Software radio measurements of Earth atmosphere's refractive indices

摘要

An atmosphere imaging device is being constructed to investigate its ability to measure the Earth atmosphere's three-dimensional (3D) refractive indices for use to help monitor climate change. With the recent advancements of Software Defined Radio (SDR) and Global Positioning Systems (GPS) with clocks having timers of 10 second precision, a method to three-dimensionally and continuously measure the Earth Atmosphere's refractive indices has been devised. The method is based upon the synchronous measurement of the time taken for a radio wave to travel from the source via the ionosphere to arrive at receivers place at known positions from the radio wave source. This method will allow us to measure small phase shifts between the receivers providing information on the propagation of the radio wave through the Earth's atmosphere, which is a function of the refractive indices within its multiple layers. Testing will help determine the full extent of the device's applicability. Although this device will measure locally, its placement at numerous locations could be used to help monitor the Earth's atmosphere over a large region and possibly globally, connected using current radio technology, enhancing our understanding of the magnitude and patterns of Earth's climate change.