Welcome to the L3 Harris Geospatial documentation center. Here you will find reference guides and help documents.
﻿

### TS_SPECTROGRAM

TS_SPECTROGRAM

The TS_SPECTROGRAM generates a spectrogram of a given vector.

This routine is written in the IDL language. Its source code can be found in the file TS_SPECTROGRAM.pro in the lib subdirectory of the IDL distribution.

## Examples

`t = findgen(100000)`
`data = sin(2*!pi*.02*t) + sin(2*!pi*.12*t) + sin(2*!pi*.22*t) + sin(2*!pi*.32*t) + sin(2*!pi*.42*t)`
`result = TS_SPECTROGRAM(data, window=512, overlap=128)`
`i = image(result, RGB_TABLE=colortable(72), title='TS_SPECTROGRAM')`

IDL displays: ## Syntax

Result = TS_SPECTROGRAM( X [, /DOUBLE] [, FREQ=value] [, SAMPLE_FREQ=value] [, TIME=value] [, OVERLAP=value] [, WINDOW=value] )

## Return Value

The result is a [WINDOW/2, 1+(X.length - WINDOW)/OVERLAP] array which describes [time, frequencies].

## Arguments

### X

An n-element single- or double-precision floating-point vector.

## Keywords

### DOUBLE

Set this keyword to force the computations to be done in double-precision arithmetic.

### FREQ

If set to a named variable, FREQ will contain the frequency vector for the spectrogram.

### SAMPLE_FREQ

Set to the sample frequency of the input data.

### TIME

If set to a named variable, TIME will contain the time vector for the spectrogram.

### OVERLAP

An integer describing the number of points of window overlap. Defaults to WINDOW/2.

Note: OVERLAP is extremely data dependent.

### WINDOW

An integer giving the size of the window. Defaults to 1024.

Note: WINDOW is extremely data dependent.

## Version History

 8.4 Introduced