netCDF dataset along one dimension without copying the dataset or redefining its structure. The structure of a netCDF dataset can be changed, though this sometimes causes the dataset to be copied.
  • Sharable. One writer and multiple readers may simultaneously access the same netCDF file.

Note that NetCDF data can be browse and used through other software, like:

Other binary format

GDR are available in binary format. Note that Topex/Poseidon and Jason-1 GDR formats are slightly different. Data files are generated according to the big endian byte-ordering convention, which stores the most significant byte in the lowest memory address (the word is stored "big-end-first"). Depending on your computer, you may need to swap bytes. Reading software are available. Please refer to the appropriate handbook for further information.

Ascii format

Aviso data are no longer distributed in ascii format, since a classical data set is ten to twenty times smaller in binary. If you prefer such a format, you can try and use the Opendap, which is able to access online NetCDF data and to convert them in plain ascii.

ArcGIS format

Aviso data are not distributed in ArcGIS format. We invite you to use the Marine Geospatial Ecology Tools (MGET). MGET is an open source geoprocessing toolbox developed by Duke University Marine Geospatial Ecology Lab designed for coastal and marine researchers and GIS analysts who work with spatially-explicit ecological and oceanographic data. MGET includes over 150 tools (among which the Aviso downloading tool) useful for a variety of tasks, such as converting oceanographic data to ArcGIS formats. Currently under development are tools for identifying rings and eddy cores in sea surface height images, for analyzing connectivity networks, for estimating fishing effort when no effort data are available, for predicting hard bottom habitat from coarse grain bathymetry, and much more.

Marine Geospatial Ecology Tools main page, command line syntax and expressions for downloading Aviso SSH Dataset to ArcGIS Rasters.