Phase II: Issues Take home points: 1) Is it StandardInterferometry? (better to say No if you don’t know) 2) Note time increases for frequency issues (LO4/Hanning/IF Trx issues, etc, etc.) Stuartt Corder

Issues: Structure How does SB work? What are overheads? (FYI) –Details come in phase II bootcamp –Phase II explicit discussions for divisions (coming slides) –15s per (sub)scan (sequence) initiation, ~1s per subscan. –Bandpass/AmpCal is normal subscan sequence (can do N) –Tsys takes ~4*3+15 in R8.1 (4*15 in R8.0.3) General OT considerations for next Cycle: –Revise the overhead estimates (needs testing in R8.1) –Better description of limits of performance in “Standard Calibration”

Issues: Structure Scattered/clustered objects –Scattered objects work well in StandardInterferometry.py –Clustered objects not so much. –New mode for the clustered case in the work Multiple spectral specs, band switching –Need to define spectral spec phase differential calibration (in the works) –Currently extremely painful to set up in the OT (how topic for PIIBC) –New mode for multi-specspecs in the works Split executions –Nominal SB time is ~1hr ( hr): Stability considerations –Cannot share bandpass between executions –Can in principle share amplitude calibration OT considerations for next cycle –Inclusions of ‘other’ modes for auto generation of phase II (won’t need to comment on this) –Better guidelines on dividing up target lists/surveys

Issues: Extra time/bands Spectral window set ups (R8.0.3 exclusive) –TFBLO/LO4 needs different values-->two spectral specs. –Easy calculation: lines in same sideband separated by >N GHz (N=2 for bands 3 & 7, 3 at band 6, and 6 at band 9). Lines at extreme upper or lower portion of IF in opposite sidebands (closer than (1+BW/2) GHz to IF edge). –Don’t spend too much time on this. May not be a problem –“Execution may require splitting into separate spectral specs.” 5-6 GHz considerations –Band 6 has 5-10GHz IF, but if you occupy (up to 6) you can do better by pushing up. Can calculate this easily. –Split vs do at the same time…about break even. –“Note for scheduling: Double time likely”

Issues: Extra time/bands Hanning issues –If halving bandwidth, do they need two spectral specs to get it back? If so note “Spectral Spec cycle.” –If just giving them poorer velocity resolution, no comment Extra basebands: flux cal or continuum –Just note it. Extra calibration requirements: –Note calibration limits required –If calibration requires specific split, note for scheduling FDM vs TDM considerations –FDM is a pain! Slow. Tsys is more difficult. PhII discussion with PI Optimum frequencies: Advise based on frequency group discussion

Phase II: What to comment on What is StandardInterferometry.py and what does it do (and doesn’t do)? –Single science field sources (>=1 pointing) –Single spectral spec (except for pointing) –No differential calibration (in a smart way) Why is this an important consideration? –Auto generation of StandardInterferometry.py SBs is “pretty good” in R8.1.1 (saw examples yesterday) –Minor modifications needed but have time to get it done –We can use OT even in R8.0.3 (data model is same) When StandardInteferometry.py is okay: –Single science field sources –Long executions for sensitivity considerations of multiple sources or multiple spectral specs –Multiple sources/specspec with no need for uv-coverage

Phase II: What to comment on What to say to help: –Big bold type: “Not well suited for standard interferometry” (better to say it isn’t if you aren’t sure) –Make notes if: Groups of sources that can share a calibrator: “Calibrator share” Cycling spectral setups (especially in band) that can expand uv- coverage: “SpectralSpec cycle” Notes where frequency referencing/band/bandwidth switching can be useful/necessary “Phase difference calibration needed.” No phase cal needed (this doesn’t fit into StandardInterferometry either…): “No phase calibration” Other stuff that doesn’t qualify (if there are any of these approved, we may be in trouble)…”Depends on what you see.” More on StandardInterferometry if there is time/interest (Tsys/SBR, Attenuators, Pointing, Virtual Field sources, etc, etc…, )