Improving county access to high-resolution imagery

Author: Linda Duffy

As a subscriber to theHXGN内容程序through the State of Washington, ruralJefferson Countyin the United States benefits from access to the most current high-resolution aerial imagery available. Highly useful decision-support tools are created by overlaying the imagery with detailed county-wide GIS data. The insights obtained from combining information lead to more-informed analysis, faster approval processes and better services to internal and external customers.

Unique county characteristics

杰斐逊县（Jefferson County）涵盖了一个不同的地理区域，该地理区域为政府管理员带来了特殊挑战。太平洋沿线的海岸线位于奥林匹克半岛上，形成了该县的西部边界，而东部地区包括四个小镇，一个运输港口，几个岛屿，农田和一个活跃的海军设施。在西杰斐逊县和东杰斐逊县之间，由联邦政府管理的奥林匹克国家公园和奥林匹克国家森林。总共约有31,000名居民分散了5,654平方公里。

由于地形的不同，从东汤森港的县城到西部的太平洋海岸，现场检查可能会很耗时且昂贵，从而导致建筑许可证批准，基础设施计划和环境保护工作导致延误。政府和私人用户都受益最新的航空影像because it providesdetailed information in and around the area of interestand减少了对面对面访问的需求。

“空中图像,我们可以看到结构,outbuildings, and natural features, and when combined with contours, we can make a lot of determinations from the office,”says Kevin Hitchcock, GIS analyst/cartographer, Jefferson County Central Services.“In a rural community like ours, online maps are used for a variety of activities, such as planning new developments and evaluating impacts on streams and wetlands. The Public Lands Records database also includes sales history and other information for every property in the county, making it easy to do research without leaving the office.”

Improved basemap

2015年，与华盛顿州的整个县和市政当局进行了评估cost-sharing to obtain high-resolution aerial imagery整个州。必须从当地司法管辖区的一定程度的参与才能使其具有成本效益。在杰斐逊县，部门经理和行政人员一致认为，签署将是有益的。最终，该县签订了为期三年的合同receive imagery through the HxGN Content Program。

The HxGN Content Program collects speculative off-the-shelf orthorectified imagery of the US, parts of Europe, and populated areas of Canada to create a database available to customers. The goal is to acquirecloud-free 30-centimetre resolution, 4-band imagery over less populated areas, and 15-cm resolution over metro areas with a population greater than 50,000. In 2017, Jefferson County received30厘米分辨率的航空影像, a welcome update to its 1-metre basemap obtained in 2011 through the National Agriculture Imagery Program (NAIP).

Jefferson County Central Services GIS团队的目标是开发和维护有效的全县资源，以满足政府机构和公众的需求。历史和当前的图像和GIS数据层可通过ESRI ArcGIS Web应用程序查看和打印。由托管的图像地图服务Valtus, part of Hexagon, allows users to add the content as a layer to any GIS webmap. The public can download the existing shapefiles, such as tax parcels, but not the actual imagery. Government employees are authorised to download the imagery to create derivative products and to perform analysis.

对社区的好处

杰斐逊县创造了一个user-friendly GIS其中包含广泛的信息。在线地图档案包括丰富数据层,如分区防火区,school districts, roads, emergency services, and channel migration zones overlaid on the high-resolution imagery。

Within the county, frequent users of spatial and map information include the departments of Environmental Health, Public Works, Community Development and the Assessor. Emergency responders, such as police and firefighters, are aided by the address point layer to pinpoint the fastest way to reach someone in need, while engineers in the private sector can more easily design septic systems byanalysing online data。对于海岸线属性，开发人员检查是否有额外的监管限制，以确保符合与海岸线和侵蚀问题的距离。

“Access to high-resolution aerial imagery through the HxGN Content program makes it easier to visualise an area of interest, in detail and in the broader context of the surrounding terrain,”says Hitchcock.“我们通过使用在线工具完成工作来节省时间和金钱。当我们继续探索应用程序时，可能会有更高决议来支持更好的决策。”