  The Cosmic Microwave Background anisotropies are difficult to measure at
large angular scales. In this paper, we present a new analysis of the \Planck\
High Frequency Instrument data that brings the cosmological part and its major
foreground signal close to the detector noise. The solar dipole signal, induced
by the motion of the solar system with respect to the CMB, is a very efficient
tool to calibrate a detector or a set of detectors with high accuracy. In this
work, the solar dipole signal is used to extract corrections of the frequency
maps offsets reducing significantly uncertainties. The solar dipole parameters
are refined together with the improvement of the high frequency foregrounds,
and of the CMB large scales cosmological anisotropies. The stability of the
solar dipole parameters is a powerful way to control the galactic foregrounds
removal in the component separation process. It is used to build a model for
Spectral Energy Distribution spatial variations of the interstellar dust
emission. The knowledge of these variations will help future CMB analyses in
intensity, and also in polarization to measure faint signal related to the
optical reionization depth and the tensor-to-scalar ratio of the primordial
anisotropies. The results of this work are: improved solar dipole parameters, a
new interstellar dust model, and a large scale cosmological anisotropies map.
