Chapter 22_ Arrays and Tasseled Cap Google Earth Engine.pdf

Chapter 22: Arrays and Tasseled Cap

This chapter provides a workow to explore arrays and the Tasseled Cap transformation for an area near Lake Champlain, Vermont, United States.

The full GEE code can be found here.

Functions

Data Acquisition & Preprocessing

/**

* Creates a Tasseled Cap image for Landsat 5

// Define array of Tasseled Cap coefficients

var coefficients = ee.Array([

[ 0.3037, 0.2793, 0.4743, 0.5585, 0.5082, 0.1863 ],

[ -0.2848, -0.2435, -0.5436, 0.7243, 0.0840, -0.1800 ],

[ 0.1509, 0.1973, 0.3279, 0.3406, -0.7112, -0.4572 ],

[ -0.8242, 0.0849, 0.4392, -0.0580, 0.2012, -0.2768 ],

[ -0.3280, 0.0549, 0.1075, 0.1855, -0.4357, 0.8085 ],

[ 0.1084, -0.9022, 0.4120, 0.0573, -0.0251, 0.0238 ]

]);

// Select bands for use in Tasseled Cap

// Matrix multiplication: 6x6 times 6x1

var components_image = ee.Image(coefficients)

.matrixMultiply(array_image_2d)

// Remove extra dimensions

.arrayProject([0])

// Convert to regular image

.arrayFlatten([['brightness', 'greenness', 'wetness', 'fourth', 'fifth', 'sixth']]);

return components_image;

}

"type": "rectangle"

}

] */

ee.Feature(

ee.Geometry.Polygon(

[[[-74.72224061263952, 45.50738144646654],

[-74.72224061263952, 43.32625155252435],

[-71.89875428451452, 43.32625155252435],

[-71.89875428451452, 45.50738144646654]]], null, false),

{