A process for correcting the time stamp of recordings such as photographs, obtained in many locations. An onboard clock records a time stamp for each photograph. GPS tracking data is obtained during movement of the camera. A time correction is sought, to account for an unknown error in the onboard clock, relative to the trusted GPS time data. To this end, an assigned location of each photograph is generated from the location tracking data and from an estimated time correction. Indicators of an appropriate time correction include clustering of the assigned locations, and correlation of the assigned locations to locations of reduced velocity. A GUI can be used to enable user assessment of clustering and/or correlation, and indication of a suitable time correction. Or, algorithmic assessment can be used. The determined time correction can be used to correct each photograph's time stamp.