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| Column Name | VO Equivalent | Source | Comments | ||
|---|---|---|---|---|---|
| target_name | target_name | OBJECT Keyword | |||
| center_ra (center_position) | s_ra | Center of Ra Axis | |||
| center_dec (center_position) | s_dec | Center of Dec Axis | |||
| field_of_view | s_fov | Average of NAXISn*CRDELn of the Spacial Axes | |||
| spacial_region | s_region | Derived from Spacial Data | STC-S String Defined in the TAP (Dowler, et al 2010) | ||
| ra_element_count | s_xel1 | Relevent NAXISn Keyword | |||
| dec_element_count | s_xel2 | Relevent NAXISn Keyword | |||
| spacial_resolution | s_resolution | Average of CRDELn of the Spacial Axes | |||
| image_stop_time | t_max | Temporal domain information for an image is dependent upon the observation(s) used in its generation. Some controlling process (Like Vlass Manager, whatever imaging pipeline we create, and any image manipulation software we use) will need to supply it. | |||
| image | .image_start_time | t_min | |||
| image_integration_time | t_exptime | temporal_element_count | t_xel | ||
| frequency_min( observing_band) | em_min | Minimum of Spectral Axis | The spectral information is recoverable from the FITS header, and will identify the | observing receiver(s)spectral coverage, and total bandwidth processed for the image. | |
| frequency_max (observing_band) | em_max | Maximum of Spectral Axis | |||
| spectral_resolution | em_res_power | Spectral CRDELn Keyword | |||
| spectral_element_count | em_xel | Spectral NAXISn Keyword | |||
| image_units | o_ucd | BTYPE & BUNIT Keywords | Description of the physical quantity measured in the image | ||
| polarization_id | pol_states | Deduced from NAXISn Keyword | More clarity is required for polarization information, as the exemplar files (Vlass quicklook images) have limited information available. Some method of conveying information about images (in CTYPE/CUNIT keywords, or via outside information) is required to get anything other than an overly simplistic assumption (NAXISn = 1 means Stokes I and NAXISn = 4 means Full Stokes Parameters). | ||
| polarization_element_count | pol_xel | Relevent NAXISn Keyword | |||
Currently, there is insufficient information provided about the polarization information of the image in the quicklook FITS headers. There is a STOKES axis, but no further information is provided. Since Single Epoch images will be created in Stokes I, Q, and U, that information must be provided to distinguish the files. Adding the stokes parameter name to the CTYPEn or CUNITn header keywords would solve this issue. | |||||
| telescope | instrument_name | TELESCOP Keyword | The observing instrument(s) | This must accommodate images for multiple instruments (i.e. VLA + Single Dish) | |
| file_id | automatically generated | link to information about the physical file | |||
| image_id | obs_id | automatically generated | Unique Identifier for the Image | ||
| image_units | fileo_ | idautomatically generated | link to information about the physical fileucd | BTYPE & BUNIT Keywords | Description of the physical quantity measured in the image |
| max_intensity | These values are can be determined from the data portion of the image file in conjunction with the BSCALE & BZERO keywords. The library which is used for FITS interaction for ingestion can perform these calculations, but no information about the speed of results is yet available. | ||||
| min_intensity | |||||
| rms_noise | |||||
| thumbnail | weblog, a PNG with identical name |
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| VO Requirement | Value | Source |
|---|---|---|
access_url | ||
| access_estsize | files.filesize, or combined value for an image set | |
| dataproduct_type | 'image' | default |
| access_format | 'fits' | default |
obs_publisher_did | Obtained upon registering with the Virtual Observatory | |
| facilty_name | 'NRAO' | default |
| t_resolution | images.image_integration_time | |
| t_xel | 1 | default |
| em_xel | 1 | default |
| pol_xel | 1 | default |