Disclosed embodiments pertain to combining Reference Signal Time Difference (RSTD) measurements from partial measurement sessions that result when a single measurement session is interrupted by one or more interruption events including Out of Service (OOS) or Inter-Frequency Handover (IFH) events. In some embodiments, first Time Of Arrival (TOA) measurements of cellular signals during a plurality of discontiguous partial measurement sessions separated by one or more interruption events may be obtained. Second TOA measurements based on a reference time source may be obtained for a plurality of the first TOA measurements from at least two partial measurement sessions. A cell associated with a second TOA measurement may be selected as a reference cell and for each non-reference cell associated with a second TOA measurement, a corresponding RSTD measurement may be obtained relative to the selected reference cell.