TPAR 18 observing log
Quick cycle was carried out starting at 22:00 hours.
At 00:00 the 2nd stage temperature was still at 4:00K so started observing at Q band while the reciver stabilized.
Weather - clear, but warm with a ground mist ~ 20 ft high.
Q-band OOF maps:
Scans 1-5 peak & focus all on 0854+2006
T_sys at q-band = 70K
az pointing -.02' el +0.13', lfcy -1.0mm
Scan 6 - q-band focus daisy - lfcy=-20, 8 arc second offset in pointing at start of the file (based on quadrant detector) - radius=2', period=25s - Overall the scan looks OK.
Scan 7 aborted
Scan 8 - q-band focus daisy, lfcy=-20, 14 arc second jump in poinint at start of scan, lasts about 10 seconds - tried different phase at start, same scan parameters.
Scan 9-14 - more focus daisy radius=2', period=60s, 120s duration, lfcy=-20mm - 6 arcsecond jump lasted about 20 seconds. LFCY's of [-20,-13,-6,1,8,15]
Scan 15-19 peak-focus - lfcy +1mm
Scan 20 OOF map -20mm
Scan 21 OOF map +1mm (best focus)
Scan 22 OOF map +22mm
Scans 23-27 point and focus
Scan 28 - aborted peak focus
Scan 29-31 OOF map lfcy's -20mm,+1mm,+22mm in az/el not encoder.
**For some reason the GBT is not centering the maps on the source**.
1:36am sky clear above us - maybe some clouds over mountain - The maps just will not center.
Scan 32-36, peak & focus - lfcy=-0.33mm, az=-0.0143', el 0.0927'
Scans 37 aborted because of 10' jumps at the turnarounds. Was to be: Q-band OOF maps with wider el scan to get source neerer the center of the map.- big (25' jump in the quadrant detector at the start of the scan.
Brian updated the path to get round this.
Scans 38 q-band OOF - figured out what the problem is - the q band beams are offset from boresight.
CORRECT THIS use beam 1 NOT beam C
Scan 39-41 OOF maps using beam 1. -20,+1,+22mm (back to the narrower scan)
39 = 2008_01_08_07:03:19.fits
40 = 2008_01_08_07:08:56.fits
41 = 2008_01_08_07:14:33.fits
PUT MUSTANG IN THE FOCUS
biases set up using cal by hand - no down ramp taken so we can take an OOF map quicker
Scan 42 CAL scan (1.2V) - bad file
ASTRID crashed - restarted
Scan 43 CAL scan (1.2V) - 56 working detectors
Scans 44-47 parfocus daisy -20,-10,0,5mm daisy rad=0.7', period 25s excitation of feedarm V. small.
Scans 48-52 parfocus daisy -2,0,2,4,6mm 0.3' radius
Scans 53,54 focus daisy +8,+10mm - BEST focus = 2mm = peak amplitude, 4mm = most round - choose 2mm
Scan 55 quick daisy at 2mm, 100seconds, period = 25s, 0.3' radius.
Scans 56,57,58 OOF at -7mm,2mm,11mm
56 = 2008_01_08_08:09:04.fits = az,el at midpoint = 221.80, 66.95
57 = 2008_01_08_08:11:32.fits = az,el at midpoint = 223.02, 66.62
58 = 2008_01_08_08:14:00.fits = az,el at midpoint = 224.21, 66.29
We are seeing 10" jumps in the feed-arm at the start of the OOF maps.
Scans 59,60,61 repeat OOF
59 = 2008_01_08_08:16:57.fits
Scan 62 30 second blank scan
Scan 63 CAL file
TURN zernikes off
Repeat OOF map
Scans 64,65,66 OOF with zernikes off
64 = 2008_01_08_08:29:09.fits
65 = 2008_01_08_08:31:36.fits
66 = 2008_01_08_08:34:04.fits
GO TO MARS :)
67 aborted
Scans 68-75 focus daisies on Mars -20,-15,-10,-5,0,5,10,15
Scan 76 subreflector scan -30mm to +30mm in 30 seconds
Scan 77 subreflector scan -30mm to +30mm in 120 seconds
Scans 78,79,80 focus scans -2mm, 0mm, +2mm
Scan 81 subreflector daisy
Scan 82 subreflector daisy with 2arcminute offset in az - 1/f noise has started to come - we are too low 26 degrees elevation.
Scan 83 30 seconds on blank field for weight at low elevation.
THE WIND IS ZERO - the fog is not.
Scan speed tests.
3C279 (1256+0547)
Scan 84 - aborted
Scan 85 - blank scan (30 seconds)
Scan 86 - CAL 1.2V - only on for half the file
Scan 87 - CAL file 1.2V
Scans 88,89,90,91,92 focus scans -15,-8,-1,6,13
We still see 1/f noise in most the detectors
Scan 93 - a tipping scan going up to access to see if noise goes away.- It does
Scan 94 Cal 1.2V
Scan 95 Blank
Scan 96 - tip back down to see if noise comes back.
Scan 97 quick daisy in focus (-1mm)
TESTS OF MAPPING
Scan 98 r=0.3', p=20s, 120s q-daisy -
Scan 99 r=0.3', p=10s, 120s q-daisy - quad detector +-2" (8 at start)
Scan 100 r=1.6' period=50s, 120s q-daisy
Scan 101 r=1.6' period=30s, 120s q-daisy - peak quadrant detector offset 4', settled down in 10s to 2'
Scan 102 r=1.6' period=20s, 120s q-daisy - peak offset 6', after 10 seconds settles down to 3'
At the moment it is reading degraded, noise & out of range.
Scan 103 r=1.6' period=10s, 120s q-daisy - peak offset 5', after 10 seconds settles down to few arcseconds.
Scan 104 r=1.6' period=10s, 120s q-daisy - :-) fast scans look fine - we can map quickly
Scan 105 r=11' period=30s, 120 seconds
Scan 106 r=11' period=20s, 120 seconds q-daisy - 10 arc second bump in quadrant detector, settles doown to around 5-6' - clearly part of scan pattern
Scan 107 r=11' period=10s, 120 second q-daisy - 18 arcsecond spike + 10 arcseconds oscillations in our scan stratagy
Scan 108 subreflector daisy centered on source.
Scan 109 subreflector daisy 2' offset for source in az.
;-( subreflector daisy gives BAD beams off-axis
Scan 110 Cal 1.2V
Scan 111 blank 30 seconds
Scans 112,113,114 quick focus lfcy -6,0,6mm
Go to 1120+237 (50-100mJy source)
Scans 115,116,117 Focus lfcy -6,0,6mm
Scan 118 r=0.3', p=20s, 120s q-daisy
Scan 119 r=0.3', p=10s, 120s q-daisy
Scan 120 r=1.6' period=50s, 120s q-daisy
Scan 121 r=1.6' period=30s, 120s q-daisy
Scan 122 r=1.6' period=20s, 120s q-daisy .
Scan 123 r=1.6' period=10s, 120s q-daisy
-- SimonDicker - 22 Jan 2008
|
Revision r1.6 - 09 Jun 2008 - 16:50 GMT - ToddHunter
|
Content copyright © 1999-2007 by the contributing authors.
All material on this collaboration platform is the property of the contributing authors.
|
| |