====== MeerKAT S band receiver commissioning (public part) ====== This area is for notes and results on the receiver commissioning. The namespace ''[[projects:mkat_sband|projects:mkat_sband]]'' is private to the MPIfR, the subspace ''[[projects:mkat_sband:pub:start|projects:mkat__sband:pub]]'' has public read access. ===== Links and external info ===== [[https://archive.sarao.ac.za/proposalid/SSV-20200929-OW-01/order/true/|SARAO web archive for commissioning proposal SSV-20200929-OW-01]] [[https://www.google.com/maps/d/viewer?hl=en&mid=1cGIe7eVdlZIk_YL5TyTw5kmYo1g&ll=-30.715290268345356%2C21.4427763122559&z=13|Map of array]] ==== SARAO google drive S band ==== [[https://drive.google.com/drive/folders/1_Cc_1-d86HrNx0bGxtNbmJudp2rgt_EQ|main]] [[https://docs.google.com/spreadsheets/d/1Kcn48aHiSXWQGsyCg1gFJL12ohdVVIlazhyaWkJoNkg/edit?skip_itp2_check=true#gid=1500988692|receptor status]] [[https://docs.google.com/spreadsheets/d/1eVk43O1ZKbCWLaD_M_JKbQ4ROevFWJniiOHfXI1WJLg/edit?usp=sharing|S band install SN]] ==== SKA Africa JIRA ==== [[https://skaafrica.atlassian.net/jira/software/c/projects/SBAND/issues/SBAND-197|Review of SARAO provided test data]] [[https://skaafrica.atlassian.net/jira/software/c/projects/SBAND/issues|S band main page]] ===== Subband identifiers ===== [[https://skaafrica.atlassian.net/browse/SBAND-197?focusedCommentId=129532|reference]] All in MHz: ^ name ^ centre ^ range ^ ^ S0 | 2187.50 | 1750.00 - 2625.00 | ^ S1 | 2406.25 | 1968.75 - 2843.75 | ^ S2 | 2625.00 | 2187.50 - 3062.50 | ^ S3 | 2843.75 | 2406.25 - 3281.25 | ^ S4 | 3062.50 | 2625.00 - 3500.00 | **Please note that these are the total band ranges, the usable range is smaller. See [[projects:mkat_sband:pub:decfilters#final_design_ver2|description of the decimation filters]] for details.** ===== Filters ===== A discussion of the digital decimation filters can be found [[projects:mkat_sband:pub:decfilters|here]]. ===== Phased array/pulsar mode ===== TO DO ===== Imaging/correlator mode ===== ==== Data sets ==== [[projects:mkat_sband:pub:imobs_list|List of data sets]] (automatically created with ''obs_info.py'') The data sets can be found in ''/fpra/polmag/01/MK_S_BAND_COM/MS/'', some have copies (also of variants) in ''/media/storage_1/wucknitz/MEERKAT''. Own conversion to MS via ''mvftoms.py'' have their capture block number as directory name, ones via the archive have e.g. ''1603193556_sdp_l0.ms''. ==== Theory/procedures ==== We determine delays and phases with [[projects:mkat_sband:pub:fringefit|fringe-fitting (click for details)]] per baseline. After calibrating the phases per baseline, we can [[projects:mkat_sband:pub:snrdet|measure the SNR (click for details)]] per baseline and channel and try to separate the baseline values to obtain station-based parameters. A similar approach is used for the [[projects:mkat_sband:pub:bandpass|bandpass (amplitude and phase, click for details)]]. ==== Results ==== **[[projects:mkat_sband:pub:results_obs|Details of results for individual observations can be found here.]]** ==== Collected SEFD and bandpass information ==== === Results for typical antennas === The performance of the entire array can be estimated best by taking the median (or some other percentile) over all antennas. Here are corresponding results from the 2022-11-19 observations (see below). First we take the median over all antennas and plot both polarisations individually: {{:projects:mkat_sband:pub:sefd_allants_pols.pdf|Both polarisations}} Second we average the polarisations but show the 10/50/90% percentile over all antennas. This means we see the typical range of antennas: {{:projects:mkat_sband:pub:sefd_allants_perc.pdf|10/50/90% percentiles, polarisations averaged}} In both files the first five panels show the individual subbands S0/1/2/3/4, the last one combines them all. The yellow vertical lines are the transition frequencies from one subband to the next. In reality the subbands are overlapping, but I always used the inner part where possible. == Files with the numbers == [[https://cloud.mpifr-bonn.mpg.de/index.php/s/NCkN2o9a2wGAQGH|Here the same data are provided as text files with space-separated numbers.]] The first line in each file describes the fields (the same for all). === Results for individual antennas === For a quick overview of the performance of all antennas, we provide curves for all antennas from relevant observations over all available subbands. **The first set of plots is meant to represent the latest measurements. These are currently the final SEFD measurements of 2022-11-19 at high elevations:** {{:projects:mkat_sband:pub:sefd_latest.pdf|PDF with SEFD curves}} \\ {{:projects:mkat_sband:pub:bandpass_latest.pdf|PDF with bandpass curves}}\\ {{:projects:mkat_sband:pub:bandpass_corr_latest.pdf|PDF with bandpass curves, amplitude corrected for digital decimation filter for a better comparison}}\\ {{:projects:mkat_sband:pub:sefd_bandpass_latest.pdf|PDF with SEFD and bandpass curves (dB)}}\\ {{:projects:mkat_sband:pub:sefd_bandpass_corr_latest.pdf|PDF with SEFD and bandpass curves (dB), amplitude corrected for digital decimation filter for a better comparison}} Note that the scales for some antennas are treated specially here for the moment, because the SEFD and bandpass phases are not in normal ranges. The filter-corrected bandpass curves can be used to see how consistent the bandpass is between observations in different subband modes. This is possible because of a large overlap between the bands. In order to study the differences between the two polarisations, we also provide plots of the logarithm of the radio pol0/pol1 for bandpass (signal, green), noise (SEFD, yellow) and signal-to-noise (red): {{:projects:mkat_sband:pub:polratio_latest.pdf|Ratio pol0/pol1 of signal, noise and signal/noise}} Different signal levels for the two polarisation can move the green and yellow curves up or down together but would not affect the red one. **The following plots include all observations, which makes very large and difficult to view. These are mainly good for historical purposes:** {{:projects:mkat_sband:pub:sefd_allants.pdf|PDF with SEFD curves}} \\ {{:projects:mkat_sband:pub:bandpass_allants.pdf|PDF with bandpass curves (linear)}}\\ {{:projects:mkat_sband:pub:bandpass_corr_allants.pdf|PDF with bandpass curves (linear), amplitude corrected for digital decimation filter for a better comparison}} \\ {{:projects:mkat_sband:pub:sefd_bandpass_allants.pdf|PDF with SEFD and bandpass curves (dB)}}\\ {{:projects:mkat_sband:pub:sefd_bandpass_corr_allants.pdf|PDF with SEFD and bandpass curves (dB), amplitude corrected for digital decimation filter for a better comparison}} Here are the corresponding plots of the logarithm of the radio pol0/pol1 for bandpass (signal, green), noise (SEFD, yellow) and signal-to-noise (red): {{:projects:mkat_sband:pub:polratio_allants.pdf|Ratio pol0/pol1 of signal, noise and signal/noise (all obs)}} **[[projects:mkat_sband:pub:decfilters#test_observations|A comparison of old and new decimation filters can be found here.]]** ==== Status of receivers (from interferometric data) ==== [[https://project.mpifr-bonn.mpg.de/projects/meerkat-meerkat-installation-and-commissioning/wiki/Rx_states|Receiver status (table at MPIfR)]] \\ [[https://cloud.mpifr-bonn.mpg.de/index.php/s/iNLBCorSAbY2f3w|new receiver status table (MPIfR)]]\\ [[https://docs.google.com/spreadsheets/d/1vkU8JbORwRnFbOLsAbmyU3Sf4chTLwfOdXe26Yq93r4/edit?usp=sharing|Pieter Kotze's receiver status table]] These are just rought numbers taken from the plots of the final measurements (only at the best frequencies). The replacement status is not necessarily up to date: ^ ant ^ best SEFD pol 0/1 [Jy] ^ batch ^ notes ^ ^ m000 | 390/410 | 1 | | ^ m001 | 390/400 | 2 | | ^ m002 | 390 | 1 | | ^ m003 | 390 | 1 | from previous obs, not included in last | ^ m004 | 400 | 1 | from previous obs, not included in last | ^ m005 | 400/420 | 1 | | ^ m006 | 390/440 | 1 | | ^ m007 | 410 | (was pre-prod) | | ^ m008 | 400 | (replaced) | | ^ m009 | 400 | 3 | | ^ m010 | 400/410 | 3 | | ^ m011 | 380/400 | 1 | | ^ m012 | 400/470 | 2 | | ^ m013 | 400 | 2 | | ^ m014 | 410/400 | 3 | | ^ m015 | 420/**450** | 3 | **second pol huge variations with freq** | ^ m016 | 410 | 2 | | ^ m017 | 430/410 | 3 | | ^ m018 | 420 | 2 | | ^ m019 | 400/470 | 3 | | ^ m020 | 390/440 | 3 | | ^ m021 | 400 | 1 | | ^ m022 | 400/470 | 2 | | ^ m023 | 380/410 | 2 | | ^ m024 | 410/400 | 4 | | ^ m025 | 400/420 | 3 | | ^ m026 | 470 | 3 | | ^ m027 | 400 | 2 | | ^ m028 | 380/420 | 4 | | ^ m029 | 430/440 | 4 | | ^ m030 | 400 | 1 | | ^ m031 | 400 | 3 | | ^ m032 | 420/400 | 3 | | ^ m033 | 390 | 3 | | ^ m034 | 400/440 | 3 | | ^ m035 | 400 | 3 | | ^ m036 | 400/**700** | 3 | **second pol very bad** | ^ m037 | 400 | 4 | | ^ m038 | 400/420 | 2 | | ^ m039 | 390 | 4 | | ^ m040 | 390/420 | 4 | | ^ m041 | 390/430 | 4 | | ^ m042 | 410/430 | 4 | | ^ m043 | 400 | 1 | from previous obs, not included in last | ^ m044 | 430 | 4 | | ^ m045 | 400 | 1 | | ^ m046 | 450 | 4 | | ^ m047 | 400 | 4 | | ^ m048 | 420/390 | 2 | | ^ m049 | 430/410 | 1 | | ^ m050 | 370/380 | 2 | | ^ m051 | 400/450 | 4 | | ^ m052 | 390/420 | 4 | | ^ m053 | 410/400 | 1 | | ^ m054 | 390 | 2 | | ^ m055 | 400/410 | 4 | | ^ m056 | 420 | 1 | from previous obs, not included in last | ^ m057 | 370/380 | 1 | | ^ m058 | 450/390 | 4 | | ^ m059 | 370/400 | 2 | | ^ m060 | 430 | 1 | | ^ m061 | 410 | 2 | | ^ m062 | 420/400 | 2 | **high bumps in first polarisation** | ^ m063 | 390/400 | 2 | | Three receivers/antennas (m015,m036,m062) are having problems at the moment. The others are all good, but have slightly different SEFD levels. ==== Noise variations ==== [[projects:mkat_sband:pub:noisevar|Analysis of several types of system noise variations]]