Overview of NetCDF formatted data

Objective

We're going to start a new project soon. The meteorological Office requires that the data be processed in NetCDF format, which is a well-encapsulated data structure that needs to connect some libraries and invoke specific APIs to operate.

But I know very little about this, so I used the Sunday morning to learn the access method of this data structure, laying the groundwork for the follow-up project development.

NetCDF Overview

The NETCDF full name is the network Common data format, which is the web-wide, generic. This data-format file is widely used in the meteorological field and is now being extended to many other areas.

From the mathematical relationship, the data stored in the NetCDF structure has many pairs of functions, and "many" refers to the dimension, and "One" is the value of the variable.

Obviously, the most important feature of this data structure is the ability to use multidimensional matrices conveniently.

Contents of the NetCDF file

1. Variables (Variables)

is physical data. For example, to store a Typhoon wind field, then the "Longitude x degrees North y degrees of Speed Z m/S" is a variable.

It is important to note that this variable is a generalized variable, which also contains the arguments x and Y, from the point of view of the mathematical function, where the essence of a variable is actually a specific function correspondence relationship.

When referring to the term variable, it is sometimes referred to as a collection of all variables.

2. Dimension (Dimension)

A dimension corresponds to the range of values of the arguments in a variable, that is, the range of latitude and longitude in 1.

3. Properties (Attribute)

Variables and dimensions are only dimensionless numbers in NetCDF, so there must be some way to get people to understand what these numbers mean, and attributes come in handy here.

If you have defined a variable named temperature, the following line of code:

Temperature:units = "Celsius"

The implication is that the physical unit of the temperature variable is Celsius.

In addition, in addition to physical units, a variable has many properties to set, so it can store data in a comprehensive way.

The NetCDF format data is described in the following code:

1 NetCDF name{2     // defining the number of dimensions 3     Variables:  ... // Defining Variables 4     // Properties 5     Data: ... // Data 6 }

Overview of NetCDF formatted data