The apparent temperature of the radiant energy impinging on an object that is reflected off the object and enters the instrument. Originates from the scene behind and surrounding the instrument, as viewed from the target. The reflection of this background appears in the image and affects temperature measurements.The apparent temperature of the radiant energy impinging on an object that is reflected off the object and enters the instrument. Originates from the scene behind and surrounding the instrument, as viewed from the target. The reflection of this background appears in the image and affects temperature measurements. The apparent temperature of the radiant energy impinging on an object that is reflected off the object and enters the instrument. Originates from the scene behind and surrounding the instrument, as viewed from the target. The reflection of this background appears in the image and affects temperature measurements.