Maine Orthoimagery Municipal South Portland 2005 (Imagery Layer)

Tile Download Link 2005 6" pixel resolution orthoimagery of South Portland from May 6, 2005. Provided by the Maine Office of GIS and the Maine GeoLibrary Board. As the prime contractor, Bradstreet Consultants, Inc. used the aerial photography flown in one session on May 6, 2005, by Richard Crouse & Associates, Inc. of Frederick, MD who acquired approximately 1335 photos @ 1"=600' with airborne GPS using a Wild RC-30 (#13261) aerial camera. Bradstreet Consultants, Inc. painted and repainted ground targets for photo survey control points (~200) to support full analytical aerotriangulation. The aerotriangulation solution was used to set up each stereopair of photos for orthorectification and DTM compilation. The ortho imagery was created by scanning (14 microns (um) per pixel or 1815 dpi) the original 1"=600' scale film and employing a digital terrain model (DTM) from updating some town's original DTM and some town's from scratch using the 1"=600' scale negatives or diapositives using both analytical and softcopy (digital) stereoplotter in the Kork KDMS format.瓦片下载链接：2005年5月6日拍摄的南波特兰（South Portland）6英寸像素分辨率正射影像（orthoimagery）数据集。该数据集由缅因州地理信息办公室（Maine Office of GIS）与缅因州地理图书馆委员会（Maine GeoLibrary Board）提供。作为总承包商，布拉德斯特里特咨询有限公司（Bradstreet Consultants, Inc.）采用了马里兰州弗雷德里克市理查德·克劳斯联合有限公司（Richard Crouse & Associates, Inc.）于2005年5月6日单次飞行获取的航空摄影影像：该作业团队使用搭载机载GPS的威尔德RC-30（Wild RC-30，编号#13261）航空相机，以1英寸=600英尺的比例尺拍摄了约1335张照片。布拉德斯特里特咨询有限公司布设并重新涂刷了约200个用于摄影测量控制点的地面靶标，以支撑全解析航空三角测量作业。该航空三角测量解算结果被用于为正射纠正（orthorectification）与数字地形模型（DTM, digital terrain model）编绘作业配置每一组立体像对。本正射影像数据集的制作流程如下：以14微米（μm）每像素（等效1815dpi）的分辨率扫描原始1英寸=600英尺比例尺胶片，并采用数字地形模型（DTM）——该模型部分由部分城镇的原有DTM更新迭代而来，部分则基于1英寸=600英尺比例尺负片或透明正片（diapositives）从零构建——作业过程中同时使用了解析型立体测图仪与软拷贝（数字）型立体测图仪，并采用Kork KDMS格式存储最终成果。