Science Technology
Science Technology
Does the USGS have APIs?
An API (Application Programming Interface) enables application programs to interact with each other and share data. The USGS has many different APIs. Some are listed on a central site . A list of popular USGS APIs includes: Earthquakes EROS Machine-to-Machine (satellite data and imagery) Geomagnetism Mineral Resources Online Spatial Data Publications Warehouse The National Map (base geospatial...
What is Landsat Next?
Landsat Next is the next planned Earth observing satellite mission collaboration between the USGS and NASA. The mission will ensure continuity of the longest space-based record of Earth’s land surface, and fundamentally transform the breadth and depth of actionable information freely available to end users. It will provide new capabilities for the next generation of Landsat users. The enhanced...
What is radiometric resolution?
Radiometric resolution relates to how much information is perceived by a satellite’s sensor. While the human eye detects color, Landsat sensors measure energy reflecting or emitted from the earth and relay that information as an image to users in varying degrees of greyscale. The higher the radiometric resolution, the more shades of grey the user sees. Landsat data are characterized by digital...
What is a Landsat satellite constellation?
Landsat 8 and Landsat 9 work as a satellite constellation. This means that these two nearly identical satellites work in tandem as a system. Each satellite circles the Earth every 16 days, with their two orbits offset by time so that every location on the planet is imaged every eight days. The satellite constellation of Landsat 8 and Landsat 9 is in a near-polar orbit on the Worldwide Reference...
Why does my Landsat Collection 2 Surface Temperature product have missing data?
Landsat Collection 2 Surface Temperature products are generated from several input data sources and atmospheric profiles. This includes NASA's Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global Emissivity Dataset (GED) . The ASTER GED dataset is created from all clear-sky pixels of ASTER scenes acquired from 2000 through 2008. While this dataset has a global spatial...
What is the LandsatLook Viewer?
Use the LandsatLook Viewer to view and access USGS Landsat satellite Collection 2 data. Use the Viewer to: Query the Landsat archive by area of interest, sensor, acquisition date, or cloud cover. Filter out cloud-contaminated pixels within a mosaic. Export images in a PNG (Portable Network Graphics) format. Generate and download a video animation time-lapse mosaic. Learn More: LandsatLook Viewer
How do I use a scale factor with Landsat Level-2 science products?
Landsat Level-2 products are written as scaled integers to allow us to convert the data from floating point to integer for delivery. In most cases these are written to a 16-bit integer, which saves disk space and provides faster download times. Each floating point pixel has an offset applied and then multiplied by a gain to bring the value into the 16-bit integer (or unsigned integer) range. These...
When do I need an Amazon Web Services (AWS) account to access Landsat data in the cloud? Is there a cost for that?
Landsat data continue to be freely available through traditional USGS tools such as EarthExplorer , but if you prefer to access the data in the cloud, an Amazon Web Services (AWS) account is required. Landsat data are available in the cloud via the AWS Oregon us-west-2 region. There is no charge for the Landsat data, but charges from the cloud vendor might apply for any storage, processing, and...
Are Landsat data in the cloud still considered to be within the public domain?
Yes. Regardless of where the USGS has stored the files, Landsat data are controlled by the USGS and considered to be an official USGS record in the public domain. Permission is not required for use. We do request that you acknowledge the USGS as the source. Learn More: USGS Copyrights and Credits statement Landsat Commercial Cloud Data Access
How do I use Quality Assessment (QA) bands that are delivered with Landsat products?
Some Landsat products include Quality Assessment (QA) bands with unsigned integers that represent bit-packed information for each pixel. Details for individual products are at: Landsat Level-1 (Collection 1 and Collection2) Landsat Level-2 Surface Reflectance Landsat Level-2 Provisional Aquatic Reflectance These files must be unpacked to a binary form to be used effectively. The bit-packed...
What updates were made in Landsat Collection 2?
Landsat Collection 2 marks the second major reprocessing event of the USGS Landsat archive. Continuing the tiered collection management structure implemented in Landsat Collection 1 , Landsat Collection 2 introduces several advancements in data processing, algorithm development, as well as data access and distribution capabilities, including: Improved per-pixel geodetic accuracy by incorporating...
What is the naming convention for Landsat Collection 2 Level-1 and Level-2 scenes?
The naming convention for Landsat Collection 2 Level-1 products remains the same as in Collection 1 . While most of Landsat Collection 2 scenes are produced to both Surface Reflectance (SR) and Surface Temperature (ST), a small number of scenes cannot be processed to ST due to missing auxiliary data. The naming convention of Landsat Collection 2 Level-2 products indicates the data included for...