A Vicarious Technique for Understanding and Diagnosing Hyperspectral Spatial Misregistration

Area of Science:

• Remote Sensing
• Optical Engineering
• Spectroscopy

Background:

• Pushbroom hyperspectral imaging (HSI) systems capture spectral data for each pixel.
• Spatial misregistration affects spectral integrity and requires accurate characterization.
• Existing laboratory tests do not account for real-world airborne platform conditions.

Purpose of the Study:

• To develop and demonstrate a novel vicarious technique for field-based HSI performance testing.
• To bridge the gap between laboratory and field testing of HSI systems.
• To focus on extracting and understanding hyperspectral spatial misregistration.

Main Methods:

• Utilized convex mirrors for a novel vicarious testing technique.
• Developed a fast and simple extraction method for Point Spread Function (PSF) width and keystone.
• Assessed off-axis spatial misregistration and compared it with on-axis behavior.
• Exploited ortho-rectification errors using convex mirrors for fixed pushbroom HSI systems.

Main Results:

• The convex mirror technique effectively measures hyperspectral spatial misregistration in field conditions.
• Identified key contributors to spatial misregistration as a function of wavelength.
• Demonstrated that off-axis performance can be assessed and compared to on-axis.
• Showcased the utility of convex mirrors for analyzing ortho-rectification errors.

Conclusions:

• The proposed vicarious technique offers a practical solution for field-based HSI system characterization.
• This method is applicable to various airborne and satellite-based HSI systems, including UAVs.
• Accurate spatial misregistration assessment is crucial for maintaining spectral integrity in HSI data.