Georeferenced Scans of National Oceanic and Atmospheric Administration (NOAA) T-Sheets Collected Along the New Jersey Coastline from 1839-1875

Historical shoreline surveys were conducted by the National Ocean Service (NOS), dating back to the early 1800s. The maps resulting from these surveys, often called t-sheets, provide a reference of historical shoreline position that can be compared to modern data to identify shoreline change. The t-sheets are stored at the National Archives and many have been scanned by the National Oceanic and Atmospheric Administration (NOAA) and are available on the NOAA Shoreline Web site (http://www.shoreline.noaa.gov/data/datasheets/t-sheets.html). While some scanned t-sheets were georeferenced and digitized by NOAA, still others remain as non-georeferenced raster files (http://nosimagery.noaa.gov/images/shoreline_surveys/survey_scans/NOAA_Shoreline_Survey_Scans.html).
New_Jersey_1839_75_t-sheets.zip features 8 georeferenced raster t-sheets for the New Jersey coastline from 1839 to 1875. The data were scanned by NOAA, but were not georeferenced. The t-sheets included in this data release are: T-121 (1839), T-119 Part 1 (1841), T-1084 (1868), T-1166 (1870), T-1333 (1871), T-1315a (1872), T-1371 (1874), T-1407 (1875). Digital files were georeferenced, corrected to a modern datum, and shorelines digitized to provide a vector polyline depicting the historical shoreline position using ArcGIS 10.3.1. GEoreferenced t-sheets were used to delineate and shorelines for use in long-term shoreline and wetland analyses for Hurricane Sandy wetland physical change assessment.

美国国家海洋服务局（National Ocean Service, NOS）所开展的海岸线历史测绘工作，其历史可追溯至19世纪初。这些测绘工作产出的海图通常被称为T型测绘海图（t-sheets），可为历史海岸线位置提供参照基准，可与现代观测数据对比以识别海岸线变迁情况。此类T型测绘海图均存储于美国国家档案馆，其中多数已由美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）完成扫描，并可在NOAA海岸线官方网站（http://www.shoreline.noaa.gov/data/datasheets/t-sheets.html）获取。尽管部分已扫描的T型测绘海图已由NOAA完成地理配准与数字化处理，但仍有大量仅以未地理配准的栅格文件形式留存（http://nosimagery.noaa.gov/images/shoreline_surveys/survey_scans/NOAA_Shoreline_Survey_Scans.html）。
New_Jersey_1839_75_t-sheets.zip 数据集包含8幅针对1839年至1875年新泽西州海岸线的已地理配准栅格T型测绘海图。该数据已由NOAA完成扫描，但未进行地理配准。本次发布的数据中包含的T型测绘海图如下：T-121（1839年）、T-119 第一部分（1841年）、T-1084（1868年）、T-1166（1870年）、T-1333（1871年）、T-1315a（1872年）、T-1371（1874年）以及T-1407（1875年）。研究团队使用ArcGIS 10.3.1对数字文件进行了地理配准、现代基准面校正，并对海岸线进行数字化处理，生成了用于表征历史海岸线位置的矢量折线。已地理配准的T型测绘海图被用于勾勒海岸线，以开展长期海岸线与湿地分析工作，服务于飓风桑迪湿地物理变化评估项目。