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Radiometric Dating  

NSDL National Science Digital Library

The first website (1), created by Pamela J. W. Gore at Georgia Perimeter College, provides a concise explanation of the geologic principles of radiometric dating. Students can learn about the fundamentals of half lives, isotopes, and dating minerals. Secondly, the Museum Victoria offers a useful overview of radioactive decay of Potassium-40 and Carbon-14 (2). The website discusses the benefits of isotopes for the research interests of geologists and physicists. Next, Dr. Ben Waggoner at the University of Central Arkansas provides an online educational slide show discussing the assumptions, objections, and accuracy of radiometric dating (3). With an abundance of figures and images, visitors can learn about dateable materials, decay principles, and more. The fourth website, developed by Professor Stephen A. Nelson at Tulane University, provides a detailed mathematical explanation of the principles of radiometric dating (4). Users can view the data utilized for the corrections and can access the on-line form of CALIB, which converts radiocarbon ages to calendar years. The sixth website describes the Scottish Universities Research and Reactor Centre's work utilizing luminescence and radiocarbon dating (6). Through this expansive website, visitors can learn about the centre's many research projects including radioactive contamination, isotope geology, and environmental gamma spectrometry. Next, the North Carolina State University provides a fun, educational activity about radioactive isotope decay (7). Students can learn about the half lives of elements with the use of only candy, bags, and graph paper. Lastly, the University of North Carolina - Chapel Hill chemistry department discusses five different types of radioactive decay (8). After examining the numerous equations, students can test their dating skills by solving the practice problems.


Tulane University: Radiometric Dating  

NSDL National Science Digital Library

The fourth website, developed by Professor Stephen A. Nelson at Tulane University, provides a detailed mathematical explanation of the principles of radiometric dating. The site is divided into sections which include: Principles of Radiometric Dating; The Rb/Sr System; The U, Th, Pb System; and The Age of the Earth. Other dating methods are covered briefly as well, such as potassium argon (K-Ar) dating and carbon-14. Professor Nelson concludes with a description of other users of isotopes.

Nelson, Stephen A.



Radiometric Dating in Geology.  

ERIC Educational Resources Information Center

|Described are several aspects and methods of quantitatively measuring geologic time using a constant-rate natural process of radioactive decay. Topics include half lives and decay constants, radiogenic growth, potassium-argon dating, rubidium-strontium dating, and the role of geochronology in support of geological exploration. (DS)|

Pankhurst, R. J.



Radiometric Dating in Geology.  

ERIC Educational Resources Information Center

Described are several aspects and methods of quantitatively measuring geologic time using a constant-rate natural process of radioactive decay. Topics include half lives and decay constants, radiogenic growth, potassium-argon dating, rubidium-strontium dating, and the role of geochronology in support of geological exploration. (DS)

Pankhurst, R. J.



In situ radiometric dating on Mars: Investigation of the feasibility of K-Ar dating using flight-type mass and X-ray spectrometers  

NASA Astrophysics Data System (ADS)

The absolute chronology of Mars is poorly known and, as a consequence, a key science aim is to perform accurate radiometric dating of martian geological materials. The scientific benefits of in situ radiometric dating are significant and arguably of most importance is the calibration of the martian cratering rate, similar to what has been achieved for the Moon, to reduce the large uncertainties on absolute boundary ages of martian epochs. The Beagle 2 Mars lander was capable of performing radiometric date measurements of rocks using the analyses from two instruments in its payload: (i) the X-ray Spectrometer (XRS) and (ii) the Gas Analysis Package (GAP). We have investigated the feasibility of in situ radiometric dating using the K-Ar technique employing flight-like versions of Beagle 2 instrumentation. The K-Ar ages of six terrestrial basalts were measured and compared to the 'control' Ar-Ar radiometric ages in the range 171-1141 Ma. The K content of each basalt was measured by the flight spare XRS and the 40Ar content using a laboratory analogue of the GAP. The K-Ar ages of five basalts broadly agreed with their corresponding Ar-Ar ages. For one final basalt, the 40Ar content was below the detection limit and so an age could not be derived. The precision of the K-Ar ages was ˜30% on average. The conclusions from this study are that careful attention must be paid to improving the analytical performance of the instruments, in particular the accuracy and detection limits. The accuracy of the K and Ar measurements are the biggest source of uncertainty in the derived K-Ar age. Having investigated the technique using flight-type planetary instrumentation, we conclude that come of the principle challenges of conducting accurate in situ radiometric dating on Mars using instruments of these types include determining the sample mass, ensuring all the argon is liberated from the sample given the maximum achievable temperature of the mass spectrometer ovens, and argon loss and non-radiogenic argon in the analysed samples.

Talboys, D. L.; Barber, S.; Bridges, J. C.; Kelley, S. P.; Pullan, D.; Verchovsky, A. B.; Butcher, G.; Fazel, A.; Fraser, G. W.; Pillinger, C. T.; Sims, M. R.; Wright, I. P.



Radiometric Dating of Large Volume Flank Collapses in The Lesser Antilles Arc.  

NASA Astrophysics Data System (ADS)

It is now admitted that flank collapses, probably triggered by magmatic inflation and/or gravitational collapses, is a recurrent process of the evolution of the Lesser Antilles Arc volcanoes. Large magnitude debris avalanche deposits have been identified offshore, in the Grenada basin (Deplus et al., 2001; Le Friant et al., 2001). The widest extensions have been observed off the coast of Dominica and St Lucia, with associated volumes up to 20 km3. Another large-scale event, with marine evidences probably covered by sediments and latter flank collapses, has been inferred onland from morphological evidences and characteristic deposits of the Carbets structure in Martinique. We present radiometric dating of these three major events using the K-Ar Cassignol-Gillot technique performed on selected groundmass. Both volcanic formations preceding flank collapses (remnants of the horseshoe shaped structures or basal lava flows) and following landslides (lava domes) have been dated. In the Qualibou depression of St. Lucia, the former structure has been dated at 1096+-16 ka and the collapse constrained by dome emplacement prior to 97+-2 ka (Petit Piton). In Dominica, several structures have been associated with repetitive flank collapse events inferred from marine data (Le Friant et al., 2002). The Plat-Pays event probably occurred after 96+-2 ka. Inside the inherited depression, Scotts Head, which is interpreted as a proximal pluri-kilometric megabloc from the Soufriere avalanche, has been dated at 14+-1 ka, providing an older bound for this event. In Martinique Island, three different domes within the Carbets structure have been dated at 335+-5 ka. Assuming a rapid magma emplacement following pressure release due to deloading, this constrains the age of this high magnitude event. Finally, these results obtained from three of the most voluminous flank collapses provide constraints to estimate the recurrence of these events, which represent one of the major hazards associated with volcanoes of the Lesser Antilles Arc.

Quidelleur, X.; Samper, A.; Boudon, G.; Le Friant, A.; Komorowski, J.



Radiometric Dating  

NSDL National Science Digital Library

This site covers the use of radioactive decay as a clock to determine the age in years of events in earth history. The activity uses coin tosses to describe isotopes, both stable and unstable, and radioactive decay.

Colbath, G. K.; College, Cerritos


Investigation of the Feasibility of in situ Radiometric Dating on Mars using the Beagle 2 Gas Analysis Package and X-ray Spectrometer  

NASA Astrophysics Data System (ADS)

There are significant scientific returns to establishing an in situ age for Martian geological materials perhaps most notably to perform a calibration of the Martian cratering rate Beagle 2 was to have attempted a radiometric dating of rocks accessible by the lander We have investigated the feasibility of 40K-40Ar radiometric dating of basalt rocks utilising versions of the Beagle 2 Gas Analysis Package GAP a miniature mass spectrometer and the X-ray Spectrometer XRS Several basalts were used in the study of 39Ar-40Ar radiometric ages in the range 171 - 1141 Ma The K content of each basalt was measured by the flight spare XRS and the 40Ar content using a next-generation model of the GAP We report on the results from these analyses Having investigated the technique using flight-like instrumentation we discuss operational aspects of conducting in-situ radiometric dating on Mars using robotic spacecraft with particular emphasis on Mars landers

Talboys, D. L.; Pullan, D.; Wright, I. P.; Verchovsky, A. B.; Kelley, S. P.; Fraser, G. W.; Sims, M.; Pillinger, C. T.


Radiometric Dating of Ochoan (Permian) Evaporites, WIPP (Waste Isolation Pilot Plant) Site, Delaware Basin, New Mexico, USA.  

National Technical Information Service (NTIS)

We have attempted radiometric dating of halide-sulfate salts and clay minerals from the Delaware Basin, New Mexico, USA, as part of geochemical study of the stability of the evaporite sequence at the WIPP (Waste Isolation Pilot Plant - a US DOE facilty) s...

D. G. Brookins S. J. Lambert



The Relationship between Balancing Reactions and Reaction Lifetimes: A Consideration of the Potassium-Argon Radiometric Method for Dating Minerals  

ERIC Educational Resources Information Center

|A detailed examination of a commonly accepted practice in geology offers an example of how to stimulate critical thinking, teaches students how to read reactions, and challenges students to formulate better experiments for determining mineral ages more accurately. A demonstration of a Potassium-Argon radiometric method for dating minerals is…

Howard, William A.



The Relationship between Balancing Reactions and Reaction Lifetimes: A Consideration of the Potassium-Argon Radiometric Method for Dating Minerals  

ERIC Educational Resources Information Center

A detailed examination of a commonly accepted practice in geology offers an example of how to stimulate critical thinking, teaches students how to read reactions, and challenges students to formulate better experiments for determining mineral ages more accurately. A demonstration of a Potassium-Argon radiometric method for dating minerals is…

Howard, William A.



Artifact correction and absolute radiometric calibration techniques employed in the Landsat 7 image assessment system  

USGS Publications Warehouse

The Landsat-7 Image Assessment System (IAS), part of the Landsat-7 Ground System, will calibrate and evaluate the radiometric and geometric performance of the Enhanced Thematic Mapper Plus (ETM +) instrument. The IAS incorporates new instrument radiometric artifact correction and absolute radiometric calibration techniques which overcome some limitations to calibration accuracy inherent in historical calibration methods. Knowledge of ETM + instrument characteristics gleaned from analysis of archival Thematic Mapper in-flight data and from ETM + prelaunch tests allow the determination and quantification of the sources of instrument artifacts. This a priori knowledge will be utilized in IAS algorithms designed to minimize the effects of the noise sources before calibration, in both ETM + image and calibration data.

Boncyk, Wayne, C.; Markham, Brian, L.; Barker, John, L.; Helder, Dennis



Progress on radiometric dating of Wolfcamp brines using ⁴He and ⁴°Ar  

Microsoft Academic Search

Ground water samples (brines) from deep wells in the Palo Duro Basin, Texas are being analyzed for noble gases in an attempt to obtain radiometric ages for these brines. The brines contain radiogenic ⁴He and ⁴°Ar produced from the radioactive decay of U, Th, and K. Consideration of hydrochemical data for the brines, various isotopic, chemical, and mineralogical data for

A. Zaikowski; B. J. Kosanke; N. Hubbard



Radiometric dating of the type-site for Homo heidelbergensis at Mauer, Germany.  


The Mauer mandible, holotype of Homo heidelbergensis, was found in 1907 in fluvial sands deposited by the Neckar River 10 km southeast of Heidelberg, Germany. The fossil is an important key to understanding early human occupation of Europe north of the Alps. Given the associated mammal fauna and the geological context, the find layer has been placed in the early Middle Pleistocene, but confirmatory chronometric evidence has hitherto been missing. Here we show that two independent techniques, the combined electron spin resonance/U-series method used with mammal teeth and infrared radiofluorescence applied to sand grains, date the type-site of Homo heidelbergensis at Mauer to 609 ± 40 ka. This result demonstrates that the mandible is the oldest hominin fossil reported to date from central and northern Europe and raises questions concerning the phyletic relationship of Homo heidelbergensis to more ancient populations documented from southern Europe and in Africa. We address the paleoanthropological significance of the Mauer jaw in light of this dating evidence. PMID:21041630

Wagner, Günther A; Krbetschek, Matthias; Degering, Detlev; Bahain, Jean-Jacques; Shao, Qingfeng; Falguères, Christophe; Voinchet, Pierre; Dolo, Jean-Michel; Garcia, Tristan; Rightmire, G Philip



Progress on radiometric dating of Wolfcamp brines using /sup 4/He and /sup 40/Ar  

SciTech Connect

Ground water samples (brines) from deep wells in the Palo Duro Basin, Texas are being analyzed for noble gases in an attempt to obtain radiometric ages for these brines. The brines contain radiogenic /sup 4/He and /sup 40/Ar produced from the radioactive decay of U, Th, and K. Consideration of hydrochemical data for the brines, various isotopic, chemical, and mineralogical data for the aquifer rocks and noble gas production rates allow estimating the age of the brines to be about 130 million years at two wells. At a third well interaquifer mixing has occurred and the age is presently indeterminate. 9 references, 3 figures, 1 table.

