HF ATMOSPHERIC RADIO NOISE ON HORIZONTAL DIPOLE ANTENNAS IN THAILAND
Abstract
The noise power available from the equivalent of lossless half-wave horizontal dipole antennas 23 feet above ground was measured on 2.3, 5.0, and 10.0 MHz at Laem Chabang, Thailand from August 1967 through February 1968. Data were obtained using dipoles oriented magnetically north-south and east-west at the same site where data were being taken with a standard ARN-2 21.75-foot vertical monopole. The noise power available from the dipoles is significantly less than that available from the monopole in the lower part of the HF band, but this difference tends to decrease as frequency increases, becoming negligible at 10.0 MHz at night. The effect of local electrical storms on the average noise power observed with the horizontal antennas was studied. It appears that local electrical storms can cause a significant increase in observed average noise power at 2.3 MHz. The observed increases in average noise power during local storms may be smaller than the actual increases in noise-power flux density at the site because of the limitations of our instrumentation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1968
- Accession Number
- AD0681879
Entities
People
- George H. Hagn
- John M. Yarborough
- Rangsit Chindahporn
Organizations
- SRI International