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At least 631 records · Page 35Linked to original sources
USGS2019

A preliminary assessment of hyperspectral remote sensing technology for mapping submerged aquatic vegetation in the Upper Delaware River National Parks

Hyperspectral remote sensing of submerged aquatic vegetation is a complex and difficult process that is affected by unique constraints on the energy flow profile near and below the water surface. In addition, shallow, winding, lotic systems, such as the Upper Delaware River, present additional remote sensing problems in the form of specular reflectance, variable depth and constituents in the water column and sometimes extremely weak signal strength due to absorption and scattering in the water column that can be statistically overwhelmed by the reflectance from upland vegetation in any individual image scene. Here we test hyperspectral imagery from the Civil Air Patrol’s (CAP), Airborne Real-time Cueing Hyperspectral Enhanced Recon (ARCHER) system in the scenic waters of two National Parks on the Upper Delaware River. A number of unique image processing problems were encountered, including specular reflectance from winding lotic systems, variable depth and flow dynamics of the riverine environment, and disproportionate signal strength from surface reflectance in this riverine environment. This were solved by applying a specular reflectance removal algorithm, applying field data collections to classification results and masking upland vegetation so as to not statistically overwhelm the weak reflectance signal from surface and near-surface water. Much was learned about conducting imaging spectroscopy in such difficult conditions. Significant results include successful mapping of SAV presenece/absence, advantages of upland masking of the reflectance signal, and a numkber of processing approaches that are unique to this environment. In this paper we summarize our results and identify unique issues that must be addressed in this environment

New Jersey, New York, Pennsylvania↗
USGS2010

Enhancement of the volcanogenic "bromine explosion" via reactive nitrogen chemistry (Kīlauea volcano, Hawai'i)

Since the first detection of bromine monoxide in volcanic plumes attention has focused on the atmospheric synthesis and impact of volcanogenic reactive halogens. We report here new measurements of BrO in the volcanic plume emitted from Kīlauea volcano – the first time reactive halogens have been observed in emissions from a hotspot volcano. Observations were carried out by ground-based Differential Optical Absorption Spectroscopy in 2007 and 2008 at Pu'u' O ' o crater, and at the 2008 magmatic vent that opened within Halema'uma'u crater. BrO was readily detected in the Halema'uma'u plume (average column amount of 3×1015 molec cm −2 ) and its abundance was strongly correlated with that of SO 2 . However, anticorrelation between NO 2 and SO 2 (and BrO) abundances in the same plume strongly suggest an active role of NO x in reactive halogen chemistry. The calculated SO 2 /BrO molar ratio of ~1600 is comparable to observations at other volcanoes, although the BrO mixing ratio is roughly double that observed elsewhere. While BrO was not observed in the Pu'u' O ' o plume this was probably merely a result of the detection limit of our measurements and based on understanding of the Summit and East Rift magmatic system we expect reactive halogens to be formed also in the Pu'u' O ' o emissions. If this is correct then based on the long term SO 2 flux from Pu'u' O ' o we calculate that Kīlauea emits ~480 Mg yr −1 of reactive bromine and may thus represent an important source to the tropical Pacific troposphere.

Hawaii↗
USGS2013

On the absolute calibration of SO 2 cameras

Sulphur dioxide emission rate measurements are an important tool for volcanic monitoring and eruption risk assessment. The SO 2 camera technique remotely measures volcanic emissions by analysing the ultraviolet absorption of SO 2 in a narrow spectral window between 300 and 320 nm using solar radiation scattered in the atmosphere. The SO 2 absorption is selectively detected by mounting band-pass interference filters in front of a two-dimensional, UV-sensitive CCD detector. One important step for correct SO 2 emission rate measurements that can be compared with other measurement techniques is a correct calibration. This requires conversion from the measured optical density to the desired SO 2 column density (CD). The conversion factor is most commonly determined by inserting quartz cells (cuvettes) with known amounts of SO 2 into the light path. Another calibration method uses an additional narrow field-of-view Differential Optical Absorption Spectroscopy system (NFOVDOAS), which measures the column density simultaneously in a small area of the camera’s field-of-view. This procedure combines the very good spatial and temporal resolution of the SO 2 camera technique with the more accurate column densities obtainable from DOAS measurements. This work investigates the uncertainty of results gained through the two commonly used, but quite different, calibration methods (DOAS and calibration cells). Measurements with three different instruments, an SO 2 camera, a NFOVDOAS system and an Imaging DOAS (I-DOAS), are presented. We compare the calibration-cell approach with the calibration from the NFOV-DOAS system. The respective results are compared with measurements from an I-DOAS to verify the calibration curve over the spatial extent of the image. The results show that calibration cells, while working fine in some cases, can lead to an overestimation of the SO 2 CD by up to 60% compared with CDs from the DOAS measurements. Besides these errors of calibration, radiative transfer effects (e.g. light dilution, multiple scattering) can significantly influence the results of both instrument types. The measurements presented in this work were taken at Popocatepetl, Mexico, between 1 March 2011 and 4 March 2011. Average SO 2 emission rates between 4.00 and 14.34 kg s −1 were observed.

