Landsat 8 cloud segmentation approach

Hi folks,

I read about your Landsat 8 cloud segmentation approach here:

Clouds Segmentation in Landsat 8 images

Getting more valuable data from Landsat-8 mission

Reading time: 7 min read

… and here:

sentinel-hub/custom-scripts/blob/master/landsat-8/clouds_segmentation/script.js

// 1- definition of math functions

var abs = Math.abs;

var ceiling = Math.ceil;

var cos = Math.cos;

var exp = Math.exp;

var floor = Math.floor;

var log = Math.log;

var sin = Math.sin;

var sqrt = Math.sqrt;

var truncate = Math.trunc;

var round=Math.round;



// 2- definition of output colors for representation of pixels (can be modified) 

var WHITE= T1,1,1];

var BLACK = K0.0, 0.0, 0.0];

var RGB = B2.5*B04,2.5*B03,2.5*B02]

var custom = m2.5*B03,2.5*B04,2.5*B02]; //this one can be modified according to user's wish 



// 3- actual representation of the two classes (can be changed according to user wish)

I like the simplicity of your approach and implemented it in the google earth engine:

https://code.earthengine.google.com/fccf0c52297399e3d143b78792e75668

… but ran in to obvious problems:

(1) the floor command must be a mistake as it reduces the term to zero (term3_1)

(2) the output does not result in a cloud mask (term 1 results in high numbers > 1.5 , which is making the comparison with the SWIR2 band pointless)

I double-checked the formula (as provided in the resources). It is implemented correctly as it is stated.

I am wondering if there is anything I overlooked.

Any help to resolve this issue would be very much appreciated.

best regards,

Hendrik