[Elecraft] {KX1} DX question

[stan levandowski]

Does anyone know the basis of the "distance" reported under "Details" in 
QRZ.com entries?

I recently worked HB9FBG on 500 milliwatts with 6 regular "AA" Eveready 
batteries (at least that's what my inline wattmeter said) on a 40 meter 
dipole up in my attic.  The distance from me to HB9FBG was reported as 
3947.8 miles.  Does anyone know if this represents "GPS miles", a 
straight line approximation, miles reported from some table derivation, 
miles that represent some approximation of a radio signal's trip up to 
the ionosphere and back down...? I'm no math genius when it comes to 
trig but it seems that there could be quite a mileage distance.  Also, 
the ".8" in QRZ.com's mileage suggests some technology is at work!

Stan WB2LQF
"HF-QRP-CW  - Doing more with less for over 50 years now!"