Landsat scientist works to improve farm water monitoring

The US Geological Survey said that Yun Yang, a member of the 2026-2030 Landsat Science Team, was working to improve evapotranspiration and albedo estimation. Her research aimed to give farmers better information about the water their individual fields required.

Yang, an assistant professor at Cornell University, sought more accurate, detailed and timely Landsat data for water management. Farmers and water managers used Landsat data in models that estimated crop water use and informed decisions about efficient water use and reporting requirements.

Yang also served as a consortium partner and nonprofit board member for OpenET, a Landsat-based platform. OpenET used six evapotranspiration models to create an ensemble model that was used throughout the United States. The platform gave Yang information about what data users needed from the Landsat Science Team.

As a first step, Yang and colleague Zhuosen Wang sought to improve estimates of Landsat albedo for use in the ALEXI/DisALEXI evapotranspiration model. Landsat 8 and 9 revisited land and coastal surfaces around the globe every eight days. Adding Sentinel-2 observations through the Harmonized Landsat Sentinel-2 product would increase albedo observations to several times a week.

Yang planned to test the enhanced albedo product in ALEXI/DisALEXI by replacing a simpler method. She also intended to refine a system that combined Landsat thermal observations with data from other remote sensing instruments. The system could provide more frequent observations at a resolution that showed more detail.

The evapotranspiration work aimed to help farmers determine when to start irrigation, how much to irrigate and whether their fields showed signs of stress. Yang described Landsat as the gold standard for evapotranspiration estimation and said its combination of features remained the core source of data.