Two South African amateur radio associations, the South African Radio League (SARL) and AMSAT SA, are planning to launch an umbrella association that will link up with scientists in various electronic and physics disciplines to enhance research opportunities. The two organisations are currently involved in propagation research on 5 MHz, and a study of the rapid increases in the radio frequency noise floor, its causes and possible mitigation, and the possible slowing down of the noise pollution which will ultimately render the radio spectrum useless for communication, particularly for weak signal communication.
The new organisation will be known as Amateur Radio Science Citizen Investigation, or HamSCI SA. It is based on the successful HamSCI which has been operating in the US and the UK for several years. The concept of HamSCI was started by US scientists who study upper atmospheric and space physics and who are also licensed radio amateurs. HamSCI SA will be a platform for the publicity and promotion of projects that are consistent with the following objectives:
HamSCI SA will be a means of fostering collaborations between professional researchers and radio amateurs. It will assist in developing and maintaining standards and agreements between all people and organisations involved. HamSCI SA will not be an operations or funding programme, nor a supervisory organisation. HamSCI SA will not perform research on its own. Rather, it will support other research programmes such as the SARL’s 5 MHz propagation study, the RF noises monitoring projects, and programmes funded by structures such as the National Research Foundation.
The SARL and AMSAT SA invite interested persons to join the HamSCI SA initiative and offer their expertise. “It will work two ways”, says SARL president, Nico van Rensburg. “It will create interesting activities for radio amateurs, in particularly for the new generation of young people who have been bitten by the ‘radio bug’ but need more challenges than just communications. For the scientific community it means that they can involve many more people in their projects and make a contribution to make science popular.”
Fig 1: Block diagram of a RF noise floor monitoring system. The system is operational on four sites with data daily uploaded to a central server.
Contributing to radio technology
Since the beginning of the amateur radio service in South Africa in the early 1900, radio amateurs have made significant contributions to radio technology and the understanding of radio science. This work must be continued today, as the ITU Radio regulations state that a primary purpose of the amateur radio service is the continuation and extension of the amateur’s proven ability to contribute to the advancement of the radio art. Recent advances in the fields of computing, software-defined radio, and signal processing provide unprecedented opportunities to meet this mandate, specifically in the field of radio science. These opportunities are already beginning to be realised with the advent of systems such as the reverse beacon network (RBN), the weak signal propagation reporting network (WSPRNet), and PSKReporter. In addition, enabling amateurs to make and contribute legitimate scientific observations will expose amateur radio to a wider community of people interested in science around the world.
In the US, HamSCI’s first major project was the study of the effects on the ionosphere of the 21 August 2017 solar eclipse. On that day, a total solar eclipse traversed the continental United States and caused large‐scale changes in ionospheric densities. These were detected as changes in medium‐ and high‐frequency radio propagation by the Solar Eclipse QSO Party citizen science experiment organised by the HamSCI. This was the first eclipse‐ionospheric study to make use of measurements from a citizen‐operated, global‐scale HF propagation network and developed tools for comparison to a physics‐based model ionosphere. Eclipse effects were observed for ±20 mins on 1,8 MHz, ±45 mins on 3,5 and 7 MHz, and ±1 hour on 14 MHz, and were consistent with eclipse‐induced ionospheric densities. Observations were simulated using the HF radio wave ray tracing toolbox (PHaRLAP) in conjunction with the eclipsed SAMI3 ionospheric model. PHaRLAP was developed by the Defence Science and Technology Organisation (DSTO) in order to study the propagation of radio waves through the ionosphere. PHaRLAP provides a variety of ray tracing engines of various sophistication from 2D ray tracing to full 3D magnetoionic ray tracing.
Model results suggest 1,8; 3,5; and 7 MHz refracted at h≥125 km altitude with elevation angles θ≥22°, while 14 MHz signals refracted at h<125 km with elevation angles θ<10°. More than 5000 radio amateurs participated in the project which has resulted in several scientific papers.
In South Africa, individual amateurs and other in small groups carry out experiments but these are not generally well documented and often valuable information is lost.
Many radio amateurs unwittingly generate a large portion of data during their regular amateur radio operations. A good example of this is the annually SARL High Frequency contest during which hundreds of radio amateurs transmit over a two- or three-hour period, logging the details of every contact they make. Similar on a world-wide basis is international contests where thousands of radio amateurs are active over a 24-hour period. There is massive volume of data collected, however it is unstructured and currently perhaps not that useful, scientifically speaking. This is where collaboration with scientists can make the difference.
The SARL is in partnership with AMSAT SA, who will drive the initial thrust to get HamSCI SA off the ground. If you would like to be part of HamSCI SA and be invited to their launch conference later this year send your contact details to admin@amsatsa.org.za with HamSci SA in the subject line.
