Abstract: Three-dimensional electron density distributions in the solar corona are reconstructed for 100 Carrington rotations (CR 2054 – 2153) during 2007/03 – 2014/08 using the spherically symmetric method from polarized white-light observations with the inner coronagraph (COR1) onboard the twin Solar Terrestrial Relations Observatory (STEREO). These three-dimensional electron density distributions are validated by comparison with similar density models derived using other methods such as tomography a…