ATNF VLBI Wiki

Setup v490a.1cm-icrf:

Setup v490a.1cm:

Mode changes:
164 18:30:00 v490a.1cm
164 18:40:00 v490a.1cm-icrf
164 19:25:00 v490a.1cm
165 01:10:00 v490a.1cm-icrf
165 01:50:00 v490a.1cm
165 07:15:00 v490a.1cm-icrf

Ftp: ftp://ftp.atnf.csiro.au/pub/people/vlbi/v490/v490a

IMPORTANT: Please make sure you have version 2.0 of the vex file, this was updated late on 12 June

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 ò??ICRFò?? 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.

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 4×16 MHz setup 880.2 and 900.2 MHz should give coherence in IF#1 and IF#2 respectively, while for the 2×16 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.

For the ATCA please phase-up antennas CA01 through CA04 for this experiment. I have put specific ò??phase-upò?? 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.

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

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Parkes onsource flagging
ATCA onsource flagging
Mopra onsource flagging
Mopra Tsys (plot)
Parkes Tsys

ATCA Weather
Mopra Weather
Parkes Weather

Mopra Tsys
Parkes Tsys
ATCA Tsys