Assuming the ionosphere to consists of a uniform a layer at a height of 500 km and with critical frequency 5 MHz, calculate the minimum and maximum ranges at which a 12 MHz signal mav be received by means of single-hop transmission. Calculate also the ranges at which both single-hop and double-hop transmission may contribute to the received signal lake the radius of the earth to be 6370 km.

 

What is the radius of the sphere formed by the ionosphere? That is a big hint...

 

Yes, this can be done with simple chordal geometry, if you assume the ionosphere to be fairly "specular'.

eric