Progress 09/30/08 to 09/30/13
Outputs
Target Audience: Environmental, Agricultural Geophysics Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest? The results were disseminated through journal publications, presentations at technical society meetings, and through a published book chapter in Agricultural Geophysics. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
A unique survey protocol was developed that quantifies near-surface preferential flow using ground-penetrating radar (GPR), global positioning systems (GPS), and a neural network (NN) pattern classifier. The survey field protocol consists of a mobile GPR system that repeatedly spirals outward along a prescribed course, gathering subsurface data continuously for several hours. After first establishing dry initial-state pattern signatures, metered irrigation begins within a centrally located water-ponding ring. Following vertical infiltration, the water percolates downward and radiates outward from the central application point throughout the subsurface along preferential flow pathways, and the wetting fronts are highlighted by GPR. A radargram NN pattern classifier rapidly segments the profiles by similarities. Within the sequential radargrams during water application, only those specific geo-referenced locales that reveal pattern shifts from the initial dry state are recognized as being excited by water flow phenomena. Pattern shifts have been found to highlight the preferential flow channels that occur within the patterns of highly complex radargrams. Visual data showed surface-applied water moving beneath the surface from water applied at 25 mm/hr that infiltrated 2 m to a perching horizon, and thence traveling at lateral velocities of 40 m/hr.
Publications
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Progress 01/01/12 to 12/31/12
Outputs
OUTPUTS: Abandoned agricultural tile drainage systems can unknowingly provide a pathway for waterborne agrochemicals into surface and ground waters. As such, these systems merit increased attention on water quality impact. An important first step is mapping the derelict drainage networks, some of which may possibly co-exist within functioning drainage systems. A remote sensing methodology was developed to locate abandoned tile drains using real-time kinematic (RTK). GIS-based solution for mapping the sky-blockages for agricultural fields across entire regions was developed based upon spatial landform feature layers, such as terrain elevations (levies, ridges, side slopes), forecast satellite availability from mission planning software, and terrain coverage maps (trees, open, fields perimeters). Using the tool for specific fields, a visual risk estimate is provided as to the degree that the additional GNSS satellite constellations will improve the reliability of mobile RTK machine control, as opposed to only using the GPS-only satellite constellation. Utilizing real-time kinematic (RTK) technology for automated tractor steering requires communication with a reference base station. The traditional base configuration is a tripod-mounted instrument placed near the roving tractor. During field operations, the tractor rover receives data from the base via its radio broadcasts. This concept has been technologically surpassed by the modeled (virtual) reference station (VRS); whereupon, a remote computer creates a virtual base station using geospatial coordinates sent from the roving tractor, and also from data that it gathers from a network of continuously-operating reference stations (CORS). The modeled VRS solution is communicated from the networked server back to the tractor rover using cellular broadband. The VRS solution is mathematically optimized for the rover, and is specific to the rover's location. There has been producer debate and industry posturing concerning accessing a CORS-referencing network over wireless broadband for agricultural tractor/machine RTK control. The appropriateness of proprietary vs. open protocols is often ambiguous as it is complicated with numerous issues, most of which involves the array of non-compatible, brand-specific hardware available within the precision agriculture sector. Specifically, farmer debate has been over the more appropriate selection of a reference station type, either: 1) a single CORS that is closest to the rover, or 2) a modeled base optimized for the rover. A literature review and study were enacted using GIS assessments as to the more appropriate CORS base selection for agricultural producers in Tennessee. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Effective Real Time Kinematic (RTK) mobile machine control requires a sufficient number of positioning satellites that are both fully visible and ideally situated. Critical to obtaining the highest degree of accuracy and precision for reliable machine control are the initial acquiring of a solution (i.e., obtaining an RTK "fix" solution), the continuously maintaining of this fix, and if it is lost, rapidly reestablishing the fix. Losing fix is a common occurrence when operating near trees, landforms, and tall buildings that cause significant sky blockage. Operators can increase the probability of acquiring and maintaining a fix by incorporating more satellites from multi-national Global Navigation Satellite System (GNSS) constellations. However, this added capability by adding satellite numbers is only of practical economic benefit when operating near trees or across terrain causing partial sky blockages. Due to the additional expense in upgrading mobile machine control to full GNSS coverage capabilities, upgrade considerations should include the impact of sky blockages about production fields by the rolling terrain and nearby landforms, and most importantly, by field-surrounding tree canopies. The study and literature review found the options available to agricultural producers depend upon the following parameters: 1) the operator's brand, model, and legacy of RTK equipment, 2) the brand, topology, and availability of a CORS network, and 3) the spatial location of the producer's fields within a networked CORS topology. When available, a stable VRS solution using cellular broadband was found preferable when accessing a CORS network; however, producer options are often limited by noted RTK equipment manufacturers taking strict proprietary and protectionist stances within their agricultural product lines. A GIS toolset was developed to aid extension specialists in advising producers as to their options, or lack thereof, for their specific field locales.
