Soil moisture conditions have an impact upon virtually all aspects of Army activities and are increasingly affecting its
systems and operations. Soil moisture conditions affect operational mobility, detection of landmines and unexploded
ordinance, natural material penetration/excavation, military engineering activities, blowing dust and sand, watershed
responses, and flooding. This study further explores a method for high-resolution (2.7 m) soil moisture mapping using
remote satellite optical imagery that is readily available from Landsat and QuickBird. The soil moisture estimations are
needed for the evaluation of IED sensors using the Countermine Simulation Testbed in regions where access is difficult
or impossible. The method has been tested in Helmand Province, Afghanistan, using a Landsat7 image and a QuickBird
image of April 23 and 24, 2009, respectively. In previous work it was found that Landsat soil moisture can be predicted
from the visual and near infra-red Landsat bands1-4. Since QuickBird bands 1-4 are almost identical to Landsat bands 1-
4, a Landsat soil moisture map can be downscaled using QuickBird bands 1-4. However, using this global approach for
downscaling from Landsat to QuickBird scale yielded a small number of pixels with erroneous soil moisture values.
Therefore, the objective of this study is to examine how the quality of the downscaled soil moisture maps can be
improved by using a data stratification approach for the development of downscaling regression equations for each
landscape class. It was found that stratification results in a reliable downscaled soil moisture map with a spatial
resolution of 2.7 m.
Soil moisture conditions have an impact upon virtually all aspects of Army activities and are increasingly affecting its
systems and operations. Soil moisture conditions affect operational mobility, detection of landmines and unexploded
ordinance, military engineering activities, blowing dust and sand, watershed responses, and flooding. This study explores
a novel method for high-resolution (2.7 m) soil moisture mapping using remote satellite optical imagery that is readily
available from Landsat and QuickBird. The soil moisture estimations are needed for the evaluation of sensors for
Improvised Explosive Devices (IEDs) using the Countermine Simulation Test Bed in regions where access is denied.
The method has been tested in Helmand Province, Afghanistan, using a Landsat7 and a QuickBird image of April 23 and
24, 2009, respectively. The first implementation of the method yielded promising results.
Soil moisture conditions influence practically all aspects of Army activities and are increasingly affecting its systems and
operations. Regional distributions of high resolution soil moisture data will provide critical information on operational
mobility, performance of landmine and UXO sensors, and meteorological conditions at the km scale. The objective of
this study is to calibrate RADARSAT-2 surface soil moisture estimates with field measurements in the semi-arid Middle
Rio Grande Valley of New Mexico. RADARSAT-2 was launched in December 2007 and is the first SAR sensor to offer
an operational quad-polarization mode. This mode allows to generate soil moisture (and cm-scale surface roughness)
maps from single data sets. Future combination of such maps into time series will lead to further accuracy enhancement
through additional exploitation of soil moisture evolution constraints. We present RADARSAT-2 soil moisture maps,
field soil moisture measurements, and soil moisture maps derived from optical imagery. In addition, future work is
proposed that may contribute to enhanced algorithms for soil moisture mapping using RADARSAT-2.
A thorough understanding of thermal soil regimes is critical information for a wide variety of disciplines
and engineering applications as well as for the evaluation of potential and limitations of thermal and optical
sensors. In this study we have developed a procedure for the evaluation of global thermal soil regimes.
First, pedotransfer functions are used to derive thermal soil properties (volumetric soil heat capacity and
thermal conductivity) from readily available soil data on texture, bulk density, and organic carbon. Next,
the average annual soil temperature is derived from the average annual air temperature. Then, the thermal
top boundaries are derived either for well-watered sites using the daily and annual air temperature
amplitudes as proxies for the daily and annual soil surface temperature amplitudes or for a wide range of
environmental conditions using the model HYDRUS1D. A thorough validation of the proposed procedure
is needed for the quantification of the probability with which soil thermal regimes can be predicted.
One of the Department of Defense's most pressing environmental problems is the efficient detection and identification
of unexploded ordnance (UXO). In regions of highly magnetic soils, magnetic and electromagnetic sensors often detect
anomalies that are of geologic origin, adding significantly to remediation costs. In order to develop predictive models for
magnetic susceptibility, it is crucial to understand modes of formation and the spatial distribution of different iron
oxides. Most rock types contain iron and their magnetic susceptibility is determined by the amount and form of iron
oxides present. When rocks weather, the amount and form of the oxides change, producing concomitant changes in
magnetic susceptibility. The type of iron oxide found in the weathered rock or regolith is a function of the duration and
intensity of weathering, as well as the original content of iron in the parent material. The rate of weathering is controlled
by rainfall and temperature; thus knowing the climate zone, the amount of iron in the lithology and the age of the surface
will help predict the amount and forms of iron oxide. We have compiled analyses of the types, amounts, and magnetic
properties of iron oxides from soils over a wide climate range, from semi arid grasslands, to temperate regions, and
tropical forests. We find there is a predictable range of iron oxide type and magnetic susceptibility according to the
climate zone, the age of the soil and the amount of iron in the unweathered regolith.
