Important!. Help about BitwiseAnd() Operator.

[Natalia Quintero]

Hi everyone!. I want to mask clouds and cloud shadows in L4, L5, L7 using the following code example for L8 in Google Earth Engine. If someone  knows how to modify the code to serve on these sensors would be very useful. Thank you.

Map.add

// Landsat Surface Reflectance Pixel QA Flags

// The main scene.

var scene = ee.Image('LANDSAT/LC08/C01/T1_SR/LC08_202032_20170601');

// Surface reflectance is a unitless ratio scaled to the range 0-10000

// and typically less than 2000.

Map.addLayer(scene, {min: 58, max: 10390, bands: ['B5', 'B6', 'B4']},

             'Surface Reflectance');

// The "pixel_qa" and "sr_cloud_qa" bands have various flags encoded in

// different bits.  We extract some of them as individual mask bands.

// Note: Cloud masking information is present in both "pixel_qa" and

// "sr_cloud_qa", but the former is likely to present more accurate results.

// pixel_qa Bit 1: Clear pixel indicator.

// pixel_qa Bit 2: Water indicator.

// pixel_qa Bit 3: Cloud shadow indicator.

// pixel_qa Bit 5: Cloud indicator.

// pixel_qa Bits 6-7: Cloud confidence.

// sr_cloud_qa Bit 1: Dense dark vegetation.

var clear = scene.select('pixel_qa').bitwiseAnd(2).neq(0);

clear = clear.updateMask(clear);

var cloud = scene.select('pixel_qa').bitwiseAnd(32).neq(0);

cloud = cloud.updateMask(cloud);

var cloud_shadow = scene.select('pixel_qa').bitwiseAnd(8).neq(0);

cloud_shadow = cloud_shadow.updateMask(cloud_shadow);

var water = scene.select('pixel_qa').bitwiseAnd(4).neq(0);

water = water.updateMask(water);

// Cloud confidence is comprised of bits 6-7.

// Add the two bits and interpolate them to a range from 0-3.

// 0 = None, 1 = Low, 2 = Medium, 3 = High.

var cloud_conf = scene.select('pixel_qa').bitwiseAnd(64)

    .add(scene.select('pixel_qa').bitwiseAnd(128))

    .interpolate([0, 64, 128, 192], [0, 1, 2, 3], 'clamp').int();

var cloud_conf_vis_param = {

    min: 0, max: 3, palette: ['000000', '666666', '999999', 'ffffff']

};

// Show various bits from the pixel_qa and sr_cloud_qa bands.

Map.addLayer(clear, {palette: '000000,ff0000'}, 'Clear');

Map.addLayer(cloud, {palette: '000000,ffffff'}, 'Cloud');

Map.addLayer(cloud_shadow, {palette: '000000,ffff00'}, 'Cloud Shadow');

Map.addLayer(water, {palette: '000000,0000ff'}, 'Water');

Map.addLayer(cloud_conf, cloud_conf_vis_param, 'Cloud Confidence');