MeerKAT S band receiver commissioning (public part)

This area is for notes and results on the receiver commissioning. The namespace projects:mkat_sband is private to the MPIfR, the subspace projects:mkat__sband:pub has public read access.

SARAO web archive for commissioning proposal SSV-20200929-OW-01

Map of array

main

receptor status

S band install SN

Review of SARAO provided test data

S band main page

reference

All in MHz:

Please note that these are the total band ranges. The filters are pretty narrow so that significantly less is usable.

A discussion of the digital decimation filters can be found here.

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.

We determine delays and phases with fringe-fitting (click for details) per baseline. After calibrating the phases per baseline, we can 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 bandpass (amplitude and phase, click for details).

Details of results for individual observations can be found here.

For a quick overview of the performance of all antennas, we provide curves for all antennas from all relevant observations over all available subbands (sorted by observation id):

PDF with SEFD curves
PDF with bandpass curves (linear)
PDF with bandpass curves (linear), amplitude corrected for digital decimation filter for a better comparison
PDF with SEFD and bandpass curves (dB)
PDF with SEFD and bandpass curves (dB), amplitude corrected for digital decimation filter for a better comparison

In addition we have plots that only include post-repair data for the receivers that have been fixed at some point. They are sorted by subband:

PDF with SEFD curves
PDF with bandpass curves
PDF with bandpass curves, amplitude corrected for digital decimation filter for a better comparison
PDF with SEFD and bandpass curves (dB)
PDF with SEFD and bandpass curves (dB), amplitude corrected for digital decimation filter for a better comparison

The following plots are meant to represent the latest status of measurements. Only the latest observations are included (currently only the S2 and S4 of 11th Oct 2021):

PDF with SEFD curves
PDF with bandpass curves
PDF with bandpass curves, amplitude corrected for digital decimation filter for a better comparison
PDF with SEFD and bandpass curves (dB)
PDF with SEFD and bandpass curves (dB), amplitude corrected for digital decimation filter for a better comparison

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):

Ratio pol0/pol1 of signal, noise and signal/noise (all obs)
Ratio pol0/pol1 of signal, noise and signal/noise (only good obs)

And here the same for only the latest measurements:

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.

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. This is probably because those receivers were not ready for observations.

Receiver status (table at MPIfR)
new receiver status table (MPIfR)
Pieter Kotze's receiver status table

These are just rought numbers taken from the plots (only at the best frequencies):

Total "good": 50, minor issues: 15, bad: 1, no signal yet: 3

TO DO