I spent 15 years of my career working on very high precision opticial angle encoders that were used in satellites to provide position feedback as the camera systems did scans of their field of view. The accuracy required from these encoders was on the order of 10 arc-seconds with an update rate of 1600 Hz.

The Himawari-8 and (some of the) GOES series satellites use these encoders when capturing images.

It is very interesting for me to be able to see the full disk images and know that I helped in a small way to make them possible.

The MAC application Downlink uses these images, and the author kindly presents the sources for the images.

goes east