From whence the Fresnel Zone constant of proportionality?
From whence the Fresnel Zone constant of proportionality?
(OP)
Calculation of the Fresnel Zone given as r=M*sqrt( 1/F * (d1d2/(d1+d2))) uses 72.1 and 17.3 as the constant of proportionality (M) for r in feet and meters respectively. Does anyone know where this constant comes from? I've tried plugging-and-chugging with feet-to-miles, and f=c/lambda, but I can't see how M converts units and comes out from under the root.
RE: From whence the Fresnel Zone constant of proportionality?
R1^2(squared)=lambda(d1d2/d) where all quantities are in the same units.
Also, the following equation is given when in mixed units:
R1m=2280*sqr(d1d2/Fd)
where R is the radius in feet
d is in miles
F is in Megahertz
Also maybe these refernces may help:
http://www.softwright.com/faq/engineering/Fresnel%20Zone%20Clearance.html
http://www.wirelessapplications.com/wireless/services/lostFound/images/path_clear2_Final.pdf
http://www.cocom.com/pdffiles/App_Note_7_PTZ-3_Range_Calculations.pdf (scroll down to Fresnel calc)
RE: From whence the Fresnel Zone constant of proportionality?
Joseph Bardwell