A great day for measurements, a better day for a hike
When the team gathered for breakfast in the morning of 16 March, the skies head cleared up completely. These incredible conditions persisted throughout the entire day. Once solar measurements were started, Sébastien, Erik and Ellen went out for an extended walk. After about 45 minutes, they made it to the end of the ridge, taking some time to enjoy the remarkable views. During the whole day, the half moon was visible. The small walking party made it back to the Ridge Lab well in time for heading down to the weather station around 4:30 pm. The day had more than 11:30 hours of daylight.
Today's weather conditions were ideal for near infrared (NIR) measurements with the Bruker 125HR. Erik and Sébastien installed the CaF2 beamsplitter in the instrument and started solar measurements. Sébastien connected the pressure sensor to record surface pressure during the NIR measurements. 196 NIR measurements were taken in total.
Kristof took advantage of the sunny day and calibrated the PEARL-GBS sun-tracker. Pierre and Peter took off the dome and installed two desiccant tubes to help the dome stay frost free. Kristof spent the afternoon aligning the pickoff mirrors to get the sun shining on the webcam for active tracking.
Even though Kristof made some progress, there's more work to be done during the last few days of the intensive campaign.
Since the skies were very clear today, Ellen opted for solar measurements with PARIS-IR right after arriving at the Ridge Lab. Even though the instrument had been running during the night - which used to cause some issues previously - everything went smoothly and PARIS-IR collected data from about 9:45 am to 6:30 pm. Ellen ended up shutting the instrument down remotely after completing 56 solar measurements.
Emily made CRL measurements for 21h 50 minutes on the 15th March 2016 UTC. Snow on the hatch halted measurements between 06:16 and 09:27 UTC. Luckily, Emily was still awake at this time, and was able to take advantage of the hatch-closed time to do the second required depolarization calibration for the campaign. This involved a lamp and depolarizer. The laser power and beam shape were also assessed, and both were acceptable.
After running into some problems with the DIAL the previous day, Pierre, Emily, Peter and Ghazal found all the broken hoses and replaced them with new ones. The team investigated the laser and confirmed that all parts of it were in good shape. The chiller was re-connected to the laser and is functioning normally. The laser is running again and the system is aligned.