GLAD Landsat ARD: Global Landsat Surface Reflectance Time Series

Global Landsat Analysis Ready Data (ARD) provides a spatially and temporally consistent 16-day time series of normalized surface reflectance from 1997 to the present, operationally updated every 16 days. The dataset is created by the Global Land Analysis and Discovery Lab (GLAD) at the University of Maryland for land cover mapping and change detection. Only data from 2020 onward is available on AWS, with older data accessible via the UMD API.

Use Cases

• Land cover classification and mapping based on consistent surface reflectance time series.
• Detecting land use and land cover change over time based on the 16-day operational updates.
• Environmental monitoring and analysis based on globally consistent, tiled Landsat data.
• Developing machine learning models for satellite image analysis based on normalized reflectance values.

Strengths

• Provides a consistent 16-day time series from 1997 to the present.
• Operationally updated every 16 days, offering near-real-time data.
• Data is normalized for surface reflectance, enhancing comparability across time and space.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Only data from 2020 onward is available on AWS; accessing older data requires a separate API.
• Last update date is unknown; freshness unverified.

Provenance

Source

Global Land Analysis and Discovery Lab (GLAD) at the University of Maryland.

Collection Method

Processed Landsat satellite imagery.

Time Range

1997 to present.

Freshness

Operationally updated every 16 days.

Geography

Global.