Reference Pointing Testing

Date SB # Ptg. band Obs. band Notes TelCal version CBE version Plots
July 04, 2010 1446040 C-OSRO; C-RSRO None First testing script, to check if applying OSRO vs. RSRO C-band pnt results worked. Concluded that pointing algorithm was wrong since we were recovering only 60% of introduced offset.     Results
Feb 10, 2011 3197779

Ku-OSRO; X-OSRO

Ku/X

Series of observations of 3C48 to compare reference pointing using Ku and X bands. Flux densities tested using Ku blind pointing, Ku reference pointing, and X reference pointing; all values within a few percent. Magnitudes of pointing solutions are comparable in X and in Ku. Further tests are planned to compareKu and X pointing solutions using deliberate offsets (day and night), as well as compring flux desnities in higher frequency bands when using Ku reference pointing.

    THIG0002.feb8.pdf
Aug 11, 2010 1758717 C-OSRO; X-OSRO; K-OSRO; None Target is observed with a 0" and 40" offset from the phase center, pointing solutions should be able to recover this offset regardless of observing frequency. C-OSRO recovers 41.9", X-OSRO 40.4" and K-OSRO 38.5". Only a few antennas get K-band ptg solutions on every loop, maybe a 40" offset is too large for K-band, need to repeat this test with 20" instead. Also, ea12 and ea16 still present a large difference between the ptg solutions for C and X,K-band, maybe due to a collimation problem (see Results #2). 1.5.23 July 2nd Results Results #2
Aug 11, 2010 1766026 C-OSRO; C-RSRO None Target is observed with a 0" and 40" offset from the phase center, pointing solutions should be able to recover this offset regardless of mode (either OSRO or RSRO). Test was also performed to check the previous result where scatter in C-OSRO ptg solutions was larger than for C-RSRO. Both modes recover a 42" offset, and their scatter is comparable. 1.5.23 July 2nd Results
Aug 10, 2010 1748981 C-OSRO; C-RSRO; X-OSRO; None The target is observed with a 0" and 40" offset from the phase center, pointing solutions should be able to recover this offset regardless of the observing frequency. C-OSRO recovers 36.4", C-RSRO 37.5" and X-OSRO 36.0", but the scatter on the C-OSRO solutions seems large compared with previous tests. 1.5.23 July 2nd Results
Aug 08, 2010 1725931 X-OSRO Q/K/Ka-RSRO Test designed as standard observing SB, to quantify the number of dropped scans before/after pointing. For this dataset: (1) Scans after a pointing scan are always affected. (2) Scans before a pointing scan were never affected. (3) There only one symptom: for the scans affected a fraction of the data could is present and the rest flagged (and zeroes). (4) Between 1/2 and 1/3 of the scan length is flagged and zeroed. 1.5.22 July 2nd No plots, just observing strategy
Aug 08, 2010 1725585 C-OSRO Q/K/Ka-RSRO Test designed as standard observing SB, to quantify the number of dropped scans before/after pointing. For this dataset:(1) Scans after a pointing scan are always affected. (2) Scans before a pointing scan were never affected. (3) There only one symptom: for the scans affected a fraction of the data could is present and the rest flagged (and zeroes). (4) Between 1/2 and 1/3 of the scan length is flagged and zeroed. 1.5.22 July 2nd No plots, just observing strategy
Aug 08, 2010 1714472 C-OSRO & RSRO; K-RSRO Test designed as standard observing SB to find a strategy for reference pointing when switching between bands during regular science observations, and to check that both RSRO and OSRO pointing give the same ptg solutions. 1.5.22 July 2nd Results
Aug 08, 2010 1747238 C-OSRO K-RSRO Test designed as standard observing SB, to quantify the number of dropped scans before/after pointing. There is one C-band pnt scan and 4 RSRO K-band standard scans per loop, and there are a total of 10 loops. The K-band scans are 50, 43 and 30 sec long. At least for this dataset: (1) Scans after a pointing scan are always affected. (2) Scans before a pointing scan were only affected once. (3) There are three different symptoms: a scan could be completely missing (not even listed on 'listobs'), or it could be entirely flagged (and the flagged data is mostly zeroes), or a fraction of the data could be present and the rest flagged (again mostly zeroes). (4) There seems to be a dependence in the number of dropped scans after pointing and the length of the scan. For scans of 50 and 43 sec duration only the first scan after pointing is affected, but the 30 sec scans the two scans after pointing are affected. 1.5.22   No plots, just observing strategy
Aug 08, 2010 1747112 C-OSRO; X-OSRO None On-source and off-source (offset by 40 arcseconds) test. There are no missing scans, and pointing solutions for all pointing scans were obtained. The average offset recovered by the pointing solutions is 39.5" for Cband and 35.3" for Xband. The X-band ptg results are consistently below the C-band ptg results for most antennas. Antennas 4, 20 and 26 have a quite large (and wrong) offset measured in one of the ptg sessions. In the case of ea04 the zero-point offset is too large compared to the other measurements, and for ea20 and ea26 is the 40"-offset that is too large compared to the other measurements. 1.5.22 July 2nd Results
