Category Archives: Results

Around the world in 8 days

I’ve flown half way round the world and back during the past week and a half.  I’ve crisscrossed the Arabian Sea and the Atlantic Ocean.  I’ve been within spitting distance of the equator and seen the snow-covered landscape of Greenland!

All my raw results are posted below.  You be the scientist.  Can you make any conclusions of your own?  Does changing altitude make much of a difference at the equator?  Does it make a difference over Greenland?  What’s the average dose at 41,000′ down south?  How about up north?  What’s the dosage rate over Europe?

Riyadh to Maldives:

Multi Frame 1

Maldives to Riyadh:

Multi Frame 2

Riyadh to Paris:

Multi Frame 7

London to Detroit:

Multi Frame 3

I’ve flown over Greenland many times, but it’s always either been covered in cloud or too dark to see.  I got lucky on this flight and captured these pictures at high noon.  Notice how long the shadows are, even two months past the winter solstice?  These shots are at 62 degrees North latitude.

Greenland 1-resized

The depth of the snow in the picture above must be thousands of feet deep.  It fills in the valleys completely, leaving the craggy mountain peaks poking out like they were pine trees on an upper mountain slope.

Below is a gigantic glacier, ending in the frozen ocean.

Greenland 2-resized

Detroit to Greenville:

Multi Frame 4

Greenville to London:

Multi Frame 5

How much fuel does it take to fly from South Carolina to London?  About a truck and a half worth!


London To Riyadh:

Multi Frame 6

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Radiation Over the North Atlantic

I did my first Atlantic crossing in the Gulfstream IV, a couple days ago.  I can’t tell you how cool it is to be in a jet with such great endurance.  I’ve flown a lot of smaller jets that couldn’t even make it across the US without stopping for go go juice.  So it’s really nice to be in a jet with some LEGS!  The flight was non-stop from Savannah, GA to London.  Flight time was seven and a half hours.



Most airliners fly between 30,000′ and 39,000′.  We were up at 41,000′ getting our silly heads cooked like microwave lasagnas!  That’s good news for my blog, but bad news for my hairline!

NAT3-resized  NAT2-resized

According to the data, above, my accumulated dose of Gamma rays went up from my year’s total of 51.12uSv to 75.39.  My calculator’s telling me that’s an accumulation of 24.27uSv in one day!  And, that’s why aircrew need to have dosimeters.

The average radiation at 41,000′ was 4.0 uSv/hr over the North Atlantic ocean.

The track, above, has a strange gap around New York.  That’s what happens when the detector comes unplugged from the iPad.  It keeps recording the radiation data, faithfully, but it normally gets its GPS coordinates from the iPad.  Without the iPad it defaults to 00 oo’oo” North, 00 00’00″West, which is by Africa, as you can see.  When I realized the detector was not all the way plugged in, I fixed it and made sure it stayed in for the rest of the trip across the pond.

Now, here’s something you need know!  I have just found out that there is more radiation up there than just Gamma rays.  Gamma should be the majority fraction, but I need to get more data about the contributing quantities of the other types of radiation.  The following is a list of the types of ionizing radiation that I’m aware of:

  • Gamma ray
  • X-Ray
  • Alpha (a kind of particle)
  • Beta (another kind of particle)
  • Neutron (the unattached, high-energy kind)
  • Electron (These are, supposedly, a different kind than electrical electrons.  A physicist told me it was too complicated to explain!)
  • Proton (the unattached, high-energy kind)

My next project is to find out what levels of radiation these different types contribute to the whole.  When I figure it out, I’ll let you know!

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New Years Day – 2014

Howdy folks!  It’s been a long time since I posted any results.  I spent a bunch of weeks training in the simulator.  The flight simulation may be accurate, but the simulation of radiation at flight altitude was way off!  Then I went to work for two weeks but forgot to bring my detector!  Then vacation, etc. and the end result is two months with very little data.

Anyway, I do have some results from Christmas vacation flights.  Again, like before, these were relatively low altitude flights, and the results were, predictably, low.  But, as promised, I’m posting everything, low and high.

The location for these flights was in the Northeast, US.

New Year 2014

December 24th 2013

Raleigh-Durham, NC to Philadelphia, PA:

Max radiation at 25,000′ – .96 uSv/Hr

Min radiation at 25,000′ – .92 uSv/Hr

Average radiation at 25,000 – .93uSv/Hr

Philadelphia, PA to Burlington, VT

Max radiation at 25,000’ – 1.35 uSv/Hr

Min radiation at 25,000’ – 1.14 uSv/Hr

Average radiation at 25,000’ – 1.27 uSv/Hr

December 30th 2013

Boston to Raleigh-Durham

Note:  Due to turbulence, the flight crew changed altitude a lot in search of smoother air.  So I got some data for a few different altitudes, as shown below:

Average radiation at 26,000’ – 1.26 uSv/hr

Average radiation at 24,000’ – 1.26 uSv/hr

Average radiation at 22,000’ – .74 uSv/hr

Average radiation at 20,000’ – .76 uSv/hr

Dallas to Raleigh at 35,000 Feet

The night of November 26 I flew from Dallas, TX to Raleigh-Durham, NC.  Maximum altitude was 35,000 feet.  However, it was really turbulent so the crew elected to descend to 29,000 feet after 15 minutes and stay there till descent an hour later.

On the ground in Dallas, the radiation level was .06 uSv/hr (micro-Seiverts per hour).

At 29,000 feet the average radiation level was 1.5 uSV/Hr

At 35,000 feet the average radiation level was 2.4 uSv/Hr

The flight departed at midnight, Eastern Standard time.  Flight duration from wheels up to wheels down was 2 hours and 5 minutes.

Total radiation dose and the max radiation received can be seen in the screen shots below.

DFW-RDUTotal-resized    DFW-RDUMax-resized

If I’d stayed on the ground in Dallas I would have received .126 micro-Seiverts of radiation.  Instead, I received the above quantity of 2.74 micro-Seiverts.

The objective, here, is not to convince you to stay on the ground and never fly.  No way.  The radiation received on short flights like this, flown once in a while, ads very little to ones total, yearly count.  For example, between this flight and my last flight three weeks previous (see previous post) I received 37.3 uSv while hanging out in Dallas.

We want to keep our annual radiation dose under 4,000 micro-Seiverts per year.  Living in Dallas, one would get about 500 uSv per year from background radiation.  If one flew every 3 weeks on a flight like this, one would only get another 50 uSv.  That totals 550 uSv per year.  Far, far below the accepted “safe dose” for the public.

In a few weeks, I’m supposed to do a flight to Saudi Arabia.  It will be interesting to see what 16 hours at varying altitudes and latitudes will total up to.

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First Flight

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:

  1. At low(ish) altitude (30,000’)
  2. 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.

RDU-DFW Route            IMG_0127

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.