REMTILT

Description

REMTILT removes the planar tilt from each layer of the displacement product. The least squares technique is used to solve the best planar fit which is then subtracted from the data to remove the tilt.

Parameters

remtilt(fili, options, filo)

Name	Type	Caption	Length	Value range
FILI *	str	Input folder, or text file	1 -
OPTIONS	str	Option to remove mean value.	0 -	yes| no Default: yes
FILO *	str	Database output file name	1 -

* Required parameter

Parameter descriptions

FILI

The name of the input file to be processed. The input file must contain unwrapped displacement values written as integer or real values. Only th ePIX file format (*.pix) is supported.

OPTIONS

Setting this parameter to "Yes" removes the mean of the original input and sets the mean of the output to zero. Setting the parameter to "no" preserves the mean of the original.

FILO

Specifies the name of the PIX file to be generated. The corrected output file will contain the identical number of layers as the input. This file must not already exist.

This file must not already exist.

Details

REMTILT uses a least squares technique to compute the coefficients (c0, c1, c2) of the best fit plane and removes any residual tilt in the displacement values. The coefficients are computed separately for each input layer.

When the OPTIONS parameter is set to 'Yes', the output will have a mean value of zero. The output is given as D - (c0 + c1x + c2y) where x and y are the image column and row number respectively and D is the original displacement value. When the OPTIONS parameter is set to 'No' the planar offset c0 is set to zero and the original mean is preserved with the output value given as D - (c1x +c2y).

The NODATA values (as defined by the "NO_DATA_VALUE" metadata tag) are excluded from the tilt correction computations.

Examples

Remove the tilt from the displacement layers generated by INSDMV but preserve the mean of the original input.

from pci.remtilt import remtilt

fili    =  "INSDMV_output.pix"           #input file from insdmv
options =  "No"
filo    =  "NO_TILT_ORIGINAL_MEAN.pix"	#original mean output

remtilt(fili, options, filo)
        

Remove the tilt from the displacement layers generated by INSDMV and set the mean of the output to zero.

from pci.remtilt import remtilt

fili    =  "INSDMV_output.pix"           #input file from insdmv
options =  "yes"
filo    =  "NO_TILT_ZERO_MEAN.pix"		#output with zero mean

remtilt(fili, options, filo)