Overview

SkySat® imagery provides high-resolution data suitable for a wide range of mapping and analytical applications.

Product documentation describes spatial resolution and orthorectification workflows, but it does not always state positional accuracy metrics or recommended mapping scales. This article helps you interpret SkySat data for mapping purposes.

Spatial resolution vs positional accuracy

It is important to distinguish between two measures:

• Ground Sample Distance (GSD): the size of one pixel on the ground. For SkySat, this is about 0.5 – 0.6 meters.
• Geometric or positional accuracy: how accurately features are located in real-world coordinates, expressed as CE90 or RMSE.

High spatial resolution does not automatically imply high absolute positional accuracy.

SkySat geometric accuracy

SkySat orthorectified products typically achieve:

• RMSE: less than 10 meters.
• CE90: 10 – 15 meters.

These values represent absolute horizontal accuracy for standard orthorectified imagery. Accuracy can improve when:

• Ground Control Points (GCPs) are applied.
• Higher-quality elevation models are used.
• Additional co-registration is performed.

Orthorectification workflow

SkySat imagery is processed to correct geometric distortions caused by terrain and sensor viewing geometry, using:

• Rational Polynomial Coefficients (RPCs).
• Digital Elevation Models (DEMs).

This process produces map-projected, analysis-ready imagery, though residual positional error can remain depending on conditions.

Recommended mapping scales

Because official mapping scale recommendations are not explicitly defined, you can apply standard cartographic practice based on positional accuracy. Using a conservative approach:

• About 10 – 15 meters CE90 is suitable for mapping scales of approximately 1:25,000 to 1:50,000.

In practice:

• Features are visually detailed at sub-meter resolution.
• Absolute positioning supports medium-scale mapping applications.