CCDINTEN

Description

CCDINTEN measures the change in total radar backscattering between a test image and a reference image by comparing the sum of the intensities of the input channels. Given two registered detected or single-look complex SAR images, CCDINTEN determines the overlap area, normalizes the intensity values based on the total span of intensity values, and calculates the change (represented as a percentile).

Parameters

ccdinten(fili, filref, dbic, filo, winsize)

Name	Type	Caption	Length	Value range
FILI *	str	Input complex or detected SAR image	1 -
FILREF *	str	Reference complex or detected SAR image	1 -
DBIC	List[int]	Input SAR image channels	0 -
FILO *	str	Output intensity change metric raster	1 -
WINSIZE	List[int]	Window size (pixels)	0 - 1	1 | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 17 | 19 | 21 | 23 | 25 | 27 | 29 | 31 | 33 Default: 1

* Required parameter

Parameter descriptions

FILI

Specifies the name of the input file that contains the test SAR image data.

The data may be integer, real, or complex valued. This file must have the same georeferencing, pixel size, viewing geometry, bit depth, matrix representation, and calibration type as the specified reference image.

FILREF

Specifies the name of the file that contains the reference SAR image data.

The data may be integer, real, or complex valued, but it must preserve the same structure as the input test image. This file must have the same georeferencing, pixel size, viewing geometry, bit depth, matrix representation, and calibration type as the specified input image.

DBIC

Optionally specifies the list of input channels to be processed. The specified channels must exist for both the test and reference images, and must be comparable; that is, they must have the same data type and polarization. By default, all channels from the input test and reference files are used to compute the change.

FILO

Specifies the name of the output file that is created.

The specified file must not already exist.

The direction of change is inferred by visual inspection of the output.

WINSIZE

Optionally specifies the size of the square window that is moved over the images. All of the pixels in the window are averaged together for the value of the center pixel. The window size value must be an odd integer. By default, no averaging is performed.

Details

CCDINTEN measures the change in total radar backscattering between the test and reference SAR images. If the image is single-look complex, the intensity is derived and output to the specified output file. CCDINTEN is NoData-aware, meaning that pixels that contain the value defined as 'NoData' in the metadata of the input file(s) are excluded from processing. The overlap area is automatically extracted.

It is recommended that you ingest the input and reference images through SARINGEST, check the pixel alignment (or run AUTOSHIFT), and filter the data (to reduce false alarm rate) before computing the change.

CCDINTEN also supports integer or real valued speckle filtered data as test or reference file input. A number of speckle filters that work on the intensity, amplitude, or complex data may be applied to the files before running CCDINTEN.

Example

This example uses two RADARSAT-2 Fine QuadPol images created by SARINGEST to measure the changes in intensity between September 19th and September 25th.

from pci.ccdinten import ccdinten

fili = 'rsat2_FQ15_sep19.pix' 		# Input image file name
filref = 'rsat2_FQ15_sep25.pix' 	# Reference image file name
dbic = [] 				# Uses all channels to detect change
filo = 'sep19_sep25_ccdinten.pix' 	# Output file name
winsize = [5] 				# Use a processing window of 5 by 5

ccdinten(fili, filref, dbic, filo, winsize)