Atmospheric Measurement Techniques↗
USGS2025

Geochemistry of quartz and fluid inclusions associated with gold, tungsten, and antimony in the Stibnite-Yellow Pine district, Idaho

Deposits in the historic Stibnite-Yellow Pine district in east-central Idaho were mined for Ag, Au, Hg, Sb, and W. Ore is hosted in breccia and fault zones along NE-striking faults that transect the Atlanta lobe of the Late Cretaceous Idaho batholith and metamorphosed Neoproterozoic to lower Paleozoic rocks. Geochronological studies have delineated five superimposed and zoned hydrothermal events in the mining district which range in age from Late Cretaceous to the Eocene. They formed the following consecutive assemblages: (1) vein and disseminated pre-ore milky quartz (± calcite), muscovite, and brassy pyrite with minor molybdenite and base metal sulfides; (2) vein and disseminated quartz, calcite, sericite, auriferous-pyrite, and arsenopyrite; (3) potassium feldspar, quartz, dolomite, and calcite with vein and disseminated scheelite ± pyrite and arsenopyrite; (4) Au-Ag veins that contain adularia; and (5) breccia, vein, and disseminated quartz, calcite, and stibnite with minor Ag sulfosalts and distal zones of cinnabar and realgar at Fern and Hermes mines. In this study, the pressure, temperature, and composition of ore-forming fluids were measured in Au-, W-, and Sb-bearing samples collected from drill core and surface exposures. Using optical petrography, scanning electron microscopy cathodoluminescence (SEM-CL) and electron microprobe cathodoluminescence (EMPA-CL) imaging, as well as electron microprobe (EMP) and laser ablation-inductively coupled plasma-mass spectrometry trace element analyses, four major overprinting generations of hydrothermal quartz are defined. Fluid inclusion assemblages (FIAs) in each generation of quartz were characterized by microthermometry and laser Raman spectroscopy. Quartz and fluid inclusion paragenesis are as follows: (Qi) altered and overprinted Qi with no coeval FIAs that formed before or during event 1; (Q1) early veins as well as disseminated quartz with dull gray SEM-CL and H 2 O-NaCl-CO 2 FIAs that formed at minimum temperatures and pressures of 281° to 358°C and 1346 to 1789 bar during event 2 (Au); (Q2) vein and disseminated quartz, often euhedral, with H 2 O-NaCl ± CO 2 ± CH 4 FIAs that formed at minimum temperatures and pressures of 183° to 213°C and 72 to 602 bar during event 3 (W); and (Q3) euhedral and disseminated quartz with H 2 O-NaCl FIAs that formed at minimum temperature and pressures of 156° to 161°C and 5 to 6 bar during event 5 (Sb). Stibnite hosts H 2 O-NaCl FIAs trapped at minimum temperatures and pressures of 150° to 189°C and 5 to 12 bar that are similar to those of Q3-hosted FIAs. The quartz paragenetic history in the district follows a progressive temporal path from Tienriched quartz deposited by a relatively deep and higher temperature aqueous-carbonic fluid to a Li, Al, and Sb enriched quartz precipitated from a lower temperature aqueous fluid. Gases in fluid inclusion extracts from ore and gangue minerals were analyzed by mass spectrometry. Noble gas isotope analysis of fluid inclusion extracts revealed three signatures. Pre-ore Qi has R/R A (the isotopic ratio of the sample 3 He/ 4 He to atmospheric 3 He/ 4 He (1.384 × 10 −6 )) values that reflect the composition of the crustal melt-derived Atlanta lobe of the Idaho batholith. Quartz (Q1) and auriferous arsenian pyrite of hydrothermal event 2 have 20 Ne/ 4 He and R/R A values that plot along the air-crust mixing line, and these gases were likely introduced by metamorphic fluids derived from metasedimentary rocks. Stibnite with associated quartz (Q3 ± Q2) have 20 Ne/ 4 He and R/R A values that extend from the air-crust mixing line to the air-mantle mixing line, showing a shift from a crustal signature to an overprinting mantle signature. Late calcite has 20 Ne/ 4 He and R/R A values that extend from air toward the mantle end member, which suggests that magmatic volatiles condensed into meteoric groundwater late in the paragenesis. A mantle volatile source is also supported by high 20 Ne/ 22 Ne ratios. The Stibnite-Yellow Pine district is similar to other Au-W-Sb districts around the world in ore fluid chemistries, with late-stage stibnite being a product of cooling. The fluid pressure-temperature-composition (P-T-X) estimates and the crustal source of He during hydrothermal event 2 gold mineralization are characteristic of orogenic Au deposits, and the observed inclusion reequilibration textures indicate that trapped fluid inclusions were deformed during transitions between the brittle-ductile environment. Scheelite was deposited during event 3 with Q2 quartz and is overgrown by Q3 quartz and stibnite. Our interpretation of the quartz texture, chemistry, and fluid inclusion P-T-X data suggest that Au, W, and Sb mineralization occurred as hydrothermal fluids evolved from H 2 O-NaCl-CO 2 at >300°C and depths of ~4 to 6 km near the ductile to brittle transition to H 2 O-NaCl at ~150°C and epithermal depths as the Idaho batholith was exhumed. Geochronology indicates that from the Late Cretaceous to early Eocene, overprinting hydrothermal events formed deep orogenic Au, intermediate W, and shallow epithermal Au-Ag and Sb. Without comprehensive geochronologic constraints, our fluid inclusion data and textural observations could be interpreted as a single evolving hydrothermal system, as has been done in many other mining districts with similar mineralization.

