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projects:mkat_sband:pub:results_obs [2021/12/17 16:04]
wucknitz 		projects:mkat_sband:pub:results_obs [2023/06/23 14:14] (current)
wucknitz
Line 919: Line 919:
 See [[projects:mkat_sband:pub:fringefit|Fringe-fitting]] for more explanations on these fits. See [[projects:mkat_sband:pub:fringefit|Fringe-fitting]] for more explanations on these fits.
  
 +Here are plots that simulate the phasing efficiency. It is assumed that the delays are calibrated on the target at the beginning (top) or centre (middle) or end (bottom) of the observation. Different numbers of antennas (starting at the core) are included (several curves). These efficiencies are for the actually used observing frequency.
 +Because I have dispersive and non-dispersive effects separated, I can extrapolate these results to other frequencies, if needed.
 +
 +This is for narrow-band observations in the centre of the subband. I could include bandwidth effects, but they are not significant at these levels.
 +
 +{{:projects:mkat_sband:pub:1636719400_phaseff_obsfreq.png?direct&250}}
 +
 +Here is the same, but scaled to 600 MHz frequency (lower end of UHF). The dispersive and non-dispersive effects are of course scaled separately.
 +
 +{{:projects:mkat_sband:pub:1636719400_phaseff_600mHz.png?direct&250}}
 +
 +Results of a more general statistical analysis can be found in {{:projects:mkat_sband:pub:1636719400_phaseff_obsfreq.pdf}}. Each page is for a selection of antennas. The upper panels show the phasing efficiency for each time bin calibrated with each other time bin. The lower panel show this as function of time lag between calibration and target time (percentiles for certain fractions of the time). Not that the number of samples is small on the right end of this plot, so it is less statistically meaningful there.
 +
 +The same is available scaled to 600 MHz in {{:projects:mkat_sband:pub:1636719400_phaseff_600mHz.pdf}}.
 +
 +Note that the phases are more stable in UHF than S band. This is because in S band the ionosphere is only a very minor contribution. The troposphere scales down at lower frequency. The ionosphere becomes more important but still is not too problematic. The behaviour is slightly different at long baselines, where the ionosphere is comparatively stronger, because its gradients extend over longer distances.
  
  
Line 994: Line 1010:
   * There are stronger short-term fluctuations than in 1636719400. Was the weather different?   * There are stronger short-term fluctuations than in 1636719400. Was the weather different?
   * There are periods with increased wide-band noise. Not sure if this is due to an active Sun. Interestingly the amplitude solutions are lower by a few per cent at those time. Maybe the levels are too high?   * There are periods with increased wide-band noise. Not sure if this is due to an active Sun. Interestingly the amplitude solutions are lower by a few per cent at those time. Maybe the levels are too high?
 +
 +Here are plots that simulate the phasing efficiency. It is assumed that the delays are calibrated on the target at the beginning (top) or centre (middle) or end (bottom) of the observation. Different numbers of antennas (starting at the core) are included (several curves). These efficiencies are for the actually used observing frequency.
 +Because I have dispersive and non-dispersive effects separated, I can extrapolate these results to other frequencies, if needed.
 +
 +This is for narrow-band observations in the centre of the subband. I could include bandwidth effects, but they are not significant at these levels.
 +
 +{{:projects:mkat_sband:pub:1638617387_phaseff_obsfreq.png?direct&250}}
 +
 +Here the same for 600 MHz:
 +
 +{{:projects:mkat_sband:pub:1638617387_phaseff_600mHz.png?direct&250}}
 +
 +And here the statistics for the observed frequency and for 600 MHz: 
 +{{:projects:mkat_sband:pub:1638617387_phaseff_obsfreq.pdf}}
 +{{:projects:mkat_sband:pub:1638617387_phaseff_600mHz.pdf}}
 +
 +
 +
 +==== Tests of new filters 2022-06-08 ====
 +
 +The new filter coefficients were installed on 1st June 2022. On 8th tests were run in each of the subbands. Dump time was 8 sec, each observation had 10 min. Only baseline lengths (xy) > 300 m were used. The antenna set was the same for all five observations.
