SWAP and LYRA Calibration Campaign between 2021-Jun-23 03:00 UT and 2021-Jun-24 11:30 UT

We inform all PROBA2 data users that there will be no regular science data from SWAP between about 2021-Jun-23 03:00 UT and 2021-Jun-24 11:30 UT due to a special SWAP calibration campaign. LYRA data may sporadically be available during the campaign. However, we warn our users not to count on the availability of data from either of the sun-observing PROBA2 instruments during Wednesday and Thursday morning of this week.

 

After a period of occultation, the SWAP campaign will start on 2021-Jun-23 at 03:00 UT with a regular SWAP calibration at normal detector temperatures, during which the satellite will be off-pointed by 5 degrees to obtain dark current images (thus without the Sun in the frame). After this first part of the campaign, we return to regular sun-centered imaging for a short time. Starting from 10:19 UT, we will perform a so-called "bake-out" of SWAP, where the temperature of the SWAP detector will be increased to about 50 degrees (as opposed to the temperatures around -0.5 degrees that we normally get at this time of year). Once the heating is stopped (after ~23h), the spacecraft will again be off-pointed by five degrees and while the detector is cooling down, both SWAP and LYRA will measure temperature-sensitive dark current, the main source of instrumental noise. These measurements will allow us to improve the calibration of our observations. Once normal SWAP detector temperatures are again reached, the satellite will be returned to its nominal sun-centered pointing and regular SWAP imaging and LYRA measurements will recommence around 11:30 UT on 2021-Jun-24.