HAMNET Report 9th February 2020

Earth’s upper atmosphere has strange dense layers of ions that are constantly appearing and disappearing and which can hamper radio communication. The same thing has now been found on Mars, offering a new chance to understand this poorly studied phenomenon, says the New Scientist.

Writing on 3rd February, the report notes that the ionosphere is the layer of the atmosphere about 60 to 1000 kilometres up, that is full of charged particles. When those particles are temporarily blown into clumps by the wind, they form what researchers call sporadic E layers in the lower reaches of the ionosphere.

“They act like a mirror in the sky, and radio signals bounce off of them,” says Glyn Collinson at NASA’s Goddard Space Flight Centre in Maryland. “When you turn on your favourite radio station and it’s jammed by another station, you have probably been the victim of a sporadic E layer.”

They don’t just interfere with commercial radio stations, though – they can also block radar signals that are used to detect aircraft and ballistic missiles, he says.

E layers are difficult to study on Earth, because they appear and disappear unpredictably and they are at an altitude that is too high for aircraft to reach and too low for satellite orbits. But Collinson and his colleagues have spotted them in the Martian atmosphere for the first time, where they might be far easier to study.

The team found signs of 34 E layers in data from NASA’s “Mars Atmosphere and Volatile Evolution” (MAVEN) spacecraft. The layers form higher in the Martian atmosphere, so MAVEN is flying right through them and they are probably too high to interfere with any future radio communications on the ground, Collinson says.

MAVEN also found “rifts” in the planet’s atmosphere – areas with abnormally few charged particles that are the opposite of E layers and have never been spotted on Earth. The layers and rifts seem always to form at the same spots because of how the charged particles in Mars’s ionosphere react to its tangled magnetic field. That could make them far easier to predict and study there, which could teach us more about them and help us deal with their effects on radio communications here.

“MAVEN has already explored more of these at Mars than we have ever explored on Earth,” says Collinson. “It’s giving us a place where we can finally study this thing that’s happening right above us all the time, that you wouldn’t know about, unless your radio starts speaking Portuguese!”

From Anette and Brian Jacobs has come a report of the Midvaal Fast One Cycle Challenge. This race is run by the Vaal Rotarians every year towards the end of January. This year the event took place on 26th January 2020.

The event consists of a very short, a short, and a long cycle race departing from Midvaal Raceway in Meyerton, and finishing at the same venue.

HAMNET Gauteng South was requested to assist with this event again. Requirements were to set up communications in the organizer’s VOC with HAMNET members placed strategically in the field. Their role was to report on the progress of the race, investigate and report any incidents as requested, and report anything to the VOC considered important to the success of the race. These usually relate to potholes, traffic, water tables, route demarcation, marshals, metro or traffic police, and, last but not least, the safety of the cyclists.

HAMNET Gauteng South also assisted with communications for the deployment of ambulances as requested by the VOC commander or Ambulance head, as well as making tracking information available to all the managers in the VOC. HAMNET was also responsible for the “Tail-end Charlie” function which ensures that no cyclists is left stranded on the road. A reconnaissance unit was also dispatched 30 minutes before the start of the race start to check the condition of the route. HAMNET also provided telephone support and a filtered and fire-walled internet access to all the personnel in the VOC.

HAMNET Gauteng South, East Rand and Vaal’s members made themselves available for this event, with Riaan ZS4PR and Leon ZS6LMG as the event coordinators. This event was a full-on training event for many of the newer HAMNET operators who shadowed and assisted the more experienced operators. Alan ZS4HWG was in charge of the VOC, with Gideon ZS6GJA being the main radio operator. Awie ZS6AVI was the runner and Gideon’s relief. Ambulance Comms was the responsibility of Linda ZS6LML, with Jaco ZS6JCO as Linda’s runner and relief. Johan ZS6DMX, Eugene ZS6ECJ, Leon ZS6LMG and Deon ZS6DAB were responsible for the technical support of the VOC. Jacques ZS6JV was tasked with Venue Communications.

Some of the members were already at the Midvaal race track on 25 January to assist with setting up the VOC and getting radios and tracker units ready for installation in the ambulances. These members also slept over at the raceway ready for the early start the next day. The braai that was hosted by the Vaal members was really great and the camaraderie experienced was fantastic.

On the day of the event 26 January, Midvaal Traffic closed the roads and no entry without permits was allowed. From 03:00 in the morning the HAMNET members were ready to start installing the equipment in the ambulances, but these only arrived shortly before 05:00, which put some pressure on the team.

At 05:00, Riaan ZS4PR and Leon ZS6LMG briefed all the HAMNET team members while enjoying a hotdog and refreshments supplied by the Vaal members. At 05:15 the HAMNET member assigned to do the recce left to do the route inspection. At 05:30 the rest of the team deployed to their respective locations. By 05:50 the final report-in and comms checks were done, ready for the start of the race at 06:00.

The event finished around 14:00, and all units reported back to the venue to enjoy a boerewors roll and cold drinks again supplied by the Vaal team. After a short debrief everyone departed for home, each reporting on the Telegram group when they had reached home safely.

Brian thanks the operators once again for a job well done!

HAMNET Western Cape assisted at the 99er Cycle tour around Durbanville yesterday, and I’ll have a report back on that event next week.

This is Dave Reece ZS1DFR reporting for HAMNET in South Africa.