The PSRDADA format is used internally within the MWAX correlator and beamformer components. It is not user-facing.The PSRDADA format is used internally within the MWAX correlator and beamformer components. It is not user-facing.
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Pre Correlator
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Keyword | Valid values or Example | Used By | Description | ||
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HDR_SIZE | 4096 | PSRDADA | Required by PSRDADA - size of header in bytes (should always be 4096) | ||
POPULATED | 0 | 1 | mwax_db2correlate2db | Used to ensure the correlator does not read an incomplete file. 0 means the file is not yet complete, 1 means the file is ready for consumption | ||
OBS_ID | 1244973688 | mwax-db2fits | Obs_id of this observation | ||
SUBOBS_ID | 1244973688 | mwax-db2fits | GPS second of this part of the observation. Increments in 8 sec intervals | ||
MODE | MWAX_CORRELATOR MWAX_VCS NO_CAPTURE | mwax_db2correlate2db mwax-db2fits | This matches the "mode" from the existing metadata database/schedule. | ||
UTC_START | 2018-10-11-05:26:14 | PSRDADA mwax-db2fits | Required by PSRDADA. This is the UTC start date/time of the subobservation(?). Used by mwax-db2fits to append a human readable date/time to the filename produced. | ||
OBS_OFFSET | 0 (n seconds since start of observation) | PSRDADA mwax-db2fits | Required by PSRDADA. I believe this is the number of seconds offset from the start of the observation. First subobservation will have this set to 0. Second subobservation will be 8, etc. | ||
NBIT | 8 | mwax_db2correlate2db | Bits per sample (should always be 8) | ||
NPOL | 2 | mwax_db2correlate2db mwax-db2fits | Polarisations per tile (i.e. rf_chains) (should always be 2) | ||
NTIMESAMPLES | 64000 | mwax_db2correlate2db | Number of timesamples in each input sub-block of a subobservation (nominally sub-blocks are 50 ms) | ||
NINPUTS | 256 | n rfinputs | mwax_db2correlate2db | Number of signal paths present in the input subobservation file, to be correlated (must be <= NINPUTS_XGPU) | ||
NINPUTS_XGPU | 256 | n rfinputs in multiples of 16 | mwax_db2correlate2db | Number of signal paths actually correlated by xGPU (must be a multiple of 16; must match the number of paths that xGPU has been configured for) | ||
APPLY_PATH_WEIGHTS | 0 | 1 | mwax_db2correlate2db | Should scalar path weights be applied prior to correlation (for gain normalisation and/or sub-arraying) | ||
APPLY_PATH_DELAYS | 0 | 1 | mwax_db2correlate2db | Should fractional path delays be applied prior to correlation (for phasing up to a correlation pointing centre) | ||
APPLY_PATH_PHASE_OFFSETS | 0 | 1 | mwax_db2correlate2db | Should path phase offsets be applied prior to correlation (for fringe-stopping, in conjunction with applying path delays) | ||
APPLY_COARSE_DERIPPLE | 0 | 1 | mwax_db2correlate2db | Should coarse PFB channeliser de-ripple be applied within the F-stage, prior to cross-correlation (key/value pair not currently implemented) | ||
DR_PARAM | NULL | deripplev1 | mwax_db2correlate2db | If APPLY_COARSE_DERIPPLE==1 then this value tells db2correlate2db which deripple settings to use (key/value pair not currently implemented) | ||
INT_TIME_MSEC | 200 - 8000 | mwax_db2correlate2db mwax-db2fits | Correlator integration time (milliseconds) | ||
FSCRUNCH_FACTOR | 40 (1 - 6400) | mwax_db2correlate2db mwax-db2fits | Correlator frequency scrunch factor: number of ultrafine 200 Hz fine channels to average together | ||
APPLY_VIS_WEIGHTS | 0 | 1 | mwax_db2correlate2db | Should data occupancy weights be applied to normalise the output visibilities | ||
TRANSFER_SIZE | 5275652096 | PSRDADA mwax_db2correlate2db | Total number of bytes of input data for one subobservation (of nominally 8 seconds) | ||
PROJ_ID | G0008 | mwax-db2fits | Project ID of observation | ||
EXPOSURE_SECS | 8 (in incremements of 8 seconds) | mwax-db2fits | Duration of observation in seconds | ||
COARSE_CHANNEL | 76 (0 - max receiver channel number == 255) | mwax-db2fits | Receiver channel number | ||
CORR_COARSE_CHANNEL | 9 | (1 - coarse channel max) | mwax-db2fits | Correlator channel number - which correlator channel "index" is this? e.g. first channel would be 1. In a 24 channel system, last channel would be 24. This would map to gpubox01-24 in the legacy Correlator | ||
SECS_PER_SUBOBS | 8 | mwax_db2correlate2db mwax-db2fits | Number of seconds per subobservation | ||
UNIXTIME | 1539235574 | mwax-db2fits | Unix time of the start of this observation. This field is used by mwax-db2fits to provide a UNIX timestep for each integration throughout the observation. | ||
UNIXTIME_MSEC | 0 | mwax-db2fits | Unix time milliseconds offset of the start of this observation. This will always be 0 with the current setup, but is here for completeness. | ||
FINE_CHAN_WIDTH_HZ | 10000 | mwax-db2fits | Correlator output fine channel width in Hz | ||
NFINE_CHAN | 128 | mwax_db2correlate2db mwax-db2fits | Correlator output number of fine channels | ||
BANDWIDTH_HZ | 1280000 | mwax-db2fits | Coarse channel passband width in Hz, i.e. the channel spacing | ||
SAMPLE_RATE | 1280000 | mwax_db2correlate2db | Actual sample rate of input data in samples/s (whether critically-sampled or oversampled). | ||
MC_IP | 0.0.0.0 | mwax-db2fits | Multicast IP for this coarse channel (for debug purposes) | ||
MC_PORT | 0 | mwax-db2fits | Multicast port for this coarse channel (for debug purposes) | ||
MWAX_U2S_VER | X.Y.Z | mwax_db2fits | Version number of mwax_u2s used to capture the UDP packets for this subfile | ||
MWAX_SUB_VER | 1 | mwax_u2s | Version number of subfile format. A value of 2 indicates the presence of the following fields: | ||
IDX_PACKET_MAP | (OFFSET)+(SIZE)¹ | mwax_u2s | Location and size of packet map in block 0 metadata0 metadata - note that the packetmap has been present in subfiles going back to some time in 2023, but the offsets have only been correct since u2s version 2.10 (rolled out ~ may 7 2024) | ||
IDX_METAFITS | (OFFSET)+(SIZE)¹ | mwax_u2s | 0+0 | deprecated/never implemented. Ignore if present. Location and size of copy of metafits file at time of the observation (the key/value pair exists but the metafits info is not currently written). This was dropped before we ever implemented the embedding, older subfiles may contain spurious entries. | |
IDX_DELAY_TABLE | (OFFSET)+(SIZE)¹ | mwax_u2s | Location and size of delay table in block 0 metadata | ||
IDX_MARGIN_DATA | (OFFSET)+(SIZE)¹ | mwax_u2s | Location and size of margin data section in block 0 metadata | ||
IDX_OCCUPANCY_TABLE | (OFFSET)+(SIZE)¹ | mwax_u2s | Location and size of data occupancy table in block 0 metadata (this key/value pair is currently not implemented) |
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