The Broadband Radiometers (BBR) consist of modified Kipp & Zonen CM-22 pyranometers (to measure solar irradiance) and CG-4 pyrgeometers (to measure IR irradiance) (see http://www.kippzonen.com/). The modifications to make these instruments more suitable for aircraft use include new instrument housings and amplification of the signal at the sensor. The instruments are run in current-loop mode to minimize the effects of noise in long signal cables. The housing is sealed and evacuated to prevent condensation or freezing inside the instrument. Each BBR has the following properties: Field-of-view: Hemispheric Temperature Range: -65C to +80C Estimated Accuracy: 3-5% Data Rate: 10Hz