Solar-wind 3-D reconstruction tomography based on interplanetary scintillation (IPS) studies provides fundamental information for space-weather forecasting models, and gives the possibility to determine heliospheric column densities. Here we compare the time series of Solar-wind column densities derived from long-term observations of pulsars, and the Solar-wind reconstruction provided by the UCSD IPS tomography. This work represents a completely independent comparison and validation of these techniques to provide this measurement, and it strengthens confidence in the use of both in space-weather analyses applications. Comment: Published in Journal of Advances in Space Research
