ATNF VLBI Wiki

v490c

Description	Measuring the proper motions of the Large and Small Magellanic Clouds
Antennas	At-Cd-Ho-Mp-Pa-Hh
Start	263 10:00:00
Stop	263 23:59:44
PI	S.P. Ellingsen

Setup v490c.1cm:

Station Modes	At Cd Ho Mp Pa
Channel 1	`IFP#1-LO 22211 - 22227 MHz USB RCP`
Channel 2	`IFP#1-HI 22227 - 22243 MHz USB RCP`
Channel 3	`IFP#2-LO 22211 - 22227 MHz USB LCP`
Channel 4	`IFP#2-HI 22227 - 22243 MHz USB LCP`
DAS 1 Skyfreq	22227 MHz
Bandwidth	16 MHz
DAS Mode	vsop.pro (telescope)

Station Modes	Hh
Channel 1	`22211 - 22227 MHz USB RCP`
Channel 2	`22211 - 22227 MHz USB LCP`
Channel 3	`22227 - 22243 MHz USB RCP`
Channel 4	`22227 - 22243 MHz USB LCP`
Bandwidth	16 MHz
DAS Mode	Mark5

Setup v490c.1cm-icrf:

Station Modes	At Cd Ho Mp Pa
Channel 1	`IFP#1-LO 22000 - 22016 MHz USB RCP`
Channel 2	`IFP#1-HI 22016 - 22032 MHz USB RCP`
Channel 3	`IFP#2-LO 22500 - 22516 MHz USB LCP`
Channel 4	`IFP#2-HI 22516 - 22532 MHz USB LCP`
DAS 1 Skyfreq	22016 & 22516 MHz
Bandwidth	16 MHz
DAS Mode	vsop.pro (telescope)

Station Modes	Hh
Channel 1	`22000 - 22016 MHz USB RCP`
Channel 2	`22016 - 22032 MHz USB RCP`
Channel 3	`22500 - 22516 MHz USB LCP`
Channel 4	`22516 - 22532 MHz USB LCP`
Bandwidth	16 MHz
DAS Mode	Mark5

Mode changes:
263 10:00:00 v490c.1cm
263 10:08:00 v490c.1cm-icrf
263 10:58:30 v490c.1cm
263 14:29:00 v490c.1cm-icrf
263 15:12:48 v490c.1cm
263 18:45:00 v490c.1cm-icrf
263 19:29:55 v490c.1cm
263 23:00:25 v490c.1cm-icrf
263 23:06:05 v490c.1cm
263 23:22:05 v490c.1cm-icrf

Ftp: ftp://ftp.atnf.csiro.au/pub/people/vlbi/v490/v490c

Comments:

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 third 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 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 (these tones apply for both Hobart and Ceduna).

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 v490c.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 CA05 for this experiment. The sources 0100-760, 0601-706 and 0530-727 should all be suitable for phasing the array (in addition to the fringe finder sources) and have been marked with the AUTOPHASE_DETERMINE intent in the vex file.

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. Record using the following channel ranges.

v490c.1cm	Channels 5-8
v490c.1cm-icrf	Channels 1,2,7,8

cdisko should make these changes automatically but it should be monitored carefully.

The information below for Parkes has been copied from the v490b experiment and may need to be updated.

Parkes LO can be controlled using the “losched” command. It assume the initial setup has been made usign a normal lo_setup file. Run if as pksobs on joffrey: