For decades, scientists have used high-resolution reflectance spectra of minerals and soils to determine soil mineralogy, and to assess soil physical properties. A major breakthrough in these studies has been the use of visible-near infrared spectroscopy to develop quantitative calibrations for rapid characterization of soil nutrients and physical properties. The coupling of this technology with remote sensing data, georeferenced ground surveys, and new spatial statistical methods has resulted in the improved capability for large area soil assessments. Rapid spectroscopic soil analysis breaks the bottleneck of sample collection and lab testing, and permits the assessment of soil quality on a large number of representative samples covering expansive geographic areas.
Expansive spectral libraries continue to be developed for the interpretation and application of spectra to soils analysis. The spectral library approach allows calibrations based on small numbers of selected samples to be applied to the rapid analysis of thousands of samples. These studies overlap into many practical applications, including hazardous waste and environmental applications, agriculture, hydrology, and soil fertility assessment.
Other related applications include the analysis of plant tissue to assess such things as water and nutrient status. These applications are based on both canopy- and leaf-level measurements of reflectance. Employing the same quantitative methods used to develop soil nutrient calibrations, researchers have developed calibrations for a wide range of plant biochemicals, including chlorophyll, xanthophylls (and other pigments), lignin, cellulose, and total nitrogen. In addition to analysis of photosynthetic biomass, these methods have also been applied to rapid analysis of seed nutrient properties for crops such as corn, wheat, rice, soybeans, and canola.
Crop photosynthetic modeling is another application. These studies require the measurement of photosynthetic radiation above, below, and within a crop canopy. By measuring spectral irradiance, rather than just a single integrated reading, researchers can better study the interplay of the various secondary pigments.
The ability to accurately perform reflectance and radiometric measurements of vegetation and soil in the field is critical to all of these applications. The ASD FieldSpec® line of spectroradiometers offers a wide range of configuration options for both contact measurements (such as leaves or in a soil profile pit) and stand-off measurements (such as those needed to measure canopy reflectance). The FieldSpec uses a flexible fiber optic cable with several different accessories, giving researchers many options for acquiring critical data. Bringing a level of device portability that only ASD can provide, the FieldSpec also helps you work in some of the most remote regions of the planet.
Scientists around the world use ASD instruments in their soils and crops research. Examples of some of their work are available below.
Prediction of soil content using near-infrared spectroscopy
Sensing Soil Quality in Lab and Field
Clay Mineral Analysis of the USGS Cannon Park Core (CHN-800) Using Near Infrared Reflectance Spectra, Charleston, South Carolina
Soil Science and Biogeography, Department of Geography, University of Zürich
Spectroradiometer Analysis of Clays from the Petrified Forest Member of Triassic Chinle Formation, Southwestern Utah
Image Analysis Sediments and Paleoenvironments
Southern Africa Validation of EOS (SAVE) Status Report Period of Report: 6 June 2000 -- 28 Sept. 2001
NASA JPL AVIRIS Science and Applications Workshop (jointly written with Alex Held)
Global Products of Vegetation Leaf Area and Fraction Absorbed PAR From Year One of MODIS Data
Sucrose Transporter StSUT4 from Potato Affects Flowering, Tuberization, and Shade Avoidance Response
Protocol for the screening of the Uniform Mu maize population with near infrared reflectance spectroscopy
Detection of Carbon Stock Change in Agricultural Soils Using Spectroscopic Techniques
Trace Chemical Detection Through Vegetation Sentinels and Fluorescence Spectroscopy
Assessing the Performance of HYPERION in Relation to Eucalypt Biochemistry
Documentation of Ruokolahti Campaign— Finland, June 2000
Detection and Site-Specific Control of Weeds Through Remote Sensing
Dana, Gayle L., Cathy M. Tate, and Sharon L. Dewey. 1994. McMurdo LTER: Using narrow band spectroradiometry to assess algal and moss communities in a dry valley stream. Antarctic Journal of the United States--Review 1994. pp. 232-234
Sondankylä, Finland, the SIFLEX (Solar Induced Fluorescence Experiment) Campaign
The study on the comparison of ADEOS-II GLI NDVI and other sensors NDVI by using field experiment data
Hyperspectral Vegetation Indices for Determining Agricultural Crop Characteristics
Hyperspectral Field Spectrometry for Estimating Greenbug (Homoptera: Aphididae) Damage in Wheat
Geological and Geobotanical Studies of Long Valley Caldera, CA, USA Utilizing New 5m Hyperspectral Imagery
Indiviual Spectral Reflectance Curves of the overstory species in LBL, Kentucky
Wyoming Assessment Project and Remote Sensing of Leafy Spurge
Spectral Separability among Six Southern Tree Species
Computational Modeling Support to the Remote Sensing Technologies Center
The Dais La Peyne Experiment: Using the Optical and Thermal Dais Bands to Survey and Model the Surface Temperature
Spectral Acquisitions for Evaluation and Validation of EO -1 for Sustainable Development
Image Analysis Sediments and Paleoenvironments