What is considered a transmission obstruction?
Frequencies around 1600 MHz go through most plastics, rubber, glass, and most fabrics (cotton, wool, polyester, nylon, most other synthetics) with almost no attenuation. Wood between the SPOT and the sky is a no-no. Wood will attenuate the signals quite a bit. A thick canopy of leaves also attenuates those frequencies a lot. Your body, and almost anything containing water also attenuates the signal a lot. Metal, concrete, stone, asphalt, brick, earth, between the SPOT and the sky will kill the signal completely.
