Computer-program model for predicting horizontally and vertically polarized VLF atmospheric radio noise at elevated receivers

A computer program was developed that can predict horizontally and vertically polarized atmospheric radio noise at any altitude or location in the Earth-ionosphere waveguide in the very-low-frequency (VLF) range from 10 to 30 kHz. The new program, HORNS, uses the outputs of two previously written programs, COMPWR and NOISLAN, which predict the vertical electric noise field at the ground. The HORNS program computes all the field components at any altitude using the vertical electric field at the Earth's surface as a basis. Predicted values from several versions of the new model were compared with presently available data. The results are encouraging, but more data are needed to test the model.