You are on the right track. The way channels / frequencies , scatter , refract defract , reflect is effected buy variable factors , the density of the earth , the construction of buildings , the heights of transmitting antennas and receiving antennas , the angles of reflections , and on and on. There is phenomonon called ground wave where tv signals can be stronger at one inch to about 3 feet above ground , usually about 1 foot to 1 and 1/2 feet. Ronard at
http://www.ronard.com , has tree mounts , tall straight pine trees work well , climb up the tree , clear away branches so the branches do not break up the antenna in the wind , and mount a antenna up there. There are antennas that mount at the back of the antenna like the Winegard HD9095P and Antennas Direct C5 and also others.