NOS Hydrographic Survey bottom sample recovery

The National Oceanic and Atmospheric Administration (NOAA) National Ocean Service (NOS) Hydrographic Survey Division (HSD) and National Geophysical Data Center (NGDC) recently completed a joint project to provide web access to hydrographic survey metadata from the NOS Hydrographic Survey Metadata Database (HSMDB). The new online metadata display is offered on the NGDC web site (http://www.ngdc.noaa.gov/mgg/bathymetrv/hvdro.html) under the product name Rap Sheet. One innovative feature of this view is a link to the growing database of seabed "bottom type" derived from samples collected during surveys. These samples provide seabed type annotations for nautical charts, but also have applications outside the navigation community. Bottom samples must have a source with adequate geographic location and description. This paper examines the four sources of HSMDB bottom samples: Oceanographic Log "M" Sheets, Descriptive Report tabular listing, digital feature files in CARIS .hob format, and survey Detached Position plots. Preliminary results of the author\´s ongoing review suggest that adequate bottom type information exists for only seventy percent of the 8,400 surveys with verified metadata in HSMDB (H08000, c.1952, to the present). This paper will discuss efforts to address the remaining thirty percent of surveys for which there is currently incomplete and/or conflicting bottom sample information in the database. Specifically the discussion will focus on: 1) Auditing the current post-H08000 HSMDB bottom sample holdings, 2) Finding "M" log sheets or survey tabular lists for uncorroborated data and resolving NGDC cruise and HSMDB display conflict, 3) Extracting bottom sample metadata from modern survey digital feature files in CARIS .hob format, and 4) completing all HSMDB Rap Sheet bottom samples with matching NGDC display and NOS count from the best available source