Radio Jove is a NASA-supported project for education and outreach in radio astronomy. It uses fairly modest equipment to detect radio emissions from the planet Jupiter, from the Sun, and from our Galaxy.
The WKU Radio Jove experiment has been run for several ASTR 214 classes in the past few years. Its two dipole antennas capture radio emissions at a frequency of about 20 MHz (wavelength of 15 m) and translate it into a (very weak) electrical current, which is conducted along the coaxial feed line cables to the receiver, where it is amplified and converted into an audio-frequency signal that is recorded digitally. The data are retrieved every few days and then converted into an uncalibrated estimate of the received power by squaring the audio waveform signal (a measure of voltage vs. time) and computing its average over small, equal time intervals. Your task is to examine these data and report your findings for each of the questions below.
Each linked page shows a series of thumbnail plots, one per 24-hour day. Clicking on a thumbnail plot will show a larger version. Each 24-hour plot starts at 06:00 Universal Time (UT) = midnight Central Standard Time (CST).
Each plot is labeled with the range of dates when it was observed. The vertical axis is uncalibrated received power as described above. The horizontal axis is Universal Time (a.k.a. Greenwich Mean Time) in hours, where midnight of the first "day" shown is 0, midnight of the second "day" is 24, etc. Central Standard Time (CST) is 6 hours behind UT. Although the radio equipment does not detect visible light, the "daytime" signal is generally much stronger than the "nighttime" signal, because the Sun excites the ionosphere during the day, allowing it to reflect undesirable contaminating signals, called "radio-frequency interference" (RFI), from over the horizon -- even from thousands of miles of miles away -- into the radio receiver. As a result, RFI is much more prominent in daytime than nighttime, although RFI can appear at night as well. The daytime RFI is a mixture of human-generated radio chatter and lightning strikes, which occur roughly 100 times per second in the tropics. Most of the radio signal power in the plots during the day is RFI, not sunlight or any other "celestial" emission. (The upper panel shows the raw data, while the lower panel has some of the worst RFI filtered out -- strong spikes lasting only a second or so -- but this still leaves a lot of "ambient" RFI.) Inspect a few plots and estimate, as a ratio, about how much stronger the typical daytime RFI is than the ambient night sky emission.