Systems and methods for harmonic analysis of soil

Abstract

Systems and methods for harmonic analysis of soil are provided herein. Some methods include converting a first frequency of an operating signal into a second, higher frequency relative to the first frequency to create a stimulating signal, transmitting the stimulating signal into soil, and determining attenuation based on a comparison of a responsive signal and the operating signal.

What is claimed is: 
     
         1 . A method, comprising:
 selecting a first frequency for an operating signal used by a sensor;   converting the first frequency of the operating signal into a second frequency to create a stimulating signal, the second frequency being a harmonic of the first frequency;   transmitting the stimulating signal into soil;   receiving a responsive signal based on the stimulating signal;   converting the responsive signal at the second frequency back into the first frequency for comparing a waveform of the responsive signal to a waveform of the operating signal at the first frequency;   comparing a second count of the responsive signal in the first frequency to a first count of the operating signal in the first frequency, the first count and the second count being a number of waves; and   determining attenuation using the responsive signal, the attenuation corresponding to a difference between the first count and the second count and the attenuation being indicative of clay within the soil.   
     
     
         2 . The method according to  claim 1 , wherein the first frequency is at least approximately 50 MHz. 
     
     
         3 . The method according to  claim 1 , wherein the second frequency is a second harmonic of the first frequency. 
     
     
         4 . The method according to  claim 1 , wherein a volume of clay within the soil correlates to a magnitude of the attenuation. 
     
     
         5 . The method according to  claim 1 , further comprising repeating the method for a range of values for the first frequency. 
     
     
         6 . A device, comprising:
 a harmonic sensor circuit that produces an operating signal at a first frequency and emits a stimulating signal at a second frequency that is a harmonic of the first frequency;   a processor; and   a memory for storing instructions, the processor executing the instructions to:
 control the harmonic sensor circuit to emit the stimulating signal into soil; and 
 determine attenuation of the stimulating signal in the soil based on an analysis of a responsive signal that has been converted back in to the first frequency relative to the operating signal; 
   wherein the processor determines attenuation of the responsive signal by:   converting the responsive signal from the second frequency to the first frequency; and   comparing a second count of the responsive signal in the first frequency to a first count of the operating signal in the first frequency, the first count and the second count being a number of waves, the attenuation corresponding to a difference between the first count and the second count.   
     
     
         7 . The device according to  claim 6 , further comprising a communications interface, the processor being configured to transmit a message to a cloud service that is indicative of the attenuation. 
     
     
         8 . The device according to  claim 6 , wherein the first frequency is at least approximately 50 MHz. 
     
     
         9 . The device according to  claim 6 , wherein the second frequency is a second harmonic of the first frequency. 
     
     
         10 . The device according to  claim 6 , wherein a volume of clay within the soil correlates to a magnitude of the attenuation. 
     
     
         11 . The device according to  claim 10 , wherein the processor is configured to vary the first frequency over a range of values. 
     
     
         12 . A method, comprising:
 converting a first frequency of an operating signal into a second, higher frequency relative to the first frequency to create a stimulating signal;   transmitting the stimulating signal into soil; and   determining attenuation based on a comparison of a responsive signal and the operating signal;   wherein determining attenuation in the responsive signal comprises:
 converting the responsive signal from the second, higher frequency to the first frequency; and 
 comparing a second count of the responsive signal in the first frequency to a first count of the operating signal in the first frequency, the first count and the second count being a number of waves, the attenuation corresponding to a difference between the first count and the second count. 
   
     
     
         13 . The method according to  claim 12 , wherein determining attenuation comprises comparing waveforms of the responsive signal and the operating signal. 
     
     
         14 . The method according to  claim 12 , further comprising selecting the first frequency from a range of frequencies of approximately 50 MHz to 70 MHZ, inclusive. 
     
     
         15 . The method according to  claim 12 , wherein a volume of clay within the soil correlates to a magnitude of the attenuation.