The solution:
SEP Hydrographic routinely uses post-processed navigation solutions for these types of survey, and using SBET (Smartbase & Singlebase) invariably resolves these errors.
Our confidence in this methodology is often validated when vessel mounted LiDAR is complemented with Terrestrial Laser Scanning (TLS). The TLS data is surveyed using Total Stations, increasing the positional accuracy compared to the marine dataset. Where the same objects or structures have been captured by both the marine and terrestrial dataset, post-processed dynamically acquired data has always matched the TLS data.