Doplatch: A mobile, normal incidence H. F. doppler measuring equipment for the study of the spatial correlation of traveling ionospheric disturbances

An understanding of the morphology of travelling ionospheric disturbances is essential to short-range high-frequency direction finding, particularly for systems employing vertical triangulation and dynamic tilt correction techniques. A variety of methods have been used in the past to study these disturbances, but to date little statistical information has been obtained on the extent to which they can be correlated in space. In support of research in this area, a compact mobile H.F. doppler probe has been developed for deployment at spaced locations. Each of a group of such systems measures the apparent height of the local ionosphere and provides a doppler signature of overhead disturbances for later comparison and interpretation.