Improving hydrographic information ‐ zones of confidence (ZOC) for New Zealand

In July 2004 HSA Systems Ltd (HSA) commenced an eighteen month project for Land Information New Zealand (LINZ) to assess and assign Zones of Confidence (ZOCs) to all hydrographic surveys incorporated within 138 hydrographie charts of New Zealand. The project required each hydrographie survey to be assessed in relation to the data quality aspects of the International Hydrographie Organisation (IHO) S‐57 Standard (IHO, 2000). This paper will describe the process by which HSA assessed in excess of 1,792 hydrographie survey fair sheets and allocated 1,465 ZOCs to survey areas.

Keywords:

• Hydrographie surveys
• zones of confidence
• hydrographie standards
• electronic navigational charts