Overview of Signal Processing

A signal, by definition, contains information. Any signal obtained from a physical process also contains noise. It is often difficult or impossible to make sense of the information contained in a digital signal by looking at it in its raw form—that is, as a sequence of real values at discrete points in time. Signal analysis transforms offer natural, meaningful, alternate representations of the information contained in a signal.

This section describes IDL's digital signal processing tools. Most of the procedures and functions mentioned here work in two or more dimensions. For simplicity, only one dimensional signals are used in the examples.

Routines for Signal Processing

For a list of IDL signal processing routines, see the functional category of "Signal Processing" (IDL Quick Reference). There you will find a brief introduction to the routines. More detailed information is available in the IDL Reference Guide.

Running the Example Code

The examples in this section are written to take advantage of iTools. The example code is part of the IDL distribution. All of the files mentioned are located in the examples/doc/signal subdirectory of the IDL distribution. By default, this directory is part of IDL's path; if you have not changed your path, you will be able to run the examples as described here. See !PATH (IDL Reference Guide) for information on IDL's path.