Auroral imaging from a spinning satellite.

Area of Science:

• Space physics
• Satellite instrumentation
• Optical imaging

Background:

• Optimizing in situ particle and field measurements requires spinning auroral research satellites.
• Simultaneous optical aurora imaging from spinning satellites necessitates complex, expensive stable platforms or camera derotation.
• Existing solutions often suffer from image blur due to spin axis misalignments.

Purpose of the Study:

• To propose a novel, cost-effective solution for simultaneous optical aurora imaging from spinning satellites.
• To overcome the challenges of stable platforms and camera derotation.
• To correct for image blur caused by satellite spin axis misalignments.

Main Methods:

• A despinning flat 45° mirror directs the camera's field of view toward the spacecraft nadir.
• Cameras are mounted parallel to the satellite's spin axis.
• A real-time derotation algorithm using lookup tables and integer additions corrects for image rotation and axis misalignment.

Main Results:

• The proposed system was simulated, including a 1.8° spin axis misalignment.
• The derotation algorithm successfully despun images and corrected for axis misalignment.
• Full-resolution, continuous auroral observation was achieved.

Conclusions:

• The novel mirror and derotation algorithm system offers a viable solution for optical aurora imaging from spinning satellites.
• This approach is cost-effective and overcomes limitations of previous methods.
• The system enables high-resolution, continuous auroral observation, enhancing in situ measurements.