Determination of the Leaf Inclination Angle (LIA) through Field and Remote Sensing Methods: Current Status and Future Prospects

The leaf inclination angle (LIA), defined as the or needle to horizontal plane, is vital in radiative transfer, precipitation interception, evapotranspiration, photosynthesis, and hydrological processes. This paper reviews field remote sensing methods determine LIA. In field, LIA determined using direct indirect methods. include contact, photographic, light detection ranging (LiDAR) methods, while are composed of gap fraction, four-component, polarization measurement can obtain accurately at individual leaves, crown, plot scales, whereas work well for crops level. estimate mainly based on empirical, transfer model, fraction More advanced inversion strategies validation studies necessary improve robustness estimation. future studies, automated observation systems be developed incorporated into existing ground networks enhance spatial coverage.