  In the near future, Parker Solar Probe and Solar Orbiter will provide the
first comprehensive in-situ measurements of the solar wind in the inner
heliosphere since the Helios mission in the 1970s. We describe a reprocessing
of the original Helios ion distribution functions to provide reliable and
reproducible data to characterise the proton core population of the solar wind
in the inner heliosphere. A systematic fitting of bi-Maxwellian distribution
functions was performed to the raw Helios ion distribution function data to
extract the proton core number density, velocity, and temperatures parallel and
perpendicular to the magnetic field. We present radial trends of these derived
proton parameters, forming a benchmark from which new measurements in the inner
heliosphere will be compared to. The new dataset has been made openly available
for other researchers to use, along with the source code used to generate it.
