{"id":866,"date":"2026-10-14T06:08:48","date_gmt":"2026-10-14T06:08:48","guid":{"rendered":"https:\/\/helpwithmygisassignment.com\/blog\/?p=866"},"modified":"2026-10-14T06:08:48","modified_gmt":"2026-10-14T06:08:48","slug":"land-surface-temperature-qgis-landsat","status":"publish","type":"post","link":"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/","title":{"rendered":"Land Surface Temperature (LST) Calculation in QGIS using Landsat 8\/9"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_89 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#Land_Surface_Temperature_LST_Calculation_in_QGIS_using_Landsat_89\" >Land Surface Temperature (LST) Calculation in QGIS using Landsat 8\/9<\/a><ul class='ez-toc-list-level-2' ><li class='ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#Introduction\" >Introduction<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#What_You_Need\" >What You Need<\/a><ul class='ez-toc-list-level-2' ><li class='ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#1_Landsat_8_or_Landsat_9_Level-1_data\" >1. Landsat 8 or Landsat 9 Level-1 data<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#2_QGIS\" >2. QGIS<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#3_Basic_raster_mathematics\" >3. Basic raster mathematics<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#Step_1_Calculate_Top-of-Atmosphere_Spectral_Radiance\" >Step 1: Calculate Top-of-Atmosphere Spectral Radiance<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#TOA_Radiance_Formula\" >TOA Radiance Formula<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#11_Find_the_coefficients\" >1.1 Find the coefficients<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#12_Calculate_radiance_in_QGIS\" >1.2 Calculate radiance in QGIS<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#Why_do_this\" >Why do this?<\/a><\/li><\/ul><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#Step_2_Convert_TOA_Radiance_to_Brightness_Temperature\" >Step 2: Convert TOA Radiance to Brightness Temperature<\/a><ul class='ez-toc-list-level-2' ><li class='ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#21_Brightness_Temperature_Formula\" >2.1 Brightness Temperature Formula<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#22_Calculate_Kelvin_temperature\" >2.2 Calculate Kelvin temperature<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#23_Convert_Kelvin_to_Celsius\" >2.3 Convert Kelvin to Celsius<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#Step_3_Calculate_NDVI_and_Fractional_Vegetation_Cover\" >Step 3: Calculate NDVI and Fractional Vegetation Cover<\/a><ul class='ez-toc-list-level-2' ><li class='ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#31_Calculate_NDVI\" >3.1 Calculate NDVI<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#32_Interpret_NDVI\" >3.2 Interpret NDVI<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-19\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#33_Calculate_Fractional_Vegetation_Cover\" >3.3 Calculate Fractional Vegetation Cover<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-20\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#Example\" >Example<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-21\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#Important\" >Important<\/a><\/li><\/ul><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-22\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#Step_4_Estimate_Land_Surface_Emissivity\" >Step 4: Estimate Land Surface Emissivity<\/a><ul class='ez-toc-list-level-2' ><li class='ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-23\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#What_is_emissivity\" >What is emissivity?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-24\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#41_A_commonly_used_emissivity_relationship\" >4.1 A commonly used emissivity relationship<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-25\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#42_Calculate_emissivity_in_QGIS\" >4.2 Calculate emissivity in QGIS<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-26\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#Step_5_Apply_the_Final_LST_Formula_in_Raster_Calculator\" >Step 5: Apply the Final LST Formula in Raster Calculator<\/a><ul class='ez-toc-list-level-2' ><li class='ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-27\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#51_Final_LST_formula\" >5.1 Final LST formula<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-28\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#52_QGIS_Raster_Calculator_expression\" >5.2 QGIS Raster Calculator expression<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-29\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#Important_unit_rule\" >Important unit rule<\/a><\/li><\/ul><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-30\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#Creating_an_LST_Map_in_QGIS\" >Creating an LST Map in QGIS<\/a><ul class='ez-toc-list-level-2' ><li class='ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-31\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#1_Open_Layer_Properties\" >1. Open Layer Properties<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-32\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#2_Choose_a_temperature_classification\" >2. Choose