Authors: Bin Zhuang (UNH), Noé Lugaz (UNH), Nada Al-Haddad (UNH), Camilla Scolini (UNH), Charles J. Farrugia (UNH), Florian Regnault (UNH), Emma E. Davies (ASWO), Wenyuan Yu (UNH), Réka Winslow (UNH), and Antoinette B. Galvin (UNH)

Coronal Mass Ejections (CMEs) are large-scale solar eruptions that expel huge clouds of magnetized plasma and magnetic flux from the corona to the heliosphere. Combining remote observations and in-situ measurements in the innermost heliosphere allows us to directly compare CME properties and validate the estimates derived through both techniques, which helps better understand CME evolution within the heliocentric distance of 0.5 au. We focus on a CME event that erupted on 2022 March 10 by combining the remote observations of heliospheric imagers (HIs) on board the STEREO-A spacecraft and the in-situ measurements from Solar Orbiter (SolO) which was in the innermost heliosphere at ~0.44 au during the time when the CME arrived at SolO between March 11 and 12. We find that the evolutions of the CME front and rear edges in remote images were consistent with the in-situ CME measurements. The CME is found to be associated with a density enhancement at its rear edge in both remote and in-situ observations, which validates the use of the signature of density enhancement following CMEs to accurately identify the CME rear edge. We also compare the radial expansion, one of the fundamental properties of CMEs, of different CME substructures and find that the radial expansion of the whole CME structure is consistent with the in-situ estimates obtained at the same time from SolO. However, we do not find such consistencies for the flux rope region inside the CME which may be due to uncertainties in identifying the exact flux rope boundaries from the remote images.