In this paper we present the results of recent field and laboratory studies of the mineralogy and magnetic properties of
young and/or weakly developed soils in Montana and California. The Chevallier Ranch UXO site in Montana is
characterized by a basaltic plug and radiating feeder dikes, which is found surrounded by shales of the Spokane
Formation. The site in California consists of an offset alluvial fan soil chronosequence of Little Rock Creek along the
Mojave section of the San Andreas fault. The fan sediments include significant amounts of mafic material. The fan ages
range from 16 to 413 thousand years. The results of magnetic susceptibility measurements and laboratory analysis of
mineralogy demonstrate that the magnetic susceptibility in these soils is predominantly correlated with parent material
and less with age or landscape position. Slow rates of soil forming processes lead to relatively low frequency dependence
in magnetic susceptibility as compared to similar-age soils in tropical environments. The magnetic character of the soils
can be accurately predicted with a previously developed model.
In this paper we present the results of a study of some soil magnetic properties in Ghana. The soils sampled formed in different parent materials: Granites, Birimian rocks, and Voltaian sandstones. We discuss the role of environmental controls such as parent material, soil drainage, and precipitation on the magnetic properties. The main conclusion of this reconnaissance study is that the eight different soil types sampled have their own unique magnetic signature. Future research will have to confirm whether this conclusion holds for other soils in Ghana. If it does, the measurement of magnetic soil properties may become a viable complement for the investigation of soil erosion, land degeneration, and pedogenesis. The magnetic soil properties measured would probably not pose any limitations for the use of electromagnetic sensors for the detection of land mines and UXO.
In recent years it has become apparent that the performance of detection sensors for land mines and UXO may be seriously hampered by the magnetic behavior of soils. In tropical soils it is common to find large concentrations of iron oxide minerals, which are the predominant cause for soil magnetism. However, a wide range of factors such as parent material, environmental conditions, soil age, and drainage conditions control soil development. In order to predict whether magnetic-type iron oxide minerals are present it is important to understand the controlling factors of soil development. In this paper we present a conceptual model for predicting magnetic soil characteristics as a function of geological and environmental information. Our model is based on field observations and laboratory measurements of soils from Hawaii, Ghana, and Panama. The conceptual model will lead to the development of pedotransfer functions that quantitatively predict the occurrence and nature of magnetism in soils.
Magnetic soils can seriously hamper the performance of electromagnetic sensors for the detection of buried land mines and unexploded ordnance (UXO). Soils formed on basaltic substrates commonly have large concentrations of ferrimagnetic iron oxide minerals, which are the main cause of soil magnetic behavior. Previous work has shown that viscous remanent magnetism (VRM) in particular, which is caused by the presence of ferrimagnetic minerals of different sizes and shapes, poses a large problem for electromagnetic surveys. The causes of the variability in magnetic soil properties in general and VRM in particular are not well understood. In this paper we present the results of laboratory studies of soil magnetic properties on three Hawaiian Islands: O’ahu, Kaho’olawe, and Hawaii. The data show a strong negative correlation between mean annual precipitation and induced magnetization, and a positive correlation between mean annual precipitation and the frequency dependent magnetic behavior. Soil erosion, which reduces the thickness of the soil cover, also influences the magnetic properties.
The presence of magnetic iron oxides in the soil can seriously hamper the performance of electromagnetic sensors for the detection of buried land mines and unexploded ordnance (UXO). Previous work has shown that spatial variability in soil water content and texture affects the performance of ground penetrating radar and thermal sensors for land mine detection. In this paper we aim to study the spatial variability of iron oxides in tropical soils and the possible effect on electromagnetic induction sensors for buried low-metal land mine and UXO detection. We selected field sites in Panama, Hawaii, and Ghana. Along several horizontal transects in Panama and Hawaii we took closely spaced magnetic susceptibility readings using Bartington MS2D and MS2F sensors. In addition to the field measurements, we took soil samples from the selected sites for laboratory measurements of dual frequency magnetic susceptibility and textural characteristics of the material. The magnetic susceptibility values show a significant spatial variation in susceptibility and are comparable to values reported to hamper the operation of metal detectors in parts of Africa and Asia. The absolute values of susceptibility do not correlate with both frequency dependence and total iron content, which is an indication of the presence of different types of iron oxides in the studied material.
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