Field Deployable Soil Observation Topographic Differential Absorption LiDAR (SOTDiAL)

Abstract

A soil analysis system that provides a field deployable device that is configured to remotely measure in situ soil suction through correlation with relative humidity at the soil surface.

What is claimed is: 
     
         1 . A soil analysis system that provides a field deployable device that is configured to remotely measure in situ soil suction through correlation with relative humidity at the soil surface comprising: an active element where light energy is both transmitted and received and a passive element where light energy is received. 
     
     
         2 . The system of  claim 1  wherein external light is used by said passive element. 
     
     
         3 . The system of  claim 1  wherein active light energy is transmitted by two low-power cavity diode lasers. 
     
     
         4 . The system of  claim 1  wherein active light energy is transmitted by two low-power cavity diode lasers arranged in a self-chirped homodyne laser detection scheme tuned to wavelengths of 823.3-nm and 847.0-nm. 
     
     
         5 . The system of  claim 1  wherein the wavelengths used by said active element corresponds with water absorption and reflection characteristics. 
     
     
         6 . The system of  claim 1  wherein the wavelengths used by said passive element receives light range from the visual to the near-infrared spectrum (400-nm to 2500-nm). 
     
     
         7 . The system of  claim 1  wherein said active and passive elements of the system operate in tandem. 
     
     
         8 . The system of  claim 1  wherein laser light is emitted onto the surface of a soil, while light is also received simultaneously through said optical aperture. 
     
     
         9 . The system of  claim 8  wherein laser light is partially scattered into the atmosphere and light energy is reflected back into said aperture of the system. 
     
     
         10 . The system of  claim 9  wherein the system is adapted to also use the remaining backscatter of sun light. 
     
     
         11 . The system of  claim 1  wherein the system analyzes the spectra of transmitted and received light and performs a correlation with relative humidity at the soil surface to determine in situ properties of the soil, including soil water potential (i.e. soil suction). 
     
     
         12 . The system of  claim 1  wherein said optical aperture is a tripod-based telescope. 
     
     
         13 . The system of  claim 1  wherein said light emitting device and said optical aperture are motorized. 
     
     
         14 . The system of  claim 1  wherein said light emitting device and said optical aperture are motorized and provide a 360-degrees of data collection. 
     
     
         15 . The system of  claim 1  wherein the spatial and temporal resolution are up to 1500 feet. 
     
     
         16 . A method of performing soil analysis comprising the steps of: providing a field deployable device that is configured to remotely measure in situ soil suction through correlation with relative humidity at the soil surface, said field deployable device having an active element where light energy is both transmitted and received and a passive element where light energy is received by the device. 
     
     
         17 . The method of  claim 16  wherein external light is used by said passive element. 
     
     
         18 . The system of  claim 16  wherein the wavelengths used by said active element correspond with water absorption and reflection characteristics. 
     
     
         19 . The method of  claim 16  wherein said active and passive elements of the system operate in tandem. 
     
     
         20 . The method of  claim 16  wherein said light energy is a laser light that is emitted onto the surface of a soil, while light is also received simultaneously through said optical aperture. 
     
     
         21 . The method of  claim 16  wherein laser light is partially scattered into the atmosphere, but some light energy is reflected back into the aperture of the system, while the remaining backscatter of sun light into the system. 
     
     
         22 . The system of  claim 21  wherein based on the spectra of transmitted and received light a correlation is performed with relative humidity at the soil surface to determine in situ properties of the soil, including soil water potential (i.e. soil suction), plasticity and fines content of the soil.