Aug 07, 2010 1714472 C-OSRO; C-RSRO K-RSRO Test designed as standard observing SB to find a strategy for reference pointing when switching between bands during regular science observations. No wideband data was obtained for this trial. 1.5.22 Aug 6 None
Aug 07, 2010 1747238 C-OSRO K-RSRO Test designed as standard observing SB, to quantify the number of dropped scans before/after pointing. There is one C-band pnt scan and 4 RSRO K-band standard scans per loop, and there are a total of 10 loops. This 10 loops are split into 3 different loops, where the K-band scans are 50, 43 and 30 sec long on each loop. No wideband data was obtained for this trial. 1.5.22 Aug 6 None
Aug 07, 2010 1747112 C-OSRO; X-OSRO None On-source and off-source test (offset by 40"). No missing scans, pointing solutions for all pointing scans were obtained. The average offset recovered by the pointing solutions is 37" for Cband and 34" for Xband. The X-band ptg results are consistently below the C-band ptg results for most antennas. 1.5.22 Aug 6 Results
July 31, 2010 1725585, 1725931 C-OSRO; X-OSRO Q/K/Ka-RSRO On this two trials: About half the reference pointing scans failed, in the sense that they had missing data and did not find a pointing solution. Also, standard scans get dropped right after pointing. Comparing the C and Xband solutions it seems that ea12 and ea16 have a collimation error. 1.5.20   Results
July 31, 2010 1669463 C-OSRO; C-RSRO C-RSRO Script to check that OSRO and RSRO pnt give the same solutions. This trial hosed the CBE when doing ref ptg in RSRO mode, only one valid pointing solution was found in OSRO mode, so no results are available. 1.5.20   None
July 30, 2010 1711833 C-OSRO; C-RSRO C-RSRO same setup as SB#1669463 but observing frequency is shifted by 0.3GHz to avoid some RFI that appeared in previous test. On this two trials: the first trial has no data between the cycle of RSRO-3min-ptg and the cycle of OSRO ptg. The second time it ran there is no more data after the first cycle of RSRO pointing was completed. The OSRO ptg solutions in the attached plot come from the first run, while the RSRO ptg solutions come from the second time the SB ran. The results indicate that both OSRO and RSRO give the same solutions. 1.5.20   Results
July 28, 2010 1669463 C-OSRO; C-RSRO C-RSRO Script to check that OSRO and RSRO pnt give the same solutions. In between ptgs we have two standard observing scans (C-RSRO) to check for missing scans and such problems. Also, since we've had some instances with RSRO ptg not finding a solution in a 3min scan, we added an extra loop with 5min scans during RSRO ptg. Results indicate that both OSRO and RSRO give the same solutions. 1.5.20   Results
July 25, 2010 1669463 C-OSRO; C-RSRO C-RSRO Script to check that OSRO and RSRO pnt give the same solutions. In between ptgs we have two standard observing scans (C-RSRO) to check for missing scans and such problems. Also, since we've had some instances with RSRO ptg not finding a solution in a 3min scan, we added an extra loop with 5min scans during RSRO ptg. Too few pnt solutions to proceed with analysis (Only one RSRO pnt solutions for when target is on phase center, but the solutions when target is offset are not present). 1.5.18   No results
July 15, 2010 1653099 C-OSRO; X-OSRO None The target is observed with a 0", 20", and 40" offset from the phase center, and the pointing solutions should be able to recover these offsets regardless of the observing frequency. Unfortunately no pointing results for X band were present in this test, so no comparison is available. But at least C-band now returns the right value for the pointing offset that we introduced. 1.5.17   Results
July 09, 2010 1653099 C-OSRO; X-OSRO None The target is observed with a 0", 20", and 40" offset from the phase center, and the pointing solutions should be able to recover these offsets regardless of the observing frequency. With this test we found that there is a 20-25% difference between C and X band, and none of them     Results
July 09, 2010 1653099 C-OSRO; X-OSRO None The target is observed with a 0", 20", and 40" offset from the phase center, and the pointing solutions should be able to recover these offsets regardless of the observing frequency. With this test we found that there is a 20-25% difference between C and X band, and none of them recover the offset introduced.     Results
July 08, 2010 1646494 C-OSRO; C-RSRO None C-band ptg using OSRO, RSRO 1GHz and RSRO 2GHz. The target is observed with a 0", 20", and 40" offset from the phase center, and the pointing solutions should be able to recover these offsets. Offset recovered was 30-40% lower than expected, only one set of solutions of RSRO C-band pointing.     Results
July 04, 2010 1446040 C-OSRO; C-RSRO None Script to check if applying OSRO vs. RSRO C-band pnt results worked. Too few pnt solutions to proceed with analysis (No RSRO pnt solutions).     None

