Chapter 18_ Spectral Indices and Math Google Earth Engine.pdf

Chapter 18: Spectral Indices and Math

This chapter provides a workow to create spectral indices for Rocky Mountain National Park, Colorado, United States. The full GEE code can be

found here.

Functions

Data Acquisition & Preprocessing

/**

* Calculate and add NDVI band to Landsat 8 image

};

// NDSI - Snow

var add_ndsi = function(image) {

var ndsi = image.normalizedDifference(['B3', 'B6']).rename('NDSI');

return image.addBands(ndsi);

};

// Define boundary for Rocky Mountain National Park, Colorado (from GEE Asset)

var rmnp_boundary = ee.FeatureCollection("users/calekochenour/Rocky_Mountain_National_Park__Boundary_Polygon");

// Landsat 8

.sort('CLOUD_COVER')

.first()

.clip(rmnp_boundary);

var mar_apr = landsat8_t1_sr

.filterDate('2018-03-01', '2018-04-30')

.filterBounds(rmnp_boundary)

.sort('CLOUD_COVER')

.first()

.clip(rmnp_boundary);

var may_jun = landsat8_t1_sr

.filterDate('2018-07-01', '2018-08-31')

.filterBounds(rmnp_boundary)

.sort('CLOUD_COVER')

.first()

.clip(rmnp_boundary);

var sep_oct = landsat8_t1_sr

.filterDate('2018-09-01', '2018-10-31')

.filterBounds(rmnp_boundary)

.sort('CLOUD_COVER')

.first()

.clip(rmnp_boundary);

// Add NDSI band

jan_feb = add_ndsi(jan_feb);

mar_apr = add_ndsi(mar_apr);

may_jun = add_ndsi(may_jun);

jul_aug = add_ndsi(jul_aug);

sep_oct = add_ndsi(sep_oct);

nov_dec = add_ndsi(nov_dec);