Ionospheric Imaging Using NVIS

Real-time estimation of relevant ionospheric parameters is required for military applications and to further our understanding of space weather and its societal and technological impacts. Currently, a major limitation in the modeling of ionospheric physics is a complete lack of input data measurements. The HF transmitter/receiver system proposed here contributes measurements of the bottom-side ionosphere. With modern HF components and signal processing, a low-power, inexpensive HF transmitter array and receiver system can be used for ionospheric specification and we seek to develop this further. The reduction in transmitter power attained with signal processing reduces total system cost, permitting a significant increase in HF transmitter/receiver density, which, in turn, allows for more accurate estimation of ionospheric parameters, such as the 3-D electron density. The system uses novel narrowband signal processing and unique dual-frequency estimation of the 3-D electron density along with E- and D-layer absorption. In addition, Doppler shift data extracted from the measurements can provide additional information on the transient motion of bottom-side ionosphere.