Pulsar Observation Ingestion

Requirements: Collection Support: VLA Pulsar Observation

JIRA Ticket: SSA-6377 - Getting issue details... STATUS

Pulsar file ingestion and metadata extraction will proceed similarly to an EVLA SDM ingestion with possible additional (science, ancillary?) products, identified in a metadata.json file.

Binned Imaging Observations

In binning mode there are no additional products. The only science product is the execution block as defined by the SDM. The SDM will contain an additional table, Pulsar.xml which will give the metadata for the scans using binning mode. Scan information is retrieved using a standard SDM approach: Main.xml contains scans and a pointer to a Config Description which contains a pointer to a Data Description which may contain a pointer to an entry in the Pulsar table. If there is no pointer to the Pulsar table in the Data Description, binning mode was not used for that scan.


<row>
<dataDescriptionId>DataDescription_15</dataDescriptionId>
<polOrHoloId>Polarization_0</polOrHoloId>
<spectralWindowId>SpectralWindow_15</spectralWindowId>
</row>

<row>
<dataDescriptionId>DataDescription_16</dataDescriptionId>
<polOrHoloId>Polarization_0</polOrHoloId>
<pulsarId>Pulsar_0</pulsarId>     <--- indicates binning mode for the scan
<spectralWindowId>SpectralWindow_0</spectralWindowId>
</row>

Phased-array Observations

Examples: /lustre/aoc/sciops/pdemores/

.cf calibration files

.ar pulsar data files

File set: 18A-210_sb35398245_1_1.58270.41125583333

Associated files:

<file set>.scan_id.subscan_id.IF_name.Index_within_subscan/IF_[.ar | .cf]

Metadata

For the PSRFITS files:


Observing Mode	hdu['PRIMARY'].header['OBS_MODE']
Number of bins	hdu['SUBINT'].header['NBIN']
Time resolution
Number of channels	hdu['SUBINT'].header['NCHAN']
Number of polarization products	hdu['SUBINT'].header['NPOL']
Period
Dispersion Measure	hdu['SUBINT'].header['DM']

Notes

It is possible for an observation to use 'mixed-modes'. Some scans could use binning mode and other scans could use phased-array mode.

Summary

For binned mode, the pulsar metadata is part of the SDM and can be handled with an extension of the standard SDM ingestion with additional fields in the database for the metadata.

For phased-array mode, the pulsar metadata is contained in the .ar and .cf PSRFITS files. In this case, it might be technically more feasible to extract the metadata from the PSRFITS files and place them in a metadata.json file that represents metadata per scan/subscan (IF?).

The PSRFITS files represent ancillary products of the execution block science product. They do, however, provide additional metadata for the execution block at the individual scan level.

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Binned Imaging Observations

Phased-array Observations

Metadata

Notes

Summary

Questions