Category Archives: ionosphere

Sorry US; Europeans Listen to Space with GRAVES

Posted on by

In Europe, the GRAVES radar station beams a signal on 143.050 MHz almost straight up to detect and track satellites and space junk. That means you will generally not hear any signal from the station. However, [DK8OK] shows how you can–if you are in Europe–listen for reflections from the powerful radar. The reflections can come from airplanes, meteors, or spacecraft. You can see a video from [way1888] showing the result of the recent Perseid meteor shower.

Using a software-defined radio receiver, [DK8OK] tunes slightly off frequency and waits for reflections to appear in the waterfall. In addition to observing the …read more

Continue reading Sorry US; Europeans Listen to Space with GRAVES→

40-Acre HAARP Rides Again, And They Want You To Listen

Posted on by

News comes to us this week that the famous HAARP antenna array is to be brought back into service for experiments by the University of Alaska. Built in the 1990s for the US Air Force’s High Frequency Active Auroral Research Program, the array is a 40-acre site containing a phased array of 180 HF antennas and their associated high power transmitters. Its purpose it to  conduct research on charged particles in the upper atmosphere, but that hasn’t stopped an array of bizarre conspiracy theories being built around its existence.

The Air Force gave up the …read more

Continue reading 40-Acre HAARP Rides Again, And They Want You To Listen→

Lost Moon Found: The Satellite That Came Back to Life

Posted on by

The late 1950s and early 1960s were a tumultuous time in world history. The Cold War between the East and the West was in full-swing, driving the new fields of nuclear weapons and space exploration and giving the period its dual monikers of “Atomic Age” and “Space Age.”

Changes in these fields often went hand in glove, with developments in one requiring responses in the other. In 1958, the US conducted nuclear tests in the Pacific that effectively destroyed the ionosphere over the test site and shut down high-frequency communications to places like Hawaii and New Zealand. The strategic implications …read more

Continue reading Lost Moon Found: The Satellite That Came Back to Life→

Bombing The Sky For The Sake Of Radio

Posted on by

If you are familiar with radio propagation you’ll know that radio waves do not naturally bend around the earth. Like light and indeed all electromagnetic radiation if they are given a free space they will travel in a straight line.

At very high frequencies this means that in normal circumstances once a receiver moves over the horizon from a transmitter that’s it, you’re out of range and there can be no communication. But at lower frequencies this is not the case. As you move through the lower end of the VHF into the HF (Short Wave) portion of the spectrum …read more

Continue reading Bombing The Sky For The Sake Of Radio→