2016 November - Revision history

Dgary at 11:12, 2 April 2017

2017-04-02T11:12:16Z

← Older revision		Revision as of 11:12, 2 April 2017
Line 1:		Line 1:
			[http://www.ovsa.njit.edu/wiki/index.php/Expanded_Owens_Valley_Solar_Array#Observing_Log Back to Observing Log]

	= Nov 04 =		= Nov 04 =
	'''19:18 UT''' Reboot ROACHes to clear fault light and test whether large delays are still present. They were power-cycled and reloaded.		'''19:18 UT''' Reboot ROACHes to clear fault light and test whether large delays are still present. They were power-cycled and reloaded.

Dgary: /* Nov 27 */

2016-11-28T02:21:39Z

Nov 27

← Older revision		Revision as of 02:21, 28 November 2016
Line 187:		Line 187:
	'''15:45 UT''' Yes! The pointing data on 3C273 are great, now. Clearly it needed the sign change in the P1 coefficient. This will work well for the purpose, so now we can proceed with getting pointing measurements over the whole sky and doing the fitting to get all of the pointing coefficients for Ant 14.		'''15:45 UT''' Yes! The pointing data on 3C273 are great, now. Clearly it needed the sign change in the P1 coefficient. This will work well for the purpose, so now we can proceed with getting pointing measurements over the whole sky and doing the fitting to get all of the pointing coefficients for Ant 14.

	'''16:40 UT''' I just completed the series of calpnt calibrations, and also wrote the analysis software to reduce it. The results are great, so are applicable to a more complete pointing calibration.		'''16:40 UT''' I just completed the series of calpnt calibrations, and also wrote the analysis software to reduce it. The results are great, so are applicable to a more complete pointing calibration. Now going to normal solar observing.

			'''21:32 UT''' The system started having a lot of trouble, restarting files, due to dropped packets, I assume, before the DPP finally crashed. I did not discover it until a few hours later, but anyway Jack wanted to test a new ROACH design, so we rebooted and did tests for while.

	= Nov 28 =		= Nov 28 =
	'''02:14 UT''' Started a repeat of the ''three-src.scd'' observation from last night, now that the wind has died down a bit. It is still right on the edge of the limit, though. This should fix the low-SNR problem we had last night.		'''02:14 UT''' Started a repeat of the ''three-src.scd'' observation from last night, now that the wind has died down a bit. It is still right on the edge of the limit, though. This should fix the low-SNR problem we had last night.

Dgary: /* Nov 27 */

2016-11-28T02:19:08Z

Nov 27

← Older revision		Revision as of 02:19, 28 November 2016
Line 186:		Line 186:

	'''15:45 UT''' Yes! The pointing data on 3C273 are great, now. Clearly it needed the sign change in the P1 coefficient. This will work well for the purpose, so now we can proceed with getting pointing measurements over the whole sky and doing the fitting to get all of the pointing coefficients for Ant 14.		'''15:45 UT''' Yes! The pointing data on 3C273 are great, now. Clearly it needed the sign change in the P1 coefficient. This will work well for the purpose, so now we can proceed with getting pointing measurements over the whole sky and doing the fitting to get all of the pointing coefficients for Ant 14.

			'''16:40 UT''' I just completed the series of calpnt calibrations, and also wrote the analysis software to reduce it. The results are great, so are applicable to a more complete pointing calibration.

	= Nov 28 =		= Nov 28 =
	'''02:14 UT''' Started a repeat of the ''three-src.scd'' observation from last night, now that the wind has died down a bit. It is still right on the edge of the limit, though. This should fix the low-SNR problem we had last night.		'''02:14 UT''' Started a repeat of the ''three-src.scd'' observation from last night, now that the wind has died down a bit. It is still right on the edge of the limit, though. This should fix the low-SNR problem we had last night.

Dgary: /* Nov 27 */

2016-11-28T02:16:14Z

Nov 27

← Older revision		Revision as of 02:16, 28 November 2016
Line 186:		Line 186:

	'''15:45 UT''' Yes! The pointing data on 3C273 are great, now. Clearly it needed the sign change in the P1 coefficient. This will work well for the purpose, so now we can proceed with getting pointing measurements over the whole sky and doing the fitting to get all of the pointing coefficients for Ant 14.		'''15:45 UT''' Yes! The pointing data on 3C273 are great, now. Clearly it needed the sign change in the P1 coefficient. This will work well for the purpose, so now we can proceed with getting pointing measurements over the whole sky and doing the fitting to get all of the pointing coefficients for Ant 14.