a temperature classification<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-33\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#3_Compare_different_land-cover_types\" >3. Compare different land-cover types<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-34\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#Using_LST_to_Study_Urban_Heat_Islands\" >Using LST to Study Urban Heat Islands<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-35\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#Important_distinction\" >Important distinction<\/a><\/li><\/ul><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-36\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#Common_Mistakes\" >Common Mistakes<\/a><ul class='ez-toc-list-level-2' ><li class='ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-37\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#Mistake_1_Using_the_wrong_emissivity_formula_or_threshold\" >Mistake 1: Using the wrong emissivity formula or threshold<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-38\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#Mistake_2_Mixing_Kelvin_and_Celsius\" >Mistake 2: Mixing Kelvin and Celsius<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-39\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#Mistake_3_Using_the_wrong_metadata_coefficients\" >Mistake 3: Using the wrong metadata coefficients<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-40\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#Mistake_4_Using_Band_11_instead_of_Band_10_without_explaining_why\" >Mistake 4: Using Band 11 instead of Band 10 without explaining why<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-41\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#Mistake_5_Forgetting_clouds_and_cloud_shadows\" >Mistake 5: Forgetting clouds and cloud shadows<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-42\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#Complete_QGIS_LST_Workflow\" >Complete QGIS LST Workflow<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-43\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/#Summary_Takeaways\" >Summary &amp; Takeaways<\/a><\/li><\/ul><\/nav><\/div>\n<h1><span class=\"ez-toc-section\" id=\"Land_Surface_Temperature_LST_Calculation_in_QGIS_using_Landsat_89\"><\/span>Land Surface Temperature (LST) Calculation in QGIS using Landsat 8\/9<span class=\"ez-toc-section-end\"><\/span><\/h1>\n<h2><span class=\"ez-toc-section\" id=\"Introduction\"><\/span>Introduction<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>When calculating <b data-path-to-node=\"1,0\" data-index-in-node=\"18\">Land Surface Temperature QGIS Landsat<\/b> datasets, remember that LST is the temperature of the Earth&#8217;s surface as measured by a thermal remote-sensing sensor. Unlike air temperature measured by a weather station, LST describes the temperature of the land surface itself\u2014for example, a road, building roof, bare soil, or vegetation canopy.<\/p>\n<p>For Landsat 8 and Landsat 9, the <strong>Thermal Infrared Sensor (TIRS)<\/strong> provides thermal information through Bands 10 and 11. <strong>Band 10<\/strong> covers approximately 10.6\u201311.19 \u00b5m and is commonly used for single-band LST calculations. Although the native thermal resolution is 100 m, Landsat 8\/9 thermal products are delivered resampled to 30 m. <a href=\"https:\/\/www.usgs.gov\/faqs\/what-are-band-designations-landsat-satellites?utm_source=chatgpt.com\" target=\"_blank\" rel=\"noopener\">USGS<\/a><\/p>\n<p>The important point is that the temperature recorded by the satellite is not immediately the true land surface temperature. The original Level-1 image contains calibrated digital numbers that must first be converted to <strong>top-of-atmosphere (TOA) spectral radiance<\/strong>, then to <strong>brightness temperature<\/strong>. Surface emissivity must subsequently be estimated to account for the fact that different materials emit thermal energy differently. USGS provides the required radiometric coefficients and thermal constants in the scene&#8217;s MTL metadata file. <a href=\"https:\/\/www.usgs.gov\/landsat-missions\/using-usgs-landsat-level-1-data-product?utm_source=chatgpt.com\" target=\"_blank\" rel=\"noopener\">USGS<\/a><\/p>\n<p>LST is particularly useful for studying the <strong>Urban Heat Island (UHI)<\/strong> effect. Urban materials such as asphalt, concrete, and rooftops can become considerably warmer than vegetated or rural surfaces. By producing an LST map in QGIS, you can identify spatial patterns of surface heating and compare temperature differences between built-up areas, vegetation, water, and bare soil.<\/p>\n<hr \/>\n<h1><span class=\"ez-toc-section\" id=\"What_You_Need\"><\/span>What You Need<span class=\"ez-toc-section-end\"><\/span><\/h1>\n<p>Before beginning the <strong>Land Surface Temperature QGIS Landsat<\/strong> workflow, prepare the following.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"1_Landsat_8_or_Landsat_9_Level-1_data\"><\/span>1. Landsat 8 or Landsat 9 Level-1 data<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>For this workflow, download <strong>Collection 2 Level-1<\/strong> imagery.