-- Main.Laura Perez - 16 Aug 2010

Topic attachments
I Attachment Action Size Date Who Comment
THIG0002.feb8.pdfpdf THIG0002.feb8.pdf manage 196 K 2011-02-10 - 16:48 UnknownUser Results of first THIG0002 tests for Ku reference band pointing.
TRSR0020_Aug07_sb1747112_ptg_offset40_C_X.pngpng TRSR0020_Aug07_sb1747112_ptg_offset40_C_X.png manage 60 K 2010-08-16 - 12:18 UnknownUser  
TRSR0020_Aug08_C_X_ptg_offset.pngpng TRSR0020_Aug08_C_X_ptg_offset.png manage 45 K 2010-08-16 - 12:20 UnknownUser  
TRSR0020_RSRO_vs_OSRO_2_ptg_July30.pngpng TRSR0020_RSRO_vs_OSRO_2_ptg_July30.png manage 73 K 2010-08-16 - 12:11 UnknownUser  
TRSR0020_RSRO_vs_OSRO_3_ptg_July31.pngpng TRSR0020_RSRO_vs_OSRO_3_ptg_July31.png manage 77 K 2010-08-16 - 12:14 UnknownUser  
TRSR0020_RSRO_vs_OSRO_4_ptg.pngpng TRSR0020_RSRO_vs_OSRO_4_ptg.png manage 128 K 2010-08-16 - 12:23 UnknownUser  
TRSR0020_RSRO_vs_OSRO_ptg.pngpng TRSR0020_RSRO_vs_OSRO_ptg.png manage 100 K 2010-08-16 - 12:10 UnknownUser  
TRSR0020_sb1646494_pointing.pngpng TRSR0020_sb1646494_pointing.png manage 44 K 2010-08-16 - 12:02 UnknownUser  
TRSR0020_sb1653099_1_000_ptg.pngpng TRSR0020_sb1653099_1_000_ptg.png manage 63 K 2010-08-16 - 12:04 UnknownUser  
TRSR0020_sb1653099_1_001_ptg.pngpng TRSR0020_sb1653099_1_001_ptg.png manage 61 K 2010-08-16 - 12:06 UnknownUser  
TRSR0020_sb1653099_1_002_ptg.pngpng TRSR0020_sb1653099_1_002_ptg.png manage 42 K 2010-08-16 - 12:08 UnknownUser  
TRSR0020_sb1748981_ptg_offset40_C_X.pngpng TRSR0020_sb1748981_ptg_offset40_C_X.png manage 97 K 2010-08-16 - 12:25 UnknownUser  
TRSR0020_sb1758717_ptg_40_offset_C_X_K.pngpng TRSR0020_sb1758717_ptg_40_offset_C_X_K.png manage 72 K 2010-08-16 - 12:57 UnknownUser  
TRSR0020_sb1758717_ptg_offset_recovered_C_X_K.pngpng TRSR0020_sb1758717_ptg_offset_recovered_C_X_K.png manage 69 K 2010-08-16 - 12:54 UnknownUser  
TRSR0020_sb1766026_ptg_offset40.pngpng TRSR0020_sb1766026_ptg_offset40.png manage 61 K 2010-08-16 - 12:33 UnknownUser  
pointing.pngpng pointing.png manage 20 K 2010-08-16 - 11:56 UnknownUser  
Topic revision: r6 - 2011-02-10, JohnCannon
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