Irrigation Control through Acoustic Proximal Sensing of the Onset of Surface Water
Irrigation is a useful crop enhancement procedure up to the point where free surface water appears. However, over-irrigation can lead to an accumulation of free water on the soil surface, which in turn results in overland flow and a high risk of contaminant loss. The current work addresses the probl...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2020-11-01
|
| Series: | Remote Sensing |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2072-4292/12/22/3800 |
| _version_ | 1797547395346595840 |
|---|---|
| author | Stuart Bradley Anna Radionova Chandra Ghimire Laura Grundy Seth Laurenson Val Snow |
| author_facet | Stuart Bradley Anna Radionova Chandra Ghimire Laura Grundy Seth Laurenson Val Snow |
| author_sort | Stuart Bradley |
| collection | DOAJ |
| description | Irrigation is a useful crop enhancement procedure up to the point where free surface water appears. However, over-irrigation can lead to an accumulation of free water on the soil surface, which in turn results in overland flow and a high risk of contaminant loss. The current work addresses the problem of measuring free water on the surface of agricultural soils by a real-time acoustic remote sensing method. Directional acoustic transmitter and receiver arrays are used to define a “footprint” on the ground from which changes in reflectance are sensed. These arrays are mounted on a moving irrigator. Chirp signals are used to provide along-path resolution and to ensure robustness against unwanted acoustic background noise from farm machinery and the irrigator. Field measurements have been conducted above a well-defined “quadrat” with controlled and measured water content and also with the instrument mounted on an operational irrigator. A structured light camera mounted above the footprint is used to validate surface water fraction. It is found that the areal fraction of free water on the soil surface can be reliably estimated from changes in the amplitude of the reflected sound waves. The mechanism giving rise to the observed acoustic reflectivity changes is discussed and a model is developed which agrees with normalized intensity observations with a coefficient of determination R<sup>2</sup> between 0.65 and 0.83. The rms error between model predictions and observations is comparable to the rms variation of the measurements, indicating that there is insignificant error due to the choice of model. |
| first_indexed | 2024-03-10T14:43:36Z |
| format | Article |
| id | doaj.art-24a43f0ea93a4e38910d8fc8cd980d3d |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-03-10T14:43:36Z |
| publishDate | 2020-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-24a43f0ea93a4e38910d8fc8cd980d3d2023-11-20T21:35:41ZengMDPI AGRemote Sensing2072-42922020-11-011222380010.3390/rs12223800Irrigation Control through Acoustic Proximal Sensing of the Onset of Surface WaterStuart Bradley0Anna Radionova1Chandra Ghimire2Laura Grundy3Seth Laurenson4Val Snow5Inverse Acoustics Ltd., 73 Daffodil Street, Auckland 0604, New ZealandSchool of Physical Sciences, The University of Adelaide, Adelaide, SA 5005, AustraliaAgResearch—Lincoln Research Centre, Private Bag 4749, Christchurch 8140, New ZealandAgResearch—Lincoln Research Centre, Private Bag 4749, Christchurch 8140, New ZealandAgResearch—Lincoln Research Centre, Private Bag 4749, Christchurch 8140, New ZealandAgResearch—Lincoln Research Centre, Private Bag 4749, Christchurch 8140, New ZealandIrrigation is a useful crop enhancement procedure up to the point where free surface water appears. However, over-irrigation can lead to an accumulation of free water on the soil surface, which in turn results in overland flow and a high risk of contaminant loss. The current work addresses the problem of measuring free water on the surface of agricultural soils by a real-time acoustic remote sensing method. Directional acoustic transmitter and receiver arrays are used to define a “footprint” on the ground from which changes in reflectance are sensed. These arrays are mounted on a moving irrigator. Chirp signals are used to provide along-path resolution and to ensure robustness against unwanted acoustic background noise from farm machinery and the irrigator. Field measurements have been conducted above a well-defined “quadrat” with controlled and measured water content and also with the instrument mounted on an operational irrigator. A structured light camera mounted above the footprint is used to validate surface water fraction. It is found that the areal fraction of free water on the soil surface can be reliably estimated from changes in the amplitude of the reflected sound waves. The mechanism giving rise to the observed acoustic reflectivity changes is discussed and a model is developed which agrees with normalized intensity observations with a coefficient of determination R<sup>2</sup> between 0.65 and 0.83. The rms error between model predictions and observations is comparable to the rms variation of the measurements, indicating that there is insignificant error due to the choice of model.https://www.mdpi.com/2072-4292/12/22/3800surface water runoffacoustic sensor arrayreflected sound wavereflection from rough surfaces |
| spellingShingle | Stuart Bradley Anna Radionova Chandra Ghimire Laura Grundy Seth Laurenson Val Snow Irrigation Control through Acoustic Proximal Sensing of the Onset of Surface Water Remote Sensing surface water runoff acoustic sensor array reflected sound wave reflection from rough surfaces |
| title | Irrigation Control through Acoustic Proximal Sensing of the Onset of Surface Water |
| title_full | Irrigation Control through Acoustic Proximal Sensing of the Onset of Surface Water |
| title_fullStr | Irrigation Control through Acoustic Proximal Sensing of the Onset of Surface Water |
| title_full_unstemmed | Irrigation Control through Acoustic Proximal Sensing of the Onset of Surface Water |
| title_short | Irrigation Control through Acoustic Proximal Sensing of the Onset of Surface Water |
| title_sort | irrigation control through acoustic proximal sensing of the onset of surface water |
| topic | surface water runoff acoustic sensor array reflected sound wave reflection from rough surfaces |
| url | https://www.mdpi.com/2072-4292/12/22/3800 |
| work_keys_str_mv | AT stuartbradley irrigationcontrolthroughacousticproximalsensingoftheonsetofsurfacewater AT annaradionova irrigationcontrolthroughacousticproximalsensingoftheonsetofsurfacewater AT chandraghimire irrigationcontrolthroughacousticproximalsensingoftheonsetofsurfacewater AT lauragrundy irrigationcontrolthroughacousticproximalsensingoftheonsetofsurfacewater AT sethlaurenson irrigationcontrolthroughacousticproximalsensingoftheonsetofsurfacewater AT valsnow irrigationcontrolthroughacousticproximalsensingoftheonsetofsurfacewater |