<\/p>\n<p>You need at least:<\/p>\n<ul>\n<li><strong>Band 4 \u2014 Red<\/strong><\/li>\n<li><strong>Band 5 \u2014 Near Infrared (NIR)<\/strong><\/li>\n<li><strong>Band 10 \u2014 Thermal Infrared<\/strong><\/li>\n<li><strong>MTL metadata file<\/strong><\/li>\n<\/ul>\n<p>Landsat Collection 2 Level-1 products contain the spectral bands and an MTL metadata file containing the coefficients required to convert the digital numbers into radiance and brightness temperature. <a href=\"https:\/\/www.usgs.gov\/landsat-missions\/landsat-collection-2-level-1-data?utm_source=chatgpt.com\" target=\"_blank\" rel=\"noopener\">USGS<\/a><\/p>\n<p>For the NDVI calculation:<\/p>\n<div>\n<pre dir=\"ltr\"><code>NDVI = (NIR \u2212 Red) \/ (NIR + Red)\r\n\r\nNDVI = (Band 5 \u2212 Band 4) \/ (Band 5 + Band 4)<\/code><\/pre>\n<\/div>\n<p>For thermal calculations, use <strong>Band 10<\/strong>.<\/p>\n<blockquote><p><strong>Important:<\/strong> Do not copy generic radiance coefficients from another Landsat scene. Use the <code dir=\"ltr\">RADIANCE_MULT_BAND_10<\/code>, <code dir=\"ltr\">RADIANCE_ADD_BAND_10<\/code>, <code dir=\"ltr\">K1_CONSTANT_BAND_10<\/code>, and <code dir=\"ltr\">K2_CONSTANT_BAND_10<\/code> values contained in your own MTL file.<\/p><\/blockquote>\n<h2><span class=\"ez-toc-section\" id=\"2_QGIS\"><\/span>2. QGIS<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Install a current version of <strong>QGIS<\/strong>.<\/p>\n<p>You should be comfortable with:<\/p>\n<ul>\n<li>Loading raster layers<\/li>\n<li>Opening <strong>Raster Calculator<\/strong><\/li>\n<li>Creating raster outputs<\/li>\n<li>Using layer properties<\/li>\n<li>Applying raster symbology<\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"3_Basic_raster_mathematics\"><\/span>3. Basic raster mathematics<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Most of this workflow can be performed using the QGIS<a href=\"https:\/\/helpwithmygisassignment.com\/blog\/calculate-field-values-arcgis-qgis\/\"> <strong>Raster Calculato<\/strong><strong>r<\/strong>.<\/a><\/p>\n<p>You will eventually create:<\/p>\n<div>\n<pre dir=\"ltr\"><code>Band 10\r\n   \u2193\r\nTOA Radiance\r\n   \u2193\r\nBrightness Temperature\r\n   \u2193\r\nNDVI\r\n   \u2193\r\nFractional Vegetation Cover\r\n   \u2193\r\nLand Surface Emissivity\r\n   \u2193\r\nLST<\/code><\/pre>\n<\/div>\n<hr \/>\n<h1><span class=\"ez-toc-section\" id=\"Step_1_Calculate_Top-of-Atmosphere_Spectral_Radiance\"><\/span>Step 1: Calculate Top-of-Atmosphere Spectral Radiance<span class=\"ez-toc-section-end\"><\/span><\/h1>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-1073\" src=\"https:\/\/helpwithmygisassignment.com\/blog\/wp-content\/uploads\/2026\/10\/Gemini_Generated_Image_6klbns6klbns6klb-1024x559.jpg\" alt=\"Land Surface Temperature QGIS Landsat\" width=\"1024\" height=\"559\" srcset=\"https:\/\/helpwithmygisassignment.com\/blog\/wp-content\/uploads\/2026\/10\/Gemini_Generated_Image_6klbns6klbns6klb-1024x559.jpg 1024w, https:\/\/helpwithmygisassignment.com\/blog\/wp-content\/uploads\/2026\/10\/Gemini_Generated_Image_6klbns6klbns6klb-300x164.jpg 300w, https:\/\/helpwithmygisassignment.com\/blog\/wp-content\/uploads\/2026\/10\/Gemini_Generated_Image_6klbns6klbns6klb-768x419.jpg 768w, https:\/\/helpwithmygisassignment.com\/blog\/wp-content\/uploads\/2026\/10\/Gemini_Generated_Image_6klbns6klbns6klb.jpg 1408w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/p>\n<p>The Landsat Level-1 thermal image initially contains calibrated digital numbers (<strong>DNs<\/strong>). These must be converted into physical spectral radiance values.<\/p>\n<p>USGS specifies the following equation for Level-1 data: <a href=\"https:\/\/www.usgs.gov\/landsat-missions\/using-usgs-landsat-level-1-data-product?utm_source=chatgpt.com\" target=\"_blank\" rel=\"noopener\">USGS<\/a><\/p>\n<h3><span class=\"ez-toc-section\" id=\"TOA_Radiance_Formula\"><\/span>TOA Radiance Formula<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<div>\n<pre dir=\"ltr\"><code>L\u03bb = ML \u00d7 Qcal + AL<\/code><\/pre>\n<\/div>\n<p>Where:<\/p>\n<ul>\n<li><strong>L\u03bb<\/strong> = TOA spectral radiance<\/li>\n<li><strong>ML<\/strong> = multiplicative radiance scaling factor<\/li>\n<li><strong>Qcal<\/strong> = pixel digital number (DN)<\/li>\n<li><strong>AL<\/strong> = additive radiance scaling factor<\/li>\n<\/ul>\n<p>For Landsat Band 10, the metadata will contain:<\/p>\n<div>\n<pre dir=\"ltr\"><code>RADIANCE_MULT_BAND_10\r\nRADIANCE_ADD_BAND_10<\/code><\/pre>\n<\/div>\n<h2><span class=\"ez-toc-section\" id=\"11_Find_the_coefficients\"><\/span>1.1 Find the coefficients<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Open the MTL file that came with your Landsat scene.<\/p>\n<p>Search for:<\/p>\n<div>\n<pre dir=\"ltr\"><code>RADIANCE_MULT_BAND_10<\/code><\/pre>\n<\/div>\n<p>and:<\/p>\n<div>\n<pre dir=\"ltr\"><code>RADIANCE_ADD_BAND_10<\/code><\/pre>\n<\/div>\n<p>You may see values similar to:<\/p>\n<div>\n<pre dir=\"ltr\"><code>RADIANCE_MULT_BAND_10 = ...\r\nRADIANCE_ADD_BAND_10 = ...<\/code><\/pre>\n<\/div>\n<p><strong>Use the actual values from your scene.<\/strong><\/p>\n<h2><span class=\"ez-toc-section\" id=\"12_Calculate_radiance_in_QGIS\"><\/span>1.2 Calculate radiance in QGIS<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Open:<\/p>\n<p><strong>Raster \u2192 Raster Calculator<\/strong><\/p>\n<p>Your expression will conceptually be:<\/p>\n<div>\n<pre dir=\"ltr\"><code>(\"Band10@1\" \u00d7 ML) + AL<\/code><\/pre>\n<\/div>\n<p>Replace <code dir=\"ltr\">ML<\/code> and <code dir=\"ltr\">AL<\/code> with the values from your MTL file.