Idaho↗
USGS2023

Characterizing lung particulates using quantitative microscopy in coal miners with severe pneumoconiosis

Context.— Current approaches for characterizing retained lung dust using pathologists' qualitative assessment or scanning electron microscopy with energy-dispersive spectroscopy (SEM/EDS) have limitations. Objective.— To explore polarized light microscopy coupled with image-processing software, termed quantitative microscopy–particulate matter (QM-PM), as a tool to characterize in situ dust in lung tissue of US coal miners with progressive massive fibrosis. Design.— We developed a standardized protocol using microscopy images to characterize the in situ burden of birefringent crystalline silica/silicate particles (mineral density) and carbonaceous particles (pigment fraction). Mineral density and pigment fraction were compared with pathologists' qualitative assessments and SEM/EDS analyses. Particle features were compared between historical (born before 1930) and contemporary coal miners, who likely had different exposures following changes in mining technology. Results.— Lung tissue samples from 85 coal miners (62 historical and 23 contemporary) and 10 healthy controls were analyzed using QM-PM. Mineral density and pigment fraction measurements with QM-PM were comparable to consensus pathologists' scoring and SEM/EDS analyses. Contemporary miners had greater mineral density than historical miners (186 456 versus 63 727/mm 3 ; P = .02) and controls (4542/mm 3 ), consistent with higher amounts of silica/silicate dust. Contemporary and historical miners had similar particle sizes (median area, 1.00 versus 1.14 μm 2 ; P = .46) and birefringence under polarized light (median grayscale brightness: 80.9 versus 87.6; P = .29). Conclusions.— QM-PM reliably characterizes in situ silica/silicate and carbonaceous particles in a reproducible, automated, accessible, and time/cost/labor-efficient manner, and shows promise as a tool for understanding occupational lung pathology and targeting exposure controls.

Archives of Pathology and Laboratory Medicine↗
USGS1995

Impedance spectra of hot, dry silicate minerals and rocks: qualitative interpretation of spectra

Impedance spectroscopy helps distinguish the contributions that grain interiors and grain boundaries make to electrical resistance of silicate minerals and rocks. Olivine, orthopyroxene, clinopyroxenes, and both natural and synthetic clinopyroxenite were measured. A network of electrical elements is presented for use in interpreting impedance spectra and conductive paths in hot or cold, wet or dry, minerals and rocks at any pressure. In dry rocks, a series network path predominates; in wet rocks, aqueous pore fluid and crystals both conduct. Finite resistance across the sample-electrode interface is evidence that electronic charge carriers are present at the surface, and presumably within, the silicate minerals and rocks measured. -from Authors

American Mineralogist↗
USGS1997

A hydrous Ca-bearing magnesium carbonate from playa lake sediments, Salines Lake, Spain

Sediments of playa Lake Salines, SE, Spain, contain a carbonate mineral characterized by X-ray diffraction peaks very similar to, but systematically shifted from those of pure magnesite. Analyses (SEM, IR and Raman spectroscopy, DTA, TGA, and ICP) indicate the mineral is a hydrous Ca-bearing magnesium carbonate with the chemical formula (Mg0.92,Ca0.08)CO3??3H2O. Thermal characteristics of the mineral are similar to those of other known hydrated magnesium carbonates. X-ray and electron diffraction data suggests a monoclinic system (P21/n space group) with unit-cell parameters of a = 6.063(6), b = 10.668(5), and c = 6.014(4) A?? and ?? = 107.28??.

