Attending to the goal of the Solar Genome Project, which aims to deliver open-source methods and information exchange for characterization of the solar resource of the globe, the Solar Ecology Collaborative Lab at Penn State designed two low-cost and accurate solar radiometric systems: the SID and the ASE.
SID is short for Solar Irradiance Detector. It was developed to be a system composed of a single pyranometer (usually intended to measure the Global Horizontal Irradiance - GHI) but is capable of working with two pyranometers (GHI and Plane of Array (POA) Irradiance). The system also measures air temperature and internal system temperature.
ASE is short for the All Seeing-Eye radiometric system. It was developed with the concept of Multi-Pyranometer Arrays (MPA) in mind and utilizes 5 pyranometers (or six, one for POA). All 5 solar irradiance sensors measure the global irradiance (one sensor measures the GHI and the other four sensors measure global tilted irradiance). This configuration is coupled with machine learning algorithms to make the ASE capable of providing information about the different components of the solar irradiance (i.e. global, direct, and diffuse). Just like the SID system, the ASE is also capable of measuring the air temperature and internal system temperature.
If you are interested in any (or both) of the projects, check: