30-meter resolution Harmonized Landsat and Sentinel-2 (HLS) imagery has been available in Worldview since 2021 as two Nadir Bidirectional Reflectance Distribution Function (BRDF)-Adjusted Reflectance layers: one from the Operational Land Imager (OLI) aboard the Landsat 8 and Landsat 9 platforms, and the other from the Multi-Spectral Instrument (MSI) aboard the ESA (European Space Agency) Sentinel-2A, Sentinel-2B, and Sentinel-2C platforms.
Due to the high spatial resolution of the imagery, the swath width is narrower and the temporal resolution is lower for OLI and MSI than for the Moderate Resolution Imaging Spectroradiometer (MODIS) or the Visible Infrared Imaging Radiometer Suite (VIIRS). (See the Worldview HLS tour story to learn more.) As a result, there won’t be daily, high-resolution images across the globe, and you might not find an image for the area you are looking at on that particular day.
This is where Worldview’s new “Available Imagery Dates” option comes into play: If you are zoomed into a particular part of the world and would like to see when HLS imagery is available, you can open the “Options” panel and select a date from the “Available Imagery Dates” list. This will allow you to find dates that have imagery for that area of interest.
Try it by following the steps below:
- Open Worldview
- Zoom into your area of interest
- Click on the red “+ Add Layers” button in the lower left corner of the Layer List
- Type in “HLS” in the Search box or click on the “Featured” tab and select “Land Surface Reflectance | Harmonized Landsat Sentinel-2”
- Add Reflectance (Nadir BRDF-Adjusted)” for “Landsat 8 & 9/OLI” and “Sentinel-2/MSI”
- Close the Layer Picker by clicking on the “X” in the upper right corner of the window
- See that the two reflectance layers are greyed out and have a circle with a diagonal line through it, indicating that there is no imagery for the current day. If you hover over the blue exclamation mark additional notifications are provided
- Click on the “View Options” button on the right side of each Reflectance layer
- The Option panel opens to the right of the Layer List and shows a list of “Available Imagery Dates”
- Select one of the dates listed
- See HLS imagery appear on the map for that specific layer
This feature is especially useful if you are zoomed into a location on the map and aren’t able to visualize HLS imagery. Using the “Available Imagery Dates” option, you will find imagery that covers at least 80% of the map view.
View the video below for a demonstration of this new feature.