Evaluating Outside Source Interferometric Data for Chart Updates

TitleEvaluating Outside Source Interferometric Data for Chart Updates
Publication TypeConference Proceedings
AuthorsBongiovanni, C, Schmidt, V
Conference Name2016 Canadian Hydrographic Conference
Conference DatesMay 16-19
PublisherCanadian Hydrographic Association
Conference LocationHalifax, Nova Scotia, Canada
Keywordschart updates, Interfermometric data

Incorporation of “outside source” bathymetric data is advantageous to maintaining accurate and current NOAA nautical charts. Whether from governmental, academic, or commercial sources, many surveys are conducted annually around the country for purposes other than hydrography. While many of these surveys adhere only to some degree to the NOAA and International Hydrographic Office requirements, when properly vetted they provide useful information for survey reconnaissance and chart updates. Most outside source data comes from beam-forming sonars similar to those used by NOAA. However, a small portion comes from interferometric (non beam-forming, phase measuring) systems, which until recently NOAA did not accept for internal or contract survey work. This exclusion results from the volume of data and noisy nature of first generation systems, whose data proved difficult for NOAA’s standard processing methods and software to accommodate. Here we investigate a USGS survey within Buzzards Bay, MA, collected with a first generation SEA SwathPlus interferometric sonar. Methods are shown for assessing the data for hydrographic purposes. In addition, methods are proposed for assessing survey uncertainty allowing the data to be used for charting. Guidelines are given for collection and processing of data that may aid in their future use for hydrography.