<\/p>\n<p>For example, if your metadata contained hypothetical values:<\/p>\n<div>\n<pre dir=\"ltr\"><code>ML = 0.0003342\r\nAL = 0.1<\/code><\/pre>\n<\/div>\n<p>your expression would be:<\/p>\n<div>\n<pre dir=\"ltr\"><code>(\"Band10@1\" * 0.0003342) + 0.1<\/code><\/pre>\n<\/div>\n<p>Save the result as:<\/p>\n<div>\n<pre dir=\"ltr\"><code>B10_TOA_Radiance.tif<\/code><\/pre>\n<\/div>\n<h3><span class=\"ez-toc-section\" id=\"Why_do_this\"><\/span>Why do this?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>The DN is essentially a coded measurement. Radiance converts that measurement into a physical quantity describing the thermal energy detected by the sensor.<\/p>\n<hr \/>\n<h1><span class=\"ez-toc-section\" id=\"Step_2_Convert_TOA_Radiance_to_Brightness_Temperature\"><\/span>Step 2: Convert TOA Radiance to Brightness Temperature<span class=\"ez-toc-section-end\"><\/span><\/h1>\n<p>Now that you have spectral radiance, you can convert it into <strong>brightness temperature<\/strong>.<\/p>\n<p>Brightness temperature is the temperature a theoretical perfect emitter would need to have to produce the observed radiance.<\/p>\n<p>It is <strong>not yet the final LST<\/strong> because the Earth&#8217;s surface is not a perfect emitter.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"21_Brightness_Temperature_Formula\"><\/span>2.1 Brightness Temperature Formula<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>USGS gives the following conversion: <a href=\"https:\/\/www.usgs.gov\/landsat-missions\/using-usgs-landsat-level-1-data-product?utm_source=chatgpt.com\" target=\"_blank\" rel=\"noopener\">USGS<\/a><\/p>\n<div>\n<pre dir=\"ltr\"><code>T = K2 \/ ln((K1 \/ L\u03bb) + 1)<\/code><\/pre>\n<\/div>\n<p>Where:<\/p>\n<ul>\n<li><strong>T<\/strong> = brightness temperature in Kelvin<\/li>\n<li><strong>K1<\/strong> = thermal conversion constant<\/li>\n<li><strong>K2<\/strong> = thermal conversion constant<\/li>\n<li><strong>L\u03bb<\/strong> = TOA spectral radiance<\/li>\n<li><strong>ln<\/strong> = natural logarithm<\/li>\n<\/ul>\n<p>The MTL file contains:<\/p>\n<div>\n<pre dir=\"ltr\"><code>K1_CONSTANT_BAND_10\r\nK2_CONSTANT_BAND_10<\/code><\/pre>\n<\/div>\n<p>Again, use the values belonging to your specific scene.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"22_Calculate_Kelvin_temperature\"><\/span>2.2 Calculate Kelvin temperature<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>In QGIS Raster Calculator:<\/p>\n<div>\n<pre dir=\"ltr\"><code>K2 \/ ln((K1 \/ \"B10_TOA_Radiance@1\") + 1)<\/code><\/pre>\n<\/div>\n<p>Save this as:<\/p>\n<div>\n<pre dir=\"ltr\"><code>Brightness_Temperature_K.tif<\/code><\/pre>\n<\/div>\n<h2><span class=\"ez-toc-section\" id=\"23_Convert_Kelvin_to_Celsius\"><\/span>2.3 Convert Kelvin to Celsius<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Most GIS maps are easier to interpret in Celsius.<\/p>\n<p>Use:<\/p>\n<div>\n<pre dir=\"ltr\"><code>Temperature(\u00b0C) = Temperature(K) \u2212 273.15<\/code><\/pre>\n<\/div>\n<p>In QGIS:<\/p>\n<div>\n<pre dir=\"ltr\"><code>\"Brightness_Temperature_K@1\" - 273.15<\/code><\/pre>\n<\/div>\n<p>Save the result as:<\/p>\n<div>\n<pre dir=\"ltr\"><code>Brightness_Temperature_C.tif<\/code><\/pre>\n<\/div>\n<blockquote><p><strong>Check your result:<\/strong> A normal terrestrial scene should not suddenly produce temperatures of hundreds or thousands of degrees Celsius. Extremely abnormal values usually indicate a scaling-factor, metadata, NoData, or formula problem.<\/p><\/blockquote>\n<hr \/>\n<h1><span class=\"ez-toc-section\" id=\"Step_3_Calculate_NDVI_and_Fractional_Vegetation_Cover\"><\/span>Step 3: Calculate NDVI and Fractional Vegetation Cover<span class=\"ez-toc-section-end\"><\/span><\/h1>\n<p>Brightness temperature alone does not provide an accurate estimate of LST because different surfaces have different <strong>emissivities<\/strong>.<\/p>\n<p>A common way to estimate emissivity is to use vegetation information derived from <strong>NDVI (Normalized Difference Vegetation Index)<\/strong>.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"31_Calculate_NDVI\"><\/span>3.1 Calculate NDVI<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Landsat 8\/9 uses:<\/p>\n<ul>\n<li><strong>Band 4 = Red<\/strong><\/li>\n<li><strong>Band 5 = NIR<\/strong><\/li>\n<\/ul>\n<p>The NDVI equation is:<\/p>\n<div>\n<pre dir=\"ltr\"><code>NDVI = (NIR \u2212 Red) \/ (NIR + Red)<\/code><\/pre>\n<\/div>\n<p>Therefore:<\/p>\n<div>\n<pre dir=\"ltr\"><code>NDVI = (Band 5 \u2212 Band 4) \/ (Band 5 + Band 4)<\/code><\/pre>\n<\/div>\n<p>In QGIS Raster Calculator:<\/p>\n<div>\n<pre dir=\"ltr\"><code>(\"Band5@1\" - \"Band4@1\") \/\r\n(\"Band5@1\" + \"Band4@1\")<\/code><\/pre>\n<\/div>\n<p>Save it as:<\/p>\n<div>\n<pre dir=\"ltr\"><code>NDVI.tif<\/code><\/pre>\n<\/div>\n<h2><span class=\"ez-toc-section\" id=\"32_Interpret_NDVI\"><\/span>3.2 Interpret NDVI<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>A simplified interpretation is:<\/p>\n<div>\n<div>\n<div>\n<table>\n<thead>\n<tr>\n<th>Surface<\/th>\n<th>Typical NDVI behavior<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Dense vegetation<\/td>\n<td>High positive values<\/td>\n<\/tr>\n<tr>\n<td>Grass\/crops<\/td>\n<td>Moderate positive values<\/td>\n<\/tr>\n<tr>\n<td>Bare soil<\/td>\n<td>Low positive values<\/td>\n<\/tr>\n<tr>\n<td>Built-up surfaces<\/td>\n<td>Low or near-zero values<\/td>\n<\/tr>\n<tr>\n<td>Water<\/td>\n<td>Usually negative<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n<p>The exact values vary according to season, surface conditions, atmospheric effects, and preprocessing.<\/p>\n<hr \/>\n<h2><span class=\"ez-toc-section\" id=\"33_Calculate_Fractional_Vegetation_Cover\"><\/span>3.3 Calculate Fractional Vegetation Cover<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Fractional vegetation cover, commonly written as <strong>Pv<\/strong>, estimates the proportion of vegetation within a pixel.<\/p>\n<p>A widely used approach is:<\/p>\n<div>\n<pre dir=\"ltr\"><code>Pv = ((NDVI \u2212 NDVImin) \/\r\n      (NDVImax \u2212 NDVImin))\u00b2<\/code><\/pre>\n<\/div>\n<p>Where:<\/p>\n<ul>\n<li><strong>Pv<\/strong> = fractional vegetation cover<\/li>\n<li><strong>NDVImin<\/strong> = minimum NDVI for the selected scene\/study area<\/li>\n<li><strong>NDVImax<\/strong> = maximum NDVI for the selected scene\/study area<\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"Example\"><\/span>Example<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Suppose your study area has:<\/p>\n<div>\n<pre dir=\"ltr\"><code>NDVImin = 0.05\r\nNDVImax = 0.80<\/code><\/pre>\n<\/div>\n<p>For a pixel with:<\/p>\n<div>\n<pre dir=\"ltr\"><code>NDVI = 0.50<\/code><\/pre>\n<\/div>\n<p>then:<\/p>\n<div>\n<pre dir=\"ltr\"><code>Pv = ((0.50 \u2212 0.05) \/ (0.80 \u2212 0.05))\u00b2\r\n\r\nPv = (0.45 \/ 0.75)\u00b2\r\n\r\nPv = 0.36<\/code><\/pre>\n<\/div>\n<p>The pixel therefore has an estimated fractional vegetation cover of <strong>0.36<\/strong>, or approximately <strong>36%<\/strong>.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Important\"><\/span>Important<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Do not automatically use <code dir=\"ltr\">-1<\/code> and <code dir=\"ltr\">+1<\/code> as NDVImin and NDVImax unless your methodology specifically calls for those theoretical limits.<\/p>\n<p>For a student project, it is usually better to document how you determined the minimum and maximum values for your study area.<\/p>\n<hr \/>\n<h1><span class=\"ez-toc-section\" id=\"Step_4_Estimate_Land_Surface_Emissivity\"><\/span>Step 4: Estimate Land Surface Emissivity<span class=\"ez-toc-section-end\"><\/span><\/h1>\n<p>Now we need to account for <strong>surface emissivity (\u03b5)<\/strong>.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"What_is_emissivity\"><\/span>What is emissivity?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Imagine two surfaces at exactly the same physical temperature:<\/p>\n<ul>\n<li>A dark roof<\/li>\n<li>Vegetation<\/li>\n<\/ul>\n<p>They may not emit thermal radiation in exactly the same way.<\/p>\n<p><strong>Emissivity<\/strong> describes how efficiently a real surface emits thermal radiation compared with an ideal blackbody.<\/p>\n<p>This matters because the satellite measures emitted radiation, not temperature directly.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"41_A_commonly_used_emissivity_relationship\"><\/span>4.1 A commonly used emissivity relationship<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>For a simplified NDVI-based workflow, land surface emissivity can be estimated using:<\/p>\n<div>\n<pre dir=\"ltr\"><code>\u03b5 = 0.004 \u00d7 Pv + 0.986<\/code><\/pre>\n<\/div>\n<p>Where:<\/p>\n<ul>\n<li><strong>\u03b5<\/strong> = land surface emissivity<\/li>\n<li><strong>Pv<\/strong> = fractional vegetation cover<\/li>\n<\/ul>\n<p>This is a commonly used empirical approximation for vegetation-based LST workflows.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"42_Calculate_emissivity_in_QGIS\"><\/span>4.2 Calculate emissivity in QGIS<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Open <strong>Raster Calculator<\/strong> and enter:<\/p>\n<div>\n<pre dir=\"ltr\"><code>(0.004 * \"Pv@1\") + 0.986<\/code><\/pre>\n<\/div>\n<p>Save the output as:<\/p>\n<div>\n<pre dir=\"ltr\"><code>Emissivity.tif<\/code><\/pre>\n<\/div>\n<p>Your emissivity raster should generally contain values close to 1.<\/p>\n<blockquote><p><strong>Important:<\/strong> This is a simplified emissivity model. More advanced LST studies may use land-cover-specific emissivity values, ASTER GED emissivity products, or atmospheric correction methods.<\/p><\/blockquote>\n<hr \/>\n<h1><span class=\"ez-toc-section\" id=\"Step_5_Apply_the_Final_LST_Formula_in_Raster_Calculator\"><\/span>Step 5: Apply the Final LST Formula in Raster Calculator<span class=\"ez-toc-section-end\"><\/span><\/h1>\n<p>Now we have the three major components needed for the simplified single-channel LST calculation:<\/p>\n<ol start=\"1\">\n<li><strong>Brightness temperature<\/strong><\/li>\n<li><strong>Surface emissivity<\/strong><\/li>\n<li><strong>Thermal wavelength<\/strong><\/li>\n<\/ol>\n<p>The final step is to combine them.