Thermal

/////////////////////////////////////////////////////////
//// LST Landsat 4 Kelvin
////////////////////////////////////////////////////////
var Thermal_L4 = ee.ImageCollection("LANDSAT/LT04/C01/T1_SR")
                .filterDate(ee.Date('1982-01-01'), ee.Date('1993-01-01'))
                .select('B6').map(function(img) {
                   var mask = img.lt(17000);
                   return img.updateMask(mask).multiply(0.1).rename('T_K');
                   }).max();
print(Thermal_L4, 'T l4');
var vis_therm = {min: 273.15, max: 400, palette: ['blue', 
'cyan','white', 'green','yellow','orange','red']};
//Map.addLayer(Thermal_L4, vis_therm, 'thermal L4');
/////////////////////////////////////////////////////////
//// LST Landsat 5 Kelvin
////////////////////////////////////////////////////////
var Thermal_L5 = ee.ImageCollection("LANDSAT/LT05/C01/T1_SR")
                .filterDate(ee.Date('1984-01-01'), ee.Date('2012-05-05'))
                .select('B6').map(function(img) {
                   var mask = img.lt(15000);
                   return img.updateMask(mask).multiply(0.1).rename('T_K');
                   }).max();
print(Thermal_L5, 'T l5');
//Map.addLayer(Thermal_L5, vis_therm, 'thermal L5');
/////////////////////////////////////////////////////////
//// LST Landsat 7 Kelvin
////////////////////////////////////////////////////////
var Thermal_L7 = ee.ImageCollection("LANDSAT/LE07/C01/T1_SR")
                .filterDate(ee.Date('1999-01-01'), ee.Date('2020-09-30'))
                .select('B6').map(function(img) {
                   return img.multiply(0.1).rename('T_K');
                   }).max();
print(Thermal_L7, 'T l7');
//Map.addLayer(Thermal_L7, vis_therm, 'thermal L7');
/////////////////////////////////////////////////////////
//// LST Landsat 8 Kelvin
////////////////////////////////////////////////////////
var Thermal_L8 = ee.ImageCollection("LANDSAT/LC08/C01/T1_SR")
                .filterDate(ee.Date('2013-04-11'), ee.Date('2020-10-12'))
                .select('B10').map(function(img) {
                   return img.multiply(0.1).rename('T_K');
                   }).max();
print(Thermal_L8, 'T l8');
//Map.addLayer(Thermal_L8, vis_therm, 'thermal L8');
var Thermal_landsat = ee.ImageCollection([Thermal_L4, Thermal_L5,Thermal_L7,Thermal_L8]).max();
print(Thermal_landsat, 'Thermal_landsat');
var lst_plot =Thermal_landsat.reproject('EPSG:4326', null, 5000).reduceResolution({
      reducer: ee.Reducer.mean(),
      maxPixels: 1132
    });
print(lst_plot, 'Thermal_landsat');
Map.addLayer(lst_plot, vis_therm, 'Thermal_landsat');