Testing Satellite Communications Links on Top of the WorldDecember 2016
Topics: Communications Technology (General), Military Operations (General), Sensing and Signal Processing (General), Systems Engineering
Modeling and simulation can help predict the performance of military systems in many environments. But in some cases, there’s no substitution for boots on the ground. Especially if that ground is frozen.
Despite the harsh environment, melting icecaps are creating opportunities for trade routes, cruise ships, and access to natural resources in the Arctic. With so many more people expected to visit and work there in the near future, there's likely to be an uptick in incidents requiring emergency response.
That's a key reason why MITRE's Shelley Johnson is leading an effort to help ensure that the military's communications hardware can perform well during Arctic missions. Johnson is a systems engineer embedded at U.S. Northern Command (NORTHCOM) in Colorado Springs, which would support the Arctic emergency response if there's an accident in the region.
Communications infrastructure will be critical during military missions and homeland security or defense events in the Arctic. Intelligence systems, command and control, and humanitarian support are only a portion of the actions requiring communications capabilities, she says.
Life in a Northern Town
In June 2016, Johnson went to Barrow, Alaska—the northernmost U.S. city—as the technical lead for the NORTHCOM communications Arctic testing team, which represents a public-private partnership. The trip was the first of a three-part effort to test the performance of communications systems, including different types of antennas. As a MITRE engineer, one of Johnson's roles included serving as the technical "bridge" between the team's government and industry members.
Barrow's population qualifies it as a city. But it's isolated, with little infrastructure that response teams can rely upon. No roads in or out. Fuel to power generators, lights, and snowmobiles, is delivered once a year. Barrow is populated by the Iñupiat, an indigenous Inuit ethnic group that hunts for whales as a significant portion of its subsistence.
Besides addressing functional aspects of antennas, working on the ground highlighted a variety of issues that response teams need to consider when operating around Barrow, she says. The military needs to be mindful of local culture and its impact on the population when consuming food and other limited resources.
As the tests got underway, wideband communications terminals exceeded expectations. But narrowband terminals, which are smaller and more transportable, ran into unanticipated struggles.
The high-frequency (HF) testing performed as expected. There were days when the atmosphere allowed for outstanding communications between Barrow and Anchorage, as well as Barrow and Canadian partners. Other days were a complete blackout.
Johnson says adjusting the frequency range was critical to establishing communications over HF. This is when being there in person really paid off.
"There are a lot of models you can use for communications in the Arctic, but they don't account for interaction with the ionosphere, the Earth's magnetic forces, and other types of interference."
Interference from Polar Conditions, not Polar Bears
To address these issues, Johnson pulled together a team of MITRE signal processing experts to develop a more powerful prototype antenna—one that uses a focused, narrow beam designed to overcome various types of interference. The team includes Jonathon Cheah, who supports the MUOS program office in San Diego. Janet Werth, who leads the Global Aircrew Strategic Network Terminal effort in Bedford, is contributing antenna modeling expertise.
The plan is to test the prototype antenna during a return trip to Barrow in July 2017. This will allow for long daylight hours and temperatures of 20–30F° —similar test conditions to the June 2016 test, Johnson says. Other MITRE staff will help address issues relating to ionospheric activity and weather that affect both narrowband and HF communications, as well as contributing expertise towards the addition of wideband high frequency systems in future tests.
It's important to remember, Johnson says, every scenario that happens in the lower 48 states is possible in the Arctic. However, many of the communications systems used in the lower 48 do not operate as well or at all in the Arctic. Two MITRE research projects are currently looking at these challenges.
It's all part of a larger research effort by the company to use data from the Arctic to inform communication models operating under stressful operating conditions. Those models may ultimately include a combination of current or future commercial, military, satellite, radio frequency, and terrestrial systems.
Keeping Cool with Communications at 50 Below
In the interim, Johnson will return to the Arctic in February 2017, when there is little daylight and temperatures may drop to 50 degrees below zero. That trip will help the Navy address communications issues ahead of Ice Exercise (ICEX) 2018, she said. The ICEX exercises take place every two years to evaluate new capabilities for the Arctic mission. A three-person team will examine the best way to set up satellite communications terminals in the extreme cold and observe how that equipment functions in those conditions.
NORTHCOM has partnered with the Navy Arctic Submarine Lab to support ICEX 18. Johnson is slated to be the technical lead for this effort.
"The first cruise ship passed through the region in August. More and more will make the journey," Johnson notes. "When is one of them going to run into the ice? It's not a question of 'will something happen?' It's a matter of 'when.'"
—by Jeremy D. Singer