I flew on American Airlines from Raleigh-Durham, NC (KRDU) to Dallas, TX (KDFW) on November 3rd. It was my first trial of my gamma ray detector.
Being in the back of the plane, I was able to watch the detector as we took off and climbed up to 28,000 feet. It was a low altitude flight, presumably to defeat headwinds from the west. But the point is, I wasn’t in the pilot seat so I had a lot of time to watch the detector. As we climbed in altitude the digits rapidly climbed from .09 uSv/hr to 1.5 uSv/hr in the air. Later, the numbers climbed some more, and over Little Rock, Arkansas, the numbers peaked at 1.79 uSv/hr. Then, as we descended into Dallas, the gamma rays quickly died down to ground level which has ended up being a constant of about .05-.07 uSv/hr here in Dallas.
Here I am (looking dumb because I’ve been in the Gulfstream class all day) at Flightsafety with my iPad. The Polismart II detector is sticking out the bottom.
And now I know that Dallas is a very, very low radiation place! In terms of radioactivity, it’s a good place to live. Raleigh was usually nearly twice as high (.11 or so). But I’m splitting hairs. Both places are so near zero compared to flight altitudes that it doesn’t even matter.
1.79 uSv/hr, the peak on this flight, is quite a bit lower than what I’d been predicting. The reason is that we were:
- At low(ish) altitude (30,000’)
- At low latitude (35 degrees North)
So, yes, there’s much, much more radiation in the upper atmosphere than on the ground! It’s not that I had a doubt. But it was just really interesting to see the numbers clicking up with the altitude, in real time, on my iPhone!
In the future, I’ll be creating a neat way to view data, but, for now, here’s the raw screen shots of the flight.
Here is the flight path, as recorded on my phone during the flight. You can see the highest reading in the upper-left corner. There is a gap in the route because my phone lost GPS coverage for a little while. The image on the right is the total dose received for the entire flight.
If I’d stayed at home, I would have received about .23 uSv during the two and a half hours I was actually in the air. Instead, I got 3.01.
It was a good trial run. Over the next year I’ll be gathering data around the world. Keep checking back to see the numbers I get. And as I educate myself on this subject, I’ll post the basic information that flyers need without all the geek engineering terms that are so prevalent in radiation related websites.