Measurements of HF backscatter cross section for striations created by ionospheric heating at different power levels
Abstract
Ionospheric field-aligned irregularities induced by a heating facility were studied by HF backscatter radar. A power law relation between the received echo power and the stepwise changed heater power with an exponent varying between 1.5 and 1.9 is found. The radar cross section at 14 MHz is on the order of 35 to 55 dBsm, and a maximum volume cross section 0.00000036/m. Recording sequences for three different environmental ionospheric conditions are discussed. During favorable conditions backscatter echoes are observed at the lowest heater ERP of 14 MW. The cross section then saturates at 98 MW ERP and exhibits a pronounced decrease at higher heater ERP. During less favorable conditions the saturation level is not reached even at full power of 280 MW ERP. A correlation seems to exist between variations in the derived Hall current and the variation in cross section of the heater-induced field-aligned irregularities.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- April 1985
- Bibcode:
- 1985STIN...8616481H
- Keywords:
-
- Backscattering;
- Ionospheric Heating;
- Radar Scattering;
- Electric Current;
- Hall Effect;
- High Frequencies;
- Ionospheric Currents;
- Output;
- Radar Echoes;
- Scattering Cross Sections;
- Communications and Radar