A portable soil surface roughness instrument for automatic two-dimensional profile roughness measurement in the field
Soil surface roughness, which refers to the unevenness of the soil surface, is an important factor that affects the radar backscatter coefficient and the microwave emissivity of the surface. Surface geometrical roughness has important applications in fields such as agriculture, soil science, weather and climate prediction, and geology. To measure roughness, the instrument is mounted on a tripod and uses a laser to punch out horizontal points at intervals of 1 cm using rotary scanning. The instrument then performs ranging and calculates the height of each point based on the current rotation angle and distance. This allows it to obtain a surface height profile with a length of 1 meter. Finally, the instrument determines the roughness and relevant length of the soil surface. Field experiments were carried out with this instrument and a pin meter. The roughness values obtained from the instrument were highly correlated with those obtained by the pin roughness meter. Compared to traditional contact methods, this instrument has the advantages of a simple structure, good portability, and a high degree of automation. It can be used in the field of microwave remote sensing or soil science.