pnm mod.destripe

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Description

Destripe removes periodic scan lines introduced by sensor mis-calibration. This type of striping is often seen in Landsat MSS data (every 6th line) and Landsat TM data (every 16th line). This function will calculate the mean of lines either side of the Nth line and add the standard deviation of that mean.

Located in "pnm_mod" module.

Arguments and Return Values

Inputs: an array containing orbital data

Outputs: an array that has been cleaned up

Usage

Syntax: pnm_mod.destripe(data = VAL [,detectors = INT] )

data:      any davinci array hopefully containing some Landsat data
detectors: The number of detectors is the periodicity of the striping 
(i.e. 6 for MSS and 16 for TM). The algorithm assumes VERTICAL striping 
- i.e., the data should be in the acquired format (horizontal strips).

Examples

dv> a=read("A2/Tempe_Land_rect.vicar")
.......A2/Tempe_Land_rect.vicar: VICAR bsq image: 1500x1500x7, 32 bits
1500x1500x7 array of float, bsq format [63,000,000 bytes]

dv> b=pnm_mod.destripe(a,26)
1500x1500x7 array of float, bsq format [63,000,000 bytes]

dv> display(do_dcs(a,7,5,2))
performing a 7-5-2 stretch
Writing /tmp/dv_7970/wCDtVo: 1500x1500x3 PNG file.
dv> display(do_dcs(b,7,5,2))
performing a 7-5-2 stretch
Writing /tmp/dv_7970/Dokx8q: 1500x1500x3 PNG file.

Images

ls tm before.jpgls tm after.jpg

Two images (before-left and after-right pair). It is difficult to distinguish the difference in this case mostly because of the high signal to noise which lowers the visibility of the striping.

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Recent Core Changes

Modified On: 02-26-2010

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