VEGAS Team Meeting

January 14, 2013

Attendees

CALTECH, UC-B, & Columbia

NRAO:

Meeting Notes:

VEGAS Mode Development Status:

Action Items:

1. half part of the IF band has poor SNR. why? is it fixed already? how to fix?
   • Tests on cable integrity downstream of the RF splitter will be conducted during maintenance tomorrow.
   • The Gain/TSYS slope is probably not an issue if the spectrometer can be balanced for applied power levels
2. the start up problem:
   • how often does it occur?
     • About 1 in 10 times
   • how quickly can we recover?
     • Quickly now there is code that flags of no data is being produced
   • how much observation time is lost)?
     • Not an excessive amount
   • how to fix?
3. 16 bins of the spectra have poor SNR. (an FPGA design problem).
   • does this affect timing?
     • no
   • is the problem understood?
     • need to test with test pulsar
   • do we need to fix it before observations?
     • no
4. valon locking problem.
   • Solved by a power cycle - inconsistent status between python GUI and laptop
5. what else needs to get fixed before we observe?
   • 12 second gaps
     • after 'arm' command the counter increments - the time offset from the manager shows increasing and the jumps value at ~12 seconds
       • maybe missing data
       • or FPGA code
       • Anish will circulate with actual FPGA data and count plot
       • "Show stopper" unless this is well understood previous to observation
   • Two hour+ data collection (first test tonight)
6. what tests should we do before we have enough confidence to start observing?
   • Test Pulsar
   • Known Pulsar - with gap to prove obs can be combined
   • Two hour+ data collection (first test tonight)
   • On-Off continuum obs for sensitivity

Other items: