Function pamoja_lora_fresnel_radius_mm 

#[unsafe(no_mangle)]
pub extern "C" fn pamoja_lora_fresnel_radius_mm(
    near_m: u32,
    far_m: u32,
    frequency_hz: u32,
) -> u32

Returns the radius of the first Fresnel ellipsoid at a point on a path.

This is Recommendation ITU-R P.526-16, equation (2). The radius is widest halfway along the path.

Arguments

• near_m - the distance from one antenna to the point, in meters.
• far_m - the distance from the point to the other antenna, in meters.
• frequency_hz - the carrier frequency in hertz.

Returns

The radius in millimeters, or 0 for a path of no length or a frequency of zero.