Zaikowski, A.; Kosanke, B.J.; Hubbard, N.



The Varr Method: A Technique for Determining the Effective Power Patterns of Millimeter-Wave Radiometric Antennas.  

National Technical Information Service (NTIS)

The VARR (VAriable Range Reflector) Method is a technique which has been developed to measure the effective power patterns of millimeter-wave radiometric antennas. In this method, a large movable metallic surface is oriented to reflect radiation from the ...

R. B. Patton C. L. Wilson



Direct Radiometric Dating of Hydrocarbon Deposits Using Rhenium-Osmium Isotopes  

NASA Astrophysics Data System (ADS)

Rhenium-osmium (Re-Os) data from migrated hydrocarbons establish the timing of petroleum emplacement for the giant oil sand deposits of Alberta, Canada, at 112 +/- 5.3 million years ago. This date does not support models that invoke oil generation and migration for these deposits in the Late Cretaceous. Most Re-Os data from a variety of deposits within the giant hydrocarbon system show similar characteristics, supporting the notion of a single source for these hydrocarbons. The Re-Os data disqualify Cretaceous rocks as the primary hydrocarbon source but suggest an origin from older source rocks. This approach should be applicable to dating oil deposits worldwide.

Selby, David; Creaser, Robert A.



Statistical techniques applied to aerial radiometric surveys (STARRS): discriminant-analysis methods applied to aerial radiometric data and their application to uranium favorability in South Texas. National Uranium Resource Evaluation  

SciTech Connect

In an effort to establish radiometric signatures of geologic units, ten discriminant analysis techniques were applied to aerial radiometric data collected along the Texas Gulf Coast for the US Department of Energy's National Uranium Resource Evaluation (NURE) Program. Results of this study show that partial discriminant analysis with the linear discriminant function (LDF) applied to the raw data is useful for establishing radiometric signatures and for classifying new observations. Signatures for favorable and unfavorable units along the Texas Gulf Coast were established and new observations were then classified as being from units favorable or unfavorable for hosting uranium deposits based on the established training sets.

Pirkle, F.L.; Stablein, N.K.; Koch, C.D.; Johnson, M.E.; Newman, C.K.; Bement, T.R.; Patterson, D.A.



Can Carbonates be Dated Using KAr Techniques?  

Microsoft Academic Search

To determine the feasibility of K-Ar dating of carbonates, we analyzed four carbonates, using an electron probe and noble gas mass spectrometer. Early results are not promising. K contents were <100 ppm except for one sample with a K-rich inclusion.

E. K. Olson; T. D. Swindle; D. A. Kring; D. L. Dettman; P. E. Rosenberg; P. B. Larson



New technique for surface exposure dating  

NASA Astrophysics Data System (ADS)

A new technique that allows researchers to determine the amount of time a rock sample has been exposed to daylight could find many applications in geology and archaeology. The new method, pioneered by Sohbati et al., is based on optically stimulated luminescence (OSL) bleaching profiles. OSL is the light emitted on illumination due to the release of stored energy accumulated in crystalline materials through the action of ionizing radiation from natural radioactivity. In solid rock, the latent luminescence has accumulated in response to the amount of natural ionizing radiation absorbed since rock formation. Exposure to daylight removes the acquired latent luminescence in a so-called bleaching or resetting process. In a rock surface continuously exposed to daylight, this resetting will penetrate deeper into the surface with time (the rock “bleaches”) the longer the rock is exposed, the deeper this bleaching penetrates into the surface. Therefore, measuring the extent of bleaching in a sample can provide a measure of how long the sample has been exposed to daylight.

Balcerak, Ernie



The date of snow disappearance on the Arctic tundra as determined from satellite, meteorological station and radiometric in situ observations  

Microsoft Academic Search

Satellite-derived snow cover maps for sites in Alaska, Canada, Scandinavia and Siberia were employed to assess the date when snow disappeared on the Arctic tundra and to determine whether the snow has been melting earlier in the spring in recent years. Results show that for three of the four sites there has been a tendency toward earlier snowmelt during the

James L. Foster; John W. Winchester; Ellsworth G. Dutton



Radiometric dates of uplifted marine fauna in Greece: Implications for the interpretation of recent earthquake and tectonic histories using lithophagid dates  

NASA Astrophysics Data System (ADS)

In AD 365 a great (Mw > 8) earthquake lifted up western Crete, exposing a shoreline encrusted by marine organisms, and up to 10 m of marine substrate beneath it. Radiocarbon ages determined for corals and bryozoans exposed between the paleo-shoreline and present sea level are consistent, within measurement error, with each other and with the date of the earthquake. But radiocarbon ages determined for the boring bivalve Lithophaga lithophaga found on the same substrate are at least 350 years, and up to 2000 years, older than the date of the earthquake that lifted them above sea level. These observations reveal two important effects that limit the use of radiocarbon lithophagid ages in tectonic and paleoseismological studies. The first is that the exceptional preservation potential of lithophagids allows them to remain intact and in situ long after natural death, while the substrate continues to be colonised until eventual uplift. The second, which we confirm with radiocarbon analysis of museum specimens of known age, is the incorporation of old (14C-free) carbon into lithophagid shells from the limestone host rock into which the lithophagids bored. The two effects are both significant in Crete and central Greece, and can cause the radiocarbon lithophagid ages to be up to 2000 years older than the uplift event which exposed them. Understanding these effects is important because lithophagids are far more abundantly preserved, and used to date uplift, than most other marine organisms. This study shows that they can rarely be used to distinguish uplift events, or date them to better than 1000 years, or even to distinguish whether observed uplift occurred in a single or in multiple events. After taking account of these uncertainties, the ages of the lithophagids are, however, consistent with the hypothesis that the highest prominent marine notches and exposed lithophagid holes within a few metres of sea level in Greece formed when sea level became relatively stable ~ 6000 years ago, following rapid rise after the last glacial maximum.

Shaw, B.; Jackson, J. A.; Higham, T. F. G.; England, P. C.; Thomas, A. L.



Statistical techniques applied to aerial radiometric surves (STAARS): percentile estimation with the normal and lognormal distributions  

SciTech Connect

Because of the prominence of percentile estimation in the analysis of NURE aerial radiometric data, a study was conducted to compare two methods of estimating percentiles. The two methods of estimation considered are (1) the normal distribution assumption method and (2) the lognormal distribution assumption method. An error made by assuming the data are from a normal population, when in fact the population is lognormal, causes problems primarily when estimating tail percentiles. When estimating upper percentiles, the error of assuming lognormality, when the data are really normal, has more serious consequences than does the error of assuming normality, when the data are lognormal. When estimaing lower tail percentiles, the error of failing to perform a log-transformation has more serious consequences than does the error of transforming. When estimating percentiles that are between the 10th and 80th, the consequence of either type of error is not great if the coefficient of variation is less than 0.27.

Bement, T.R.; Pirkle, F.L.



On Numerical Recovery of the Cloud Moisture Structure Using Radiometric Measurements. Nonlinear Technique Solution of the Inverse Problem  

NASA Astrophysics Data System (ADS)

Is it real to obtain a solution of a non-linear inverse problem without seeking an inverse operator but making only several simple iterations? Yes, it is possible, and the technique of [Streltsov] allows it without needs of hard work to find regularization parameters to get a stable solution. This method is also effective for remote sensing problems in which amount of measurements is less than amount of recovered parameters and additional a priory information is needed. In this work results and discussion of numerical simulation are shown of applying the technique to find solutions for a wide class of non-linear inverse problem. As an example, to formulate a problem, artificial UV radiometric data set formed by using two aircraft antennas with mutually transverse directions is constructed. For demonstration of numerical calculation results, parameters of m=40 and n=210 are chosen where m is dimension of sensor data and n is dimension of reconstructed physical profile. Reference Streltsov, Yuly. Nonlinear inverse problem. Recurrent technique. Natural and Technical Science, No.1. Moscow, 2004.

Zholudev, V. D.; Streltsov, Y. P.; Chulichkov, A.



Ion chromatography inductively coupled plasma mass spectrometry (IC-ICP-MS) and radiometric techniques for the determination of actinides in aqueous leachate solutions from uranium oxide.  


The choice of the analytical method for the determination of actinide isotopes in leachate solutions has to be made considering several parameters: detection limit for each isotope, sample preparation procedure in terms of duration and complexity, counting time and interferences. A leachate solution obtained by keeping a pellet of UO2 doped with 238Pu in contact with distilled water was investigated for the content of U and Pu isotopes by radiometric methods (alpha-, gamma-spectrometry and liquid scintillation counting). The results of the radiometric methods were compared with those obtained from the analysis performed by inductively coupled plasma mass spectrometry on-line to a system for chromatographic separation (IC-ICP-MS). The comparison confirmed that IC-ICP-MS is a powerful method for the detection of long-lived radionuclides. The radiometric methods have a detection limit two orders of magnitude lower than IC-ICP-MS in the case of short-lived radioisotopes mostly due to the low background in the detector. On the other hand, the sample preparation and the analysis duration are more time-consuming compared to IC-ICP-MS; moreover, not all isotopes can be determined by using only one radiometric technique. PMID:11220837

Solatie, D; Carbol, P; Betti, M; Bocci, F; Hiernaut, T; Rondinella, V V; Cobos, J



Radioactive Dating Game  

NSDL National Science Digital Library

Learn about different types of radiometric dating, such as carbon dating. Understand how decay and half life work to enable radiometric dating. Play a game that tests your ability to match the percentage of the dating element that remains to the age of the object.

Simulations, Phet I.; Adams, Wendy; Blanco, John; Perkins, Kathy; Podolefsky, Noah; Wieman, Carl



Analysis of plutonium isotopes in marine samples by radiometric, ICP-MS and AMS techniques  

Microsoft Academic Search

IAEA reference materials (radionuclides in the marine environment) collected in areas affected by nuclear reprocessing plants and nuclear weapons tests have been analysed by semiconductor alpha-spectrometry (SAS), liquid scintillation spectrometry (LSS) and mass spectrometric techniques (high resolution ICP-MS and AMS) with the aim of developing analytical procedures and to study the geochemical behavior of plutonium in the marine environment. The

S. H. Lee; J. Gastaud; J. J. La Rosa; L. Liong Wee Kwong; P. P. Povinec; E. Wyse; L. K. Fifield; P. A. Hausladen; L. M. Di Tada; G. M. Santos



Safeguards applications of far infrared radiometric techniques for the detection of contraband  

SciTech Connect

A new safeguards system under development employs radiometers in the 100 to 300 GHz spectral band to detect contraband, including shielding materials (used to attenuate the gamma ray emissions from nuclear materials), weapons, or explosives covertly concealed on personnel. Clothing is highly transparent at these frequencies and imaging techniques can detect contraband by its emissivity and reflectivity differences relative to human tissues. Experimental data are presented and sample images are used as a basis to discuss system advantages and limitations.

Hodges, D.T.; Reber, E.E.; Foote, F.B.; Schellenbaum, R.L.



