Radar ionospheric refraction corrections by a digital ionosonde

Ionospheric refraction is one of the factors limiting the accuracy of radar systems tracking objects in or beyond the ionosphere. In advanced systems it may be desirable to perform accurate corrections for these effects in real time, and because of the extreme variability of the ionosphere, this presupposes real time, local ionospheric measurements, e.g., by a modern digital ionosonde. The ionosonde could then be required to monitor the state of the ionosphere, compare it with model conditions, and forecast the radar refraction environment in real time. One component in this problem is the calculation of the radar refraction effects, given the ionospheric electron density profile, the apparent radar range, and look angle. Assuming that the electron density depends on height only, this paper describes such a procedure suitable for use within the Dynasonde or a similar digital ionosonde interfaced to an active radar system.