This presentation was given at the Solar Orbiter Science Activity Plan Meeting #4. It is a review on the techniques and achievements of helioseismology during the last decades. Furthermore, it gives an outlook on the science to be facilitated with ESA's space misison Solar Orbiter.

Frank Hill, Sanjay Gosain, Michael Thompson

The Solar Physics Research Integrated Network Group (SPRING) is a project to develop a geographically distributed network of instrumentation to obtain synoptic solar observations. Building on the demonstrated success of networks to provide nearly-continuous long-term data for helioseismology, SPRING will provide data for a wide range of solar research areas. Scientific objectives include internal solar dynamics and structure; wave transport in the solar atmosphere; the evolution of the magnetic field over the activity cycle; irradiance fluctuations; and space weather origins. Anticipated data products include simultaneous full-disk multi-wavelength Doppler and vector magnetic field images; filtergrams in H-Alpha, CaK, and white light; and PSPT-type irradiance support. The data will be obtained with a duty cycle of around 90% and at a cadence no slower than one minute. The current concept is a multi-instrument platform installed in at least six locations, and which will also provide context information for large-aperture solar telescopes such as EST and the DKIST. There is wide support for the idea within the EU and the US solar research communities. The project is currently completing a technical feasibility study, and we are open to and looking for participants in the science and instrument definition.

This is my talk given at the meeting in Dübendorf.

This presentation was given at the 1st ISSI International Team Meeting on "Studies of the Deep Solar Meridional Flow" (CID: iss2016). It deals with validating the Fourier-Legendre Analysis technique by using artifical data.