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CABB Observations Preparations and Observing Mark Wieringa.

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Presentation on theme: "CABB Observations Preparations and Observing Mark Wieringa."— Presentation transcript:

1 CABB Observations Preparations and Observing Mark Wieringa

2 Preparing for the observations Plan Frequencies 20/13 – not yet aiming for summed L+S or single 2 GHz band covering both 6cm – 5500 MHz 3cm – 9000 MHz mm – more freedom – two frequencies no more than 6 GHz apart At 7mm, both frequencies need to be on same side of 41 GHz Decide on single/dual freq No zoom bands yet, no choice in channel width yet In progress: 4 zooms per band; 64 MHz channels (for NASA & VLBI) RFI Now unavoidable in lower freq bands (e.g MHz) Trapped modes show up too Set tvchan range in CACOR if calibration affected Surveys in progress

3 CABBScheduler New web based scheduler New schedule format, Caobs no longer accepts old schedules New scheduler reads old format schedules (and writes new) Features Recognizes calibrators (from cal database) Find calibrator near source (search cal) Show calibrator database info Integrated velocity calculator (for zoom bands) Pick sources from your own catalogue Global changes Recalculate velocities (for different day/time) Missing Command move multiple scans

4 CABBScheduler – start

5 CABBScheduler – open file

6 CABBScheduler – calibrator info

7 CABBScheduler – frequency panels

8 CABBScheduler – listing

9 CABBScheduler – velocity calculator

10 CABBScheduler – spectral lines

11 Observing - CAOBS CAOBS Looks the same (mostly) Some commands missing (e.g., set atten/coarse, disable auto) Only mm attenuators remain Some commands added (e.g., corr dcal a) Alternative to typing in cacor window Reads only new format schedules CACAL Is no more.. Calibration is done via CABB commands CAMON Obsolete – use MoniCA gui client instead atmon – terminal based MoniCA client Available for testing, still under development

12 Observing – VNC based Caobs and cacor run in separate vncservers (on xbones and caccc0) A baseline solution at left Note: delay on cals <0.02ns Can see atmosphere on CA06

13 Observing – Vis Assistance Available – needs more ‘tuning’ for CABB Obsolete checks removed, no new ones added (yet) May be replaced by an ATCA TOAD in few months time Vis Available, working as normal May change behind the scenes SPD Available, some new commands (that may change..) [no]acs – turn auto correlation display on/off [no]ccs – turn cross correlation display on/off Off/On F1 – don’t show/show Freq 1 correlations

14 Observing - SPD

15 Observing - CACOR Command: Atts on/off Sampler tab: Rms ~20 is good

16 Observing – Setup/Calibration New CABB attenuators may need attention at new frequencies atts on / off in cacor look at ‘Samplers’ tab in CACOR to check for rms values near 20 Calibration now happens in CABB CACOR Commands: Delay calibration: dcal [a] “dcal” show calculated delays, “dcal a” applies the delay correction Phase calibration: pcal [a] Amplitude calibration: acal flux1 [flux2] [a] Supply source fluxdensity for Freq1 [and Freq2]

17 Observing – Setup/Calibration Calibration through CAOBS CAOBS passes commands on to CACOR Prefix with corr, e.g. CAOBS> corr dcal a May need to do dcal twice if delays are off a long way (>30ns) Detailed numbers only visible in CACOR window Error messages do come back to caobs When on : CAOBS> corr acal a This will fill in the flux for 1934 before sending cmd to correlator Current fit runs from 1GHz to 28 GHz, with CABB 1934 is strong enough at 7mm too (fit will be extended) A cacal command may appear in caobs Tip Detach unused antennas to avoid using them in the calibration

18 Observing with CABB Questions?


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