Microwave Transmission Characteristics of Solar Power Satellites
A summary of the analyses and performance characteristics of a high-power microwave system for transferring energy from solar power satellites in geosynchronous orbit to the earth is given. Design tradeoffs, problem areas, and simulation results for various configurations are presented.
Ionospheric heating by radio waves: Predictions for Arecibo and the satellite power station
The effect of resistive heating by radio waves on ionospheric temperatures, electron densities, and airglow emissions is examined by using numerical ionospheric structure and heat balance codes. Two cases are studied: (1) a 3-GHz, 10-GW microwave beam from a proposed satellite power station and (2) 1-MW and 3-MW beams of 15-MHz radio waves launched by the Arecibo antenna. By intent, these two cases have similar intensities and geometries of resistive heating. The most dramatic heating effects are predicted to occur in the E region, where a thermal runaway will take place. The E region electron temperature will increase from 200°K to roughly 1000°K, and the E region electron density will increase by a factor of about 3. In the F region, where thermal conductivity plays an important role, temperature increases of 200°–500°K will appear along magnetic field lines passing through the radio wave beams. Enhanced emissions in airglow and molecular infrared lines will also occur. Radio wave heating, when combined with the diagnostic capabilities of the Arecibo incoherent scatter radar, will generate new opportunities to measure the rates of atomic physics processes and neutral atmosphere temperatures and composition at D and E region altitudes.
Ionospheric heating by powerful radio waves
In addition to the communication applications that stem from the generation of field-aligned irregularities, ionospheric heating by powerful HF waves also holds promise for establishing new techniques in D-, E-, and F-region aeronomy. This paper concentrates on the application of the theory of plasma heating by ohmic and nonlinear dissipation to the special conditions of the lower ionosphere where the electron collision and disturbing wave frequencies are comparable and the upper ionosphere where electron thermal transport is large and restricted by the earth's magnetic field. We predict the magnitude and distribution of large-scale changes in the electron temperature and density in both the D and F layers under a variety of conditions. These results are compared with direct measurements or inferred changes whenever possible. 
 
We also examine the effects of specular-height mismatch, multiple frequency operation involving heater-power sharing, and antenna beam tilt on the total cross section for field-aligned scattering. The analysis is based on the concept that the energy-density distribution on the heater reflectrix computed by means of a ray-tracing technique can be related directly to the density-fluctuation intensity through an appropriate scattering model. Lastly, potential applications to aeronomy are discussed, particularly in regard to D-region measurements of the effective recombination coefficient magnitude and temperature dependence and the relative water cluster ion concentration.