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lbaops:lbajun2013:v490a [2005/04/07 08:23]
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lbaops:lbajun2013:v490a [2015/12/18 16:38] (current)
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 ===== Comments: ===== ===== Comments: =====
 +IMPORTANT: Please make sure you have version 2.0 of the vex file, this was updated late on 12 June
  
-At Cd Ho Mp PaDual frequency setup requiredWill need special ​DAS setup+Due to popular demand V490 has copied the basic strategy used for the V255 series of methanol maser astrometry experiments. ​ There are two different frequency setups, the "​ICRF"​ observations to calibrate the tropospheric delay has 2 IFs with different polarizations. ​ The second setup (the one used for the majority of the time) has a single IF with dual polarisation. ​ The times for the setup (mode) changes are given above. 
 + 
 +The purpose of these observations is to obtain the first epoch for proper motion observations of water masers in the SMC and LMC. 
 + 
 +===== Observing comments for each antenna===== 
 + 
 +==== Hobart, Ceduna :  ==== 
 + 
 +The 4 x 16 MHz bandpass setup requires feeding two separate LOs into IFP#1 and #2 on the DAS/frequency ​translator. ​ For both Hobart and Ceduna the LOs should be set to 706 MHz (IFP#1) and 206 MHz (IFP#2) for the 4 x 16 MHz setup and 495 MHz for the 2 x 16 MHz setup. ​ For Hobart use 16.37 GHz as the Agilent frequency and for Ceduna use 17.47 GHz.  For the 4x16 MHz setup 880.2 and 900.2 MHz should give coherence in IF#1 and IF#2 respectively,​ while for the 2x16 MHz use 888.64 MHz to check coherence. 
 + 
 +The level into IF#2 will change significantly between the two setups. ​ Set the level into the DAS so that it is within range for both setups. ​ Setup the system temperature measurement so that it works for both IFs for the v490a.1cm ​setup - it doesn'​t matter if the system temperature measurement doesn'​t work for the second IF during the ICRF observations as these are only to calibrate the delay. ​ Please don't change the attenuation into the DAS when the setup changes as that may change the delay. ​  
 + 
 +==== Parkes, ATCA, Mopra :  ==== 
 + 
 +For the ATCA please phase-up antennas CA01 through CA04 for this experiment. ​ I have put specific "​phase-up"​ calibrators for the ATCA in every 30 minutes or so, these are the sources 2353-686 and 0530-727. ​ Both should be around 1 Jy at 22 GHz.  Because this is a phase referencing experiment we are going to calibrators every 2 minutes. ​ The calibrators are all from the Petrov database, but they aren't in the ATCA calibrator database so their 22 GHz flux density isn't known. ​ If the following sources could be checked (during this experiment) to see if they are suitable for phasing the array, that would be much appreciated : 0110-733, 0054-713, 0456-691, 0456-703, 0442-684, 0511-681, 0518-696, 0515-674, 0526-678, 0601-706, 0534-723.  
 + 
 +Setup as for a 2p-4IF experiment (dual DAS with huygens cable for entire experiment) with DAS1 tuned to the lower frequency and DAS2 to the upper frequency. Use the feature in cdisko version 4 to automate the changes of channel selection as per the following table. 
 + 
 +| v490a.1cm | Channels 5-8 | 
 +| v490a.1cm-icrf | Channels 1,2,7,8 | 
 + 
 +==== Hart :  ==== 
 + 
 +Needs manual editting of the vex file to cope with the ICRF mode.   
 + 
 +Hart is involved for the majority of the experiment (UT times ) 1830 - 1925 : Calibration observations ; 0000 - 0150 : SMC masers and atmospheric calibration ; 0241 - 0310 : SMC masers ; 0425 - 0754 : LMC masers and atmospheric calibration
  
 ===== Observing comments for each antenna: ===== ===== Observing comments for each antenna: =====
lbaops/lbajun2013/v490a.txt · Last modified: 2015/12/18 16:38 (external edit)