  The solar wind (SW) is an outflow of the solar coronal plasma, expanding
supersonically throughout the heliosphere. SW particles interact by charge
exchange with interstellar neutral atoms and on one hand, they modify the
distribution of this gas in interplanetary space, and on the other hand they
are seed population for heliospheric pickup ions and energetic neutral atoms
(ENAs). The heliolatitudinal profiles of the SW speed and density evolve during
the cycle of solar activity. A model of evolution of the SW speed and density
is needed to interpret observations of ENAs, pickup ions, the heliospheric
backscatter glow, etc. We derive the Warsaw Heliospheric Ionization Model 3DSW
(WawHelIon 3DSW) based on interplanetary scintillation (IPS) tomography maps of
the SW speed. We take the IPS tomography data from 1985 until 2020, compiled by
\citet{tokumaru_etal:21a}. We derive a novel statistical method of filtering
these data against outliers, we present a flexible analytic formula for the
latitudinal profiles of the SW speed based on Legendre polynomials of varying
order with additional restraining conditions at the poles, fit this formula to
the yearly filtered data, and calculate the yearly SW density profiles using
the latitudinally invariant SW energy flux, observed in the ecliptic plane.
Despite application of refined IPS data set, a more sophisticated data
filtering method, and a more flexible analytic model, the present results
mostly agree with those obtained previously, which demonstrates the robustness
of IPS studies of the SW structure.
