the AUM experiments are designed to investigate and hopefully demonstrate the compatibility of the new wideband VGOS receiver with the existing S/X system. This is important for maintaining a global geodetic network during the transition to a fully global VGOS array.

The Hobart12 antenna now has a functional wideband system, with reasonable sensitivities. The initial observations of the AUM series will be made using the “VGOS”-mode DBBC3 software, recording channels with an (excessive) bandwidth of 32 MHz which will be dealt with in the correlation stage. If the current issues with the DBBC3 and its “Legacy”-mode software are resolved, we sill change over to use this instead, so the instructions may be updated - please check the page carefully each time you are starting or monitoring an AUM experiment.

The major differences for observing an AUM experiment rather than a standard S/X experiment are that there is no FS support for the hardware and that we need to run two DBBCs simultaneously to record the S- and X-band data. The recorder has also changed from the mark5B to a flexbuff which operates in a very different fashion. Preliminary scripts have been written to monitor the relevant parameters but again, these are likely to be changed and improved as needed.

Taking the existing e-remote control checklists as a template, here is a listing of the significant differences.

• Preparing the schedule file: Do not use the existing slogit scripts, but instead download the skd file directly to pcfshb and run drudg to generate the prc, snp and sum files and put them where they're needed.

cd /usr2/sched
wget ftp://cddis.gsfc.nasa.gov/vlbi/ivsdata/aux/2018/aum001/aum001.skd
drudg aum001.skd
   hb
   12
   3
   5
   0
scp /tmp/sched.tmp observer@ops-serv2:/vlbobs/ivs/logs/aum001hb.sum

  
  The next step is to convert the existing snp file into one which will control the flexbuff recordings appropriately. This is done via a script at present - please use the following commands <code>cp aum001hb.snp aum001hb.orig.snp

/usr2/sched/snp2flexbuff.sh aum001hb.orig.snp aum001hb.snp hb<\code>