Visualizing Landsat Data in ArcGIS Pro

Of the hundreds of remote-sensing satellites launched in the past half century, the Landsat program has proved especially valuable for civilian use.

This tutorial will cover the basic visualization of Landsat data in ArcGIS Pro.

Landsat

Landsat 1 was launched on 23 July 1972 and subsequent satellites have provided continuous satellite imagery of the Earth. This is arguably one of the most important scientific enterprises of our time, and if you work with remote sensing, you will probably use Landsat data on multiple occasions.

Landsat 8 (launched 11 February 2013) and Landsat 9 (launched 27 September 2021) are currently operational (NASA 2022).

Figure
Landsat VII (NASA 1999)

Temporal Resolution

Each Landsat satellite covers the entire earth every 16 days, and since the two satellites (Landsat 8 and 9) are eight days out of phase, this gives Landsat data a temporal resolution of eight days. Each Landsat satellites completes just over 14 orbits a day in a near-polar, sun-synchronous orbit so they spend as much time as possible looking at areas of the earth lit by the sun.

Figure
Landsat Orbit Coverage (NASA 2011)

Landsat data is publicly available as scenes (images) that cover an area around 100 miles square. Scenes are designated by a path number (scanning path west to east) and row number (scene location on the path south to north).

The scene below was acquired from Landsat 8 on 10 November 2015. It is path 34, row 32, covering North Central Colorado with Denver in the lower right-hand corner.

Figure
Landsat Image of Denver, 10 November 2015 (USGS)

One issue with Landsat is that since it only passes over an area every 16 days, if there happen to be clouds on that day, the ground may be totally or partially obscured and the next availble data will not be for 16 more days. Therefore, depending on the climate in your particular area of interest, you may need to plan for missing data when you plan your research.

Figure
Cloudy Landsat Image of Denver, 24 May 2020 (NASA)

Spectral Resolution

Landsat 8 and 9 capture data in 11 different bands, giving Landsat 8 and 9 a spectral resolution that includes visible light, near-infrared, short wave infrared, and thermal infrared bands (USGS 2017).

The diagram below shows the relationship of Landsat bands 1 - 9 to the visible light spectrum. Bands 10 and 11 captured by the Thermal Infrared Sensor (TIRS) are much lower frequencies and are not shown.

Figure
Landsat Bands

Spatial Resolution

Landsat 8 and 9 spatial resolution is 30 meters for most bands, except for 15 meter resolution with panchromatic (grayscale) band 8 and 100 meter resolution with thermal infrared sensor bands 10 and 11 (USGS 2017).

Figure
Landsat Pixels: Downtown Chicago, IL, 5 July 2020

Landsat data is available in three different levels (USGS 2020).

Downloading Landsat Data

The USGS makes recent and historic Landsat data freely available via the EarthExplorer website.

In order to download data, you need to register (for free). Click the Login button and select Create New Account.

Registering On USGS Earth Explorer

Once you have registered, you can log in and download scenes.

  1. Log in.
  2. Search for a location that you want to explore (Champaign, IL).
  3. For the data set, use:
  4. View scene footprints that are in the time frame of interest, that cover your area of interest, and are not covered in clouds. Be aware that for vegetation analysis, summer scenes are better.
  5. Click Download and you will be given multiple options. Download the Full-Resolution Browse (Natural Color) GeoTIFF.
  6. Select Product Options for the Landsat Collection 2 Level-1 Product Bundle and download the following:
  7. Finding and Downloading Landsat Data from Earth Explorer

    Natural Color Images

    USGS publishes preprocessed color scene images that can be downloaded directly without having to combined band files or perform additional correction. These are the Full-Resolution Browse (Natural Color) GeoTIFF option on the download dialog in EarthExplorer.

    Landsat Natural Color scenes are actually false-color images constructed with the infrared and red bands, but they often provide a clearer view of a scene and require much less work to use than images created from the red, green, and blue band files (USGS 2020).

    1. Create a new map and give it a meaningful name.
    2. Add Data with the natural color TIFF file (T1_refl.tif).
    3. Loading may take a few seconds. If asked to Build Pyramids, click OK.
    4. If you zoom in closely you can see the individual square pixels. To smooth out the edges, in the Raster Layer ribbon, change the Rendering and Resampling Type to Bilinear or Cubic.
    5. Also in the Raster Layer ribbon, change the Layer Blend to Multiply. This will use the image to color the base map, while keeping the labels and feature outlines from the base map visible.
    6. Create a layout and export as needed.
    Visualizing a natural color GeoTIFF

    Visualizing Composite RGB Images

    Composite RGB images combine red, green, and blue bands of visible light to show the scenes more closely to the way they would appear if you were viewing the earth from space. You can use the individual red (band 4), green (band 3), and blue (band 2) files from the Level-1 GeoTIFF Data Product data.

    1. Create a new map and give it a meaningful name (RGB Map).
    2. In the Analysis ribbon, click Tools open the Composite Bands tool. This will combine the different file bands into a single layer.
    3. Add your three color bands as Input Rasters. Add B4 (red), then B3 (green), and finally B2 (blue) in that order so the software knows which band is which.
    4. Give the Output Raster a meaningful name (RGB_Composite).
    5. After 30 seconds or so, the composite raster should be added to the map as a color image.
    6. In the Raster Layer ribbon, change the Layer Blend to Multiply. This will use the image to color the base map, while keeping the labels and feature outlines from the base map visible.
    7. Create a map layout and export, if needed.
    Creating and visualizing a composite RGB layer

    Normalized Difference Vegetation Index

    Bands other than visible light are useful for analyzing a variety of phenomena. For example, biogeographers commonly use a combination of red and near-infrared bands called normalized difference vegetation index (NDVI) to determine levels of vegetation in a particular area.

    NDVI is based on a characteristic that photosynthetic green plants tend to reflect infrared light to avoid overheating, but absorb red light to power the process of photosynthesis.

    Figure
    Normalized Difference Vegetation Index

    The range of the index is negative one to positive one.

    When near infrared is high and red is low, that is when living photosynthetic plants are reflecting infrared and absorbing red, making NDVI high and closer to one.

    1 - 0
    ----- = 1
    1 + 0
    

    When near infrared is low and red is high, such as with bare ground or water, NDVI is low and closer to negative one.

    0 - 1
    ----- = -1
    0 + 1
    

    This phenomena can be used with the Landsat 9 near infrared band (band 5) and the red band (band 4) to calculate an index that is highest in areas with large amounts of vegetation, and lower in areas of low vegetation.

    Because NDVI creates a set of values from -1 to +1 and has no color of its own, maps of NDVI are commonly visualized with false-color that assigns different colors to ranges of values and makes areas with high and low NDVI easier to distinguish.

    1. Create a new map and give it a meaningful name (NDVI Map).
    2. Add Data with the red band (B4) and near-infrared band (B5) GeoTIFF files.
    3. Rename the layers to their colors so the names are more meaningful (B4 = Red, B5 = Infrared).
    4. In the View ribbon, click Geoprocessing open the Raster Calculator tool. This will allow you to calculate an NDVI layer from the red and near-infrared bands.
    5. In the Map Algebra Expression box, enter the formula for NDVI using the raster layer names:

      ("Infrared" - "Red") / ("Infrared" + "Red")
      
    6. Give the Output raster a meaningful name (NDVI).
    7. The layer will automatically be added to the map as a grayscale layer with lighter colors of higher NDVI values (more vegetation) and darker colors of lower NDVI values (less vegetation).
    8. Change the Symbology to false color so the areas of vegetation stand out more clearly.
    9. In the Raster Layer ribbon, change the Layer Blend to Multiply and the Resampling to Bicubic.
    10. Hide the individual band layers.
    11. Create a map layout (RGB Layout) and add the map frame.
    12. Add a legend.
    13. Add annotations if desired.
    Creating and Visualizing an NDVI Layer

    Save Your Project

    You can save your project as a Project Package to ArcGIS Online in case you need it in the future.

    Note that Landsat raster scenes are quite large, so saving the package may take a few minutes.

    If you get a message, "There is not enough space in your online account to upload the package," try selecting the "Save package to a file" option and then going into your ArcGIS Online Content web page and uploading that .ppkx file.

    Saving a Project Package