A midlatitude HF propagation experiment over New Mexico

We describe a midlatitude ionospheric measurement experiment conducted 19–27 January 2014 at White Sands Missile Range, New Mexico, United States. This experiment was one of a series of experiments conducted under the IARPA high-frequency Geo program. The objective was to develop a data set to be used by data assimilation studies focused on modeling of the bottomside of ionosphere and high-frequency signal propagation. We outline the specific objectives of the experiment and the experimental configuration and describe the transmit sites and antenna array that allowed us to estimate angles-of-arrival for both O- and X-mode signals. We provide a detailed example from 22 January 2014. This period shows the variations characteristic of medium-scale traveling ionospheric disturbances. We use the data from this period to estimate the resolution of our angle-of-arrival measurements to be about 0.1°.