Contours--Offshore of Fort Ross, California

This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore of Fort Ross map area, California. The vector data file is included in "Contours_OffshoreFortRoss.zip," which is accessible from http://pubs.usgs.gov/ds/781/OffshoreFortRoss/data_catalog_OffshoreFortRoss.html. 10-m interval contours of the Offshore of Fort Ross map area, California, were generated from bathymetry data collected by California State University, Monterey Bay (CSUMB) and by Fugro Pelagos. Mapping was completed between 2007 and 2010, using a combination of 200-kHz and 400-kHz Reson 7125, and 244-kHz Reson 8101 multibeam echosounders, as well as 468-kHz SEA SWATHPlus interferometric system. These mapping missions combined to collect bathymetry from about the 10-m isobath to beyond the 3-nautical-mile limit of California State Waters. Bathymetric contours at 10-m intervals were generated from a bathymetric surface model. The most continuous contour segments were preserved while smaller segments and isolated island polygons were excluded from the final output. Contours were smoothed via a polynomial approximation with exponential kernel (PAEK) algorithm using a tolerance value of 60 m. The contours were then clipped to the boundary of the map area. These data are not intended for navigational purposes.本数据集为DS 781的组成部分，提供了加利福尼亚州罗斯堡近海地图区域的多张海底地形图水深等值线数据。矢量数据文件封装于"Contours_OffshoreFortRoss.zip"压缩包中，可通过链接http://pubs.usgs.gov/ds/781/OffshoreFortRoss/data_catalog_OffshoreFortRoss.html获取。 加利福尼亚州罗斯堡近海地图区域的10米间隔水深等值线，由加利福尼亚州立大学蒙特雷湾分校（California State University, Monterey Bay, CSUMB）与Fugro Pelagos采集的水深数据生成。测绘工作于2007年至2010年间完成，所用设备包括200kHz与400kHz的Reson 7125多波束测深仪（multibeam echosounders）、244kHz的Reson 8101多波束测深仪，以及468kHz的SEA SWATHPlus干涉测深系统（interferometric system）。此次测绘任务采集了约从10米等深线（isobath）至加利福尼亚州管辖海域3海里界限以外的水深数据。 10米间隔的水深等值线由水深表面模型生成，最终成果保留了连续性最优的等值线段，剔除了较短的零散线段与孤立岛状多边形。随后通过带有指数核的多项式近似（Polynomial Approximation with Exponential Kernel, PAEK）算法对等值线进行平滑处理，容差设置为60米，再将等值线裁剪至地图区域的边界范围。 本数据集并非用于导航用途。