Radio Astronomy Interest Group

Fourth Virtual Meeting 2022, March 7th/8th via zoom

Telecon Agenda:

• LMT, Peter Teuben
• GBT, Thomas Chamberlin/
• Parkes, James Dempsey
• Italian radioastronomy archive, Alessandra Zanichelli
• FAST data, Zheng Zheng

Minutes

LMT

Peter Teuben:

50 m dish 1/3 mm waveband many instruments : so spectra, 2D images, 3D spectral line cubes

raw data , calibrated data (netCDF or SDFITS)

Obscore for LMT

Make obscore tables for Level1-Level2 data and above (calibrated spectra, cubes, mosaics, ADMIT products).Hosted on dataverse (By the way : how does that fit for TAP services?)

Discussion: questions about units for resolution (arcsec always we think, but need to check ALMA), frequency support (multiple spw per observation). A plan could be same obsid different obs_publisher_did for each spectral window

GBO

Thomas Chamberlin (and Dave Frayer):

GBO data will be stored at new GBO data center and served through the NRAO archive access tool (AAT) (no VO yet for the AAT, is in the long-term plan).

up to 1 peta byte of data. PSRFITS and SDFITS (uncalibrated)

access through astroquery

Discussion: Databases : DataVerse ? -> Postgresql

best way to ensure VO compatibility - make sure ObsCore information is present (can always write a mapping). Severin suggests start with a TAP service, the TAP layer can do the translation between observatory metadata and obscore (crosswalk).

Parkes

James Dempsey described the current state of VO services from Australian radio projects - presents specs for CASDA VO services that can be placed on the IVOA RIG wiki (SDHF format).

This is it : https://bitbucket.csiro.au/projects/CPDA/repos/sdhdf_test_data/browse/uwl_191208_055418.hdf

- Data (including recent ones) obtained with old Parkes receivers are in RPFITS format. They do appear in ATOA ObsTAP services

- Data obtained with new UWL receiver are stored in SDHF format (= an HDF5 Format using the SDFITS header structure) they are available on WEB UI at ATOA but not in ObscOre

Discussion : interest from other groups for SDHF format

INAF radio archive

Alessandra Zanichelli describes the different observing modes (on/off, raster, flying scan, etc...) and the data structure. The data structure is made of table fits extension files for subscans groupped in scan directories with summary headers for all the scan (no SDFITS)

Also question of mult feed receivers

hierarchichal view --> scan entity is relevant for ObsCore ?

Then Alessandra browsed the mandatory ObsCore parameters

some questions/issues on s_fov, s_region, s_resolution, t_tresolution,

em_res_power not adapted ---> em_resolution

question of multiple spectral windows like LMT (see above)

Discussion : For different spectral windows: at waht part of raw data do people want to go ? is it OK to go back so deep .? in science gateway ..how do we articulate raw data / processed data ...

Do we describe spectral supports instead of splitting observations in several datasets ? --> may be difficult

FAST science cases and data

A presentation by Zheng :

FAST = 500 m Aperture Spherical radio telescope

5 field cabins

science and data :

HI observation, HI absorbtion, FRB, pulsars, specral data

CRAFTS : (comensal survey) half of the sky

SDFITS format is used with specific additional keywords

KY files have been developped (index files ???)

Dataset size is an issue for distribution