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"51_Final_LST_formula\"><\/span>5.1 Final LST formula<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>A commonly used single-channel correction is:<\/p>\n<div>\n<pre dir=\"ltr\"><code>LST = BT \/\r\n      [1 + (\u03bb \u00d7 BT \/ \u03c1) \u00d7 ln(\u03b5)]<\/code><\/pre>\n<\/div>\n<p>Then convert Kelvin to Celsius:<\/p>\n<div>\n<pre dir=\"ltr\"><code>LST(\u00b0C) = LST(K) \u2212 273.15<\/code><\/pre>\n<\/div>\n<p>Where:<\/p>\n<ul>\n<li><strong>LST<\/strong> = land surface temperature<\/li>\n<li><strong>BT<\/strong> = brightness temperature in Kelvin<\/li>\n<li><strong>\u03bb<\/strong> = effective wavelength of the thermal band<\/li>\n<li><strong>\u03c1<\/strong> = <code dir=\"ltr\">hc\/\u03c3<\/code>, approximately <strong>14,388 \u03bcm\u00b7K<\/strong><\/li>\n<li><strong>\u03b5<\/strong> = land surface emissivity<\/li>\n<li><strong>ln(\u03b5)<\/strong> = natural logarithm of emissivity<\/li>\n<\/ul>\n<p>For Landsat 8\/9 Band 10, a commonly used effective wavelength is approximately:<\/p>\n<div>\n<pre dir=\"ltr\"><code>\u03bb \u2248 10.895 \u03bcm<\/code><\/pre>\n<\/div>\n<p>Band 10 spans approximately 10.6\u201311.19 \u00b5m. <a href=\"https:\/\/www.usgs.gov\/faqs\/what-are-band-designations-landsat-satellites?utm_source=chatgpt.com\" target=\"_blank\" rel=\"noopener\">USGS<\/a><\/p>\n<h2><span class=\"ez-toc-section\" id=\"52_QGIS_Raster_Calculator_expression\"><\/span>5.2 QGIS Raster Calculator expression<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Using the brightness temperature <strong>in Kelvin<\/strong>, your conceptual expression is:<\/p>\n<div>\n<pre dir=\"ltr\"><code>(\r\n  \"Brightness_Temperature_K@1\" \/\r\n  (\r\n    1 +\r\n    (\r\n      (10.895 * \"Brightness_Temperature_K@1\") \/ 14388\r\n    )\r\n    *\r\n    ln(\"Emissivity@1\")\r\n  )\r\n)\r\n) - 273.15<\/code><\/pre>\n<\/div>\n<p>Save the output as:<\/p>\n<div>\n<pre dir=\"ltr\"><code>LST_Celsius.tif<\/code><\/pre>\n<\/div>\n<h3><span class=\"ez-toc-section\" id=\"Important_unit_rule\"><\/span>Important unit rule<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Do not use Celsius in the final LST equation.<\/strong><\/p>\n<p>The formula requires <strong>brightness temperature in Kelvin<\/strong>.<\/p>\n<p>The correct sequence is:<\/p>\n<div>\n<pre dir=\"ltr\"><code>Radiance\r\n   \u2193\r\nBrightness Temperature (K)\r\n   \u2193\r\nEmissivity correction\r\n   \u2193\r\nLST (K)\r\n   \u2193\r\nLST (\u00b0C)<\/code><\/pre>\n<\/div>\n<hr \/>\n<h1><span class=\"ez-toc-section\" id=\"Creating_an_LST_Map_in_QGIS\"><\/span>Creating an LST Map in QGIS<span class=\"ez-toc-section-end\"><\/span><\/h1>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-1074\" src=\"https:\/\/helpwithmygisassignment.com\/blog\/wp-content\/uploads\/2026\/10\/Gemini_Generated_Image_ld00iuld00iuld00-1024x559.jpg\" alt=\"Land Surface Temperature QGIS Landsat\" width=\"1024\" height=\"559\" srcset=\"https:\/\/helpwithmygisassignment.com\/blog\/wp-content\/uploads\/2026\/10\/Gemini_Generated_Image_ld00iuld00iuld00-1024x559.jpg 1024w, https:\/\/helpwithmygisassignment.com\/blog\/wp-content\/uploads\/2026\/10\/Gemini_Generated_Image_ld00iuld00iuld00-300x164.jpg 300w, https:\/\/helpwithmygisassignment.com\/blog\/wp-content\/uploads\/2026\/10\/Gemini_Generated_Image_ld00iuld00iuld00-768x419.jpg 768w, https:\/\/helpwithmygisassignment.com\/blog\/wp-content\/uploads\/2026\/10\/Gemini_Generated_Image_ld00iuld00iuld00.jpg 1408w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/p>\n<p>Once <code dir=\"ltr\">LST_Celsius.tif<\/code> has been created, style it so that temperature patterns are easy to interpret.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"1_Open_Layer_Properties\"><\/span>1. Open Layer Properties<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Right-click:<\/p>\n<p><strong>LST_Celsius \u2192 Properties \u2192 Symbology<\/strong><\/p>\n<p>Select:<\/p>\n<p><strong>Singleband pseudocolor<\/strong><\/p>\n<h2><span class=\"ez-toc-section\" id=\"2_Choose_a_temperature_classification\"><\/span>2. Choose a temperature classification<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>You could classify the raster into categories such as:<\/p>\n<div>\n<div>\n<div>\n<table>\n<thead>\n<tr>\n<th>LST<\/th>\n<th>Example interpretation<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>&lt;20\u00b0C<\/td>\n<td>Relatively cool<\/td>\n<\/tr>\n<tr>\n<td>20\u201325\u00b0C<\/td>\n<td>Moderate<\/td>\n<\/tr>\n<tr>\n<td>25\u201330\u00b0C<\/td>\n<td>Warm<\/td>\n<\/tr>\n<tr>\n<td>30\u201335\u00b0C<\/td>\n<td>Hot<\/td>\n<\/tr>\n<tr>\n<td>&gt;35\u00b0C<\/td>\n<td>Very hot<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n<p>These are <strong>example visualization classes<\/strong>, not universal temperature thresholds. Your study area&#8217;s climate, season, time of acquisition, and local conditions should determine appropriate classifications.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"3_Compare_different_land-cover_types\"><\/span>3. Compare different land-cover types<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Your final map might reveal patterns such as:<\/p>\n<div>\n<pre dir=\"ltr\"><code>Vegetation \u2192 cooler\r\nWater \u2192 cooler\r\nBare soil \u2192 warmer\r\nRoads \u2192 warmer\r\nDense buildings \u2192 warmer<\/code><\/pre>\n<\/div>\n<p>This is where LST becomes especially useful for <strong>Urban Heat Island GIS<\/strong> analysis.<\/p>\n<hr \/>\n<h1><span class=\"ez-toc-section\" id=\"Using_LST_to_Study_Urban_Heat_Islands\"><\/span>Using LST to Study Urban Heat Islands<span class=\"ez-toc-section-end\"><\/span><\/h1>\n<p>A simple UHI analysis can compare LST between different land-cover zones.