Aeolus tests new mirror thermal control setting

07 Jul 2020

ALADIN telescope inspection
Inspection of ALADIN telescope mirror

Aeolus telescope temperatures vary along its orbit. Last year, experts from the Aeolus Data Innovation and Science Cluster (Aeolus DISC) and ESA discovered that the satellite's wind data were affected by changes in the main mirror radial thermal gradients when compared against European Centre for Medium-Range Weather Forecasts (ECMWF) model winds. A ground processing scheme was successfully developed to correct the observed wind biases by using the information from thermal sensors in the housekeeping telemetry. The correction was implemented before Aeolus data was made public on 12 May 2020.

This week, a new setting for the Aeolus thermal control of the primary mirror will be tested to investigate further potential improvements at satellite level. The thermal control uses the information regarding temperature and heater power from previous acquisitions to determine the heating power needed with a time step of one second. The Aeolus primary mirror has six heater lines that will be changed to the new setting this week. The test will show if the gradients along the telescope can be reduced as predicted by the instrument's thermal model and lead the way to further improvements.