			= Nov 28 =
			'''02:14 UT''' Started a repeat of the ''three-src.scd'' observation from last night, now that the wind has died down a bit. It is still right on the edge of the limit, though. This should fix the low-SNR problem we had last night.

Dgary: /* Nov 26 */

2016-11-27T17:01:13Z

Nov 26

← Older revision		Revision as of 17:01, 27 November 2016
Line 172:		Line 172:
	'''13:40 UT''' I am doing an experiment. I created a new trajectory file, calpnt.trj, for off-pointing the 27-m antenna. I also created corresponding CALPNTCAL.ctl and calpnt.scd files. It does an off-pointing procedure similar to SOLPNTCAL, but spends 30 s on each spot, and of course is meant to use only a single band (e.g band14.fsq, which I am using for the test). I added P1 and P7 offsets to Ant14, so that the offsets in calpnt.trj are relative to that. One thing I can see is that the 10-min trajectory is going to start while the dish is slewing to another source, so it will miss the first couple of off-pointings. In general, though, it seems to be working!		'''13:40 UT''' I am doing an experiment. I created a new trajectory file, calpnt.trj, for off-pointing the 27-m antenna. I also created corresponding CALPNTCAL.ctl and calpnt.scd files. It does an off-pointing procedure similar to SOLPNTCAL, but spends 30 s on each spot, and of course is meant to use only a single band (e.g band14.fsq, which I am using for the test). I added P1 and P7 offsets to Ant14, so that the offsets in calpnt.trj are relative to that. One thing I can see is that the 10-min trajectory is going to start while the dish is slewing to another source, so it will miss the first couple of off-pointings. In general, though, it seems to be working!

	'''14:20 UT''' The experiment is done. It looks like it mainly worked, but I do need intermediate SLEW "scans" that can provide time for the dishes to get where they are going. I will take a look at the data and see if the SNR is high enough for these 30-s pointings. Well--there is no sign of coherence, so either something else went wrong (I could, for example, have the wrong sign for one or both of P1 and P7), or the SNR is woefully inadequate. I will check the pointing parameters later.		'''14:20 UT''' The experiment is done. It looks like it mainly worked, but I do need intermediate SLEW "scans" that can provide time for the dishes to get where they are going. '''The macro command for this purpose was later called ACQUIRE instead of SLEW.''' I will take a look at the data and see if the SNR is high enough for these 30-s pointings. Well--there is no sign of coherence, so either something else went wrong (I could, for example, have the wrong sign for one or both of P1 and P7), or the SNR is woefully inadequate. I will check the pointing parameters later.

	'''15:48 UT''' Normal solar observing begins.		'''15:48 UT''' Normal solar observing begins.

Dgary: /* Nov 27 */

2016-11-27T16:59:24Z

Nov 27

← Older revision		Revision as of 16:59, 27 November 2016
Line 177:		Line 177:

	= Nov 27 =		= Nov 27 =
	'''00:58 UT''' Started a ''three-src.scd'' schedule to observe 2136+006, 2253+161, and 0319+415, without tracking PA, and on band14 only. The pointing offsets are in P1 and P7 on Ant 14, so I will check the quality of the data after the first scan or two, to check that it is pointing well. The wind is on the edge, having been very high earlier, so I hope it dies down further.		'''00:58 UT''' Started a ''three-src.scd'' schedule to observe 2136+006, 2253+161, and 0319+415, without tracking PA, and on band14 only. The pointing offsets are in P1 and P7 on Ant 14, so I will check the quality of the data after the first scan or two, to check that it is pointing well. The wind is on the edge, having been very high earlier, so I hope it dies down further. '''NB: Later pointing indicates wrong sign on P1, so we were offpointed by 0.3 degrees => low SNR.'''

	'''01:30 UT''' I checked the phase coherence, and it looks sort of okay. The wind is causing windscrams, so I am not sure how much of the data will be good, but I'll let it keep trying.		'''01:30 UT''' I checked the phase coherence, and it looks sort of okay. The wind is causing windscrams, so I am not sure how much of the data will be good, but I'll let it keep trying.

