Data Capabilities of HELIO

HELIO does not hold any data per se, it provides integrated access to a range of different types of data from across the heliosphere through a variety of different sources.

In order to facilitate access, HELIO has established a rich search environment that is designed to allow the user to make intelligent decisions about which data sets are relevant to a particular science objective based on the origins of phenomena, how they propagate through the heliosphere and when and where different types of effects might be observed.

The search environment is based on a number of metadata services – these are summarised under Metadata Resources.

Types of Data

In order to address science use cases that span disciplinary boundaries, HELIO provides access to a wide variety of observations:

• Different types of remote-sensed observations of the Sun in a variety of wavelengths from a number of different vantage points. These include those from terrestrial ground-based observatories and spacecraft in near-Earth orbit and in different parts of the heliosphere
• Different types of in-situ observations in the environs of the Earth and other planets
• Different types of in-situ observations in other parts of the heliosphere

Near planets, HELIO includes data down to the level of the magnetosphere, where there is a magnetic field, but does not cover the ionosphere or lower.

HELIO has recently started to examine how we can improve access to certain types of ground-based observations. Because a ground-based observatory can only make observations for a fraction of the day – and this can further be interrupted by weather – it is necessary to provide access to as large a number of observatories scattered over as wide a range of longitudes as possible. The capabilities of various HELIO services should be able to help in this context.

Sources of Data

The sources of data used by HELIO include individual observatories, data archives and virtual observatories – these are summarised on the DPAS Interface Page. (Also see the hierarchy of data resources.)

To try to maximise the number of datasets available, HELIO has deliberately targeted sites that act as concentrators of observations from a number of missions and/or observatories – these include:

• NASA's Virtual Solar Observatory (VSO), CDAWeb and Planetary Data System (PDS)
• the French BASS2000 and MEDOC archives
• the UK Solar System Data Centre (UKSSDC)
• ESA's Planetary Science Archive (PSA)

Because of the way that such archives are managed, an added benefit of this approach is that once one dataset has been integrated it is relatively simple to add others.

A few datasets are available from more than one provider – included in this category are those from the SOHO and TRACE solar observatories. HELIO is able to handle datasets of this type, a capability that is managed by the DPAS using the Provider Access Table (PAT) that also tells the system how to access all datasets.

 
Last updated: 21st April 2015