Date post: | 05-Jan-2016 |
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AstroGrid Solar/STP planning AstroGrid Solar/STP planning meetingmeeting
Agenda:Agenda:
• Helioscope
• Preparing for Solar-B
• Time-series viewing application
• IVOA and time series
A PPARC funded project
Start time
End time
Helioscope
SolarSTPCataloguesSTP/time lagged
Retrieving solar system data: Helioscope
Helioscope - Lite
• Returns FITS for solar and flat files in ‘native’ format for time series (ASCII, CDF…)
• Data from 2 main archives : VSO (Virtual Solar Observatory) and CDAW space physics archive using: -API provided by VSO http://vso.nascom.nasa.gov/API/ -SOAP interface to CDAW http://cdaweb.gsfc.nasa.gov/WebServices/
• Note: at this stage requests are not in standard form, but hard coded
• Short term solution – users easily get data – typically already have software dealing with specific format
Astroscope / Helioscope
• Astroscope is based on SIAP (Simple Image Access Protocol):
POS, SIZE are mandatory parameters:
EG: http://myimages.org/cgi-bin/VOimg?POS=18.567,-30.45&SIZE=0.01
• It’s convoluted to use POS, SIZE for Solar System objects.
• Define a Simple Time-range Access Protocol that returns a votable listing files (either images or time series) within specified time range
Mandatory parameters: START, END, FORMAT
• Ok also for Astronomy time based queries, eg by having optional parameters POS, SIZE. Other optional parameter could be INSTRUMENT
Helioscope - votable
• Returns time series data in a common format - votable
• DSA plugin that converts from ASCII, CDF to votable. If request spans more than 1 flat file, joins time series into a single votable
• Provide a framework where the data holders can specify what the local format is, and how translation to Votable should be done.
• NOTE: Votable does not have a url pointing to a data file any longer- the votable contains the data points themselves!
Identifying time series column in Votable
• In the votable containing time series data, the time field needs to be identified.
• 2 possible ways: (1) Introducing a datetime type in votable or (2) using a combination of UCD and Unit attributes.
• These are some current valid UCD words related to time: (from: http://www.ivoa.net/Documents/latest/UCDlist.html )
Q | time | Time Q | time.event | Duration of an event or phenomenon Q | time.event.end | End time of event or phenomenon Q | time.event.start | Start time of event or phenomenon Q | time.obs | Observation on-time, duration Q | time.obs.end | End time of observation Q | time.obs.start | Start time of observation Q | time.resolution | Time resolution Q | time.scale | Timescale
Viewing time series
• TOPCAT required features:
-automatic conversion from ISO time format to numeric values (column identified by UCD + Unit)
-stackplot capability
Summary: Helioscope-IVOA
• Work towards Helioscope-lite has started
• IVOA work: time UCDs, Simple Time-Range Access Protocol
• Define a way to identify time column in votable
• DSA plugin / way for data centers to provide time series data as VOT
• Topcat support for time series
CTIP model – mode A
• Available to all AG users as parametrised workflow
• Mode B – will allow automatic fetching of Kp and F10.7 from RAL – working – being fine tuned before release
CTIP model – mode A – output & documentation
• Future CTIP developments: convection maps from Superdarn as input – mode C,D,…
• Documentation on output files – example plotting programs
STP science case workflow
STP science case results