Application of paleomagnetic techniques for dating hydrocarbon migration events  

SciTech Connect

Establishing a relationship between hydrocarbon migration and the precipitation of authigenic magnetite is important for the development of a method to date hydrocarbon migration using paleomagnetic techniques. Important evidence for the relationship comes from a study of light and dark-banded calcite speleothems that occur in Ordovician limestones in southern Oklahoma. The speleothems are Permian in age, based on interbedded fossils. The dark bands contain primary fluid inclusions filled with hydrocarbons that are not extensively biograded. They also possess over an order of magnitude stronger magnetization than light bands. Paleomagnetic and rock magnetic data indicate that the magnetization in the dark bands was acquired during the Early Permian and resides in magnetite. Spheres, interpreted to be authigenic magnetite, are also found in magnetic extracts from the dark calcite. The results from the light and dark bands suggest that chemical conditions created by the hydrocarbons caused precipitation of authigenic magnetite and acquisition of the associated chemical remanent magnetization.

Elmore, R.D.




Center for Biologics Evaluation and Research (CBER)

Text VersionPage 1. DATE: May 28, 2010 FROM: Dr. HP Denton, Professor of Plant Sciences and Extension Burley Tobacco Specialist, University of Tennessee ... More results from


Teaching the Mathematics of Radioactive Dating.  

ERIC Educational Resources Information Center

|Describes a method used to teach the concept of radiometric dating using mathematical equations. Explores the lack of information in textbooks on how to solve radiometric dating problems using mathematical concepts. (SAH)|

Shea, James H.





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Luminescence dating of archaeometallurgical slag: use of the SAR technique for determination of the burial dose  

Microsoft Academic Search

The potential of using luminescence techniques to date metallurgical slag of archaeological origin has been investigated. Slag is an important residue from the metal smelting process and there is no technique currently available to directly date it. An attempt has been made to apply an optically stimulated luminescence (OSL) single-aliquot technique using quartz extracted from the slag matrix. A single-aliquot



Radiometric ages of Tennessee rocks  

SciTech Connect

This report compiles and summarizes all known radiometric age determinations based on bedrock samples from Tennessee. Data are available for 89 sites. Specimens record both igneous and metamorphic events ranging in age from 1.3 billion to 220 million years before present. Tennessee rocks have been dated by techniques that measure the results of four different kinds of radioactive decay: thorium-lead, uranium-lead, potassium-argon, and rubidium-strontium. Most determinations meet normal scientific standards for reliability. This study focuses on clarifying published data by bringing together geochemical, geological, and geographical information for each site. In addition to data on the age of bedrock samples, this study presents basic information on the ages of meteorites from Tennessee and on the ages of sediments and organic remains from Ice Age fossil sites and more recent archeological sites. While bedrock ages are the thrust of the report, other kinds of absolute age determinations are briefly discussed. 98 references, 11 figures, 3 tables.

Corgan, J.X.; Bradley, M.W.



Who's on First : A Relative Dating Activity  

NSDL National Science Digital Library

In this activity, students are introduced to sequencing and geologic time through relative dating techniques. Students begin by categorizing cards of nonsense words, then move on to cards with pictures of fossils. Once students begin to grasp relative dating, they can extend their knowledge of geologic time by exploring radiometric dating and developing a timeline of Earths history. There is a teachers guide to this activity with background information and templates to use for teaching about relative dating. There are also objectives, materials, procedure, and questions.

Barber, Marsha; Bartos, Diana S.



Range and effectiveness of the unspiked K-Ar technique constrained by cross calibration with 40Ar-39Ar dated quaternary lavas  

NASA Astrophysics Data System (ADS)

The unspiked K-Ar dating method ("Cassignol" technique) can distinguish very small amounts of 40Ar* in late Quaternary lavas. Nevertheless, this particular technique, which is a sensitive and rapid dating method, relies on the basic assumptions of the 40K-40Ar chronometer. The Achilles' tendon of the method is that we cannot verify the isotopic composition of the initial argon trapped in the samples. In other terms, we must assume that, at the time of formation, the 40Ar-36Ar ratio of the sample was the modern atmospheric value (295.5). A direct comparison between the magnetic polarity of some dated samples and their radiometric ages, using the APTS reference framework, demonstrates that some unaltered groundmass samples may give erroneously old ages. These overestimations, for the most part, probably reflect excess argon. This problem is obvious for some lavas on Gran Canaria which recorded the Reunion event. In the same island, several K-Ar ages which are coherent with the magnetic polarity of the samples coincide with magnetic reversals or event boundaries. However, the inconsistencies observed between some samples and the APTS, suggest that these age determinations must be considered carefully, if they are to be used to update the GPTS. Combined K-Ar and 40Ar-39Ar experiments on multiple subsamples of groundmass separated from individual basaltic lava flows facilitates a comparison of the two techniques and provides examples of the complementary information provided by each. These experiments also confirm the effectiveness of the two techniques to date key events such as geomagnetic field reversals and climatic changes. Examples of our results from Quaternary lavas of Fuerteventura, Gran Canaria and from Patagonia, will demonstrate the effectiveness of this combined approach.

Guillou, H.; Scaillet, S.; Singer, B.; Perez Torrado, F. J.; Carracedo, J. C.



Areas of the application of the fission-track dating technique  

NASA Astrophysics Data System (ADS)

The application of the fission-track dating technique to Cenozoic volcanic formations is discussed, and it is shown that this technique is particularly suitable when the potassium-argon technique cannot be used. Also considered is the application of the fission-track technique to evaluate the time and temperature regime of relatively recent thermal events such as the slight metamorphism of young deposits, the displacement of tectonic blocks in the crust, and contact metamorphism.

Komarov, A. N.


Application of Forensic Techniques for Age Dating and Source Identification in Environmental Litigation  

Microsoft Academic Search

A multitude of forensic techniques are available for age dating and source identification, including corrosion models for underground storage tanks, the commercial availability of a compound, chemical associations with discrete types of manufacturing processes, chemical profiling, proprietary additives, stable isotope analysis, degradation models, biomarkers and contaminant transport models. The selection and use of these techniques in environmental litigation must be

Robert D. Morrison



Statistical techniques applied to aerial radiometric surveys (STAARS): application of the Huber M-estimator to aerial radiometric data for the identification of host and source areas for uranium deposits  

SciTech Connect

Throughout the aerial radiometric survey portion of the US Department of Energy National Uranium Resource Evaluation (NURE) program, the detection of significantly low or high radioelement values has been an important aid in identifying regions with either higher than expected or lower than expected radioelement concentrations. In this paper, a robust method employing Huber M-estimators has been utilized to analyze aerial radioelement data for significantly high and low values. All possibly significant highs and lows have been mapped spatially to locate geographically those areas that may be favorable as hosts and sources for uranium deposits. The robust Huber method has been automated with all referenced computer programs having been written for a CDC 6600.

Pirkle, F.L.; Koch, C.D.; Stablein, N.K.; Beckman, R.J.; Bement, T.R.; Tietjen, G.L.; Howell, J.A.



Spontaneous fission-neutron fission xenon: a new technique for dating geological events.  


A method for dating geological samples which uses fission product xenon in a manner similar to the use of radiogenic argon in the 40Ar-39Ar technique has been developed. The results of stepwise heating experiments for a zircon from the Ahaggar region in the Sahara are compared to the geochronology determined by the rubidiumstrontium, uranium-thorium-lead, and potassium-argon dating methods. PMID:17812528

Teitsma, A; Clarke, W B; Allègre, C J



MODIS radiometric accuracy and sensitivity modeling using the Radiometric Math Model (RMM)  

NASA Astrophysics Data System (ADS)

A radiometric math model (RMM) has been developed for use as an analytical tool to establish design requirements and to model performance of the moderate resolution imaging spectroradiometer (MODIS) instrument design. The MODIS instrument is scheduled for flight on the first earth observing system (EOS) AM spacecraft in mid-1998. The model represents a significant advancement in the state of the art in radiometric simulation techniques. Characteristics of the MODIS optical design, focal plane assembly (FPA), scanning and electrical parameters, and the on-board calibrators are input to the model as predicted, estimated, or measured. Primary outputs of the model are radiometric sensitivity [signal- to-noise ratio (SNR) and noise equivalent temperature (NE(Delta) T)] and radiometric accuracy. This paper describes the theory of the model, the input and output parameters, and the major program modules, and presents predictions for the current MODIS design.

Pagano, Thomas S.; Young, James B.



Radiometric instrumentation and measurements guide for photovoltaic performance testing  

SciTech Connect

The Photovoltaic Module and Systems Performance and Engineering Project at the National Renewable Energy Laboratory performs indoor and outdoor standardization, testing, and monitoring of the performance of a wide range of photovoltaic (PV) energy conversion devices and systems. The PV Radiometric Measurements and Evaluation Team (PVSRME) within that project is responsible for measurement and characterization of natural and artificial optical radiation which stimulates the PV effect. The PV manufacturing and research and development community often approaches project members for technical information and guidance. A great area of interest is radiometric instrumentation, measurement techniques, and data analysis applied to understanding and improving PV cell, module, and system performance. At the Photovoltaic Radiometric Measurements Workshop conducted by the PVSRME team in July 1995, the need to communicate knowledge of solar and optical radiometric measurements and instrumentation, gained as a result of NREL`s long-term experiences, was identified as an activity that would promote improved measurement processes and measurement quality in the PV research and manufacturing community. The purpose of this document is to address the practical and engineering need to understand optical and solar radiometric instrument performance, selection, calibration, installation, and maintenance applicable to indoor and outdoor radiometric measurements for PV calibration, performance, and testing applications. An introductory section addresses radiometric concepts and definitions. Next, concepts essential to spectral radiometric measurements are discussed. Broadband radiometric instrumentation and measurement concepts are then discussed. Each type of measurement serves as an important component of the PV cell, module, and system performance measurement and characterization process.

Myers, D.



40Ar/39Ar technique of KAr dating: a comparison with the conventional technique  

USGS Publications Warehouse

K-Ar ages have been determined by the 40Ar/39Ar total fusion technique on 19 terrestrial samples whose conventional K-Ar ages range from 3.4 my to nearly 1700 my. Sample materials included biotite, muscovite, sanidine, adularia, plagioclase, hornblende, actinolite, alunite, dacite, and basalt. For 18 samples there are no significant differences at the 95% confidence level between the KAr ages obtained by these two techniques; for one sample the difference is 4.3% and is statistically significant. For the neutron doses used in these experiments (???4 ?? 1018 nvt) it appears that corrections for interfering Ca- and K-derived Ar isotopes can be made without significant loss of precision for samples with K/Ca > 1 as young as about 5 ?? 105 yr, and for samples with K/Ca < 1 as young as about 107 yr. For younger samples the combination of large atmospheric Ar corrections and large corrections for Ca- and K-derived Ar may make the precision of the 40Ar/39Ar technique less than that of the conventional technique unless the irradiation parameters are adjusted to minimize these corrections. ?? 1971.

Brent, Dalrymple, G.; Lanphere, M. A.



Small satellite radiometric measurements  

SciTech Connect

A critical need for the Mission to Planet Earth is to provide continuous, well-calibrated radiometric data for the radiation budget. This paper describes a new, compact, flexible radiometer which will provide both spectrally integrated data and data in selected spectral bands. The radiometer design is suitable for use on small satellites, aircraft, or remotely piloted vehicles (RPVs). 12 refs., 2 figs.

Weber, P.G.



Radiometric quantities and units  

Microsoft Academic Search

Radiometric quantities and units It is logical that in a single issue devoted to a specialist topic there should be, at the outset, a brief discussion of currently agreed terminology. This does not mean that each article will comply nor every author concur with the definitions below. However, there is fairly broad agreement on the quantities and units described in

Harry Moseley; David H. Sliney



Radiocarbon dating up to 37,000 years using CO2 absorption technique  

NASA Astrophysics Data System (ADS)

The CO2 absorption method is attractive as a simple and fast sample preparation technique for low-level carbon-14 measurement. With a better understanding of the absorption process, the reproducibility of the method has been established. Using a good low-level liquid scintillation counter it is now possible to use the method for radiocarbon dating up to 37.000 y BP, a range adequate for many users.

Nair, A. R.; Sinha, U. K.; Joseph, T. B.; Rao, S. M.



Radiometric Methods for Rapid Diagnosis of Viral Infection.  

National Technical Information Service (NTIS)

Two radiometric techniques were investigated for monitoring the effect of herpes simplex virus on the Deoxyribonucleic acid synthesis of monolayers of human embryonic lung fibroblasts. DNA synthesis of infected and uninfested cells was monitored by 3H-thy...

