An evaluation of range accuracy in the Super Dual Auroral Radar Network over‐the‐horizon HF radar systems

The Super Dual Auroral Radar Network (SuperDARN) of over‐the‐horizon HF radars forms a powerful diagnostic of large‐scale ionospheric and magnetospheric dynamics in the Northern and Southern Hemispheres. Currently, the ground location of the HF radar returns is routinely determined by a simple range‐finding algorithm, which takes no account of the prevailing HF propagation conditions. This is in spite of the fact that both direct E and F region backscatter and 1½‐hop E and F region backscatter are commonly used in geophysical interpretation of the data. Here HF radar backscatter which has been artificially induced by the high‐power RF facility (ionospheric heater) operated by the European Incoherent Scatter Scientific Association at Tromsø is used to provide a range calibration for the SuperDARN radars. The known ground range, the measured radar slant range, and the group path calculated by a ray‐tracing simulation are compared. The standard algorithm for backscatter ground range location is found to be accurate to within 16 km and 60 km for direct and 1½‐hop backscatter, respectively.