Publications
- Jones, C.S., J. T. Ammons, Blair, R.H., M. E. Essington, and R. S. Freeland. 2012. Assessment of pre- and post-SMCRA minesoils in the Big South Fork National River and Recreation Area using hierarchical clustering analysis. Annual International Meetings Abstracts [CD-ROM]. ASA, CSSA, and SSSA, Madison, WI, Cincinnati, OH. 21-24 October.
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Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: Abandoned agricultural tile drainage systems can unknowingly provide a pathway for waterborne agrochemicals into surface and ground waters. As such, these systems merit increased attention on water quality impact. An important first step is mapping the derelict drainage networks, some of which may possibly co exist within functioning drainage systems. A remote sensing methodology is being developed to locate abandoned tile drains using realtime kinematic RTK. GIS based solution for mapping the sky blockages for agricultural fields across entire regions was developed based upon spatial landform feature layers, such as terrain elevations levies, ridges, side slopes, forecast satellite availability from mission planning software, and terrain coverage maps trees, open, fields perimeters. Using the tool for specific fields, a visual risk estimate is provided as to the degree that the additional GNSS satellite constellations will improve the reliability of mobile RTK machine control, as opposed to only using the GPS-only satellite constellation. Utilizing real time kinematic RTK technology for automated tractor steering requires communication with a reference base station. The traditional base configuration is a tripod-mounted instrument placed near the roving tractor. During field operations, the tractor rover receives data from the base via its radio broadcasts. This concept has been technologically surpassed by the modeled (virtual) reference station VRS whereupon, a remote computer creates a virtual base station using geospatial coordinates sent from the roving tractor, and also from data that it gathers from a network of continuously-operating reference stations CORS. The modeled VRS solution is communicated from the networked server back to the tractor rover using cellular broadband. The VRS solution is mathematically optimized for the rover, and is specific to the rovers location. There has been producer debate and industry posturing concerning accessing a CORS referencing network over wireless broadband for agricultural tractor machine RTK control. The appropriateness of proprietary vs. open protocols is often ambiguous as it is complicated with numerous issues, most of which involves the array of non compatible, brand-specific hardware available within the precision agriculture sector. Specifically, farmer debate has been over the more appropriate selection of a reference station type, either 1 a single CORS that is closest to the rover, or 2) a modeled base optimized for the rover. A literature review and study were enacted using GIS assessments as to the more appropriate CORS base selection for agricultural producers in Tennessee. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Effective Real Time Kinematic RTK mobile machine control requires a sufficient number of positioning satellites that are both fully visible and ideally situated. Critical to obtaining the highest degree of accuracy and precision for reliable machine control are the initial acquiring of a solution i.e., obtaining an RTK fix solution, the continuously maintaining of this fix, and if it is lost, rapidly reestablishing the fix. Losing fix is a common occurrence when operating near trees, landforms, and tall buildings that cause significant sky blockage. Operators can increase the probability of acquiring and maintaining a fix by incorporating more satellites from multi-national Global Navigation Satellite System GNSS constellations. However, this added capability by adding satellite numbers is only of practical economic benefit when operating near trees or across terrain causing partial sky blockages. Due to the additional expense in upgrading mobile machine control to full GNSS coverage capabilities, upgrade considerations should include the impact of sky blockages about production fields by the rolling terrain and nearby landforms, and most importantly, by field-surrounding tree canopies. The study and literature review found the options available to agricultural producers depend upon the following parameters 1 the operator's brand, model, and legacy of RTK equipment, 2 the brand, topology, and availability of a CORS network, and 3 the spatial location of the producer's fields within a networked CORS topology. When available, a stable VRS solution using cellular broadband was found preferable when accessing a CORS network however, producer options are often limited by noted RTK equipment manufacturers taking strict proprietary and protectionist stances within their agricultural product lines. A GIS toolset was developed to aid extension specialists in advising producers as to their options, or lack thereof, for their specific field locales.
