Geophysical Interpretation of Digital Ionosonde Signatures

"The high-frequency ionosonde is a familiar instrument in radio science and anessential asset for operational propagation prediction. However, the capabilityof the typical ionosonde is under-utilized: it provides a vast amount of informationabout the ionosphere and its dynamics, extending from short- through very largespatial scales, but little advantage is taken of these data.We propose a merger of software and hardware that can significantly expand thecapabilities of the ionosonde as a scientific and operational support instrument.A complex echo recognition approach to data processing has been proven by manyyears of HF radar science using the NOAA Dynasonde. The technique utilizes thefull complex signal returns, resulting in ionogram data of outstanding resolutionand precision. In trade for this enhanced function, the processing algorithmsplace stringent requirements on receiver hardware phase performance. We outlinethe software tasks necessary to adapt the approach to real-time operation in ageneralized, network-based user interface. The hardware effort will specify thereceiver performance necessary to meet data processing requirements, consideringexisting and new receiver designs, with an emphasis on the digital detectionportion of the system. The proposed approach provides a cost effective means to obtain significantperformance improvement from an asset that is essential to operationalDoD systems and to radio science research