$5.(20$ points$)$ An antenna on the roof of Broida Hall picks up a signal from a stellar radio source in our galaxy with a wavelength of $\backslash (\backslash$lambda$=10\backslash$mathrm$\{$~cm$\}\backslash )$ coming up above the horizon. Due to the proximity of the building to the ocean, the direct wave and the wave reflected off of the surface of water interfere. Find the angle of the source above the horizon when the antenna registers the $1$st and $2$nd maxima of intensity. Make a reasonable estimation of the height of the antenna above the surface of water.