H. N. Wagner M. F. Tsan



Radiometric Methods for Rapid Diagnosis of Viral Infection.  

National Technical Information Service (NTIS)

Three radiometric techniques were investigated for monitoring the effects of herpes simplex virus type I and II and cytomegalovirus on the metabolism of human embryonic lung fibroblast (WI-38) monolayers. The study was based on the hypothesis that (1) ear...

H. N. Wagner M. F. Tsan



RPro: radiometric data processor  

NASA Astrophysics Data System (ADS)

Indigo Systems, a division of FLIR Systems, Inc., has released a commercial off-the-shelf, PC-based software program named RPro. RPro, an optional component of Indigo's RTools Radiometric Software Toolkit, was developed for engineers and scientists to efficiently batch process and analyze data from high-end infrared focal plane array cameras, Fourier transform infrared (FTIR) spectrometers, high-speed radiometers, and imaging spectrometers. Many core radiometric calibration and data reduction algorithms already exist within RPro for the user with minimal infrared radiometry experience. For the advanced radiometry engineer, RPro provides a flexible and extensible graphical programming interface to easily develop custom radiometric calibration and data reduction algorithms. Moreover, adding the RPro component to RTools provides the radiometry engineer with the capability to quickly create a data reduction algorithm that when used in conjunction with MODTRAN will correct for atmospheric effects using range supplied time, space, and position information (TSPI). RPro was designed to integrate seamlessly with all other RTools components by utilizing the Standard Archive File (SAF) format maintained by the U.S. Air Force at Arnold Air Force Base, TN.

Cromwell, Brian K.; Wright, Timothy A.; McClure, John E.



First dating of groundwater with Atom Trap Trace Analysis of 39Ar - technique  

NASA Astrophysics Data System (ADS)

The importance of 39Ar as a dating tracer for the time range between 50 and 1000 years has clearly been identified [1]. So far, it has been routinely accessible only by Low-Level-Counting (LLC) in the underground laboratory in Bern requiring a sample size of several tons of water and a measuring time of several weeks [2]. Here we report on the first dating results with 39Ar using an atom optical technique known as Atom Trap Trace Analysis (ATTA). This method has been developed for rare krypton isotopes in the past decade and is now available for routine analysis [3]. However, the applicability of ATTA to 39Ar has only been demonstrated in a proof of principle experiment [4]. We will discuss the essential experimental improvements that were necessary for bringing this method to the level of dating real samples. Our apparatus achieves an atmospheric 39Ar-count-rate of 4.1(3) atoms/h, which corresponds to an 18-fold improvement over the reported results in [4]. Based on that, we dated a groundwater sample of the upper Rhine Graben to 360(68) years within one day of measurement. Further samples of the investigated aquifer system are dated similarly in order to obtain the age information for a comprehensive hydrological study. The apparatus has the potential to measure 39Ar-concentrations on small samples down to less than 1 ccSTP of Argon, corresponding to about 100 ml of air, 2.5 l of water or 1 kg of ice. This opens up the way for a broader application of 39Ar as a tracer e.g. in oceanography or glaciology, where the sample sizes are typically limited to 10 l of water or 1 kg of ice respectively. [1] Loosli, H. H. (1983), A dating method with 39Ar, Earth and Planetary Science Letters, 63, 51-62. [2] P. Collon, W. Kutschera, and Z.-T. Lu. Tracing noble gas radionuclides in the environment. Annual Review of Nuclear and Particle Science, 54(1): 39-67, 2004. [3] W. Jiang et al., An atom counter for measuring 81Kr and 85Kr in environmental samples. Geochimica et Cosmochimica Acta, 91(0):1-6, 2012. [4] Jiang, W. et al. (2011), 39Ar detection at the 10-16 isotopic abundance level with Atom Trap Trace Analysis, Phys. Rev. Lett. 106, DOI: 10.1103/PhysRevLett.106.103001.

Ritterbusch, Florian; Ebser, Sven; Welte, Joachim; Reichel, Thomas; Kersting, Arne; Purtschert, Roland; Aeschbach-Hertig, Werner; Oberthaler, Markus K.



Correlation analysis of high-resolution ocean microwave radiometric images  

Microsoft Academic Search

Recent remote sensing studies have shown that a high-resolution passive microwave imaging technique enables detailed observations of ocean variables. Multi-channel sets of ocean microwave radiometric images (OMIs) were obtained using the NOAA airborne Polarimetric Scanning Radiometer (PSR) that operated at five frequencies: 10.7, 18.7, 21.5, 37, and 89 GHz and two polarizations. Radiometric features such as mosaic spot-type structures were

Victor Raizer



Radiometric Compensation through Inverse Light Transport  

Microsoft Academic Search

Radiometric compensation techniques allow seam- less projections onto complex everyday surfaces. Im- plemented with projector-camera systems they support the presentation of visual content in situations where projection-optimized screens are not available or not desired - as in museums, historic sites, air-plane cabins, or stage performances. We propose a novel approach that employs the full light transport between a projector and

Gordon Wetzstein; Oliver Bimber



Quantifying Sediment Storage Rates and History in the NW Argentinian Cordillera Using Luminescence Dating Techniques  

NASA Astrophysics Data System (ADS)

The quebradas of the Eastern Cordillera of NW Argentina contain Late Quaternary sedimentary sequences that reflect repeated alluvial fill and incision events that have created a series of inset terrace surfaces. Variation in climate is considered to be the principle trigger driving episodes of erosion and sediment deposition, even though ongoing tectonic uplift and deformation provides oversteepened slopes and can interrupt drainage patterns. The current chronological framework is based on tephrochronology and 14C, but there are insufficient ash beds or organic remnants to produce a high resolution chronology of erosion and sediment storage. We are therefore producing a detailed chronological record of alluviation using optically stimulated luminescence (OSL) dating, combined with cosmogenic radionuclide dating to quantify erosion rates. Recent advances in single aliquot measurements of quartz have improved both precision and accuracy of the OSL dating method for sediments, where an age assessment is possible for each aliquot measured. Although initial OSL results are consistent with 14C of shells and wood samples, the majority of alluvial samples studied have wide, multimodal age distributions. There are various possible explanations for these distributions, including inadequate bleaching of some quartz grains. However, we believe the age distributions are a result of variations in the interplay of sediment source and transport mechanisms, in concert with variability in grain-to-grain bleaching, and therefore contain an archive of the inherited grains from past sedimentation events. To improve our understanding of the age distributions we are investigating small aliquot (about 50-100 quartz grains) approaches in combination with a variety of distribution analysis techniques that identify not only the age since the last solar exposure, but also the age of inherited grains. In addition to providing rates of sediment accumulation and storage, such archives of basin sedimentation (and erosion) improve our understanding of the cycling of sediments within a basin through time and identify periods of alluvial storage and erosion.

Spencer, J. Q.; Robinson, R. A.; Strecker, M. R.; Richter, A.



Landsat5 TM reflective-band absolute radiometric calibration  

Microsoft Academic Search

The Landsat-5 Thematic Mapper (TM) sensor provides the longest running continuous dataset of moderate spatial resolution remote sensing imagery, dating back to its launch in March 1984. Historically, the radiometric calibration procedure for this imagery used the instrument's response to the Internal Calibrator (IC) on a scene-by-scene basis to determine the gain and offset of each detector. Due to observed

Gyanesh Chander; Dennis L. Helder; Brian L. Markham; James D. Dewald; E. Kaita; Kurtis J. Thome; Esad Micijevic; Timothy A. Ruggles



Thematic Mapper radiometric characterization  

NASA Astrophysics Data System (ADS)

Characteristics of multispectral scanner systems that are desirable for radiometry are identified. Both 'macroscopic' and 'microscopic' studies of Landsat-4 Thematic Mapper digital image data are described which assess several of these characteristics. Included are the range and quantization of signal values, scan-angle effects, scan-direction effects, and level-shift noise characteristics. Despite good overall radiometric quality, some relatively low-amplitude artifacts were noted and correction procedures are recommended. Consideration of the use of stepwise linear system-response characteristics is recommended. The acquisition of a unique data set of coincident Landsat-4 and Landsat-5 data is noted; it was acquired before Landsat 5 reached its final orbit.

Malila, W. A.; Metzler, M. D.


Deep Springs fault, Inyo County, California: An example of the use of relative-dating techniques  

SciTech Connect

This article summarizes faulting in the Deep Springs Valley area, which was studied as part of a systematic evaluation of potentially active faults throughout California by the Division of Mines and Geology. Evaluation of surface fault-rupture hazard is authorized by the Alquist-Priolo Special Studies Zones Act of 1972. This act requires the State Geologist to delineate regulatory zones for faults that are well defined and show that displacement occurred during the last 11,000 years. Fault evaluations for the Division of Mines and Geology Fault Evaluation and Zoning Project are conducted at a detailed reconnaissance level. Evaluations are mainly based on aerial photographic interpretation in which ephemeral fault-produced landforms are identified and mapped. Young alluvial deposits and geomorphic surfaces are identified as either offset or not offset by faults. Field mapping is conducted to verify fault-related geomorphic features and to estimate ages of faulted and unfaulted deposits. The section on scarp degradation and relative dating techniques provides a brief survey of methods used in studies of the Basin and Range province. In these investigations geomorphic evidence is applied to determine the recency of faulting.

Bryant, W.A.



Investigation of the irradiation history of the Iranian dates and pistachio nuts using thermoluminescence technique  

Microsoft Academic Search

Three different varieties of Iranian fresh dates and five types of raw and salted pistachio nuts have been tested for identification of irradiation histories. Doses of 2.5, 5, 7.5 and 10 kGy from a gamma cell Gc-220 have been administrated to the samples under investigation. TL response versus dose for date and for pistachio nuts have been obtained. The effect

M. Sharifzadeh; M. Sohrabpour



Dating and sourcing fuel ash residues from Cladh Hallan, South Uist, Scotland, using magnetic techniques  

Microsoft Academic Search

Mineral magnetic and archaeomagnetic measurements have been carried out on fire ash deposits from a central hearth within a circular dwelling at the Late Bronze\\/Early Iron Age settlement site of Cladh Hallan on South Uist, Scotland. Archaeomagnetic methods date the hearths to 560–700 BC and 650–850 BC, the earliest archaeomagnetic dates produced for the Western Isles of Scotland. A range

C. Peters; C. M Batt



A novel radiocarbon dating technique applied to an ice core from the Alps indicating late Pleistocene ages  

Microsoft Academic Search

Ice cores retrieved from high-altitude glaciers are important archives of past climatic and atmospheric conditions in midlatitude and tropical regions. Because of the specific flow behavior of ice, their age-depth relationship is nonlinear, preventing the application of common dating methods such as annual layer counting in the deepest and oldest part. Here we present a new approach and technique, allowing

Theo M. Jenk; Sönke Szidat; David Bolius; Michael Sigl; Heinz W. Gäggeler; Lukas Wacker; Matthias Ruff; Carlo Barbante; Claude F. Boutron; Margit Schwikowski



Investigation of the irradiation history of the Iranian dates and pistachio nuts using thermoluminescence technique  

NASA Astrophysics Data System (ADS)

Three different varieties of Iranian fresh dates and five types of raw and salted pistachio nuts have been tested for identification of irradiation histories. Doses of 2.5, 5, 7.5 and 10 kGy from a gamma cell Gc-220 have been administrated to the samples under investigation. TL response versus dose for date and for pistachio nuts have been obtained. The effect of added ingredients such as salt in pistachio nuts, and moisture in date samples on the TL response have been studied. The fading of TL intensity of the irradiated dates and pistachio nuts have also been measured. Based on the latter results, it appears possible to identify the irradiated dates (10 kGy), within (1-2) months post-irradiation. In the salted pistachio nuts, the salt itself gives a very significant and distinguishable response. In the unsalted case, however, the difference between the irradiated and unirradiated samples seem difficult to detect due to partial overlapping of the respective responses.

Sharifzadeh, M.; Sohrabpour, M.



