Time Series markup up for testing

[Mark Taylor]

Markus,

On Wed, 5 Aug 2020, Markus Demleitner wrote:

> I've just taught DaCHS to produce what I hope is close to what Ada
> had in mind in
> 
> http://ivoa.net/documents/Notes/LightCurveTimeSeries/
> 
...
> 
> k2c9vst: http://dc.zah.uni-heidelberg.de/getproduct/k2c9vst/data/OGLE-2016-BLG-0968_VST_r_SDSS68.t
> 
> BGDS in SDSS i: http://dc.zah.uni-heidelberg.de/bgds/l/tsdl/dlget?ID=BGDS-1825-1423-i-277.1723680-14.3354807
> BGDS in SDSS r: http://dc.zah.uni-heidelberg.de/bgds/l/tsdl/dlget?ID=BGDS-0744-2158-r-115.2631363-22.6573959
> 
> Gaia DR2, in the three Gaia bands: 
> http://dc.zah.uni-heidelberg.de/getproduct/gaia/q2/1000103304040175360/RP
> http://dc.zah.uni-heidelberg.de/getproduct/gaia/q2/1000103304040175360/BP
> http://dc.zah.uni-heidelberg.de/getproduct/gaia/q2/1000103304040175360/G

These all appear to work fine in topcat as far as the TIMESYS
metadata goes.  If you load them in and look at the Columns window
(http://www.starlink.ac.uk/topcat/sun253/ColumnInfoWindow.html)
you can see that the obs_time column is marked with a "Domain" of
TIMESYS->Time, and has the special metadata items
TimesysRefposition, TimesysTimeorigin and TimesysTimescale filled
in as per the VOTable markup.

Additionally, since topcat v4.7-1 (earlier this year), you can plot
these tables in the no-longer-experimental Time Plot window 
(http://www.starlink.ac.uk/topcat/sun253/TimePlotWindow.html)
- it figures out what the time coordinate is trying to say and
plots the points on a human-readable time axis.

I'm not attempting to do anything clever with photometry.

This may be a good time to ask: if TDIG people think topcat should
be doing other stuff with this TIMESYS information, I'd be happy
to discuss it.

Mark

--
Mark Taylor   Astronomical Programmer   Physics, Bristol University, UK
m.b.taylor at bris.ac.uk +44-117-9288776  http://www.star.bris.ac.uk/~mbt/