Radio Observation
of Atmospheric Phenomena

Spectrogram of a radio wave reflection off a ionised meteor trail lasting about 60 s:

Radio monitoring means the recording of received RF-power. Independent from any technical realisation at least some basic decisions must be taken:

Passive monitoring of an existing RF-source

Radio monitoring in its simplest way engages a RF-sensor (=radio) and a recording unit. Receiving frequency, bandwidth of the sensing unit, signal-integration time, trigger threshold, recording-interval, date and total monitoring period have to be chosen appropriate to the objective. If more than one radio frequency should be monitored, the RF-sensor must allow for different frequencies. It must be operated by a control device. In case of distinct observation frequencies a time/frequency schedule has to be set up for the control device. Otherwise for a frequency-sweep the span and increment together with a schedule of timing the repetitons must be defined.

Active monitoring by generating a RF-signal and evaluate reported receptions from third persons

In this case the RF-source can be controlled by frequency, transmitting interval, transmitted power, modulation, signal protocol (digital mode), date and period. It requires to be a licensed radio amateur to work a broad range of radio frequencies. The actual monitoring is outsourced to third persons who feed their automatically generated reception reports to internet accessible databases.

Practical Implementation 

I utilised radio waves in the frequency range 10 kHz-200 MHz for the study of atmospheric phenomena. My studies focuse on (1) ionospheric topics and (2) meteor related topics. Here I present the outcome of my radio projects:

Radio monitoring of Ionosphere

A detailed analysis of the influence of coronal mass ejections on the ionosphere with radio amateur equipment was performed. It was done by transmitting WSPR-beacon signals and analysing the received reports. A density plot of the reports per distance and time showed to be a good indicator of ionospheric disturbances. Read more.

Furthermore, a one-year study on shortwave propagation was conducted based on transmitted WSPR-beacons. After processing the 250000 WSPR reports, it was instructive to observe the textbook changes in propagation at the various frequencies specifically for my location over the course of the year. Read more.

Also I took the chance of the solar eclipse occurring 2015 in Europe to observe their effect on the ionosphere by measuring the propagation of low frequency radio waves. Different transmitters at different wavelengths in the vlf- and lf-range were involved. Their signals were recorded quasi-simultaneously for several days to see, how they deviate during the eclipse. Read more.

Radio observations with an AR5000 receiver

This radio project was based on the AOR AR5000 communication receiver. It was intended for monitoring ionospheric conditions. For this purpose, the AR5000 must be controlled by a computer via the RS232 interface. The software required for this was developed by me and can be downloaded free of charge (for Windows up to version 7). The software not only controls all settings of the receiver, but also records time- and frequency-controlled incoming RF signals, essentially the level of the automatic gain control (agc). I did some sample measurements to get an idea of the possibilities of this system. Read more.

Radio Meteor and Head Echo Analysis

My most extensive project is dedicated to the radio observation of meteors. After first steps in this topic soon my interest arised in the study of meteor head echoes. Thereby, the french GRAVES-Radar was used as a very powerful transmitter for head echo reception. As a necessary prerequisite I developed a fast recording software with numerical output together with a second program to processes the gained data. Both scripts can be downloaded for free. The radio detectability of head echoes as well as the visualisation of meteor showers and major sporadic meteor origins based on head echoes were covered in depth in several studies. Read more.

Sporadic E layer Forming

I studied the occurence of sporadic E layers, which are capable to hamper the radio recording of meteors. This was done by analysing reception reports from all over Europe, generated by JS8 heartbeats I periodically sent out in the 11 m band. The solar and lunar tides could be characterised. Read more.

Furthermore, I tried to uncover the influence of meteoric influx on the seasonal variability of sporadic E occurence by analysing the Es-data of serveral European ionosondes. Read more.