The most powerful survey of the next decade to derive the desired precision galaxy distributions is the large-area multi-filter survey J-PAS, which is the culmination of multi-filter medium and narrow-band surveys. They are a different flavour of survey, half-way between photometry and spectroscopy, that provide low resolution photo-spectra of every observed pixel. Multi-filter surveys were initiated by COMBO-17, and followed by COSMOS-20, MUSYC, ALHAMBRA, SHARDS, and PAU. With 56 contiguous narrow-band filter (~145Å) observations over 8500deg² of the northern sky, J-PAS will provide R ~ 50 photo-spectra of about 200.000.000 galaxies with r < 22.5, leading to a photometric redshift precision of ~1000 km/s, and allowing emission line and stellar continuum measurements.
The PROFUSE project is developing analysis techniques to deal with luminosity/mass functions, emission lines and stellar populations, the environment, and the AGN activity from the local Universe to the high redshift regime at z > 2 using the multi-filter surveys ALHAMBRA, J-PLUS, and J-PAS.
The Javalambre-Photometric Local Universe Survey, J-PLUS, is an unprecedented photometric sky survey of 8500 deg2 visible from Javalambre, using a set of 12 broad, intermediate and narrow band filters. J-PLUS will be a powerful 3D view of the nearby Universe that will observe and characterize tens of millions of galaxies and stars of the Milky Way halo, with a wide range of Astrophysical applications.