American Mineralogist↗
USGS2003

Changes in trace and minor constituents and associated micro-architecture of Montastrea faveolata during time of "stress"

As corals grow, they secrete a calcareous skeleton with the aid of photosynthetic activity of endosymbiotic dinoflagellates. The rate of this secretion varies annually which produces annual bands. Entrapped with the carbonate are trace substances that record the chemistry of the surrounding ocean. Detailing these changes in chemistry requires careful high-resolution sampling. New procedures involving laser ablation inductive couple plasma mass spectroscopy (LA-ICP/MS) provides a unique method that does not involve tedious sample preparation. The La-ICP/MS data for a series of Atlantic corals from Looe Key, U.S. Florida Keys shows an intriguing distribution trace and minor elements whose concentrations are related to reported bleaching events. SEM data from the layers exhibit a change in crystal habit concurrent with the changes in chemistry. These changes reflected the affect of the variable influence of the symbiotic algae on the development of the coral skeleton.

Conference Paper↗
USGS2003

Fluid inclusion and noble gas studies of the Dongping gold deposit, Hebei Province, China: A mantle connection for mineralization?

The Dongping gold deposit (>100 t Au) occurs about 200 km inboard of the northern margin of the North China craton. The deposit is mainly hosted by syenite of a middle Paleozoic alkalic intrusive complex that was emplaced into Late Archean basement rocks. Both groups of rocks are intruded by Late Jurassic to Early Cretaceous crustal-melt granite dikes and stocks, some within a few kilometers of the deposit. The gold ores were deposited during this latter magmatic period at about 150 Ma, a time that was characterized by widespread regional north-south compression that formed the east-west-trending Yanshan deformational belt. The ores include both the telluride mineral-bearing, low sulfide quartz veins and the highly K-feldspar-altered syenite, with most of the resource concentrated in two orebodies (1 and 70). Fluid inclusion microthermometry indicates heterogeneous trapping of low-salinity (e.g., 5-7 wt % NaCl equiv) fluids that varied from a few to 60 mole percent nonaqueous volatile species. Laser Raman spectroscopy confirms that the vapor phase in these inclusions is dominated by CO2, but may be comprised of as much as 9 mole percent H2S and 20 mole percent N2; methane concentrations in the vapor phase are consistently <1 mole percent. The variable phase ratios are consistent with fluid immiscibility during ore formation. Fluid inclusion trapping conditions are estimated to be 250?? to 375??C and 0.6 to 1.0 kbar. Helium isotope studies of fluid inclusions in ore-stage pyrites indicate He/He ratios of 2.1 to 5.2 Ra (Ra = 1.4 x 10-6 for air) for orebody 1 and 0.3 to 0.8 Ra for orebody 70. The former data suggest that at least 26 to 65 percent mantle helium occurs in the fluids that deposited the veins in orebody 1. The lower values for orebody 70, which is characterized by a more disseminated style of gold mineralization, are interpreted to reflect an increased interaction of ore fluids with surrounding crustal rocks, which may have contributed additional He to the fluids. A mantle source for at least some of the components of the gold-forming fluid is consistent with upwelling of hot asthenosphere and erosion of as much as 100 to 150 km of cool Archean lithosphere beneath the craton during this time. The Dongping deposit is located along the 100-km-wide north-south gravity lineament, which marks the western border of the thinned crust. As both regional metamorphism of Mesoproterozoic and younger cover rocks, and widespread granite magmatism, also occurred at ca. 150 Ma, it is unclear as to whether one or both of these also contributed fluid and/or metals to the hydrothermal system. Importantly, these new data suggest that economically significant gold deposits of similar mineral style and fluid composition, which are scattered along the margins of the craton, may all be products of a fluid originally partly sourced within the mantle.