 +
 +The baseline-based plots are not included, because they take too much space on the wiki server. They can be provided on request.
 +
 +
 +
 +=== 1654713071 (PKS 1934-63) S0 10min 4k 2022-06-08 ====
 +
 +elev. 24 deg
 +
 +calibration solutions:\\
 +{{:projects:mkat_sband:pub:1654713071_res_del_8sec_solutions_ant.pdf|antenna-based}}
 +
 +SEFD and (amplitude and phase) bandpass:\\
 +{{:projects:mkat_sband:pub:1654713071_res_del_8sec_sefd_bandpass_ant.pdf|antenna-based}}
 +
 +
 +=== 1654714906 (PKS 1934-63) S1 10min 4k 2022-06-08 ====
 +
 +elev. 27 deg
 +
 +calibration solutions:\\
 +{{:projects:mkat_sband:pub:1654714906_res_del_8sec_solutions_ant.pdf|antenna-based}}
 +
 +SEFD and (amplitude and phase) bandpass:\\
 +{{:projects:mkat_sband:pub:1654714906_res_del_8sec_sefd_bandpass_ant.pdf|antenna-based}}
 +
 +
 +=== 1654716742 (PKS 1934-63) S2 10min 4k 2022-06-08 ====
 +
 +elev. 31 deg
 +
 +calibration solutions:\\
 +{{:projects:mkat_sband:pub:1654716742_res_del_8sec_solutions_ant.pdf|antenna-based}}
 +
 +SEFD and (amplitude and phase) bandpass:\\
 +{{:projects:mkat_sband:pub:1654716742_res_del_8sec_sefd_bandpass_ant.pdf|antenna-based}}
 +
 +
 +=== 1654718621 (PKS 1934-63) S3 10min 4k 2022-06-08 ====
 +
 +elev. 34 deg
 +
 +calibration solutions:\\
 +{{:projects:mkat_sband:pub:1654718621_res_del_8sec_solutions_ant.pdf|antenna-based}}
 +
 +SEFD and (amplitude and phase) bandpass:\\
 +{{:projects:mkat_sband:pub:1654718621_res_del_8sec_sefd_bandpass_ant.pdf|antenna-based}}
 +
 +
 +=== 1654720487 (PKS 1934-63) S4 10min 4k 2022-06-08 ====
 +
 +elev. 37 deg
 +
 +calibration solutions:\\
 +{{:projects:mkat_sband:pub:1654720487_res_del_8sec_solutions_ant.pdf|antenna-based}}
 +
 +SEFD and (amplitude and phase) bandpass:\\
 +{{:projects:mkat_sband:pub:1654720487_res_del_8sec_sefd_bandpass_ant.pdf|antenna-based}}
 +
 +
 +
 +== Conclusion ==
 +
 +  * 24-37 deg elevation
 +  * antennas included: ''m000 m001 m002 m003 m004 m005 m006 m007 m009 m010 m011 m012 m013 m014 m015 m016 m018 m019 m020 m021 m022 m023 m024 m026 m027 m028 m029 m030 m031 m032 m033 m034 m035 m036 m037 m038 m039 m041 m042 m044 m045 m046 m047 m049 m050 m051 m052 m053 m054 m057 m058 m059 m060 m061''
 +  * second pol bad in ''m015'', first pol bad in ''m020'', both pols not great in ''m034''
 +  * **the filters are behaving as expected**
 +  * **[[projects:mkat_sband:pub:decfilters#test_observations|Combined results and a comparison with the old filters can be found here.]]**
 +
 +
 +==== Final SEFD measurements 2022-11-19 ====
 +
 +Short 5-min observations of PKS1934-63 were done at high elevation on 19th November 2022 in each of the five subbands. Dump time was 2 sec, solution interval for the calibration was 10 sec. Only baseline lengths (xy) > 300 m were used for the analysis.
