Research on Geometric Calibration of Spaceborne Linear Array Whiskbroom Camera

Area of Science:

• Earth Observation
• Remote Sensing Technology
• Geospatial Calibration

Background:

• Accurate geographic coordinates are crucial for land surface temperature (LST) retrieval using spaceborne thermal-infrared cameras.
• High spatial resolution and wide coverage are desired for effective Earth imaging.
• Linear array whiskbroom Charge-Coupled Device (CCD) arrays enable broad-area imaging with high resolution.

Purpose of the Study:

• To propose a novel geometric model for spaceborne linear-array-scanning imaging.
• To calibrate temporal system and whiskbroom angle parameters for improved accuracy.
• To enhance the geometric accuracy of thermal-infrared imagery for LST retrieval.

Main Methods:

• Development of a spaceborne linear-array-scanning imaging geometric model.
• Focus on whiskbroom characteristics: equal time intervals and unequal angles.
• Calibration of temporal system and whiskbroom angle parameters.

Main Results:

• Experimental calibration and verification using China's YG-14 satellite.
• Achieved plane positioning accuracy better than 30 pixels without ground control points (GCPs).
• Achieved plane positioning accuracy better than 1 pixel with GCPs.

Conclusions:

• The proposed geometric model effectively calibrates spaceborne thermal-infrared cameras.
• High positioning accuracy is attainable, significantly benefiting LST retrieval.
• The model demonstrates robust performance, with or without GCPs.