Lessons learned in multi-platform hydrographic surveys

The Unites States Navy stands at the brink of transition from traditional navigation with paper charts to computer-based electronic charting. The Naval Oceanographic Office (NAVOCEANO), collector of worldwide hydrographic data for 172 years, is posturing to support this transition with state-of-the-art survey platforms, instrumentation, and processing and chart production software. Recently, NAVOCEANO, in cooperation with the National Ocean Service of the National Oceanic and Atmospheric Administration (NOS/NOAA), completed hydrographic surveys in the U.S. Pacific territories of Guam and Saipan in support of urgent Navy operational requirements. Data collection was conducted by the new multipurpose survey ship USNS Sumner, a new independent rapidly deployable survey team called the Fleet Survey Team (FST), and the Scanning Hydrographic Operational Airborne Lidar Survey (SHOALS). Each survey system brought unique capabilities to the toolbox of surveying assets. Each survey system also brought unique perils to the data validator and chart compiler with system errors that first had to be recognized, then the causes determined, and then solutions found. It was indeed fortunate that these three different collection systems were able to work the same survey area, allowing comparison of three different data sets and the discovery of potential systemic errors. Following a very thorough investigation, data from all three systems were corrected and then used for the production of both a paper nautical chart and the Digital Nautical Chart (DNC) library. This new nautical chart information was provided to NOAA and the National Imagery and Mapping Agency (NIMA) for general distribution to both the public and the fleet.