 +
 +The baseline-based plots are not included, because they take too much space on the wiki server. They can be provided on request.
 +
 +
 +=== 1668863917 (PKS 1934-63) S0 5min 4k 2022-11-19 ====
 +
 +elev. 56 deg
 +
 +calibration solutions:\\
 +{{:projects:mkat_sband:pub:1668867372_res_del+rate_10sec_solutions_ant.pdf|antenna-based}}
 +
 +SEFD and (amplitude and phase) bandpass:\\
 +{{:projects:mkat_sband:pub:1668867372_res_del+rate_10sec_sefd_bandpass_ant.pdf|antenna-based}}
 +
 +
 +=== 1668862317 (PKS 1934-63) S1 5min 4k 2022-11-19 ====
 +
 +elev. 54 deg
 +
 +calibration solutions:\\
 +{{:projects:mkat_sband:pub:1668862317_res_del+rate_10sec_solutions_ant.pdf|antenna-based}}
 +
 +SEFD and (amplitude and phase) bandpass:\\
 +{{:projects:mkat_sband:pub:1668862317_res_del+rate_10sec_sefd_bandpass_ant.pdf|antenna-based}}
 +
 +=== 1668865347 (PKS 1934-63) S2 5min 4k 2022-11-19 ====
 +
 +elev. 57 deg
 +
 +calibration solutions:\\
 +{{:projects:mkat_sband:pub:1668865347_res_del+rate_10sec_solutions_ant.pdf|antenna-based}}
 +
 +SEFD and (amplitude and phase) bandpass:\\
 +{{:projects:mkat_sband:pub:1668865347_res_del+rate_10sec_sefd_bandpass_ant.pdf|antenna-based}}
 +
 +=== 1668867372 (PKS 1934-63) S3 5min 4k 2022-11-19 ====
 +
 +elev. 57 deg
 +
 +calibration solutions:\\
 +{{:projects:mkat_sband:pub:1668867372_res_del+rate_10sec_solutions_ant.pdf|antenna-based}}
 +
 +SEFD and (amplitude and phase) bandpass:\\
 +{{:projects:mkat_sband:pub:1668867372_res_del+rate_10sec_sefd_bandpass_ant.pdf|antenna-based}}
 +
 +=== 1668869113 (PKS 1934-63) S4 5min 4k 2022-11-19 ====
 +
 +elev. 57 deg
 +
 +calibration solutions:\\
 +{{:projects:mkat_sband:pub:1668869113_res_del+rate_10sec_solutions_ant.pdf|antenna-based}}
 +
 +SEFD and (amplitude and phase) bandpass:\\
 +{{:projects:mkat_sband:pub:1668869113_res_del+rate_10sec_sefd_bandpass_ant.pdf|antenna-based}}
 +
 +
 +
 +
 +
 +== Conclusion ==
 +
 +  * 54-57 deg elevation
 +  * antennas included: ''m000 m001 m002 m005 m006 m007 m008 m009 m010 m011 m012 m013 m014 m015 m016 m017 m018 m019 m020 m021 m022 m023 m024 m025 m026 m027 m028 m029 m030 m031 m032 m033 m034 m035 m036 m037 m038 m039 m040 m041 m042 m044 m045 m046 m047 m048 m049 m050 m051 m052 m053 m054 m055 m057 m058 m059 m060 m061 m062 m063'' (''m036 m037'' missing in S1)
 +  * results generally very consistent (but somewhat variable) from antenna to antenna
 +  * ''m015'': second pol still bad (huge bumps e.g. around 2900 MHz)
 +  * ''m036'': second pol very bad
 +  * ''m062'': first pol has large bumps, e.g. just above 2200 MHz
 +  * **[[projects:mkat_sband:pub:start#collected_sefd_and_bandpass_information|Combined results can be found here.]]**
  
 
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