Here's the latest set of illustrations for Decagon Devices, Inc. This is a relatively new sensor called the "SRS" (The Spectral Reflectance Sensor). It's specifically designed for continuous monitoring of Normalized Difference Vegetation Index, or the NDVI. I think that means this sensor monitors vegetation canopies. The data can be used to track when and how fast canopies grow, which can help to water use, timing, etc.