County to update aerial imagery this spring
By Ted Pennekamp
Crawford County recently received a grant for $47,920 to pay for aerial imagery of the county that will begin this upcoming spring. The aerial imagery will be obtained by using a four-band digital mapping camera with a 6-inch pixel resolution.
Previously, the county had used a 12-inch pixel resolution camera. Thus, the aerial photos this spring will be twice the resolution as in the past.
Crawford County Property Lister GiGi Collins said the funding was obtained through a 2020 Wisconsin Land Information Based Budget Grant.
The imagery will be done through the Wisconsin Regional Orthoimagery Consortium (WROC), which is a multi-entity group which has built and maintains a multi-participant program to acquire updated digital orthoimagery and elevation data on a five-year cycle.
As part of the program, WROC representatives can provide assistance in coordinating mapping services.
Digital orthoimagery is the foundation for geographic information system (GIS) mapping, which forms a base layer from which many additional data layers are created. It combines the characteristics of an aerial image with the geometric qualities of a map. This allows GIS software to accurately measure all visible ground features in their true geographic position and allows users to make accurate distance and area calculations.
Digital orthoimagery is used throughout Wisconsin for vital purposes such as emergency planning and response, government decision-making, and sound land use policy development.
Applications can include parcel mapping, asset management, property assessment, utility facility mapping, environmental monitoring and management, impervious surface mapping, building permit tracking, zoning enforcement, emergency response, code enforcement, municipal growth planning, forest management, floodplain mapping, preliminary engineering design, change detection, and public displays.
The WROC uses the expertise of an all-Wisconsin mapping team led by Ayres Associates.
“Hopefully, we will begin this spring, because it is best when the leaves are not on the trees,” said GiGi Collins.
A variety of imagery options are available through the WROC program. There are options for natural color and infrared color in three different pixel resolutions. The 12-inch resolution has a map scale in which 1 inch equals 200 feet. The 6-inch resolution is 1 inch equals 100 feet. The 3-inch resolution is 1 inch equals 50 feet. All orthoimagery meets or exceeds accuracy standards at the 95 percent confidence level.