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lbaops:lbafeb2009:vx014batlog [2009/02/25 21:54]
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lbaops:lbafeb2009:vx014batlog [2015/12/18 16:38] (current)
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 In summary - I reckon we have shown that we can use CACAL to tie the array. No surprise there. It has shown that we can keep all 5 antennae in line to better than 20 degrees most of the time and better than 60 all of the time (in this run). We saw that the phases would be wildly different changing from point to point across the sky, so I have no doubt that every major slew will require a recal of the array. In VT11L we showed that there was no detectable effect of running CACAL on the antennae phases. We also saw that the valid solutions are carried over from scan to scan, which is good for phase referencing,​ but bad for wide slews across the sky. This could be changed. In summary - I reckon we have shown that we can use CACAL to tie the array. No surprise there. It has shown that we can keep all 5 antennae in line to better than 20 degrees most of the time and better than 60 all of the time (in this run). We saw that the phases would be wildly different changing from point to point across the sky, so I have no doubt that every major slew will require a recal of the array. In VT11L we showed that there was no detectable effect of running CACAL on the antennae phases. We also saw that the valid solutions are carried over from scan to scan, which is good for phase referencing,​ but bad for wide slews across the sky. This could be changed.
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 +Comments on the processing: ​
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 +Running CACAL all the time can produce this error
 +      -  Fatal Error: ​ Buffer overflow in cacalTyp
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 +Long slews can (must) introduce different phases for the different antennae. (Would you calibrate from 1934 to observe 0823?)
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 +The phases are corrected with in the minute. Sometimes in two steps as residual solutions from the previous observations are used (even though it is a long way away on the sky). Comparing this data to that of V255D/E (which did not use continuous cacal) one sees that in this data set the sources are noiser, but all the antennae would have phased up fine. Phases differ by less than 20^o. This is presuambly because CACAL was run on a nearby source (1934 and 1757?). There is no ca06 in this data, so they are all reasonable close. The weather was good. This will not always be the case. 
  
  
lbaops/lbafeb2009/vx014batlog.txt · Last modified: 2015/12/18 16:38 (external edit)