By Julia Calderone | KUSP News
For scientists studying the ocean, wireless communication with water-bound instruments can get murky. But a team in Moss Landing is turning to a giant helium balloon to boost their signals.
Brent Roman, a software engineer at the Monterey Bay Aquarium Research Institute, pulls a large white helium-filled balloon from the institute’s loading dock and tethered it to a deck just steps away from the ocean. It kind of looks like a smushed, plastic sphere with a giant fin jutting off the back. This big white blob isn’t just a balloon, it’s also a kite.
A Balloon the Wind Can’t Blow Down
“The man’s name who invented it is Sandy Alsop,” Roman says. “He got this idea of making a kite – or a balloon that did not blow down in the wind. If a child runs with a balloon behind him it just trails behind. On the other hand a kite has the exact opposite problem: If there’s a wind it’s great, but if the wind dies the kite falls. If we could take a kite and make it into a balloon or combine the two somehow, then we might get a device that just reliably flies.”
And the kite’s job isn’t just to fly, it also has a radio mounted on it, so Roman can communicate with instruments collecting data from the ocean. It’s kind of like a wifi hotspot.
Roman got the idea of using a helikite as a type of satellite when he was researching ocean microbes on a large catamaran in Hawaii. He was trying to communicate with an instrument that was attached to a buoy, or a drifter that floats in the water without power and collects samples from the ocean. But he was running into issues.
“This huge boat would have to follow this drifter around in the water. We couldn’t do much else because we needed to stay in contact with it. We had a satellite modem on the drifter that was very slow and very expensive and I just realized that the fundamental problem was the antenna could get high enough on the boat to get over the curvature of the Earth and the deleterious effects of the radio waves right on the Earth.”
Saving a 44,000 Mile Round Trip
Roman also figured that the current process was inefficient and costly.
“We figured that it was silly to bounce our signals off a satellite 22,000 miles above the Earth just to reach something that was only five or six miles or ten miles at most away from the boat. We were making a 44,000 mile trip to go ten miles. If we had our own satellite that was just a few hundred feet above the Earth, maybe we could accomplish the same thing not be reliant on the satellite network and have bandwidth or communication rates that would be a hundred times higher.”
Roman and his colleague Denis Klimov are currently testing the range of the kite. As they raise and lower it to different heights, they are communicating with a boat that is driving to different distances. When they lose communication with the boat, they raise the kite until they get a signal again.
“That’s what we’re learning today, just how high we need to fly the kite to get the radio propagation we’re hoping for.”
In his other tests, Roman’s had to fly the kite at about 500 feet to get a good signal, but today he’s seeing a strange result. He’s seeing a signal with the kite reeled all the way down to the deck. This isn’t consistent with his prior experiences.
“I don’t know what I’m going to do if at four miles we still have a signal. So I’m going to have to do more research to get a better understanding of what’s going on.”
Eventually, Roman would like to mount the kite onto a boat and use it to communicate with receivers as far as 10 miles away. But for now, it’s still in its early testing phases. And Roman needs to make sure that the helikite first learns how to fly.