HARN, High Accuracy Reference Network

The HARN network is comprised of 98 A-Order (0.1 ppm) and B-Order (1 ppm) stations. The HARN was based upon GPS positioning and produced highly accurate results that were the basis for the NAD 83 (91) datum adjustment by the NGS for Wisconsin. The HARN stations are generally located at a 50 km (30 mile) spacing across the state and provide solid network geometry to facilitate local densification activities.