If there was anything good about three or four days of obsessing over unidentified balloons last weekend, it’s that we all learned about a fascinating niche of amateur radio that marries tiny radio transmitters to featherweight hydrogen balloons capable of sailing around the globe—sometimes many times.
Can radar pick up a pico balloon? No if it is an electrically non-conductive material. Add aluminized plastic and a trailing antenna and it becomes the same question but favoring a positive response. The problem is that if the “aperture” is opened up enough to capture those returns a lot of other stuff appears, including some atmospheric phenomena. If the radar is looking for fast aircraft perhaps one would not normally want to see small balloons.
Did you notice that one of the missiles missed? This indicates that the radar on the missile was not as “good” as that in the aircraft. Exactly what one would think. Now the Chinese, and the rest of the world, knows more about our air defense capabilities. Or maybe the AF is cagey enough to fire an old dud just to screw them up. Spy vs. spy vs. spy.
Cool tracking site.
Great article, Paul. As far as radar tracking the actual physical balloon-payload package, I suspect the radio transmissions would be what gets tracked.
Waiting for the price point of ADS-B units to reflect the price point of the referenced disposable launch-and-forget GPS gear before I commit… LOL
An unfortunate last name, Basura = trash en espanol. I had to go back and look because I couldn’t figure out why you’d be goofing in the article that was otherwise serious (and very informative)!
That’s fascinating stuff you’ve pulled together on pico ballooning and weather balloon trash accumulations in the middle to upper atmosphere more generally. (Like the famed Sargasso Sea and mid-Pacific junk gyres, respectively.) I’d like to know more about the trajectories that get balloons to the stratosphere and which they then follow. Where do hobbyists in Illinois launch from, and what configuration of those big ole airmasses does it take to wind them up to the polar latitudes where things stabilize and they can circumnavigate repeatedly?
In the video, Basura covers HYSPLIT, the super-computer driven wind model that pico ballooners use to project trajectory. Anyone has access to it, perhaps including the Chinese. This raises an interesting question. The Washington Post reported that the Chinese balloon may have taken an unintended course, flying further north than planned.
Or did the Chinese know that was coming and launched from Hainan to intentionally ride the wave? We may never know.
https://www.washingtonpost.com/national-security/2023/02/14/china-spy-balloon-path-tracking-weather/
With regards to APRS - a number of pilots have been using APRS transmitters as a ‘free’ tracking device in lieu of subscription-based satellite trackers such as SPOT or InReach. They’re not quite an equal substitute. But for those with the technical knowledge and desire to tinker it’s a very low-cost way to allow the non-flying spouse to keep track of your whereabouts.
Radars can pick up balloons just fine, so long as they have sufficient sensitivity and so long as the tracking algorithms are tuned recognize such slow movers as something to track. (The material of the balloon envelope doesn’t have nearly as much to do with it as you seem to believe.). But, none of that really matters very much with the missiles in this case, since they have IR seeker heads (a.k.a. “heat seekers”) rather than RF (“radar”) seekers.
A good question to be sure. But it would be a mistake to assume that the first balloon shot down was completely at the whims of the winds like those (admittedly still fascinating) Pico balloons. Apples and oranges.
“We may never know.” International intrigue, science, and drama with a cheeky twist. Great stuff!
Now that we’ve got airline pilots looking UP while cruising along, we’ll doubtless get a huge upsurge in sightings. Someone needs to come up with a way to monetize this.
One of the benefits of being consumed by this particular interest, at least for a few days, is the opportunity to learn about the technology and science behind it. From the physics of buoyancy and atmospheric pressure to the intricacies of radio transmission and reception, there’s a lot to study and discover in affordable amateur radio ballooning. Now in my retirement days, I find all this rejuvenating. Thank you, “Bien Hoa” Paul.?