Contours Offshore of Point Reyes Map Map Area, California

This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore of Point Reyes map area, California. The vector data file is included in "Contours_PointReyes.zip," which is accessible from http://pubs.usgs.gov/ds/781/OffshorePointReyes/data_catalog_PointReyes.html. 10-m interval contours of the Offshore of Point Reyes 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's 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（DS 781）的此部分提供了加利福尼亚州雷耶斯角外海域制图区内多张海底地形图的水深等深线（bathymetric contours）数据。矢量数据文件封装于"Contours_PointReyes.zip"压缩包中，可通过链接http://pubs.usgs.gov/ds/781/OffshorePointReyes/data_catalog_PointReyes.html获取。 加利福尼亚州雷耶斯角外海域制图区的10米间隔等深线数据，由加州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。本次测绘工作于2007至2010年间完成，所用设备包括200kHz与400kHz的Reson 7125多波束测深仪、244kHz的Reson 8101多波束测深仪，以及468kHz的SEA SWATHPlus干涉测量系统。本次测绘任务共采集了约10米等深线至加州领海3海里以外区域的水深数据。10米间隔的水深等深线由水深表面模型生成，最终输出结果中保留了连续性最优的等深线片段，剔除了零散的短片段与孤立的岛屿多边形要素。等深线通过带指数核的多项式近似（Polynomial Approximation with Exponential Kernel，PAEK）算法进行平滑处理，平滑容差设为60米，随后将平滑后的等深线裁剪至制图区边界。本数据集不得用于导航作业。