KFPA hardware and software checks during "Shared Risk" observations

TKFPA_40, December 15, 2010: Calibration check observations of 3C48 and the Moon

Performed Daisy Map observations of 3C48 and the Moon to compare relative gains of the 7 beam after returning the Rx to the telescope. One hour of observations, all in the 7+1 beam mode with 50 MHz bandwidth, configured for NH3 1,1 and 2,2 for 7 beams and 3,3 in the +1 beam.

  • Scans 18-19: On/Off 3C48
  • Scans 20-22: Daisy scans with 30 degree starting increments on 3C48
  • Scans 23-24: On/Off 3C48
  • Scans 25-26: On/Off Moon
  • Scans 27-29: Daisy scans with 30 degree starting increments on Moon
  • Scans 30-31: On/Off Moon
  • Scans 32-33: On/Off W51

TKFPA_41, December 16, 2010: Check of mapping and calibration with no noise diode blinking.

Goal for this session was to check performance at band edges and confirm proper calibration with pipeline of data taken with the noise diode ON for the On/Off reference scans, but off for the map scans. Turning the noise diode off allows doubling the spectrometer sample rate and reducing the average Tsys. All observations were in the 7+1 50 MHz mode.

  • Scans 8-9: On/Off TMCCP at 23705 MHz (NH3)
  • Scans 10-13: On/Off TMCCP at 18652 MHz
  • Scans 14-15: On/Off TMCCP at 23705 MHz (NH3)
  • Scans 21-22: On/Off 3C123 to measure gain
  • Scans 23-25: Daisy scans with 30 degree starting increments on 3C123; Cal Blinking Off
  • Scans 26-27: On/Off 3C123
  • Scans 30-31: On/Off TMCCP - Cal Blinking ON
  • Scans 32-43: RaLongMap of TMCN - Cal Blinking OFF (half hour map)
  • Scans 44-45: On/Off TMCCP - Cal Blinking ON

TKFPA_42, December 21, 2010: Check of Sub-beam Nod, Peak using 2 beams and Nod comparision

Most observations were made during maintenance, with no antenna motion. Observations of 3C48 were with antenna motion enabled. Got good Astrid performance only when configured for pointing with beams 1 and 2. Software issue in peak data reduction.

  • Scans 5-9: Nod observations, with antenna stowed. (Source name was SGRB2)
  • Scans 10-15: SubBeamNod observations, with antenna stowed.
  • Scans 16-21: Nob observations with antenna stowed.
  • Scans 37-41: 3C48 peak and focus observations using beams 1,2
  • Scans 42-46: 3C48 peak and focus observations using beams 3,7
  • Scans 59-63: 3C48 peak and focus observations
  • Scans 64-68: 3C48 Peak and focus observations using beams 1,2
  • Scan 69: 3C48 Good Sub-reflector Nod observation; data not reduced.
  • Scans 70-74: 3c48 Peak and focus observations

TKFPA_43, December 28, 2010: Tests of 27.3 GHz performance, sub-beam node tests

These observations were made to test KFPA for more generic, single and dual beam use. First steps were to get two beam pointing and sub-reflector nod data processed in Astrid. We still need GBTIDL code to reduce SubBeamNod spectra. Observations made at low elevation, pointing dish towards the Sun, to melt snow. Did a variety of peak and focus observations with different beams. Still only good performance when using beams 1 and 2.

  • Scans 1-11: Point and focus configuration tests. Telescope stowed, not pointed at source 3C48.
pointFocus37.png pointFocus12.png
Scans 12-16: Point and focus using beams 3 and 7.
Astrid commanded the coordinates correctly.
Good data, bad fit.
Scans 17-21: Point and focus using beams 1 and 2.
Astrid commanded the coordinates correctly.
Good data, good fit, but Astrid did not use beam 2 data to improve baseline
  • Scans 12-16: J1922+15 Peak and Focus obs with beams 3,7;
    • Source is visible in beam #3 continuum display.
    • Astrid did not fit peak, but instead displays beam 7 data.
  • Scans 17-20: J1733-13 Peak and Focus obs with beams 1,2;
    • Source is visible in beam #1 data
    • Astrid fits observations, but does not use beam 2 in point/focus fit
  • Scans 24-25: W51 On/Off observations with 7+1 mode and center frequency 27.3 GHz
    • Measured Tsys using new cal values. Results were good at 27.3 GHz.
    • Tsys values ranged between 29.6 and 49.0 K, with majority below 40 K.
  • Scans 26-36: W51 RaLongMap with center frequency on HC3N lines (No Cal Blinking)
    • Non-blinking Cal is preferred mapping mode for large regions
    • Sky can be sampled at twice the rate of blinking cal mode.
    • Spectrometer integration time was 0.5 seconds
    • Mapping time was 14 minutes.
  • Scan 37: W51 Off observations
  • Scans 38-42: 3C48 Peak and focus observations with beams 1,2
    • Source is visible in beam #1 data
    • Astrid fits observations, but does not use beam 2 in point/focus fit
  • Scans 42-50: 3C48 Nod observations with all beams, observed in pairs
    • Astrid displays nod spectra correctly for all beams.
    • Astrid displays both frequency bands for beam 1, as it should.
  • Scans 51-52: 3C48 Sub-Beam-Nod observations with beams 3, 7
    • Astrid displays sub beam nod correctly in the raw form.
  • Scans 53-57: 0410+76 Peak and focus observations with beams 1,2
  • Scans 58-59: On/Off observations of IC342 (NH3)

w51_27GHz.png
W51 HC3N map at 27.3 GHz. Cal Blinking turned OFF during mapping.
Scans 26-36, Integration time 0.5 seconds. Image made with pipeline.

