| astrom | Astrom | Information about the astrometry | | |
| CDELT3 | float | The partial derivative of the coordinate with respect to the pixel index | | instr.bandwidth |
| CDELT4 | float | The partial derivative of the coordinate with respect to the pixel index | | |
| creation_date | datetime | Date this object was created | | time.epoch |
| CROTA3 | float | Rotation from the standard coordinate system | | |
| CROTA4 | float | Rotation from the standard coordinate system | | |
| CRPIX3 | int | The reference point | | instr |
| CRPIX4 | int | The reference point | | |
| CRVAL3 | float | The value of the coordinate at the reference point | | pos.wcs.crval |
| CRVAL4 | float | The value of the coordinate at the reference point | | |
| CTYPE3 | str | The name of the coordinate represented by axis | | |
| CTYPE4 | str | The name of the coordinate represented by axis | | |
| CUNIT3 | str | The unit of third axis | | |
| CUNIT4 | str | The unit of fourth axis | | |
| DATE_MAP | datetime | Date of making the map | | time |
| DATE_OBS | datetime | Date of the observation of the frame | | time.obs |
| EPOCH | str | Epoch | | time.epoch |
| filename | str | The name of the associated file | | meta.id meta.file |
| globalname | str | The name used to store and retrieve file to and from Storage | | meta.id |
| instrument | Instrument | Information about the instrument | | instr.obsty |
| is_valid | int | Manual/external flag to disqualify bad data (SuperFlag) | | meta.code |
| NAXIS | int | Number of axes | | |
| NAXIS1 | int | Number of pixels on axis 1 (RA) | | pos.wcs.naxis |
| NAXIS2 | int | Number of pixels on axis 2 (DEC) | | pos.wcs.naxis |
| NAXIS3 | int | Number of pixels on axis 3 | | pos.wcs.naxis |
| NAXIS4 | int | Number of pixels on axis 4 | | |
| OBJECT | str | Object name | | meta.id |
| OBSERVER | str | The observer | | obs.observer |
| PCDEC | float | DEc Pointing centre | | pos.eq.dec |
| PCRA | float | RA Pointing centre | | pos.eq.ra |
| PSF_BMAJ | float | Major axis of the beam | | instr.det.psf |
| PSF_BMIN | float | Minor axis of the beam | | instr.det.psf |
| PSF_BPA | float | Position angle of the beam | | instr.det.psf |
| RESTFREQ | float | line rest frequency | Hz | |