<\/p>\n<p>For example, divide your study area into:<\/p>\n<ul>\n<li><strong>Dense urban areas<\/strong><\/li>\n<li><strong>Residential areas<\/strong><\/li>\n<li><strong>Industrial areas<\/strong><\/li>\n<li><strong>Vegetated areas<\/strong><\/li>\n<li><strong>Water bodies<\/strong><\/li>\n<li><strong>Rural\/reference areas<\/strong><\/li>\n<\/ul>\n<p>Then calculate the mean LST for each zone.<\/p>\n<p>For example:<\/p>\n<div>\n<div>\n<div>\n<table>\n<thead>\n<tr>\n<th>Land cover<\/th>\n<th>Mean LST<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Dense urban<\/td>\n<td>34.2\u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Industrial<\/td>\n<td>35.1\u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Residential<\/td>\n<td>31.8\u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Vegetation<\/td>\n<td>25.4\u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Water<\/td>\n<td>23.1\u00b0C<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n<p>This can reveal spatial relationships between <strong>urbanization and surface heating<\/strong>.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Important_distinction\"><\/span>Important distinction<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>LST is <strong>not the same thing as air temperature<\/strong>.<\/p>\n<p>A satellite LST map describes the temperature of the land surface, whereas conventional weather stations measure air temperature. Therefore, avoid writing that your LST map directly represents the temperature people experience.<\/p>\n<hr \/>\n<h1><span class=\"ez-toc-section\" id=\"Common_Mistakes\"><\/span>Common Mistakes<span class=\"ez-toc-section-end\"><\/span><\/h1>\n<h2><span class=\"ez-toc-section\" id=\"Mistake_1_Using_the_wrong_emissivity_formula_or_threshold\"><\/span>Mistake 1: Using the wrong emissivity formula or threshold<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>One common error is treating emissivity as though it were a constant for every pixel.<\/p>\n<p>A vegetation-covered pixel and an impervious urban pixel can have different thermal emission properties.<\/p>\n<p>If you use an NDVI-based approach, make sure you correctly calculate:<\/p>\n<div>\n<pre dir=\"ltr\"><code>NDVI\r\n   \u2193\r\nNDVImin \/ NDVImax\r\n   \u2193\r\nPv\r\n   \u2193\r\n\u03b5<\/code><\/pre>\n<\/div>\n<p>Also make sure your emissivity raster contains sensible values rather than zeros, negative values, or values substantially greater than 1.<\/p>\n<hr \/>\n<h2><span class=\"ez-toc-section\" id=\"Mistake_2_Mixing_Kelvin_and_Celsius\"><\/span>Mistake 2: Mixing Kelvin and Celsius<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>This is one of the most important errors to avoid.<\/p>\n<p>The brightness-temperature equation produces:<\/p>\n<div>\n<pre dir=\"ltr\"><code>BT = Kelvin<\/code><\/pre>\n<\/div>\n<p>The final LST correction also expects:<\/p>\n<div>\n<pre dir=\"ltr\"><code>BT = Kelvin<\/code><\/pre>\n<\/div>\n<p>Only after the final temperature has been calculated should you convert to Celsius:<\/p>\n<div>\n<pre dir=\"ltr\"><code>\u00b0C = K \u2212 273.15<\/code><\/pre>\n<\/div>\n<p>If you insert Celsius directly into the LST equation, your result can be severely distorted.<\/p>\n<hr \/>\n<h2><span class=\"ez-toc-section\" id=\"Mistake_3_Using_the_wrong_metadata_coefficients\"><\/span>Mistake 3: Using the wrong metadata coefficients<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Do not assume that the same radiance coefficients apply to every scene.<\/p>\n<p>For each Level-1 scene, use the coefficients supplied in its <strong>MTL file<\/strong>. USGS specifically states that the Level-1 product metadata provides the radiometric scaling factors and thermal constants required for these conversions. <a href=\"https:\/\/www.usgs.gov\/landsat-missions\/using-usgs-landsat-level-1-data-product?utm_source=chatgpt.com\" target=\"_blank\" rel=\"noopener\">USGS<\/a><\/p>\n<hr \/>\n<h2><span class=\"ez-toc-section\" id=\"Mistake_4_Using_Band_11_instead_of_Band_10_without_explaining_why\"><\/span>Mistake 4: Using Band 11 instead of Band 10 without explaining why<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Landsat 8\/9 have two TIRS thermal bands. However, this tutorial uses <strong>Band 10<\/strong> for the single-band workflow.<\/p>\n<p>USGS identifies Band 10 as the first TIRS thermal band and notes that the historical calibration uncertainty of Band 11 has been larger; quantitative work should therefore carefully consider the calibration characteristics rather than blindly applying a two-band split-window approach. <a href=\"https:\/\/www.usgs.gov\/landsat-missions\/landsat-8-oli-and-tirs-calibration-notices?utm_source=chatgpt.com\" target=\"_blank\" rel=\"noopener\">USGS<\/a><\/p>\n<hr \/>\n<h2><span class=\"ez-toc-section\" id=\"Mistake_5_Forgetting_clouds_and_cloud_shadows\"><\/span>Mistake 5: Forgetting clouds and cloud shadows<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Clouds can produce extremely misleading temperature values.<\/p>\n<p>Before interpreting an LST map:<\/p>\n<ul>\n<li>Inspect the scene visually.<\/li>\n<li>Use the appropriate <strong>QA band<\/strong> where available.<\/li>\n<li>Mask clouds and cloud shadows.<\/li>\n<li>Exclude obvious invalid pixels.<\/li>\n<\/ul>\n<p>A beautiful temperature map can still be scientifically useless if cloudy pixels are included.