A collaborative effort to meet New Zealand´s mapping requirements: multibeam echosounder integration, acceptance testing, and Antarctic mapping aboard the Research Vessel Tangaroa

The National Institute of Water and Atmospheric Research Limited (NIWA) integrated a 30 kHz Kongsberg Simrad EM-300 multibeam echosounder on their research ship, the R/V Tangaroa to help meet the mapping and charting requirements of Land Information New Zealand (LINZ) and to support NIWA´s science and consulting activities. Installation of the hull-mounted multibeam system was performed during a seven-day vessel dry-docking in November 2000. The EM-300, leased to NIWA by C&C Technologies, was put through a series of stringent calibration and acceptance tests by LINZ prior to its performance of hydrographic charting in the Western Ross Sea of Antarctica. This paper details the LINZ Hydrographic Survey Standards and their specifications for the Western Ross Sea survey, NIWA´s evaluation and selection of a multibeam system to meet these standards and specifications, and the system´s integration upon the R/V Tangaroa. Predicted error budgets are provided for the EM-300´s vertical accuracy and feature detection capabilities. An evaluation of the calibration and acceptance testing and a comparison to the predicted performance of the EM-300 are provided. Conclusions resulting from the Western Ross Sea 2001 voyage, along with the mapping data collected by the EM-300, are presented. Experiences and issues associated with surveying in the harsh Antarctic environment during the February-March 2001 voyage are also detailed