Spatial resolution

The spatial resolution of an optical collection or a DEM is the smallest possible pixel size that can be obtained by its sensor. The higher the spatial resolution of a given collection is, the more pixels there are per unit area, and the more detailed ground objects are.

50 cm resolution

1.50 m resolution

10 m resolution

The spatial resolution is defined by the sensor specifications without considering the location of the object being imaged. The ground sampling distance (GSD) is the effective resolution with different constraints taken into consideration:

• Geometric constraints, that is, the geometry of the object being imaged.
• Mechanical constraints of the vehicle carrying the sensor — for example, its speed and altitude.

For geospatial images, the most important factors are vehicle speed, the curvature of the Earth, and the viewing angle.

As a result, the GSD only matches the spatial resolution at latitudes around the equator and at a 0° off-nadir viewing angle. For any other latitudes and viewing angles, the GSD will be greater than the spatial resolution. For example, there might be a 2.60 m GSD for a collection with a 1.50 m spatial resolution.

You can check the GSD of your asset as follows:

1. Open the console and go to  Data management → Map → STAC items.
2. To search for STAC items only in your workspace, click in the search bar and select My workspace. Otherwise, stay in My account. If needed, use the search bar to find STAC items with specific parameters.
3. Access the STAC item by clicking on it.
4. In the opened sidebar, expand the STAC asset and check the Ground sampling distance field.