Difference between revisions of "2019 December"

From EOVSA Wiki
Jump to: navigation, search
(Created page with "[http://www.ovsa.njit.edu/wiki/index.php/Expanded_Owens_Valley_Solar_Array#Observing_Log Back to Observing Log] == December 06 == '''12:42 UT''' We had more problems so far t...")
 
(December 06)
 
Line 3: Line 3:
 
== December 06 ==
 
== December 06 ==
 
'''12:42 UT''' We had more problems so far this month involving mainly Ant 14, perhaps exacerbated by more snow.  The X polarization on the high-frequency receiver showed a 15 dB loss of RF power, so Mark replaced the cable on Dec. 2.  However, he accidentally left a glove at the focus, which fell down into the RX Select gear mechanism, so it was stuck at some intermediate position.  The low-frequency receiver was still getting some signal, but no calibration was possible for the high-frequency receiver.  Yesterday Mark realized the problem and managed to get the receiver unstuck and working again.  Last night we finally got some reasonable calibration, which showed that a 5 ns delay difference was introduced.  I updated the delay so hopefully starting with today's data the observations will again be nominal.  Despite these problems, and the lack of a good calibration for about a week, our daily pipeline images still look pretty good!
 
'''12:42 UT''' We had more problems so far this month involving mainly Ant 14, perhaps exacerbated by more snow.  The X polarization on the high-frequency receiver showed a 15 dB loss of RF power, so Mark replaced the cable on Dec. 2.  However, he accidentally left a glove at the focus, which fell down into the RX Select gear mechanism, so it was stuck at some intermediate position.  The low-frequency receiver was still getting some signal, but no calibration was possible for the high-frequency receiver.  Yesterday Mark realized the problem and managed to get the receiver unstuck and working again.  Last night we finally got some reasonable calibration, which showed that a 5 ns delay difference was introduced.  I updated the delay so hopefully starting with today's data the observations will again be nominal.  Despite these problems, and the lack of a good calibration for about a week, our daily pipeline images still look pretty good!
 +
 +
== December 11 ==
 +
'''14:25 UT''' Just a note to say today's pipeline output, the full disk images from Dec. 9, look very good--some of the best I have seen.  These are possibly due to our finally getting a good calibration for that date.  The main remaining problem is Ant 13, whose calibration data are of very low quality except at the lowest frequencies.  I have not had time to figure out the cause.

Latest revision as of 15:28, 11 December 2019

Back to Observing Log

December 06

12:42 UT We had more problems so far this month involving mainly Ant 14, perhaps exacerbated by more snow. The X polarization on the high-frequency receiver showed a 15 dB loss of RF power, so Mark replaced the cable on Dec. 2. However, he accidentally left a glove at the focus, which fell down into the RX Select gear mechanism, so it was stuck at some intermediate position. The low-frequency receiver was still getting some signal, but no calibration was possible for the high-frequency receiver. Yesterday Mark realized the problem and managed to get the receiver unstuck and working again. Last night we finally got some reasonable calibration, which showed that a 5 ns delay difference was introduced. I updated the delay so hopefully starting with today's data the observations will again be nominal. Despite these problems, and the lack of a good calibration for about a week, our daily pipeline images still look pretty good!

December 11

14:25 UT Just a note to say today's pipeline output, the full disk images from Dec. 9, look very good--some of the best I have seen. These are possibly due to our finally getting a good calibration for that date. The main remaining problem is Ant 13, whose calibration data are of very low quality except at the lowest frequencies. I have not had time to figure out the cause.