The NetCDF User's Guide

The project page for the NetCDF User's Guide can be found at the NetCDF User's Guide Github Page.

Table of Contents

• An Introduction to NetCDF
• File Structure and Performance
• Data Types
• The Components of a NetCDF Data Set
• Improving Performance with Chunking
• NetCDF Utilities
• Writing NetCDF Files: Best Practices
• User-Defined Formats for NetCDF
• DAP2 Protocol Support
• DAP4 Protocol Support
• Documentation for Common Data Language
• Appendix A: Attribute Conventions
• Appendix B. File Format Specifications
• Appendix C. NUG Style Guide

The Purpose of NetCDF

The purpose of the Network Common Data Form (netCDF) interface is to allow you to create, access, and share array-oriented data in a form that is self-describing and portable. "Self-describing" means that a dataset includes information defining the data it contains. "Portable" means that the data in a dataset is represented in a form that can be accessed by computers with different ways of storing integers, characters, and floating-point numbers. Using the netCDF interface for creating new datasets makes the data portable. Using the netCDF interface in software for data access, management, analysis, and display can make the software more generally useful.

The netCDF software includes C, Fortran 77, Fortran 90, and C++ interfaces for accessing netCDF data. These libraries are available for many common computing platforms.

The community of netCDF users has contributed ports of the software to additional platforms and interfaces for other programming languages as well. Source code for netCDF software libraries is freely available to encourage the sharing of both array-oriented data and the software that makes the data useful.

This User's Guide presents the netCDF data model. It explains how the netCDF data model uses dimensions, variables, and attributes to store data.

Reference documentation for UNIX systems, in the form of UNIX 'man' pages for the C and FORTRAN interfaces is also available at the netCDF web site (https://www.unidata.ucar.edu/software/netcdf), and with the netCDF distribution.

The latest version of this document, and the language specific guides, can be found at the netCDF web site (https://www.unidata.ucar.edu/netcdf/) along with extensive additional information about netCDF, software that works with netCDF data.

Separate documentation of the Java netCDF library can be found at https://www.unidata.ucar.edu/software/netcdf-java/.