Publications
- Allred, B., and R. S. Freeland. 2011. Application of geophysical methods to agriculture: An overview. Fast Times: Near Surface Geophysical Sciences, 15 4, 13 25.
- Allred, B., and R. S. Freeland. 2011. Integration of Ground Penetrating Radar with Real Time Kinematic Global Positioning System Receivers for Efficient Mapping of Drainage Pipe Systems beneath Golf Course Greens. SAGEEP 24, 102 2011.
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: Rice farmers of the Missouri Bootheel are well aware that their flooded fields may leak excessively without explanation. Federal and state agencies are faced with this same perplexity in their attempts to develop artificial wetlands, as multi-million dollar impoundments about the Missouri Bootheel have inexplicably failed to hold water. A design blunder has been determined to be the cause, in that during the design phase only geotechnical soil cores were evaluated, all of which implied a contiguous gleyed horizon that was highly capable of perching water. This project employed ground-penetrating radar (GPR) to locate the cause of the excessive leakage in an abandoned waterfowl impoundment. Our surveys found long and narrow sand-filled fissures caused by liquefaction from the region's reoccurring cataclysmic earthquakes having breached the water-perching horizon. As several million dollars had been expended to construct the impoundment's earthworks and pumping network, site remediation strategies were being sought for reducing the leakage through a fissure. A 0.4-ha test pool and an internet-accessible instrumentation system were implemented within a small section of a failed impoundment, the objective of which was to measure the water loss that was attributable to a fissure. Repeatedly flooded and allowed to drain, the test pool's infiltration rate steadily increased from 4.1 to 6.6 cm d -1 . The field saturated hydraulic conductivity (K fs ) of the surface horizon was measured to be 22 cm d -1 . Water perched on an underlying gleyed horizon. The K fs of a fissure that pierced the perching gleyed horizon was measured to be 400 cm d -1 . 2) Approximately 100,000 ha of compensatory mitigated wetlands within the United States each year require annual environmental assessments. Regulatory agencies evaluate the assessments, which progress for several years following the restoration of wetlands. Core to each annual assessment is the survivorship documentation of the reestablished hydrophytic tree and shrub species. Failure to achieve a preset survival percentage is costly, as it will necessitate a mandatory replanting and an extension of the assessment period. Multiple failures within a region will promote increasing the ratio of mitigated wetland to permitted fill area, as the mandated goal is to maintain a region's wetland base. To help minimize possible mitigation failures, we developed a survey methodology to both tally plant survival and to help determine the cause of plant mortality rates via spatial interpretation. A surveyor geospatially tags and inventories the seedlings at the time of planting using a survey-grade Global Positioning System (GPS). During the follow-up assessment tallies, a handheld GPS mapping-grade receiver with an interactive Geographic Information System (GIS) directs a technician to revisit each planting locale, and while there to rank plant health and any noticeable anomalies that may be impeding plant vigor. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
This project serves to highlight the inadequacy of solely employing soil cores for determining the suitability of a water perching horizon across vast water impoundments that possess vertical drainage features, and demonstrates the application of continuous geophysical profiling technologies for subsurface profiling of landforms possessing seismic fissures. 2) The geotagging survey methodology increased the annual tallying times for our case study site by approximately 300% as compared to using a simple tally sheet. However, for this case study the GPS-based survey methodology greatly enhanced the tally efficiency, accuracy, and reliability, thereby providing a higher quality assessment report for both the permit-holder and the environmental oversight agency. Spatially displaying the resulting survey provided diagnostic feedback as to the cause of high plant mortality, which for this case study was revealed to be due to post-construction site mismanagement and third-party interference following planting.
