Global land surface characteristic parametric product - latent heat ET_ AVHRR (0.05 °) (1993) product-related files include HDF and XML files. Data entities are stored in HDF files, and product metadata information is stored in HDF and XML files. GLASS products have the characteristics of long time series, high resolution and high precision, which provide a reliable basis for the study of global environmental change. They can be widely used in the dynamic monitoring of the global, intercontinental and regional atmosphere, vegetation cover, water body and other aspects. it combines with climate change characterization parameters such as temperature and precipitation, and they can be used in global change analysis. it can provide good scientific basis, technology and data support for the global ecological environment evolution law, ecological environment monitoring, resource development and social and economic sustainable development.