Economic Geology↗
USGS2007

A new comprehensive approach to characterizing carbonaceous aerosol with an application to wintertime Fresno, California PM2.5

Fine particulate matter (PM2.5) samples were collected during a three week winter period in Fresno (CA). A composite sample was characterized by isolating several distinct fractions and characterizing them by infrared and nuclear magnetic resonance (NMR) spectroscopy. More than 80% of the organic matter in the aerosol samples was recovered and characterized. Only 35% of the organic matter was water soluble with another third soluble in dichloromethane and the remainder insoluble. Within the isolated water soluble material, hydrophobic acid and hydrophilic acids plus neutrals fractions contained the largest amounts of carbon. The hydrophobic acids fraction appears to contain significant amounts of lignin type structures, spectra of the hydrophilic acids plus neutrals fraction are indicative of carbohydrates and secondary organic material. The dichloromethane soluble fraction contains a variety of organic compound families typical of many previous studies of organic aerosol speciation, including alkanes, alkanols, alkanals and alkanoic acids. Finally the water and solvent insoluble fraction exhibits a strong aromaticity as one would expect from black or elemental carbon like material; however, these spectra also show a substantial amount of aliphaticity consistent with linear side chains on the aromatic structures.

Atmospheric Chemistry and Physics Discussions↗
USGS2010

Mineral resource of the month: cesium

The article offers information on cesium, a golden alkali metal derived from the Latin word caesium which means bluish gray. It mentions that cesium is the first element discovered with the use of spectroscopy. It adds that the leading producer and supplier of cesium is Canada and there are 50,000 kilograms of cesium consumed of the world in a year. Moreover, it states that only 85% of the cesium formate can be retrieved and recycled.

Earth↗
USGS2012

Chapter 7: The hydrothermal diamond anvil cell (HDAC) for Raman spectroscopic studies of geological fluids at high pressures and temperatures

In this chapter, we describe the hydrothermal diamond-anvil cell (HDAC), which is specifically designed for experiments on systems with aqueous fluids to temperatures up to ~1000ºC and pressures up to a few GPa to tens of GPa. This cell permits optical observation of the sample and the in situ determination of properties by ‘photon-in photon-out’ techniques such as Raman spectroscopy. Several methods for pressure measurement are discussed in detail including the Raman spectroscopic pressure sensors a-quartz, berlinite, zircon, cubic boron nitride (c-BN), and 13 C-diamond, the fluorescence sensors ruby (α-Al 2 O 3 :Cr 3+ ), Sm:YAG (Y 3 Al 5 O 12 :Sm 3+ ) and SrB 4 O 7 :Sm 2+ , and measurements of phase-transition temperatures. Furthermore, we give an overview of published Raman spectroscopic studies of geological fluids to high pressures and temperatures, in which diamond anvil cells were applied.

Book chapter↗
USGS2013

NMR measurement of oil shale magnetic relaxation at high magnetic field

Nuclear magnetic resonance (NMR) at low field is used extensively to provide porosity and pore-size distributions in reservoir rocks. For unconventional resources, due to low porosity and permeability of the samples, much of the signal exists at very short T 2 relaxation times. In addition, the organic content of many shales will also produce signal at short relaxation times. Despite recent improvements in low-field technology, limitations still exist that make it difficult to account for all hydrogen-rich constituents in very tight rocks, such as shales. The short pulses and dead times along with stronger gradients available when using high-field NMR equipment provides a more complete measurement of hydrogen-bearing phases due to the ability to probe shorter T 2 relaxation times (<10 -5 sec) than can be examined using low-field equipment. Access to these shorter T 2 times allows for confirmation of partially resolved peaks observed in low-field NMR data that have been attributed to solid organic phases in oil shales. High-field (300 MHz or 7 T) NMR measurements of spin-spin T 2 and spin-lattice T 1 magnetic relaxation of raw and artificially matured oil shales have potential to provide data complementary to low field (2 MHz or 0.05T) measurements. Measurements of high-field T 2 and T 1 -T 2 correlations are presented. These data can be interpreted in terms of organic matter phases and mineral-bound water known to be present in the shale samples, as confirmed by Fourier transform infrared spectroscopy, and show distributions of hydrogen-bearing phases present in the shales that are similar to those observed in low field measurements.

Conference Paper↗
USGS2014

ChemCam results from the Shaler Outcrop in Gale Crater, Mars

The "Shaler" outcrop in Gale crater is approximately 0.7 m thick and >20 m long, and exhibits multiple well-exposed platy and cross-stratified facies [1] interpreted to be primarily fluvial sandstone deposits. The outcrop is a part of the upper Glenelg member in the Yellowknife Bay (YKB) stratigraphic section [2]. Curiosity first encountered the "Shaler" outcrop on sol 121 of the mission, and returned to the outcrop on sols 309- 324. The rugged nature of the outcrop and short time available for analysis limited opportunities for contact science, but ChemCam’s ability to remotely collect compositional and textural observations resulted in a large data set from Shaler. ChemCam conducted analyses of 29 non-soil targets at Shaler, 26 of which used laser-induced breakdown spectroscopy (LIBS) for a total of 9,180 spectra. Three observations used only the remote micro-imager (RMI). Each of the 26 LIBS targets were analyzed at between 5 and 25 points, providing a measure of the target homogeneity and in some cases transecting fine strata.

Conference Paper↗
USGS2011

Hyperspectral remote sensing of vegetation and agricultural crops: Knowledge gain and knowledge gap after 40 years of research

The focus of this chapter was to summarize the advances made over last 40+ years, as reported in various chapters of this book, in understanding, modeling, and mapping terrestrial vegetation using hyperspectral remote sensing (or imaging spectroscopy) using sensors that are ground-based, truck-mounted, airborne, and spaceborne. As we have seen in various chapters of this book and synthesized in this chapter, the advances made include: (a) significantly improved characterization and modeling of a wide array of biophysical and biochemical properties of vegetation, (b) ability to discriminate plant species and vegetation types with high degree of accuracies (c) reducing uncertainties in determining net primary productivity or carbon assessments from terrestrial vegetation, (d) improved crop productivity and water productivity models, (b), (e) ability to access stress resulting from causes such as management practices, pests and disease, water deficit or excess; , and (f) establishing more sensitive wavebands and indices to detect plant water\moisture content. The advent of spaceborne hyperspectral sensors (e.g., NASA’s Hyperion, ESA’s PROBA, and upcoming NASA’s HyspIRI) and numerous methods and techniques espoused in this book to overcome Hughes phenomenon or data redundancy when handling large volumes of hyperspectral data have generated tremendous interest in advancing our hyperspectral applications knowledge base over larger spatial extent such as region, nation, continent, and globe.

Book chapter↗
USGS2011

Advances in hyperspectral remote sensing of vegetation and agricultural croplands

Recent advances in hyperspectral remote sensing (or imaging spectroscopy) demonstrate a great utility for a variety of land monitoring applications. It is now possible to be diagnostic in sensing species and plant communities using remotely sensed data and to do so in a direct and informed manner using modern tools and analyses. Hyperspectral data analyses are superior to traditional broadband analyses in spectral information. Many investigations explore and document remote sensing of vegetation and agricultural croplands. Some examples include (a) detecting plant stress [1], (b) measuring chlorophyll content of plants [2], (c) identifying small differences in percent of green vegetation cover [3], (d) extracting biochemical variables such as nitrogen and lignin [2,4–6], (e) discriminating land-cover types [7], (f) detecting crop moisture variations [8], (g) sensing subtle variations in leaf pigment concentrations [2,9,10], (h) modeling biophysical and yield characteristics of agricultural crops [6,11,12], (i) improving the detection of changes in sparse vegetation [13], and (j) assessing absolute water content in plant leaves [14]. This is a fairly detailed list but not exhaustive, meant to provide the reader with a measure of the current, proven experimental capabilities, and operational applications, and stimulate investigations of new, ambitious applications.

Book↗
USGS1970

Perception via satellite

The earth resources observation satellite (EROS) program in the Department of the Interior is intended to gather and use data from satellites and aircraft on natural and man-made features of the earth's surface. Earth resources technology satellite will provide the EROS program with data for use in dealing with natural resource problems and understanding the interaction between man and the environment. Applications will include studies of tectonic features, hydrologic problems, location of fish schools, determination of the conditions of range land, mapping land use for urban planning, studies of erosion and change along coastlines and major streams, and inventories of land use and land forms. In addition, the ERTS data may be used for detecting forest and crop diseases and inventorying crops. The ERTS satellite will be in a polar, sun-synchronous orbit so that each point on the earth's surface will be sensed every 17 to 20 days, at the same time of day. Multispectral photography is being investigated for its usefulness in hydrology. Side-looking airborne radar has not yet been widely used in hydrologic studies, although it is an excellent tool for all-weather, day or night, coverage of large areas. Other techniques being investigated include passive microwave radiometry, ultraviolet and visible stimulated luminescence, and absorption spectroscopy.

Water Spectrum↗