VLF IONOSPHERIC SOUNDER PROGRAM

The VLF pulse sounder is a new basic tool for studying the lower ionosphere. The system is a combination pulse sounder, phase sounder, and polarimeter. A concurrent program of system improvement and experimental study of the ionosphere has been conducted. The results of this program as presented here should be of use in planning various types of communication, navigation, and detection systems which make use of VLF propagation or distribution within the lower ionosphere. Since HF propagation is markedly affected by the lower ionosphere, the program should also ultimately contribute to systems in the HF band. This program was limited to experimental data collection. The gathered data is presented without an assessment of its theoretical value or of the experimental capability employed in its collection. (Author)