ISS_2026_Orthophotography_Control_Points.pdf

This document is a control points specification sheet for the Hamilton County, Indiana 2027 Aerial Photography and Digital Orthoimagery Project. The file establishes technical standards and requirements for ground control points that will support the aerial photography and orthoimagery acquisition and processing work. Hamilton County has established over 200 horizontal and vertical ground control points to serve as the foundation for the project's aerial triangulation and orthoimagery development activities. These control points are designed to enable contractors to extend and densify ground control using modern aerial triangulation techniques, ensuring accurate georeferencing of digital orthoimagery products at 1"=50' scale mapping accuracy. The control points specification document defines the geometric, accuracy, and quality standards that all submitted ground control data must meet to support the four-band digital aerial photography acquisition, preliminary unrectified image delivery, and three-inch pixel natural color digital orthoimagery production.

The control points technical specifications ensure that submitted ground control data meets rigorous positional accuracy requirements necessary for high-resolution orthoimagery production and professional geospatial data delivery. Contractors responding to the Request for Proposals must utilize the established ground control points according to the specifications outlined in this document and incorporate them into their aerial triangulation and digital orthoimagery processing workflows. The standardized control points framework enables consistent data quality across deliverables and supports Hamilton County's objective of obtaining reliable geospatial products suitable for advanced mapping and spatial analysis applications at the specified scale and resolution standards.