Publications
- Freeland, R. S., P. D. Ayers, and J. B. Wilkerson. 2010. Plant Survival Assessment on Wetland and Stream Mitigation Sites Using GPS/GIS Geotagging. Applied Engineering in Agriculture Vol. 26(4): 701-706.
- Freeland, R. S., W. C. Wright, and J. S. Tyner. 2010. Measuring Water Leakage from an Artificial Wetland Impacted by Earthquake Fissures. Applied Engineering in Agriculture Vol. 26(2): 255-261
- Allred, B. J., and R. S. Freeland. 2010. Agricultural Geophysics: Past, Present, Future. APPLICATION OF GEOPHYSICS TO ENGINEERING AND ENVIRONMENTAL PROBLEMS. SYMPOSIUM. 23RD 2010. (SAGEEP 2010) (2 VOLS).
- Jones, C., J. T. Ammons, R. S. Freeland, Blair, R, and Bakaletz, S. 2010. Pre- and Post- SMCRA Minesoil Acidity and Basicity in the Big South Fork National River and Recreation Area. American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America 2010 International Annual Meetings, Oct. 31-Nov. 3 in Long Beach, CA.
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: OUTPUTS This project applied a unique survey protocol that maps near-subsurface preferential flow using integrated ground-penetrating radar (GPR) and real time kinematic (RTK) satellite navigation. The survey protocol consists of a mobile GPR system that spirals outward along a prescribed course, continuously gathering subsurface data for an extended period. After first capturing the initial dry-state pattern signatures, metered water containing a tracer is applied to a centrally located water-ponding ring The water radiates outward beneath the surface as it follows preferential flow pathways, which the mobile GPR instrumentation highlights as it spirals above on the prescribe course. After data are collected, pre- and post-water time-elapsed images profiles are segmented by pattern dissimilarities. The specific locales that exhibit pattern shifts from the initial dry state are identified as dynamic water movement. Locales that exhibit pattern shifts are mapped to indicate the rate and direction of preferential flow about the near surface. PARTICIPANTS: PUBLICATIONS Abstract Freeland, R. S. 2009. Integration of RTK Surveying Techniques into GPR Surveying. Bouyoucos Conference on Agricultural Geophysics, September 8-10, 2009, Albuquerque, NM. TARGET AUDIENCES: State and Federal environmental agencies. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
OUTCOMES/IMPACTS Precision agriculture, environmental mapping, and construction benefit from subsurface imaging by revealing the spatial variability of underground features. Features surveyed of agricultural interest are bedrock depth, soil horizon thicknesses, and buried-object features such as drainage pipe. This project applies the technology in mapping subsurface hydrologic transport. For these applications, ground-penetrating radar (GPR) is an effective near-surface imaging technology. GPR technologies are used to survey large, open land tracts, whereby subsurface features are ultimately geo-referenced using a geographic information system (GIS) database. We are applying real time kinematic (RTK) satellite navigation to provide real-time position location with sub-centimeter accuracy. The system automatically embeds distance-referencing markers within the GPR image file, essentially acting as a virtual survey wheel. Markers containing geo-referenced position information are generated "on-the-go" at predefined travel increments. This GPR surveying system combined with RTK supplies high automation and has increased our overall survey and image post-processing efficiency.
Publications
- PUBLICATIONS Abstract Freeland, R. S. 2009. Integration of RTK Surveying Techniques into GPR Surveying. Bouyoucos Conference on Agricultural Geophysics, September 8-10, 2009, Albuquerque, NM.
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