Comparison of two gravity coring devices for sedimentation rate measurement by 210 Pb dating techniques  

Microsoft Academic Search

Marine sediment cores were collected in Puget Sound using a 7.6 cm diameter corer and a 15 × 15 cm square cross-section corer. The cores were dated by the 210Pb method and sedimentation rates and depth of sediment mixed layers were compared. The results show that both the sedimentation rates and the depth of sediment mixed layers obtained from small

A. E. Nevissi; G. J. Shott; E. A. Crecelius



Age validation of canary rockfish (Sebastes pinniger) using two independent otolith techniques: lead-radium and bomb radiocarbon dating.  

SciTech Connect

Canary rockfish (Sebastes pinniger) have long been an important part of recreational and commercial rockfish fishing from southeast Alaska to southern California, but localized stock abundances have declined considerably. Based on age estimates from otoliths and other structures, lifespan estimates vary from about 20 years to over 80 years. For the purpose of monitoring stocks, age composition is routinely estimated by counting growth zones in otoliths; however, age estimation procedures and lifespan estimates remain largely unvalidated. Typical age validation techniques have limited application for canary rockfish because they are deep dwelling and may be long lived. In this study, the unaged otolith of the pair from fish aged at the Department of Fisheries and Oceans Canada was used in one of two age validation techniques: (1) lead-radium dating and (2) bomb radiocarbon ({sup 14}C) dating. Age estimate accuracy and the validity of age estimation procedures were validated based on the results from each technique. Lead-radium dating proved successful in determining a minimum estimate of lifespan was 53 years and provided support for age estimation procedures up to about 50-60 years. These findings were further supported by {Delta}{sup 14}C data, which indicated a minimum estimate of lifespan was 44 {+-} 3 years. Both techniques validate, to differing degrees, age estimation procedures and provide support for inferring that canary rockfish can live more than 80 years.

Andrews, A H; Kerr, L A; Cailliet, G M; Brown, T A; Lundstrom, C C; Stanley, R D



Radiometric Realization of the Candela.  

National Technical Information Service (NTIS)

A radiometric realization of the S.I. base unit of photometry, the candela, as performed at the National Physical Laboratory, is described and the results compared with the scale currently disseminated. The realization has been carried out in accordance w...

T. M. Goodman P. J. Key



A novel radiocarbon dating technique applied to an ice core from the Alps indicating late Pleistocene ages  

NASA Astrophysics Data System (ADS)

Ice cores retrieved from high-altitude glaciers are important archives of past climatic and atmospheric conditions in midlatitude and tropical regions. Because of the specific flow behavior of ice, their age-depth relationship is nonlinear, preventing the application of common dating methods such as annual layer counting in the deepest and oldest part. Here we present a new approach and technique, allowing dating of any such ice core at arbitrary depth for the age range between ˜500 years B.P. and the late Pleistocene. This new, complementary dating tool has great potential for numerous ice core related paleoclimate studies since it allows improvement and extension of existing and future chronologies. Using small to ultrasmall sample size (100 ?g > carbon content > 5 ?g) accelerator mass spectrometry, we take advantage of the ice-included, water-insoluble organic carbon fraction of carbonaceous aerosols for radiocarbon (14C) dating. Analysis and dating of the bottom ice of the Colle Gnifetti glacier (Swiss-Italian Alps, 45°55'50?N, 7°52'33?E, 4455 m asl) has been successful in a first application, and the results revealed the core to cover most of the Holocene at the least with indication for late Pleistocene ice present at the very bottom.

Jenk, Theo M.; Szidat, SöNke; Bolius, David; Sigl, Michael; GäGgeler, Heinz W.; Wacker, Lukas; Ruff, Matthias; Barbante, Carlo; Boutron, Claude F.; Schwikowski, Margit



A new technique for precise uranium-series dating of travertine micro-samples  

NASA Astrophysics Data System (ADS)

Secondary carbonate formations, such as travertine and calcareous tufa deposits, are important archives for quaternary continental climate studies and archaeology. The extremely complex growth mechanisms result in some serious problems for precise mass spectrometric uranium-series dating. Often, detrital and organic particles contaminate the carbonate and large pore volumes yield a great potential for open system behavior. We utilized microscopic, mineralogical and geochemical methods prior to sample selection to determine the abundance of primary calcite, i.e. micrite and spar. Furthermore, the state of alteration was characterized by cathodoluminescence and trace-element analysis. We conclude that travertine and calcareous tufa are appropriate for precise U-series age determination if a) micrite and/or spar are the dominant phases; b) cathodoluminescence of both phases is weak or absent; c) Fe and Al levels are low; and d) Sr concentrations are close to the average of the studied site. We mapped and sampled solely areas of major micrite/spar abundance having minor alteration for accurate U-series dating. When this new method was applied, travertines located in eastern Germany (sites Bad Langensalza, Burgtonna and Weimar-Ehringsdorf) gave single 230Th/ 238U-ages consistent with the lithological growth sequence and greatly improved compared to previously published chronologies. In addition, we determined 230Th/U isochron ages on bulk samples that confirm our single ages. In contrast to primary calcite, pore cements are homogeneously distributed throughout the travertine fabric and reflect early diagenetic processes and/or weathering.

Mallick, Ronzon; Frank, Norbert



Real-time adaptive radiometric compensation.  


Recent radiometric compensation techniques make it possible to project images onto colored and textured surfaces. This is realized with projector-camera systems by scanning the projection surface on a per-pixel basis. Using the captured information, a compensation image is calculated that neutralizes geometric distortions and color blending caused by the underlying surface. As a result, the brightness and the contrast of the input image is reduced compared to a conventional projection onto a white canvas. If the input image is not manipulated in its intensities, the compensation image can contain values that are outside the dynamic range of the projector. These will lead to clipping errors and to visible artifacts on the surface. In this article, we present an innovative algorithm that dynamically adjusts the content of the input images before radiometric compensation is carried out. This reduces the perceived visual artifacts while simultaneously preserving a maximum of luminance and contrast. The algorithm is implemented entirely on the GPU and is the first of its kind to run in real-time. PMID:17993705

Grundhöfer, Anselm; Bimber, Oliver


PALSAR Radiometric and Geometric Calibration  

Microsoft Academic Search

This paper summarizes the results obtained from geometric and radiometric calibrations of the Phased-Array L-Band Synthetic Aperture Radar (PALSAR) on the Advanced Land Observing Satellite, which has been in space for three years. All of the imaging modes of the PALSAR, i.e., single, dual, and full polarimetric strip modes and scanning synthetic aperture radar (SCANSAR), were calibrated and validated using

Masanobu Shimada; Osamu Isoguchi; Takeo Tadono; Kazuo Isono



Radiometric acid-base titrations.  


Acid-base titrations can be performed with radiometric end-point detection by use of labelled metal salts (e.g., ZnCl(2), HgCl(2)). Owing to the formation or dissolution of the corresponding hydroxide after the equivalence point, the activity of the titrated solution linearly increases or decreases as excess of standard solution is added. The end-point of the titration is determined graphically. PMID:18960522

Erdey, L; Gimesi, O; Szabadváry, F



Dating of the Urengoi tectites by the track technique using an age standard  

NASA Astrophysics Data System (ADS)

The age of three Urengoi (northwestern Siberia) tektites was estimated by the 'repeated-polishing' version of the track technique, using the Apatite FC-3 as the age standard. The average age for the three samples was found to be 23 + or - 1.6 million years. This age does not coincide with the age of known tektite fields on the earth, and it is not close to the age of the certain impact craters on Soviet territory. It is concluded that the Urengoi tektites may have originated on a hitherto unknown tektite dispersion field.

Komarov, A. N.; Masaitis, V. L.; Ezerskii, V. A.



Geochemistry and radiometric dating of a Middle Pleistocene peat  

SciTech Connect

Uranium, lead, and sulphur data for a Middle Pleistocene interglacial peat deposit from Norfolk, UK, suggest that uptake of these elements was synchronous and confined to a single early diagenetic episode, probably coeval with peat formation. Sulphur isotope data indicate that reducing conditions have been maintained within the deposit throughout its history. Both uranium and lead concentration profiles show a marked discontinuity near the middle of the bed, probably indicating an environmental change, possibly emergence. The lead isotope data are compatible with a single lead component below the discontinuity and two components above. Groundwater is thought to be the dominant source of lead with an additional airfall component present in the upper peat. The uranium and lead concentration profiles below the discontinuity and the sulfur isotope profile throughout the peat support the view that these elements were sequestered from upwelling groundwaters. 35 refs., 9 figs., 3 tabs.

Rowe, P.J.; Atkinson, T.C. [Univ. of East Anglia, Norwich (United Kingdom); Richards, D.A.; Bottrell, S.H.; Cliff, R.A. [Univ. of Leeds (United Kingdom)] [and others



Direct Dating of Hominids Remains In Eurasia  

NASA Astrophysics Data System (ADS)

When archaeological sites are associated with human remains, it is relevant to be able to date those valuable remains for different reasons. The main one is that it avoids the stratigraphical problems which can be due to intrusive burials in the sequence. The other reason consists in the fact that human bones may be encountered out of established stratigraphical context. On the other hand, the majority of dating methods currently used are destructive and can not be applied on these precious samples particularly when they are older than 40,000 years and can not be dated by radiocarbon. Since several years, we have developped a completely non-destructive method which consists in the measurement of human remains using the gamma -ray spectrometry. This technique has been used recently by other laboratories. We present here two important cases for the knowledge of human evolution in Eurasia. The first example is Qafzeh site in Israel where many human skeletons have been unearthed from burials associated with fauna and lithic artefacts. This site has been dated by several independent radiometric methods. So, it was possible to compare our gamma results with the other results yielded by the different methods. The second case concerns the most evolved Homo erectus found in Java, Indonesia, at Ngandong site, close to the Solo river. A recent debate has been focused on the age of these fossils and their direct dating is of outmost importance for the knowledge of settlement of Modern Humans in South-East Asia.

Yokoyama, Y.; Falguères, C.


Precision and accuracy of two luminescence dating techniques for retrospective dosimetry: SAR-OSL and SAR-ITL  

NASA Astrophysics Data System (ADS)

Luminescence techniques based on thermally or optically stimulated signals are used extensively for estimating the equivalent dose (ED) of quartz samples for dating and retrospective dosimetry. This paper presents simulations of two luminescence dating protocols which use single aliquots of the quartz samples. The first protocol is the well-known single-aliquot regenerative optically stimulated luminescence (SAR-OSL) protocol for quartz. The second protocol was developed more recently and is based on a thermoluminescence (TL) signal measured under isothermal conditions (termed the SAR-ITL technique). The simulations are carried out using a recently published comprehensive kinetic model for quartz, consisting of 11 electron and hole traps and centers. The complete sequence of the two experimental protocols is simulated using the same set of kinetic parameters. The simulated dose response curves for the two protocols are found to be very similar to published experimental data. The relative intrinsic accuracy and precision of the two techniques is estimated by simulating one hundred random variants of the natural samples, and by calculating the equivalent doses using each technique. The 100 simulated natural variants are generated by keeping the transition probabilities between energy levels fixed, while allowing simultaneous random variations of the concentrations of the 11 energy levels. The SAR-OSL protocol was found to be intrinsically both more accurate and more precise than the SAR-ITL protocol. We investigate several experimental factors which affect the precision and accuracy of the two protocols. New simulations are presented for commonly used sensitivity tests consisting of successive cycles of sample irradiation with the same dose, followed by measurements of the sensitivity corrected L/T signals. These new simulations provide valuable insight into the previously reported sensitivity changes taking place during application of the SAR-ITL protocol.

