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CARTAvis / carta-frontend

Source code repository for the frontend component of CARTA, a new visualization tool designed for the ALMA, the VLA and the SKA pathfinders.
https://cartavis.github.io/
GNU General Public License v3.0
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Simbad `dist` calculation has ~0.01-0.1 arcsec difference #1669

Open panchyo0 opened 3 years ago

panchyo0 commented 3 years ago

I have also tested the sorting and filtering functions and compared with the backend sorting and filtering functions. All looking good.

one thing I noticed is the "dist" calculation has ~0.01-0.1 arcsec difference comparing to the downloaded votable. It would be good to try to make the dist calculation as precise as possible. This minor issue is not critical though.

Originally posted by @kswang1029 in https://github.com/CARTAvis/carta-frontend/pull/1651#pullrequestreview-769538429

panchyo0 commented 3 years ago

@kswang1029 open a new issue at here, we are calculate the distance by the DISTANCE() from TAP, then convert to arcsec by 3600. for example `SELECT Top 1000 , DISTANCE(POINT('ICRS', 277.4873, 48.6946), POINT('ICRS', ra, dec)) as dist FROM basic WHERE CONTAINS(POINT('ICRS',ra,dec),CIRCLE('ICRS',277.4873, 48.6946,1))=1 AND ra IS NOT NULL AND dec IS NOT NULL order by dist` not sure where the offset comes from 🤔