ATNF VLBI Wiki

VLBA sched does not “know” about the LBADR recorder. PIs have to schedule as if an S2 recorder was being used, which only allows 2 frequency channels. As such the schedule vexfile (.skd) has to be hand edited to add the extra channels. A further complication is Hobart, Tidbinbilla and Ceduna often record only half the number of channels compared to the Parkes, Mopra and ATCA.

Assuming the PI has scheduled 2 channels, dual polarization the only changed is needed in the $FREQ section. For example from:

def 8409.00MHz2x16MHz; * mode = 1 stations =Pa:At:Mp:Ho:Cd

   sample_rate = 32.000 Ms/sec;  * (2bits/sample)
   chan_def = :  8409.00 MHz : U :16.000 MHz : &CH01 : &BBC01 : &NoCal; *Rcp
   chan_def = :  8409.00 MHz : U :16.000 MHz : &CH02 : &BBC02 : &NoCal; *Lcp

enddef;

To

def 8409.00MHz2x16MHz; * mode = 1 stations =Pa:At:Mp:Ho:Cd

   sample_rate = 32.000 Ms/sec;  * (2bits/sample)
   chan_def = :  8409.00 MHz : U :16.000 MHz : &CH01 : &BBC01 : &NoCal; *Rcp
  %color=red% chan_def = :  8425.00 MHz : U :16.000 MHz : &CH02 : &BBC01 : &NoCal; *Rcp
   chan_def = :  8409.00 MHz : U :16.000 MHz : %color=red%&CH03%color=black% : &BBC02 : &NoCal; *Lcp
   %color=red%chan_def = :  8425.00 MHz : U :16.000 MHz : &CH04 : &BBC02 : &NoCal; *Lcp

enddef;

Assuming the PI has scheduled 2 channels, dual polarization a nmber of changes are needed.

Firstly, in the $MODE section, a new section for Hobart, Ceduna and Tidbinbilla is needed. E.g.:

def lba13cm-2p-4IF;

   ref $PROCEDURES = Mode_01;
   ref $FREQ = 2226.00MHz2x16MHz:At:Mp:Pa:Ho:Cd:Ti;
   ref $IF = LO@2000MHzDPolNoTone:At:Ti;
   ref $IF = LO@1600MHzDPolNoTone:Mp:Pa;
   ref $IF = LO@1500MHzDPolNoTone:Ho:Cd;

To

def lba13cm-2p-4IF;

   ref $PROCEDURES = Mode_01;

%color=red% ref $FREQ = 2226.00MHz2x16MHz:At:Mp:Pa; %color=red% ref $FREQ = 2226.00MHz2x16MHz#2:Ho:Cd:Ti;

   ref $IF = LO@2000MHzDPolNoTone:At:Ti;
   ref $IF = LO@1600MHzDPolNoTone:Mp:Pa;
   ref $IF = LO@1500MHzDPolNoTone:Ho:Cd;

In the $FREQ section change

def 2226.00MHz2x16MHz;

• mode = 1 stations =At:Mp:Pa:Ho:Cd:Ti

sample_rate = 32.000 Ms/sec; * (2bits/sample)

   chan_def = :  2226.00 MHz : U :16.000 MHz : &CH01 : &BBC01 : &NoCal; *Rcp
   chan_def = :  2226.00 MHz : U :16.000 MHz : &CH02 : &BBC02 : &NoCal; *Lcp

enddef;

to

def 2226.00MHz2x16MHz; * mode = 1 stations =At:Mp:Pa

   sample_rate = 32.000 Ms/sec;  * (2bits/sample)
   chan_def = :  2226.00 MHz : U :16.000 MHz : &CH01 : &BBC01 : &NoCal; *Rcp

%color=red% chan_def = : 2242.00 MHz : U :16.000 MHz : &CH02 : &BBC01 : &NoCal; *Rcp

   chan_def = :  2226.00 MHz : U :16.000 MHz : %color=red%&CH03%color=black% : &BBC02 : &NoCal; *Lcp

%color=red% chan_def = : 2242.00 MHz : U :16.000 MHz : &CH04 : &BBC02 : &NoCal; *Lcp %color=red% chan_def = : 2258.00 MHz : U :16.000 MHz : &CH05 : &BBC03 : &NoCal; *Rcp %color=red% chan_def = : 2274.00 MHz : U :16.000 MHz : &CH06 : &BBC03 : &NoCal; *Rcp %color=red% chan_def = : 2258.00 MHz : U :16.000 MHz : &CH07 : &BBC04 : &NoCal; *Lcp %color=red% chan_def = : 2274.00 MHz : U :16.000 MHz : &CH08 : &BBC04 : &NoCal; *Lcp enddef;

%color=red%def 2226.00MHz2x16MHz#2; %color=red%* mode = 1 stations =At:Mp:Pa:Ho:Cd:Ti %color=red% sample_rate = 32.000 Ms/sec; * (2bits/sample) %color=red% chan_def = : 2226.00 MHz : U :16.000 MHz : &CH01 : &BBC01 : &NoCal; *Rcp %color=red% chan_def = : 2242.00 MHz : U :16.000 MHz : &CH02 : &BBC01 : &NoCal; *Rcp %color=red% chan_def = : 2226.00 MHz : U :16.000 MHz : &CH03 : &BBC02 : &NoCal; *Lcp %color=red% chan_def = : 2242.00 MHz : U :16.000 MHz : &CH04 : &BBC02 : &NoCal; *Lcp enddef;

If Hobart/Ceduna etc is recording single pol then the 4 channel $FREQ def would need to be

def 2226.00MHz2x16MHz; * mode = 1 stations =At:Mp:Pa:Ho:Cd:Ti

   sample_rate = 32.000 Ms/sec;  * (2bits/sample)
   chan_def = :  2226.00 MHz : U :16.000 MHz : &CH01 : &BBC01 : &NoCal; *Rcp
   chan_def = :  2242.00 MHz : U :16.000 MHz : &CH02 : &BBC01 : &NoCal; *Rcp
   chan_def = :  2258.00 MHz : U :16.000 MHz : &CH03 : &BBC02 : &NoCal; *Rcp
   chan_def = :  2274.00 MHz : U :16.000 MHz : &CH04 : &BBC02 : &NoCal; *Rcp

enddef;

If the new mode requires the definition of additonal BBCs then these must also be added to the $BBC block. E.g. for dual polarization, 4 IFs you need to change:

def 2BBCs; * mode = 1 stations =Pa:At:Mp

    BBC_assign = &BBC01 :  1 : &IF_2N;
    BBC_assign = &BBC02 :  2 : &IF_1N;

enddef;

to

def 2BBCs; * mode = 1 stations =Pa:At:Mp

    BBC_assign = &BBC01 :  1 : &IF_2N;
    BBC_assign = &BBC02 :  2 : &IF_1N;

%color=red% BBC_assign = &BBC03 : 3 : &IF_2N; %color=red% BBC_assign = &BBC04 : 4 : &IF_1N; enddef;

Note of Ceduna, Hobart or Tidbinbilla are recording different setups from each other (e.g. a mix of single and dual pol) extra def sections will need to be created as appropriate and $MODE second changed to reflect this.