SDO Day 58: Rolls are Complete
Our initial Science Reference Boresight was defined Friday. This is the target for the fine-guidance system in science mode, or it is the imaginary line that leaves SDO and hits the center of the Sun. All of the instruments can then figure out where they are pointed with very high accuracy.
SDO completed several calibration maneuvers this week, with more coming in next 10 days. Last nite the HMI/AIA roll was done. While SDO spins slowly around the axis pointing toward the Sun the instruments take measurements at different clock angles to check out their optics. We also tried stepping the high-gain antennas separately rather than together to see if the jitter was different.
The misbehaving high-powered amplifier on the SDO2 antenna was replaced and SDO2 is being brought back into full service.
We have left the vernal equinox eclipse season and look forward to almost 5 months of uninterrupted solar measurements.