Pagonis, Vasilis; Baker, Atlee; Larsen, Meredith; Thompson, Zachary



Overview of the radiometric calibration of MOBY  

NASA Astrophysics Data System (ADS)

The Marine Optical Buoy (MOBY) provides values of water- leaving radiance for the calibration and validation of satellite ocean color instruments. Located in clear, deep ocean waters near the Hawaiian Island of Lanai, MOBY measures the upwelling radiance and downwelling irradiance at three levels below the ocean surface plus the incident solar irradiance just above the surface. The radiance standards for MOBY are two integrating spheres with calibrations based on standards traceable to the National Institute of Standards and Technology (NIST). For irradiance, the MOBY project uses standard lamps that are routinely calibrated at NIST. Wavelength calibrations are conducted with a series of emission lines observed from a set of low pressure lamps. Each MOBY instrument views these standards before and after its deployment to provide system responses (calibration coefficients). During each deployment, the stability of the MOBY spectrographs and internal optics are monitored using three internal reference sources. In addition, the collection optics for the instrument are cleaned and checked on a monthly basis while the buoy is deployed. Divers place lamps over the optics before and after each cleaning to monitor changes at the system level. As a hyperspectral instrument, MOBY uses absorption lines in the solar spectrum to monitor its wavelength stability. When logistically feasible during each deployment, coincident measurements are made with the predecessor buoy before that buoy's recovery. Measurements of the underwater light fields from the deployment vessel are compared with those from the buoy. Based on this set of absolute calibrations and the suite of stability reference measurements, a calibration history is created for each buoy. These calibration histories link the measurement time series from the set of MOBY buoys. In general, the differences between the pre- and post-deployment radiance calibrations of the buoys range from +1% to -6% with a definitive bias to a negative difference for the post- deployment values. This trend is to be expected after a deployment of 3 months. To date, only the pre-deployment calibration measurements have been used to adjust the system responses for the MOBY time series. Based on these results, the estimated radiometric uncertainty for MOBY in-water ocean color measurements is estimated to be about 4% to 8% (kequals1). As part of a collaboration with NIST, annual radiometric comparisons are made at the MOBY calibration facility. NIST personnel use transfer radiometers and integrating spheres to validate (verify) the accuracy of the MOBY calibration sources. Recently, we began a study of the stray light contribution to the radiometric uncertainty in the MOBY systems. A complete reprocessing of the MOBY data set, including the changes within each MOBY deployment, will commence upon the completion of the stray light characterization, which is scheduled for the fall of 2001. It is anticipated that this reprocessing will reduce the overall radiometric uncertainty to less than 5% (kequals1).

Clark, Dennis K.; Feinholz, Michael; Yarbrough, Mark; Johnson, B. Carol; Brown, Steven W.; Kim, Yong S.; Barnes, Robert A.



Absolute dating of Middle Pleistocene palaeontological records from the Guadix-Baza basin, Spain, using extended-range OSL dating techniques  

NASA Astrophysics Data System (ADS)

The Guadix-Baza basin, southern Spain, contains an important archive of palustrine/lacustrine records covering the late Miocene to Middle Pleistocene. Numerous palaentological sites have been described within the Guadix-Baza basin, which record faunal and climatic changes spanning the Early to Middle Pleistocene, and contain some of the earliest evidence of human presence in Europe. Chronological control for these palustrine/lacustrine sequences has been achieved via a combination of relative dating methods, such as stratigraphic correlations, palaeomagnatism and biochronology. However, in spite of the large number of research undertaken over the past 20 years, absolute chronological control is still lacking for these sites due to (i) the antiquity of the deposits, which precludes the use of radiocarbon and conventional optically stimulated luminescence (OSL) dating, and (ii) the lack of datable material for long-ranging methods, such as Ar/Ar on tephras or U-series. Conventional OSL dating of quartz is now routinely applied to sedimentary deposits that are less than 200 ka old, but it is not generally suitable for older deposits owing to saturation of the OSL signal. Over the past 10 years, a series of extended range OSL methodologies have been proposed for dating Middle Pleistocene deposits, which make use of luminescence signals with higher saturation limits. Here we report on chronologies obtained using so-called thermally-transferred (TT) OSL dating and post-IR IRSL feldspar dating of Middle Pleistocene deposits from the Baza sub-basin. In total, 5 samples were collected from deposits bracketing the main palaeontological/archaeological horizons at two sites (Huescar-1 and Cullar de Baza-1). Single-grain OSL was also applied to the youngest samples to obtain additional chronologies for comparison with the multi-grain TT-OSL and post-IR IRSL ages. The suitability of the TT-OSL and post-IR IRSL signals for dating these deposits is tested via a series of quality assurance criteria (signal composition, dose recovery tests, bleaching tests, sensitivity correction assessments). The resultant extended-age OSL chronologies are presented and used to assess (i) the accuracy of existing chronostratigraphic frameworks developed at these sites, and (ii) the wider applicability of these novel dating approaches for constraining early human presence in Europe.

Demuro, Martina; Arnold, Lee; Pares, Josep



Small satellite radiometric measurement system  

SciTech Connect

The Los Alamos Radiometric Instrument (LARI) is a compact, lightweight, adaptable radiometer for climate change-related measurements which could be carried by small satellites, manned aircraft, and RPVs for remote sensing. LARI can furnish both spectrally-integrated measurements and data in selected spectral bands. Attention is given to the benefits derived from the simultaneous operation of LARI with a compact spectrometer. The basic LARI package can be inserted into orbit with the Pegasus air-launched vehicle; well-chosen orbits facilitate the use of data from other satellites to enhance data products. 23 refs.

Weber, P.G. (Los Alamos National Laboratory, NM (United States))



Radiometric terrain correction of SPOT5 image  

Microsoft Academic Search

Remote sensing SPOT5 images have been widely applied to the surveying of agriculture and forest resources and to the monitoring of ecology environment of mountain areas. However, the accuracy of land-cover classification of mountain areas is often influenced by the topographical shadow effect. Radiometric terrain correction is important for this kind of application. In this study, a radiometric terrain correction

Xiuli Feng; Feng Zhang; Ke Wang



Chemical Principles Revisited: Archaeological Dating.  

ERIC Educational Resources Information Center

|Discusses methods used to date archaeological artifacts and other remains. They include: (1) nuclear dating techniques (radiocarbon dating, accelerator radiocarbon dating, thermoluminescence, and others); (2) chemical dating techniques (amino acid racemization, obsidian hydration dating, elemental content changes, and thermal analysis dating);…

Rowe, M. W.



Uranium-series dating of antarctic ice  

SciTech Connect

It is very interesting to date polar ice radiometrically. Bands of dust imbedded in ice are frequently observed in antarctic ice fields. This work focuses on dating ice samples with high dust contents by the uranium-series method. The author obtained uranium-series ages of 325 thousand (+/- 75) and 100 thousand (+/- 20) years for dusty ice samples from two sites in the main Allan Hills ice field. The dust-banded ice was collected from 50- to 100-centimeter depth at two sites, called Cul de Sac 100 and Cul de Sac 150. The particles in these samples were examined with an optical microscope and found to consist essentially (more than 95% of the particulates) of fine volcanic glass shards full of vesicles and microvesicles. Evidently the fine volcanic glass shards were deposited on snow, became incorporated in the ice, and moved with the ice to the Allan Hills sites. Ice samples with other types of particulates, such as terrestrial morraine, may also be amenable to uranium-series dating; however, it is difficult to date ice with less than 0.03 gram of fine particulates per kilogram of ice with their present technique. The uranium-series method can cover the age range from 10,000 to 600,000 years.

Fireman, E.L.



Small satellite radiometric measurement system  

SciTech Connect

A critical need for the US Global Change Research Program is to provide continuous, well-calibrated radiometric data for the earth's radiation budget. This paper describes a new, compact, relatively light-weight, adaptable radiometer which will provide both spectrally integrated measurements and data in selected spectral bands. The radiometer design is suitable for use on small satellites, aircraft, or remotely piloted aircraft (RPAs). An example of the implementation of this radiometer on a small satellite is given. Significant benefits derive from simultaneous measurements of specific narrow (in wavelength) spectral features; such data may be obtained by combining LARI with a compact spectrometer on the same platform. Well-chosen satellite orbits allow one to use data from other satellites (e.g. DMSP) to enhance the data product, or to provide superior coverage of specific locations. 23 refs.

Weber, P.G.



Small satellite radiometric measurement system  

SciTech Connect

A critical need for the US Global Change Research Program is to provide continuous, well-calibrated radiometric data for the earth`s radiation budget. This paper describes a new, compact, relatively light-weight, adaptable radiometer which will provide both spectrally integrated measurements and data in selected spectral bands. The radiometer design is suitable for use on small satellites, aircraft, or remotely piloted aircraft (RPAs). An example of the implementation of this radiometer on a small satellite is given. Significant benefits derive from simultaneous measurements of specific narrow (in wavelength) spectral features; such data may be obtained by combining LARI with a compact spectrometer on the same platform. Well-chosen satellite orbits allow one to use data from other satellites (e.g. DMSP) to enhance the data product, or to provide superior coverage of specific locations. 23 refs.

Weber, P.G.



Radiometric calibration of an airborne chemical imager  

NASA Astrophysics Data System (ADS)

Advances made over the past decade in multispectral and hyperspectral imaging systems, have led to a wide range of new remove sensing capabilities, including the ability to detect and image chemical vapors in the atmosphere. This sensor has application in the detection and monitoring of chemical weapons, as well as environmental pollution monitoring. Key to the continuing development of this technology is accurate and temporally stable radiometric calibration. This paper presents an overview of the system level radiometric calibration approach used for the SAFEGUARD multispectral infrared line scanner. This approach includes radiometric calibration of the sensor at the aperture, corrections for atmospheric effects and group truth validation.

Zywicki, Randall W.



Faint Young Sun, Radiocarbon dating  

NSDL National Science Digital Library

The first problem in this assignment is the culmination of the unit on energy balance and greenhouse gases. The students have already calculated blackbody temperatures as a function of albedo, sun's luminosity and distance from sun. They have also already calculated the magnitude of the greenhouse effect (optical thickness) of the modern atmosphere. In this first problem, the students apply these same calculations to the Faint Young Sun hypothesis and infer what can account for the geological evidence for liquid water on earth since 4.3 Ga. The second problem follows an introductory lecture on radiometric decay and radiometric dating. The students have seen the decay equation and learned what are decay constants and stable versus radioactive isotopes. In this problem, the students apply these concepts to radiocarbon.

Cook, Mea


Radiometric method for the rapid detection of Leptospira organisms  

SciTech Connect

A rapid and sensitive radiometric method for detection of Leptospira interrogans serovar pomona and Leptospira interrogans serovar copenhageni is described. Stuart's medium and Middlebrook TB (12A) medium supplemented with bovine serum albumin, catalase, and casein hydrolysate and labeled with /sup 14/C-fatty acids were used. The radioactivity was measured in a BACTEC 460. With this system, Leptospira organisms were detected in human blood in 2 to 5 days, a notably shorter time period than that required for the majority of detection techniques.

Manca, N.; Verardi, R.; Colombrita, D.; Ravizzola, G.; Savoldi, E.; Turano, A.



A radiometric realization of the candela  

NASA Astrophysics Data System (ADS)

A radiometric realization of the candela is described and the results compared with the scale currently disseminated. The realization was carried out in accordance with the radiometrically based Conference Generale des Poids et Mesures 1979 redefinition which quantifies the maximum spectral luminous efficacy of radiation for photopic vision as 683 lumens per watt. The excellent performance of the silicon photodiode photometers developed for this project is demonstrated, together with characteristics of the two types of lamp employed for preserving the results of the realization, and methods for improving their alignment and reproducibility.

Goodman, Teresa M.; Key, P. J.



Comparison of absolute and relative radiometric normalization use Landsat time series images  

NASA Astrophysics Data System (ADS)

For most remote sense image applications, variations in solar illumination conditions, atmospheric scattering and absorption, and detector performance need to be normalized, especially in time series analysis such as change detection. For the purpose of radiometric correction, two levels of radiometric correction, absolute and relative, have been developed for remote sense imagery. In this paper, we select the Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes (FLAASH) algorithm as the Atmospheric correction method, and compare it with an automatic method for relative radiometric normalization based on a linear scale invariance of the multivariate alteration detection (MAD) transformation. The performances of both methods are compared using a landsat TM image pairs, the results from the two techniques have been compared both visually and using a measure of the fit based on standard error statistic.

