Sonic anemometer tilt correction algorithms are discussed, focusing on the impact of tilt on stress estimates. The study shows that stress errors are largest in unstable stratification and deep convective boundary layers. Three tilt correction methods are compared: a double rotation method, a triple rotation method, and a planar fit method. The double rotation method, commonly used, leads to significant run-to-run stress errors due to sampling uncertainty in the mean vertical velocity. The triple rotation method results in even greater errors due to combined sampling errors. For sea measurements, the double rotation method overestimates surface stress due to uncorrected lateral tilt. The planar fit method reduces run-to-run stress errors and provides an unbiased estimate of lateral stress. The study highlights the importance of using a mean streamline coordinate system for sloping terrain, as it aligns with mean streamlines and simplifies comparisons with analytical theories. This coordinate system helps minimize terrain effects on turbulence measurements and allows for easier comparison with flat terrain data. However, terrain slope can affect low-level wind profiles in the presence of diabatic effects, altering surface-layer flux-profile relations. In stable boundary layers, terrain effects may still be noticeable. The use of streamline coordinates also facilitates turbulence parameterizations in numerical models. The study emphasizes the need for accurate tilt correction methods to ensure reliable stress estimates in various terrain and atmospheric conditions.Sonic anemometer tilt correction algorithms are discussed, focusing on the impact of tilt on stress estimates. The study shows that stress errors are largest in unstable stratification and deep convective boundary layers. Three tilt correction methods are compared: a double rotation method, a triple rotation method, and a planar fit method. The double rotation method, commonly used, leads to significant run-to-run stress errors due to sampling uncertainty in the mean vertical velocity. The triple rotation method results in even greater errors due to combined sampling errors. For sea measurements, the double rotation method overestimates surface stress due to uncorrected lateral tilt. The planar fit method reduces run-to-run stress errors and provides an unbiased estimate of lateral stress. The study highlights the importance of using a mean streamline coordinate system for sloping terrain, as it aligns with mean streamlines and simplifies comparisons with analytical theories. This coordinate system helps minimize terrain effects on turbulence measurements and allows for easier comparison with flat terrain data. However, terrain slope can affect low-level wind profiles in the presence of diabatic effects, altering surface-layer flux-profile relations. In stable boundary layers, terrain effects may still be noticeable. The use of streamline coordinates also facilitates turbulence parameterizations in numerical models. The study emphasizes the need for accurate tilt correction methods to ensure reliable stress estimates in various terrain and atmospheric conditions.