Florida Countywide Aerial Imagery 1940s (Georectified)

Historical imagery was obtained from University of Florida’s historical Imagery site, “Aerial Photography: Florida”, the Florida Department of Transportation (FDOT) Aerial Photo Lookup System, or from the FDEP district offices. Images downloaded from UF were saved locally and georeferenced by GIS team members, whereas the imagery received from the district offices were georeferenced by District staff. It is understood that these "pre-georeferenced" tiles were georeferenced within ArcMap by various staff from the District offices. The following applies to the imagery georeferenced in-office by the Division of Water Resource Management (DWRM): The georeferencing was completed in either ArcMap 10.3.1 or ArcGIS Pro. The following standards were held for the georeferencing process: the minimum number of control points was 10 points. The RMS value was kept at or below 5.0 for all tiles georeferenced in 1st Order Polynomial, and 2.0 for those georeferenced in 2nd Order Polynomial (where 1st Order was not possible). The maximum individual residual was at or under twice the RMS. Again, these were the standards, but the accuracy is not guaranteed. To QC for human error, once all counties for the given decade were georeferenced a comparison task was completed. This QC emphasized that this data is only a visual aid in that distances can be off 50 meters or more in some areas. These are mostly areas where there were limited reference features to georectify the original images. The smallest distance found was under 10 meters. To attain more information on this QC please contact FDEP WRM GIS. As stated in the use limitation, but emphasized here, information contained herein is provided for informational purposes only. The State of Florida, Department of Environmental Protection provides geographic information systems (GIS) data and metadata with no claim as to the completeness, usefulness, or accuracy of its content, positional or otherwise. The State and its officials and employees make no warranty, express or implied, and assume no legal liability or responsibility for the ability of users to fulfill their intended purposes in accessing or using GIS data or metadata or for omissions in content regarding such data. The data could include technical inaccuracies and typographical errors. The data is presented "as is," without warranty of any kind, including, but not limited to, the implied warranties of merchantability, fitness for a particular purpose, or non-infringement. Your use of the information provided is at your own risk. In providing this data or access to it, the State assumes no obligation to assist the user in the use of such data or in the development, use, or maintenance of any applications applied to or associated with the data or metadata. Please contact [e-mail] for more information.本数据集的历史影像来源于佛罗里达大学（University of Florida）历史影像站点"Aerial Photography: Florida"、佛罗里达州交通部（Florida Department of Transportation, FDOT）航空影像查询系统，或佛罗里达州环境保护部（Florida Department of Environmental Protection, FDEP）区域办公室。 从佛罗里达大学下载的影像将被本地存储，并由地理信息系统（Geographic Information System, GIS）团队成员完成地理配准；而从区域办公室获取的影像则由区域工作人员完成配准。 需说明的是，这批"预地理配准"瓦片均由区域办公室的多名工作人员在ArcMap中完成地理配准。 以下内容适用于由水资源管理处（Division of Water Resource Management, DWRM）在办公场所完成地理配准的影像： 本次地理配准工作在ArcMap 10.3.1或ArcGIS Pro中完成。 地理配准流程需遵循以下标准：控制点最小数量为10个。 对于采用一阶多项式完成配准的所有瓦片，其均方根误差（Root Mean Square, RMS）值需控制在5.0及以下；对于无法采用一阶多项式的场景，则采用二阶多项式配准，对应RMS值需控制在2.0及以下。 单个残差的最大值不得超过RMS值的两倍。 需再次强调，上述仅为配准标准，本数据集不保证配准精度。 为开展质量控制（Quality Control, QC）以排查人为误差，在对应十年份的所有县域影像完成配准后，将执行比对任务。 本次质量控制结果表明，本数据集仅作为视觉参考工具，部分区域的距离偏差可达50米及以上。 此类偏差多出现于原始影像可用于地理校正的参考特征有限的区域。 本次检测到的最小距离偏差小于10米。 如需获取本次质量控制的相关详情，请联系FDEP WRM GIS。 正如使用限制条款中所述，在此再次强调：本数据集所含信息仅用于参考用途。 佛罗里达州环境保护部（Florida Department of Environmental Protection, FDEP）提供的地理信息系统（Geographic Information System, GIS）数据及元数据，不对其内容、位置信息或其他方面的完整性、可用性或准确性作出任何声明。 佛罗里达州及其官员、雇员均不作出任何明示或默示担保，且不对用户在访问或使用GIS数据及元数据时能否达成预期用途，或此类数据内容存在遗漏承担任何法律责任或义务。 本数据集可能包含技术误差或排版错误。 本数据集按"as is"提供，不附带任何形式的担保，包括但不限于适销性、特定用途适用性或不侵权的默示担保。 使用者需自行承担使用本数据集信息的全部风险。 佛罗里达州在提供本数据集或其访问途径时，不承担协助用户使用该数据，或开发、使用、维护与该数据及元数据相关的任何应用程序的义务。 如需获取更多信息，请联系邮箱[e-mail]。