Hu, Yong; Liu, Liangyun; Liu, Lingling; Jiao, Quanjun



Comparison of ultrasonic and mechanical cleaning of primary root canals using a novel radiometric method  

Microsoft Academic Search

Although ultrasound is employed increasingly as an ad- junct to biomechanical preparation in clinical endodontics for adult teeth, there have been no previous investigations of this technique for primary teeth. This investigation studied the efficacy of ultrasonication compared with mechanical clean- ing in primary root canals using a novel radiometric method. The results indicated that in multiple-rooted teeth, ultrasonication with

W. Kim Seow BDS


Trace determination of nickel by combining paper chromatography with radiometric precipitation  

Microsoft Academic Search

Summary A technique combining Chromatographic separation with radiometric precipitation is described in which nickel is determined at theµg to submicrogram range. An appropriate solvent completely isolates nickel from interference on a Chromatographic strip. Nickel is then precipitated as the35S labeled nickel sulfide. Quantitative yields are obtained using radioautography and radiometry.

E. L. Chiotis; G. A. Welford; R. S. Morse



Reduction of Radiometric Miscalibration--Applications to Pushbroom Sensors  

PubMed Central

The analysis of hyperspectral images is an important task in Remote Sensing. Foregoing radiometric calibration results in the assignment of incident electromagnetic radiation to digital numbers and reduces the striping caused by slightly different responses of the pixel detectors. However, due to uncertainties in the calibration some striping remains. This publication presents a new reduction framework that efficiently reduces linear and nonlinear miscalibrations by an image-driven, radiometric recalibration and rescaling. The proposed framework—Reduction Of Miscalibration Effects (ROME)—considering spectral and spatial probability distributions, is constrained by specific minimisation and maximisation principles and incorporates image processing techniques such as Minkowski metrics and convolution. To objectively evaluate the performance of the new approach, the technique was applied to a variety of commonly used image examples and to one simulated and miscalibrated EnMAP (Environmental Mapping and Analysis Program) scene. Other examples consist of miscalibrated AISA/Eagle VNIR (Visible and Near Infrared) and Hawk SWIR (Short Wave Infrared) scenes of rural areas of the region Fichtwald in Germany and Hyperion scenes of the Jalal-Abad district in Southern Kyrgyzstan. Recovery rates of approximately 97% for linear and approximately 94% for nonlinear miscalibrated data were achieved, clearly demonstrating the benefits of the new approach and its potential for broad applicability to miscalibrated pushbroom sensor data.

Rogass, Christian; Spengler, Daniel; Bochow, Mathias; Segl, Karl; Lausch, Angela; Doktor, Daniel; Roessner, Sigrid; Behling, Robert; Wetzel, Hans-Ulrich; Kaufmann, Hermann



Dating of the Upper Pleistocene–Holocene volcanic activity of La Palma using the unspiked K–Ar technique  

Microsoft Academic Search

Combined unspiked K–Ar dating and detailed mapping have established the eruptive chronology of the Cumbre Vieja volcano in the Canary islands. The CV volcano is a large polygenetic volcano (subaerial area: 220 km2, subaerial volume: 125 km3, elevation above sea level: 2000 m), which rests on the southern flank of the older Taburiente-Cumbre Nueva volcano. We defined two stratigraphic units

Hervé Guillou; Juan Carlos Carracedo; Simon J. Day



Airborne imaging microwave radiometer. I. Radiometric analysis  

Microsoft Academic Search

The airborne imaging microwave radiometer (AIMR) was designed and built for regional scale sea ice mapping. It operates at 37 and 90 GHz (nominal), and collects radiance at two orthogonal polarizations from which one can compute horizontal and vertical polarizations. The sensitivity or precision (?T) of the radiometric data is on the order of 0.5-0.8 K for the 37 GHz

Michael J. Collins; F. G. Ross Warren; J. Lawrence Paul



Radiometric imaging for concealed weapon detection  

Microsoft Academic Search

Described here is the opportunity of concealed weapon detection using a radiometric system. The single-channel passive imaging system, which operated in the W-band allows the detection and recognition of metal and plastic subjects under clothes on a human body.

V. N. Radzikhovsky; V. P. Gorishniak; S. E. Kuzmin; B. M. Shevchuk



Radiometric and equivalent isothermal surface temperatures  

Microsoft Academic Search

The analytical solution for the heat flux from an anisothermal canopy developed from K theory by Brutsaert and Sugita [1996] (hereinafter referred to as B&S) has been extended to provide a parameterization of the difference between the radiometric and the equivalent isothermal surface temperature. The latter is the isothermal temperature at which a canopy would give the correct sensible heat

Richard D. Crago



Radiometric linearity in passive FTIR spectrometry  

Microsoft Academic Search

Passive standoff FTIR spectrometry relies on the radiance differential between a background scene and a target vapor analyte. Unlike traditional FTIR approaches controlling radiance levels within a narrow range, the passive configuration often encounters a large variance in radiance levels. This places higher demands on the passive FTIR configuration for maintaining linearity. The present study assesses the radiometric linearity of

Robert T. Kroutil; Roger J. Combs; Robert B. Knapp



Ocean color remote sensing systems - Radiometric requirements  

NASA Astrophysics Data System (ADS)

A methodology for specifying the radiometric requirements for ocean color remote sensing systems is described. Consideration is given to the noise equivalent radiance, the saturation radiance, the polarization sensitivity, and the calibration and stability. The degree of polarization across a scan line for the CZCS and MODIS orbits is presented.

Gordon, Howard R.



Radiometric Sorting of Rio Algom Uranium Ore.  

National Technical Information Service (NTIS)

An ore sample of about 0.2 percent uranium from Quirke Mine was subjected to radiometric sorting by Ore Sorters Limited. Approximately 60 percent of the sample weight fell within the sortable size range: -150 + 25 mm. Rejects of low uranium content (<0.01...

M. A. Cristovici




Microsoft Academic Search

An extended-source calibration area was set up in the Nevada Test Site ; area to encourage a standarnization of airborne radiometric instrumentation among ; several government agencies and private companies. A simulated plane-source ; array was laid out with positions at 100-ft intervals in the form of a square ; 2000 ft on a side. For gound measurements a smaller

F. J. Davis; P. W. eds. Reinhardt



Radiometric characterization of IKONOS multispectral imagery  

Microsoft Academic Search

A radiometric characterization of Space Imaging's IKONOS 4-m multispectral imagery has been performed by a National Aeronautics and Space Administration (NASA) funded team from NASA Stennis Space Center, the University of Arizona Remote Sensing Group (U of A RSG), and South Dakota State University (SDSU). Both intrinsic radiometry and the effects of Space Imaging processing on radiometry were investigated. Relative

Mary Pagnutti; Robert E. Ryan; Michelle Kelly; Kara Holekamp; Vicki Zanoni; Kurtis Thome; Stephen Schiller



Absolute Radiometric Calibration of a Spectropolarimeter  

Microsoft Academic Search

Two identical instruments have been developed for use in the field to make radiometric measurements. They have been described as spectropolarimeters because of their ability to make polarization measurements in narrow spectral passbands. They have been used as part of a NASA sponsored project to monitor the spectral and temporal response of the thematic mapper satellites. These satellites allow many

Kenneth Robert Castle



Radiometric terrain correction of SPOT5 image  

NASA Astrophysics Data System (ADS)

Remote sensing SPOT5 images have been widely applied to the surveying of agriculture and forest resources and to the monitoring of ecology environment of mountain areas. However, the accuracy of land-cover classification of mountain areas is often influenced by the topographical shadow effect. Radiometric terrain correction is important for this kind of application. In this study, a radiometric terrain correction model which based on the rationale of moment matching was made in ERDAS IMAGINE by using the Spatial Modeler Language. Lanxi city in China as the study area, a SPOT5 multispectral image with the spatial resolution of 10 m of that mountain area was corrected by the model. Furthermore, in order to present the advantage of this new model in radiometric terrain correction of remote sensing SPOT5 image, the traditional C correction approach was also applied to the same area to see its difference with the result of the radiometric terrain correction model. The results show that the C correction approach keeps the overall statistical characteristics of spectral bands. The mean and the standard deviation value of the corrected image are the same as original ones. However, the standard deviation value became smaller by using the radiometric terrain correction model and the mean value changed accordingly. The reason of these changes is that before the correction, the histogram of the original image is represented as the 'plus-skewness distribution' due to the relief-caused shade effect, after the correction of the model, the histogram of the image is represented as the normal distribution and the shade effect of the relief has been removed. But as for the result of the traditional C approach, the skewness of the histogram remains the same after the correction. Besides, some portions of the mountain area have been over-corrected. So in my study area, the C correction approach can't remove the shade effect of the relief ideally. The results show that the radiometric terrain correction model based on the rationale of moment matching is an effective model to reduce the shade effect than the traditional C correction approach, especially in the complex undulation of mountain area with lots of shade effect. In other words, the traditional C correction approach will show the better result at the plain area with less shade effect. Besides, the accuracy of the DEM data and the registration accuracy between the image and the DEM data will also influence the final correction accuracy. In order to achieve the higher radiometric terrain correction, high spatial resolution DEM data is preferred.

Feng, Xiuli; Zhang, Feng; Wang, Ke



New radiometric and petrological constraints on the evolution of the Pichincha volcanic complex (Ecuador)  

Microsoft Academic Search

Fieldwork, radiometric (40Ar\\/39Ar and 14C) ages and whole-rock geochemistry allow a reconstruction of eruptive stages at the active, mainly dacitic, Pichincha Volcanic\\u000a Complex (PVC), whose eruptions have repeatedly threatened Quito, most recently from 1999 to 2001. After the emplacement of\\u000a basal lavas dated at ?1100 to 900 ka, the eruptive activity of the old Rucu Pichincha volcano lasted from ?850 ka to

Claude Robin; Pablo Samaniego; Jean-Luc Le Pennec; Michel Fornari; Patricia Mothes; Johannes van der Plicht



A LASER RIMS Instrument to Date Igneous Rocks using Rb-Sr and Measure Elemental Chemistry  

NASA Astrophysics Data System (ADS)

Deriving global estimates of planetary geochronology from cratering statistics remains difficult because estimates of the cratering rate for planets other than the Earth and the Moon are poorly constrained. Obtaining an in-situ radiometric date for the surface of a planet provides an important constraint on the rate of crater production. The result of such a measurement is twofold: first an exact date for a local region can be determined, and secondly, global geochronology from cratering statistics becomes significantly more robust. We are building an instrument to obtain a Rubidium-Strontium (Rb-Sr) date using a laser ablation (LA) resonance ionization (RI) technique. The instrument is attractive because it has virtually no moving parts, requires minimal sample preparation, and could work with existing coring and surface grinding technologies. An additional benefit of this technique is that it can obtain elemental abundances with an accuracy of 1% or better, which is sufficient for understanding normative mineralogy, weathering and exposure to water, and sample petrogenesis. Generating a Rb-Sr date using an isochron approach requires measuring 87Sr/86Sr with a precision of better than 0.1% (preferably 0.02%), and measuring 87Rb/86Sr with a precision of better than 1%. We present data that demonstrate that off-the-shelf instruments without any calibration or optimization can measure 87Sr/86Sr using RI to a precision of 0.14%, and 87Rb/86Sr using LA to 0.6%, suggesting that an optimized LA/RI technique could be used to successfully obtain an in-situ radiometric date.

Osterloo, M. M.; Anderson, F. S.; Whitaker, T.; Miller, G.; Young, D.; Mahoney, J.; Norman, M.



Dating Violence  

ERIC Educational Resources Information Center

|Dating violence is a form of student-on-student victimization and is a serious school safety issue. Research indicates that at a minimum, 10 percent of high school students are victims of dating violence in one form or another. Among female high school students that date, some data indicate that as many as 30 percent may be victims of dating…

Stader, David L.



