4. Suppose that an airplane uses a radar to measure its altitude (What is radar?). Let the frequency of the radar be 3 GHz. Suppose further that the ground is covered with one meter of hard-packed snow. Snow is not a very good conductor (What does that mean?). What is the penetration depth of the radar signal in snow? Said another way, calculate the amount of attenuation in dB that the radar suffers because of the snow. Refer to the figure below. Also use ? = 1.5€, and the loss tangent, tand is 9 x 104 for hard-packed snow at 3 GHz. The loss tangent is defined in Equation 3.30 of the textbook. If the height h is 28,000 feet minus 1 meter of snow, calculate the round trip time for the electromagnetic signal. Assume the signal travels at the speed of light above the snow then at a slower speed in the snow (Why?) The speed reduction in the snow by itself is V = w/kr where kr is the real part of the complex wavenumber given in Eqn.3.31a. Make a 'good' assumption about u (20 pts) Snow Ground kg = ? ?? (3.31a) For conducting media, we have k = m/Me 1 - jom * = kx – jk; (3.30) where one is called the loss tangent of the conducting media.