Radiation Pattern: A chart of relative radiation intensity (or power) versus direction. Radiation Field: The electromagnetic field that radiates from an antenna and travels through space. Any frequency of electrical energy capable of propagation into space (usually above 20 kHz). Radiation: Energy that moves through space as electromagnetic waves. Reflected waves: Waves that change their direction of propagation after striking a surface that is either a conductor or an insulator. Reflecting Layer: In the ionosphere, a layer that has a free-electron density sufficient to reflect radio waves. Reflection: The turning back of a radio wave from an object or the surface of the Earth. The locus of points at which direct rays from an antenna are tangential to the surface of the Earth. Second, wood markets are interrelated, as proposed qualifying materials cannot be produced independently of traditional forest raw materials. Ironically, these efforts could result in higher overall raw material prices and would defeat the intended purpose of BCAP. Stable, overall wood demand outlook for the US forest industry: through 2020, grade logs required by hardwood and softwood lumber mills are expected to increase and stabilize, while pulpwood volumes required by paper and paperboard manufacturers are expected to remain flat and decrease.