Abraham Bradley (Astrophysics Group) Institute for STEM Research and Development Astrophysics Group Abraham Bradley (Astrophysics Group)
Institute for STEM Research and Development Astrophysics Group Background In 1912 William Henry Eccles saved the Eiffel Tower by building a radio transmitter at its top This transmitter was part of an experiment designed to determine the effects of the solar eclipse on radio communication This was done by observing the change in characteristics of the incoming signal and comparing those changes to those which occur regularly This experiment addresses the cause of the changes originally observed in 1912
Institute for STEM Research and Development Astrophysics Group Purpose Track the signal strength of radio communication during the 2017 solar eclipse Report data to the NSIF (National Institute of Standards and Technology) in order to produce a map of such effectiveness over the interval across the U.S. Determine whether it is a change in heat or light that causes radio signals to be altered during the nighttime
Ionosphere and Radio Communication (1) Institute for STEM Research and Development Astrophysics Group Ionosphere and Radio Communication (1) The ionosphere is comprised of 3 layers that decrease in density as they increase in attitude The layers are (from lowest to highest altitude): D layer, E layer, and F layer
Ionosphere and Radio Communication (2) Institute for STEM Research and Development Astrophysics Group Ionosphere and Radio Communication (2) During the day: UV radiation from the sun causes all layers to ionize (ion density correlates to gas density) The high density of ions in the D layer causes it to absorb radio waves The F layer splits into 2 layers (F1 and F2) The low density of ions in both F layers and the E layer cause them to reflect radio waves Low frequency radio waves typically become absorbed by the D layer and therefore do not reach higher altitude layers by which they would get reflected As a result radio signal strength is weakest during the day
Ionosphere and Radio Communication (3) Institute for STEM Research and Development Astrophysics Group Ionosphere and Radio Communication (3) During the night: The high density of ions in the D layer causes collisions and therefore deionization to occur without the presence of sunlight Low frequency radio waves can now pass through the deionized D layer and reach the higher altitude reflecting layers The E and F layers deionize at a much slower rate than the D layer due to their lower densities and therefore less frequent collisions This allows for radio waves to continue to be reflected off of these layers throughout the night As a result radio signal strength is strongest during the night
Institute for STEM Research and Development Astrophysics Group Experiment Crowd-sourcing data from all over the U.S. NSIF transmits time & date synchronization over 60 kHz frequency from the WWVB radio station in Fort Collins, Colorado Receiver connects to smart phone to connect data onto a designated application Data is reported through the application to NSIF and EclipseMob