The NetCDF-Java/CDM library provides a uniform API to many different scientific file formats and remote access protocols. Generally, application programmers should respect the encapsulation of these formats. When information is needed about the underlying file type, NetcdfFile.getFileTypeId(), NetcdfFile.getFileTypeVersion(), and NetcdfFile.getFileTypeDescription() methods can be called.

The Id must be unique and once registered, will never change, so that application code can test against it. Version information should have a standard form for each file type, but the form may differ between file types. The Description is human-readable and may present variations when appropriate, such as adding processing history, etc. The Reference URL(s) in this table are informational, and may change as needed.

To support this functionality, getFileTypeId(), getFileTypeVersion(), and getFileTypeDescription() methods have been added to the IOServiceProvider interface as of version 4.0.46. You will need to add these methods to your IOServiceProvider implementations. To use an IOSP implementation, you must include its module in your netCDF-java build. For more information on including modules in your build, see here.

To register your format/IOServiceProvider, or to send corrections and additions to this table, please send email to

Id Description Module Reference URL
BUFR WMO Binary Universal Form bufr
CINRAD Chinese Level-II Base Data cdm-radial
DMSP Defense Meteorological Satellite Program cdm-misc
DORADE DOppler RAdar Data Exchange Format cdm-radial
F-TDS Ferret I/O Service Provider and Server-side Analysis cdm-core
FYSAT Chinese FY-2 satellite image data in AWX format cdm-image
GempakGrid GEMPAK Gridded Data cdm-mcidas
GempakSurface GEMPAK Surface Obs Data cdm-mcidas
GINI GOES Ingest and NOAAPORT Interface cdm-image
GRIB-1 WMO GRIB Edition 1 grib
GRIB-2 WMO GRIB Edition 2 grib
GTOPO USGS GTOPO digital elevation model cdm-misc
HDF4 Hierarchical Data Format, version 4 cdm-core
HDF5 Hierarchical Data Format, version 5 cdm-core
McIDASArea McIDAS area file cdm-mcidas
McIDASGrid McIDAS grid file cdm-mcidas
netCDF NetCDF classic format cdm-core
netCDF-4 NetCDF-4 format on HDF-5 cdm-core
NEXRAD-2 NEXRAD Level-II Base Data cdm-radial
NEXRAD-3 NEXRAD Level-III Products cdm-radial
NLDN National Lightning Detection Network cdm-misc
NMCon29 NMC Office Note 29 cdm-misc
OPeNDAP Open-source Project for a Network Data Access Protocol opendap
S3 RandomAccessFile access to CDM datasets on object stores cdm-s3
SIGMET SIGMET-IRIS weather radar cdm-radial
UAMIV CAMx UAM-IV formatted files cdm-radial
UniversalRadarFormat Universal Radar Format cdm-radial
USPLN US Precision Lightning Network cdm-misc
VIS5D Vis5D grid file cdm-vs5d
Zarr Zarr dataset cdm-zarr