Hello,
I am writing a computer program to predict the radar cross section of
an aircraft.
I have got a book from the library and there is a equation in that book
where the variables are not explained.
The equation is for the radar cross section of a flat circular disk:
sigma=((pi.a^2)/tan(theta)) [J1 (4.pi.a.sin(theta)/lambda)]^2
I know that sigma is the radar cross section,
a is the radius of the disk
theta is the angle between the incident radar vector and the vector
normal to the disk surface
lambda is the wavelength of the radar wave.
I have no idea what the variable "J1" is, but I really need it.
If anybody knows, or knows anyone that would know what J1 is I would
really appreciate some help.
Thanks
Adam