<\/p>\n<hr \/>\n<h1><span class=\"ez-toc-section\" id=\"Complete_QGIS_LST_Workflow\"><\/span>Complete QGIS LST Workflow<span class=\"ez-toc-section-end\"><\/span><\/h1>\n<p>For a quick reference, your entire workflow is:<\/p>\n<div>\n<pre dir=\"ltr\"><code>Landsat 8\/9 Level-1\r\n        \u2193\r\nBand 10 DN\r\n        \u2193\r\nTOA Radiance\r\nL\u03bb = ML \u00d7 Qcal + AL\r\n        \u2193\r\nBrightness Temperature\r\nT = K2 \/ ln((K1\/L\u03bb) + 1)\r\n        \u2193\r\nNDVI\r\nNDVI = (B5 \u2212 B4) \/ (B5 + B4)\r\n        \u2193\r\nFractional Vegetation Cover\r\nPv = ((NDVI \u2212 NDVImin) \/\r\n      (NDVImax \u2212 NDVImin))\u00b2\r\n        \u2193\r\nLand Surface Emissivity\r\n\u03b5 = 0.004Pv + 0.986\r\n        \u2193\r\nLST\r\nLST = BT \/ [1 + (\u03bbBT\/\u03c1)ln(\u03b5)]\r\n        \u2193\r\nConvert K \u2192 \u00b0C\r\nLST\u00b0C = LSTK \u2212 273.15\r\n        \u2193\r\nLST MAP<\/code><\/pre>\n<\/div>\n<hr \/>\n<h1><span class=\"ez-toc-section\" id=\"Summary_Takeaways\"><\/span>Summary &amp; Takeaways<span class=\"ez-toc-section-end\"><\/span><\/h1>\n<p>Calculating <strong>Land Surface Temperature in QGIS using Landsat 8\/9<\/strong> is essentially a sequence of physical conversions rather than a single Raster Calculator operation.<\/p>\n<p>The five major stages are:<\/p>\n<ol start=\"1\">\n<li><strong>Convert Band 10 DN to TOA spectral radiance.<\/strong><\/li>\n<li><strong>Convert radiance to brightness temperature in Kelvin.<\/strong><\/li>\n<li><strong>Calculate NDVI and fractional vegetation cover.<\/strong><\/li>\n<li><strong>Estimate surface emissivity.<\/strong><\/li>\n<li><strong>Apply the emissivity correction to obtain LST and convert it to Celsius.<\/strong><\/li>\n<\/ol>\n<p>The most important formulas to remember are:<\/p>\n<div>\n<pre dir=\"ltr\"><code>L\u03bb = ML \u00d7 Qcal + AL<\/code><\/pre>\n<\/div>\n<div>\n<pre dir=\"ltr\"><code>BT = K2 \/ ln((K1 \/ L\u03bb) + 1)<\/code><\/pre>\n<\/div>\n<div>\n<pre dir=\"ltr\"><code>NDVI = (B5 \u2212 B4) \/ (B5 + B4)<\/code><\/pre>\n<\/div>\n<div>\n<pre dir=\"ltr\"><code>Pv = ((NDVI \u2212 NDVImin) \/\r\n      (NDVImax \u2212 NDVImin))\u00b2<\/code><\/pre>\n<\/div>\n<div>\n<pre dir=\"ltr\"><code>\u03b5 = 0.004Pv + 0.986<\/code><\/pre>\n<\/div>\n<div>\n<pre dir=\"ltr\"><code>LST(K) = BT \/\r\n         [1 + (\u03bb \u00d7 BT \/ \u03c1) \u00d7 ln(\u03b5)]<\/code><\/pre>\n<\/div>\n<div>\n<pre dir=\"ltr\"><code>LST(\u00b0C) = LST(K) \u2212 273.15<\/code><\/pre>\n<\/div>\n<p>The key lesson is that <strong>Band 10 does not directly give you LST<\/strong>. You must account for radiometric scaling, brightness temperature, and surface emissivity before interpreting the result as land surface temperature.<\/p>\n<p>For university GIS and remote-sensing assignments, always document your <strong>Landsat product, acquisition date, metadata coefficients, NDVI range, emissivity method, wavelength, spatial resolution, cloud masking method, and final LST formula<\/strong>. That makes your workflow reproducible and much easier to defend in a methodology section. <a href=\"https:\/\/www.usgs.gov\/landsat-missions\/using-usgs-landsat-level-1-data-product?utm_source=chatgpt.com\" target=\"_blank\" rel=\"noopener\">USGS<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Land Surface Temperature (LST) Calculation in QGIS using Landsat 8\/9 Introduction When calculating Land Surface Temperature QGIS Landsat datasets, remember that LST is the temperature of the Earth&#8217;s surface as measured by a thermal remote-sensing sensor. Unlike air temperature measured by a weather station, LST describes the temperature of the land surface itself\u2014for example, a &#8230; <a title=\"Land Surface Temperature (LST) Calculation in QGIS using Landsat 8\/9\" class=\"read-more\" href=\"https:\/\/helpwithmygisassignment.com\/blog\/land-surface-temperature-qgis-landsat\/\" aria-label=\"Read more about Land Surface Temperature (LST) Calculation in QGIS using Landsat 8\/9\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":1074,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-866","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-gis-articles"],"_links":{"self":[{"href":"https:\/\/helpwithmygisassignment.com\/blog\/wp-json\/wp\/v2\/posts\/866","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/helpwithmygisassignment.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/helpwithmygisassignment.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/helpwithmygisassignment.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/helpwithmygisassignment.com\/blog\/wp-json\/wp\/v2\/comments?post=866"}],"version-history":[{"count":3,"href":"https:\/\/helpwithmygisassignment.com\/blog\/wp-json\/wp\/v2\/posts\/866\/revisions"}],"predecessor-version":[{"id":1075,"href":"https:\/\/helpwithmygisassignment.com\/blog\/wp-json\/wp\/v2\/posts\/866\/revisions\/1075"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/helpwithmygisassignment.com\/blog\/wp-json\/wp\/v2\/media\/1074"}],"wp:attachment":[{"href":"https:\/\/helpwithmygisassignment.com\/blog\/wp-json\/wp\/v2\/media?parent=866"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/helpwithmygisassignment.com\/blog\/wp-json\/wp\/v2\/categories?post=866"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/helpwithmygisassignment.com\/blog\/wp-json\/wp\/v2\/tags?post=866"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}