TKFPA_44, January 7, 2011: Band scans. Telescope at access.

Searched for IF spurs with different configurations
  • Scans 33-60 Scan with 800 MHz bandwidth
  • Scans 61-116 Scan with 800 MHz bandwidth
  • Scans 117-191 Scan with 200 MHz bandwidth

TKFPA_45, January 11, 2011: Peak obs of 3C286

Very short test of Peak observations with different configurations. Done at end of Maintenance.

TKFPA_46, January 14, 2011: Peak obs of 3C48 and 3C123

Very short test of Peak observations with different configurations. Done at end of Maintenance.

TKFPA_47, February 17, 2011: Peak and map obs of 3C48

Study of gain calibration by Nod, Map and Peak observations of 3C48. 3C48 is a little too weak for easy use in KFPA calibration.

  • Scans 1-40: Telescope at access, no good astronomical data
  • Scans 42-109: Repeated peak and focus observations to check gain variation over an hour time interval
  • Scans 110-117: Nod spectrometer observations, but bad spectrometer setup.
  • Scans 118-149: More peak and focus obs on 3C48
  • Scans 150-157: Good Nod spectrometer obs of 3C48
  • Scans 158-165: Bad Nod spectrometer obs of 3C48
  • Scans 166-177: Two Daisy maps of 3C48

TKFPA_48, February 17, 2011: 3C48 and 3C123 Calibration checks

Continued study of gain calibration issues.

TKFPA_49, February 24, 2011: Tests at access

  • Trials of different spectrometer modes

TKFPA_50, February 25, 2011: Very short test of 12.5 MHz spectrometer modes

  • Few minutes of test obs of TMCCP after maintenance. 5 minutes of spectral line obs with 12.5 MHz bandwidth

TKFPA_51, March 1, 2011: Short calibration peak of Venus, 3 quick Daisys of Moon

  • All obs with 50 MHz NH3 7+1 mode
  • Nod sequence on 3C286

TKFPA_52, March 1, 2011: Checking Rx setup with 50 MHz bandwidth

  • No astronomical obs, GBT at access. Data taken with NH3 mode and 24718 MHz

...

TKFPA_60, March 30, 2011:

TKFPA_61, March 31, 2011: Band Scan during GBT maintenance

TKFPA_66, May 10, 2011: Optimize planet observations for calibration

Comparison of Mapping, Nod and peak measurements of the brightness of Venus, Jupiter and 3C48.

  • Scans 12-19: Good Nod scans of Venus
  • Scans 20-26: Three part daisy map of Venus
  • Scans 27-37: Two petals of Daisy maps with each beam on Venus, limited use as pattern is lopsided.
    • Realized that a short daisy should have oscilation time of X and total time of 1.5 X (ie 60s and 90s)
  • Scans 38-42: Peak/Focus on 3c48
  • Scans 42-58: Sequence of Nod observations on 3c48
  • Scans 59-69: 7 part petal map of 3c48, with 2' radius
  • Scans 70-80: 7 part petal map of 3c48, with 1.5' radius, to reduce total time
  • Scans 81-85: Peak/Focus on 3c48
  • Scans 86-96: 7 part petal map of Venus, radius 1.5'
  • Scans 97-105: 7 part petal map of Jupiter, radius 1.5'

TKFPA_67, May 17, 2011: Test configuration with DCR and ACS simultaneous

Configured telescope for 4 beam IFRack and spectrometer mapping, using script
  • configPointIf

-- GlenLangston - 2010-12-29
Topic attachments
I Attachment Action Size Date Who Comment
TKFPA_40.txttxt TKFPA_40.txt manage 2.6 K 2010-12-30 - 10:09 GlenLangston Session 40 Observing Log
TKFPA_41.txttxt TKFPA_41.txt manage 2.6 K 2010-12-30 - 10:10 GlenLangston Session 41 Observing Log
TKFPA_42.txttxt TKFPA_42.txt manage 3.8 K 2010-12-30 - 10:10 GlenLangston Session 42 Observing Log
TKFPA_43.txttxt TKFPA_43.txt manage 3.4 K 2010-12-30 - 10:11 GlenLangston Session 43 Observing Log
pointFocus12.pngpng pointFocus12.png manage 107.6 K 2010-12-30 - 10:34 GlenLangston Good data, good fit
pointFocus37.pngpng pointFocus37.png manage 146.4 K 2010-12-30 - 10:34 GlenLangston Good data, bad fit
w51KfpaHc3n.gifgif w51KfpaHc3n.gif manage 61.2 K 2010-12-29 - 10:33 GlenLangston W51 HC3N map at 27.3 GHz
w51_27GHz.pngpng w51_27GHz.png manage 35.5 K 2010-12-30 - 10:49 GlenLangston w51 HC3N line map.
Topic revision: r7 - 2011-09-13, GlenLangston
 

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