TPTCSPNT_080124 - CCB Maps and Half-power tracks at X and KA band
The plan is to get some half-power tracks under fairly high wind conditions. -- predictions are for >10 MPH this afternoon.
Start off with a CCB map of bright point source 0359+5057
Wind is low, do the map, then some half-power tracks later.
CCB setup at first was a problem because I had forgotten the "undead" command to kill CCB channels 1-8. So the first peaks were very strange. Fixed for scans 10-14.
Scans 10-14 Peak/Focus, on 0359+5057 with the CCB (script: ccbmaps.sb)
Scans 15- 47 RALongmap on same source with CCB
--light to heavy snow, 60% humidity, temp=24F, mostly cloudy; winds are picking up, up to 15 MPH during the map.
change to X-band:
Scans 48-52 : Peak/Focus on 0319+4130 Tsys about 28K (script: NewHalfPower)
Scans 53-62 : calibrate half-power offsets, az and el
L R
53: on-source: IDL calibration: 61.68 61.27 K
54: 0.4 beams off in azim 47.13 46.50 (47.13-39.10)/(0.2*82.2") = 0.488K/arcsec = L
55: 0.5 beams " 40.20 39.55 (46.50-38.47)/(0.2*82.2") = 0.488K/arcsec = R
56: 0.6 beams " 39.10 38.47
57: 10 beams " 28.32 27.73
58: on-source 61.13 60.68
59: 0.4 beams off in elev 50.62 49.97 (50.62-40.92)/(0.2*82.2) = 0.590K/arcsec = L
60: 0.5 beams 45.80 45.22 (49.97-40.32)/(0.2*82.2) = 0.587K/arcsec = R
61: 0.6 beams 40.92 40.32
62: 10 beams 28.29 27.76
Scan 63-67 : another peak/focus
Scan 68 : half power track for 33 min, offset in AZ, winds ranging 5 to 15, occasional gusts to 30MPH.
= 2008_01_24_20:25:17.fits wind1avg(rms) = 3.33(1.46) wind2avg(rms) = 2.76(1.16) wind3avg(rms) = 1.64(0.58)
winds dying down -- fairly heavy snow.
Scan 69-73 : another peak/focus 0319+4130
Scan 74 : half power track for 33 min, offset in EL; winds up to about 15 MPH = 2008_01_24_21:03:22.fits
wind1avg(rms) = 3.46(1.86) wind2avg(rms) = 2.60(1.20) wind3avg(rms) = 1.74(0.76)
change to KA-band:
Scans 75-79 : peak focus on 0319+4130 - fit did not pass
-- Dumping Snow, then will try another peak/focus
Scans 80-84 : peak/focus looks ok.
Scans 85- 89 : offset calibration ( script : ccbHalfPower)
L R L R
85: 1.79 4.96 on source ??? 389.9 481.5 Clearly, the pointing is bad. Do not use these data!
86: 2.11 5.69 0.4 beam ??? 462.7 556.3
87: 1.34 3.86 0.5 beam 294.9 377.5
88: 0.66 1.99 0.6 beam 144.8 193.5
89: 0.19 0.41 off source 41.9 40.4
Scan 90 : half-power track with AZ offset. gusts up to 30 MPH = 2008_01_24_22:04:04.fits
wind1avg(rms) = 4.86(1.89) wind2avg(rms) = 3.00(1.56) wind3avg(rms) = 2.14(1.02)
Scans 91-94 : peak/focus problems - gfm very slow in processing. skipped these results and went on
with LPCs = 0.144, 0.079 arcmins
Scans 95-99 : calibration in el direction. (script: ccbHalfPower2)
L R
95: 0.237 0.660 on source Clearly, the pointing is bad. Do not use these data!
96: 0.835 2.499 0.4 beam
97: 1.302 3.620 0.5 beam
98: 0.716 2.116 0.6 beam
99: 0.188 0.412 off source
Scan 100 : half-power track with EL offset. winds 10-15MPH, gusts to 20. = 2008_01_24_22:47:23.fits
wind1avg(rms) = 4.82(1.50) wind2avg(rms) = 1.91(1.40) wind3avg(rms) = 1.38(0.77)
only ran about 12 minutes, because we ran into the end of the schedule.
Plots of Quadrant Detector, Wind, and Inclinometer Log Data
(offsets in units of HPBW)
| scan num | band | offset | direction | duration |
| 53 | X | 0.0 | az | 20 sec |
| 54 | X | 0.4 | az | 20 sec |
| 55 | X | 0.5 | az | 20 sec |
| 56 | X | 0.6 | az | 20 sec |
| 57 | X | 10.0 | az | 20 sec |
| 58 | X | 0.0 | el | 20 sec |
| 59 | X | 0.4 | el | 20 sec |
| 60 | X | 0.5 | el | 20 sec |
| 61 | X | 0.6 | el | 20 sec |
| 62 | X | 10.0 | el | 20 sec |
| | | | | |
| 68 | X | 0.5 | az | 33 minutes |
| 74 | X | 0.5 | el | 33 minutes |
| | | | | |
| 85 | KA | 0.0 | az | 20 sec |
| 86 | KA | 0.4 | az | 20 sec |
| 87 | KA | 0.5 | az | 20 sec |
| 88 | KA | 0.6 | az | 20 sec |
| 89 | KA | 10.0 | az | 20 sec |
| | | | | |
| 90 | KA | 0.5 | az | 33 min |
| | | | | |
| 95 | KA | 0.0 | el | 20 sec |
| 96 | KA | 0.4 | el | 20 sec |
| 97 | KA | 0.5 | el | 20 sec |
| 98 | KA | 0.6 | el | 20 sec |
| 99 | KA | 10.0 | el | 20 sec |
| | | | | |
| 100 | KA | 0.5 | el | 12 min |
- scan68.pdf: scan 68 receiver-inferred pointing error
- scan74.pdf: scan 74 receiver-inferred pointing error
The half-power tracks, scans 90 and 100, have been processed in the same way as for
project '080216'. But in this case, the pointing seemed to be unstable, as noted above.
The sequence of scans 85-89 and 95-99, during which the power should strictly decrease,
going from on-source to 0.6, 0.5,0.4, and 10 beam offsets. But the power values
did not progress as they should have. We have processed the scans assuming
the conversion of 34 counts per arcsecond, as was derived from the 080216 data set.
The plots displayed for scans 90 and 100 have arcseconds as the y-axis.
Probably they are proportional to pointing errors in arcseconds, but we have no
idea just what the proportionality is.
The data may be downloaded as text files in a gzipped tar file, 'hpt_KA_Jan24.tar.gz', below.
- Scan 90 plot of inferred pointing error:
- Scan 100 : plot of inferred pointing error:
-- FrankGhigo - 09 June 2008
scan68.pdf 
scan0068.mjd 
hptrack_scan90.gif 
