Which coordinate system is HARN based on?

HARN, or High Accuracy Regional Network, is based on the North American Datum of 1983 (NAD83). The primary focus of HARN is to provide improved accuracy and precision in geodetic measurements within specific regions of North America, leveraging the advancements in GPS technology. NAD83, introduced in the early 1980s, serves as the foundation for HARN because it represents a global geodetic framework that is consistent with modern satellite positioning techniques.

HARN enhances NAD83 by incorporating high-density survey control points that offer more accurate positioning references for various applications, including mapping, surveying, and geospatial analysis. While WGS84 is a global datum widely used in many GPS applications, HARN specifically builds upon NAD83 to meet regional accuracy requirements.

The choice of HARN's reliance on NAD83 highlights the evolution of geospatial science towards more accurate datum systems, relieving previous limitations associated with older datum systems such as NAD27, which does not provide the same level of precision as its successor.