Development of SwRI High-Frequency Doppler Radar, 15-9253
Principal Investigators
Geoffrey Crowley
Brent W. Fessler
Inclusive Dates: 04/01/01 - Current
Background - The term ‘space-weather’ refers to conditions on the Sun, in the solar wind, magnetosphere, ionosphere, thermosphere, and mesosphere that can influence the performance and reliability of space-borne and ground-based technological systems and can endanger human life or health. Adverse conditions in the space environment can cause disruption of communications, navigation, electric power distribution grids, and satellite operations, leading to a broad range of socio-economic losses. Atmospheric gravity waves (AGWs) are generated by atmospheric processes, and the motion of the neutral gas in the AGW sets the ionosphere into motion, resulting in a traveling ionospheric disturbance (TID). TIDs can be thought of as traveling corrugations in the ionosphere, seriously affecting high-frequency (HF) radio communications and surveillance systems. These TIDs cause much of the fading of AM radio signals at night.
Approach - This project focuses on the development of an HF Doppler radar to monitor TID activity over Texas. The radar involves three transmitters placed approximately 50 to 100 kilometers from a central receiver located at SwRI. The hardware will be supported by a new software system to process and display the radar data. The goal of the project is to demonstrate that TIDs are ubiquitous over Texas and that they can be monitored routinely by a suitable radar. The effects of the TIDs on various radio systems will also be measured. These systems include a vertical ionospheric sounder, which can be interrogated to determine the vertical structure of the ionosphere over San Antonio.
Accomplishments - The hardware components have been deployed and tested. The receiver and data-logging computer were deployed at the SwRI field site in San Antonio. All three transmitters have been installed and tested, and they are operational. The core of the data-processing algorithm and plotting packages have been developed. SwRI has obtained Federal Communications Commission approval for all five operating frequencies. Routine operations will start by the end of 2001.