Dgary: /* Nov 27 */

2016-11-27T15:47:45Z

Nov 27

← Older revision		Revision as of 15:47, 27 November 2016
Line 184:		Line 184:

	'''14:50 UT''' The pointing observations from last night again have low SNR, but I figured out how to sum the results from all n-14 baselines and over frequency to get a good measurement. The measurement strongly indicates that the sign of P1 is wrong, as I suspected it may be. I changed the sign of P1 for Ant 14, and am now doing equivalent pointing measurements (2 each) on 3C273 and 3C286. So far, the system works as desired, which is good.		'''14:50 UT''' The pointing observations from last night again have low SNR, but I figured out how to sum the results from all n-14 baselines and over frequency to get a good measurement. The measurement strongly indicates that the sign of P1 is wrong, as I suspected it may be. I changed the sign of P1 for Ant 14, and am now doing equivalent pointing measurements (2 each) on 3C273 and 3C286. So far, the system works as desired, which is good.

			'''15:45 UT''' Yes! The pointing data on 3C273 are great, now. Clearly it needed the sign change in the P1 coefficient. This will work well for the purpose, so now we can proceed with getting pointing measurements over the whole sky and doing the fitting to get all of the pointing coefficients for Ant 14.

Dgary: /* Nov 27 */

2016-11-27T15:26:09Z

Nov 27

← Older revision		Revision as of 15:26, 27 November 2016
Line 182:		Line 182:

	'''05:55 UT''' The observations completed, with some windscrams, but I will analyze it tomorrow. Meanwhile, I was messing with calpnt again, on 3C84, and indeed the SNR is woefully inadequate for 30-s pointings. I upped it to 90s, and removed one pointing, so it will take 25 minutes to complete. I'll also check these results tomorrow. I am doing four measurements in a row, 25-min each.		'''05:55 UT''' The observations completed, with some windscrams, but I will analyze it tomorrow. Meanwhile, I was messing with calpnt again, on 3C84, and indeed the SNR is woefully inadequate for 30-s pointings. I upped it to 90s, and removed one pointing, so it will take 25 minutes to complete. I'll also check these results tomorrow. I am doing four measurements in a row, 25-min each.

			'''14:50 UT''' The pointing observations from last night again have low SNR, but I figured out how to sum the results from all n-14 baselines and over frequency to get a good measurement. The measurement strongly indicates that the sign of P1 is wrong, as I suspected it may be. I changed the sign of P1 for Ant 14, and am now doing equivalent pointing measurements (2 each) on 3C273 and 3C286. So far, the system works as desired, which is good.

Dgary: /* Nov 27 */

2016-11-27T05:58:30Z

Nov 27

← Older revision		Revision as of 05:58, 27 November 2016
Line 180:		Line 180:

	'''01:30 UT''' I checked the phase coherence, and it looks sort of okay. The wind is causing windscrams, so I am not sure how much of the data will be good, but I'll let it keep trying.		'''01:30 UT''' I checked the phase coherence, and it looks sort of okay. The wind is causing windscrams, so I am not sure how much of the data will be good, but I'll let it keep trying.

			'''05:55 UT''' The observations completed, with some windscrams, but I will analyze it tomorrow. Meanwhile, I was messing with calpnt again, on 3C84, and indeed the SNR is woefully inadequate for 30-s pointings. I upped it to 90s, and removed one pointing, so it will take 25 minutes to complete. I'll also check these results tomorrow. I am doing four measurements in a row, 25-min each.

Dgary: /* Nov 27 */

2016-11-27T01:31:55Z

Nov 27

← Older revision		Revision as of 01:31, 27 November 2016
Line 178:		Line 178:
	= Nov 27 =		= Nov 27 =
	'''00:58 UT''' Started a ''three-src.scd'' schedule to observe 2136+006, 2253+161, and 0319+415, without tracking PA, and on band14 only. The pointing offsets are in P1 and P7 on Ant 14, so I will check the quality of the data after the first scan or two, to check that it is pointing well. The wind is on the edge, having been very high earlier, so I hope it dies down further.		'''00:58 UT''' Started a ''three-src.scd'' schedule to observe 2136+006, 2253+161, and 0319+415, without tracking PA, and on band14 only. The pointing offsets are in P1 and P7 on Ant 14, so I will check the quality of the data after the first scan or two, to check that it is pointing well. The wind is on the edge, having been very high earlier, so I hope it dies down further.

			'''01:30 UT''' I checked the phase coherence, and it looks sort of okay. The wind is causing windscrams, so I am not sure how much of the data will be good, but I'll let it keep trying.