This dataset contains the metadata and measurements from a number of irradiance sensors and rooftop solar power systems in addition to clear-sky expectations for those sensors. Irradiance derived from images from the GOES-W satellite are also included. The dataset covers April, May, and June 2014 over the Tucson, AZ, area. The data is in a number of formats including CSV, plain text, HDF5, and netCDF4. See the following for a description of the NREL calibrated GHI sensor: Andreas, A.; Wilcox, S.; (2010). Observed Atmospheric and Solar Information System (OASIS); Tucson, Arizona (Data); NREL Report No. DA-5500-56494. http://dx.doi.org/10.5439/1052226 More information about the custom irradiance and rooftop PV sensors can be found in: A. T. Lorenzo, W. F. Holmgren, M. Leuthold, C. K. Kim, A. D. Cronin, and E. A. Betterton, “Short-term PV power forecasts based on a real-time irradiance monitoring network,” in 2014 IEEE 40th Photovoltaic Specialist Conference (PVSC), 2014, pp. 0075–0079.