Geochronological reconstruction of the Pleistocene evolution of the Sarre valley (France and Germany) using OSL and ESR dating techniques  

NASA Astrophysics Data System (ADS)

This paper focuses upon the Pleistocene terraces of the Sarre River, a right bank tributary of the Moselle River (NE France and SW Germany) flowing through the Vosges Massif, the eastern Paris Basin and the Rhenish Massif. Recent research has allowed the recognition of 12 well preserved alluvial terraces (Sa1 youngest to Sa12 oldest) between the present floodplain Sa0 and + 120 m relative height. The youngest terraces were dated using Optically Stimulated Luminescence (OSL). A first chronological framework was also provided for older terraces by Electron-Spin-Resonance (ESR) dating. The ages range between the end of the Early Pleistocene and the last glacial–interglacial cycle of the Late Pleistocene (ca. 1.1 Ma to 50 ka). Age ranges are consistent with the terrace elevation and stratigraphy, allowing correlation of the youngest terraces with established global climate cycles and with the younger terraces in the Moselle valley. In particular, an erosional period was recognised at the end of the Saalian, (end of MIS 6) suggesting that the terrace incision occurred at the cold-to-warm transition. This result contrasts with those obtained for the Moselle and Meurthe Rivers, where previous studies suggest that major incision took place at the beginning of the cold periods. The differences are attributed to a variable fluvial response to climate change which could relate to the presence or absence of glaciers in the upper catchment.

Cordier, Stéphane; Harmand, Dominique; Lauer, Tobias; Voinchet, Pierre; Bahain, Jean-Jacques; Frechen, Manfred



Shaft speleogenesis in Picos de Europa (North Spain): contribution of cave geomorphological mapping and U-Th dating techniques  

NASA Astrophysics Data System (ADS)

Picos de Europa Mountains are located in the North of Spain, showing more than 2,000 m thickness of Carboniferous limestone, in which the 14 % of the deepest shafts of the world are developed. This work concerns with a speleogenetical research carried out in two shafts (Torca Teyera and La Texa), using geomorphological maps and U-Th dating. The spatial distribution of cave geomorphological processes is established by the elaboration of geomorphological maps at a 1:500 scale, using genetical criteria for the classification of cave features. Cave temporal evolution is established from relative chronology between cave features and deposits and absolute dating of eight selected samples with U-series disintegration (234U/230Th). Torca Teyera Shaft (4° 52' 56.9'' W 43° 16' 33.1'' N) is a multilevel cave 4,438 m long and 738 m deep with three cave levels located at 1,300, 800-900 and 615 m.a.s.l. Cave levels are formed by phreatic and epiphreatic tubes strongly modified by vadose stream incision and breakdown processes. Fluvial and slackwater deposits, frequently covering breakdown deposits, are preserved up to 70 m over the active level and reach thickness of 3 m, appearing sometimes interbedded with flowstone. Flowstone levels usually fossilize fluvial deposits, being covered by other speleothems, as stalagmites and pool deposits. La Texa shaft (4° 58'1.3'' W 43° 15'45.2'' N), 2,231 m long and 215 m deep, presents only one cave level at 1,300 m a.s.l. formed by phreatic and epiphreatic tubes modified by vadose incision. Flowstones and dripstones are often covering fluvial (slackwater deposits) and gravity deposits, being the last the most frequently feature in shaft bottom. Eight speleothem samples from the two shafts were dated using the U-series disintegration method. Two flowstones from the middle cave level of Torca Teyera yielded ages of 185 and 238 ka, respectively. The age of a pool deposit sample and of a flowstone from the upper level exceeded 300 ka. On the other hand, three flowstone samples from Torca La Texa were dated between 156 and 181 ka, whereas the third sample is out of range of the U-Th method. Finally, one sample of a pool deposit found over flowstones is dated at 65 ka. These ages allowed us to establish a preliminary chronology of the speleogenetic events. The development of Torca Teyera and La Texa began at least during the Mid Pleistocene and in both cases it was controlled by the dropping of the base level. Fluvial activity and the grow of speleothems started prior 300 ka and both processes have been continuous up to at least 185 ka, at the middle level of Torca Teyera, and up to 156 ka at Torca La Texa. The most important flowstone of Torca La Texa precipitated at about 65 ka ago. These results are consistent to validate the previous speleogenetical models in the area, in which new shafts and canyons began to develop downwards cutting the old cave levels that remained perched during Alpine uplift.

Ballesteros, D.; Jiménez-Sánchez, M.; Giralt, S.; García-Sansegundo, J.; Sendra, G.



Thermoluminescence (TL) dating  

NSDL National Science Digital Library

Thermoluminescence (TL) dating is an important technique used to determine the ages of some ancient earth materials; in this case, sediments and certain ancient artifacts. TL energy is stored in the form of trapped electrons and quartz sand is the most commonly used mineral employed in the dating process. Topics which are discussed include basic principles of TL dating, sampling techniques and strategies, sample processing, dateable material, cost and turnaround time, other applications, and associated literature.

Price, David



Microwave radiometric signatures of temperature anomalies in tissue  

NASA Astrophysics Data System (ADS)

Because of its ability to measure the temperature-dependent power of electromagnetic radiation emitted from tissue down to several centimeters beneath the skin, microwave radiometry has long been of interest as a means for identifying the internal tissue temperature anomalies that arise from abnormalities in physiological parameters such as metabolic and blood perfusion rates. However, the inherent lack of specificity and resolution in microwave radiometer measurements has limited the clinical usefulness of the technique. The idea underlying this work is to make use of information (assumed to be available from some other modality) about the tissue configuration in the volume of interest to study and improve the accuracy of anomaly detection and estimation from radiometric data. In particular, knowledge of the specific anatomy and the properties of the overall measurement system enable determination of the signatures of localized physiological abnormalities in the radiometry data. These signatures are used to investigate the accuracy with which the location of an anomaly can be determined from radiometric measurements. Algorithms based on matches to entries in a signature dictionary are developed for anomaly detection and estimation. The accuracy of anomaly identification is improved when the coupling of power from the body to the sensor is optimized. We describe the design of a radiometer waveguide having dielectric properties appropriate for biomedical applications.

Kelly, Patrick; Sobers, Tamara; St. Peter, Benjamin; Siqueira, Paul; Capraro, Geoffrey



Radiocarbon dates on bones of extinct birds from Hawaii.  

PubMed Central

Bones from a stratified sedimentary deposit in the Puu Naio Cave site on Maui, Hawaiian Islands, reveal the late Holocene extinction of 19 species of birds. The age of the sediment and associated fauna was determined by direct radiocarbon dating (tandem particle accelerator-mass spectrometer; TAMS) of amino acids extracted from bones weighing as little as 450 mg. The 14C dates indicate that sediment has been accumulating in the lava tube for at least the last 7750 years, a suitable time frame for testing the hypothesis that Holocene extinction on islands began after human colonization. Despite growing evidence that a worldwide wave of extinctions coincided with human colonization of oceanic islands, little radiometric data have been available to date the extinction of most small fossil vertebrates on islands. The TAMS technique of dating purified collagen from the bones of small vertebrates could lead to vastly improved chronologies of extinction for oceanic islands where catastrophic mid- to late-Holocene extinction is expected or known to have occurred. Chronologies derived from nonarcheological sites that show continuous sedimentation, such as the Puu Naio Cave deposit, may also yield key evidence on the timing of earliest human settlement of Oceania. Images

James, H F; Stafford, T W; Steadman, D W; Olson, S L; Martin, P S; Jull, A J; McCoy, P C



Quaternary estimates of average slip-rates for active faults in the Mongolian Altay Mountains: the advantages and assumptions of multiple dating techniques  

NASA Astrophysics Data System (ADS)

Active faults in the Altay Mountains, western Mongolia, produce surface expressions that are generally well-preserved due to the arid central-Asian climate. Motion along the right-lateral strike-slip and oblique-reverse faults has displaced major river systems by kilometres over millions of years and there are clear scarps and linear features in the landscape along the surface traces of active fault strands. With combined remote sensing and field work, we have identified sites with surface features that have been displaced by tens of metres as a result of cumulative motion along faults. In an effort to accurately quantify an average slip-rate for the faults, we used multiple dating techniques to provide an age constraint for the displaced landscapes. At one site on the Olgiy fault, we applied 10Be terrestrial cosmogenic nuclides (TCN) and uranium-series geochronology on boulder tops and in-situ formed carbonate rinds, respectively. Based on a displacement of approximately 17m, and geochronology results that range from 20-60ky, we resolve a slip-rate of less than 1 mm/yr. We have also applied optically stimulated luminescence (OSL), 10Be TCN, and U-series methods on the Ar Hotol fault. Each of these dating techniques provides unique constraints on the relationship between the ‘age’ of a displaced surface and the actual amount of displacement, and each has inherent assumptions. We will consider the advantages and assumptions made in utilising these techniques in western Mongolia- e.g. U-series dating of carbonate rinds can provide a minimum age for alluvial fan deposition, and inheritance must be considered when using TCN techniques on boulder tops. This will be put into the context of estimating accurate and geologically relevant slip-rates, and improving our understanding of the active deformation of the Mongolian Altay.

Gregory, L. C.; Walker, R. T.; Thomas, A. L.; Amgaa, T.; Bayasgalan, G.; Amgalan, B.; West, A.



A radiometric Bode's Law: Predictions for Uranus  

SciTech Connect

The magnetospheres of three planets, Earth, Jupiter, and Saturn, are known to be sources of intense, nonthermal radio bursts. The emissions from these sources undergo pronounced long term intensity fluctuations that are caused by the solar wind interaction with the magnetosphere of each planet. Determinations by spacecraft of the low frequency radio spectra and radiation beam geometry now permit a reliable assessment of the overall efficiency of the solar wind in stimulating these emissions. Earlier estimates of how magnetospheric radio output scales with the solar wind energy input must be revised greatly, with the result that, while the efficiency is much lower than previously thought, it is remarkably uniform from planet to planet. The formulation of a radiometric Bode's Law from which a planet's magnetic moment is estimated from its radio emission output is presented. Applying the radiometric scaling law to Uranus, the low-frequency radio power is likely to be measured by the Voyager 2 spacecraft as it approaches this planet.

Desch, M.D.; Kaiser, M.L.



Hyperspectral imaging spectro radiometer improves radiometric accuracy  

NASA Astrophysics Data System (ADS)

Reliable and accurate infrared characterization is necessary to measure the specific spectral signatures of aircrafts and associated infrared counter-measures protections (i.e. flares). Infrared characterization is essential to improve counter measures efficiency, improve friend-foe identification and reduce the risk of friendly fire. Typical infrared characterization measurement setups include a variety of panchromatic cameras and spectroradiometers. Each instrument brings essential information; cameras measure the spatial distribution of targets and spectroradiometers provide the spectral distribution of the emitted energy. However, the combination of separate instruments brings out possible radiometric errors and uncertainties that can be reduced with Hyperspectral imagers. These instruments combine both spectral and spatial information into the same data. These instruments measure both the spectral and spatial distribution of the energy at the same time ensuring the temporal and spatial cohesion of collected information. This paper presents a quantitative analysis of the main contributors of radiometric uncertainties and shows how a hyperspectral imager can reduce these uncertainties.

Prel, Florent; Moreau, Louis; Bouchard, Robert; Bullis, Ritchie D.; Roy, Claude; Vallières, Christian; Levesque, Luc



The NPL Radiometric Realization of the Candela  

NASA Astrophysics Data System (ADS)

A radiometric realization of the S.I. base unit of photometry, the candela, as performed at the National Physical Laboratory, is described and the results compared with the scale established at NPL in 1937 and disseminated since 1948. The realization has been carried out in accordance with the radiometrically based redefinition given by the Conférence Générale des Poids et Mesures (CGPM) in 1979 which quantifies the spectral luminous efficacy of radiation at a specified frequency (540 × 1012 Hz) as 683 lumens per watt. The excellent performance of the siliconphotodiode photometers developed for this project is demonstrated, together with characteristics of the two types of lamp employed for preserving the results of the realization and methods for improving their alignment and reproducibility.

Goodman, T. M.; Key, P. J.



Fission track dating of kimberlitic zircons  

USGS Publications Warehouse

The only reliable method for dating kimberlites at present is the lengthy and specialized hydrothermal procedure that extracts 206Pb and 238U from low-uranium zircons. This paper describes a second successful method by fission track dating of large single-crystal zircons, 1.0-1.5 cm in dimension. The use of large crystals overcomes the limitations imposed in conventional fission track analysis which utilizes crushed fragments. Low track densities, optical track dispersion, and the random orientation of polished surfaces in the etch and irradiation cycle are effectively overcome. Fission track ages of zircons from five African kimberlites are reported, from the Kimberley Pool (90.3 ?? 6.5 m.y.), Orapa (87.4 ?? 5.7 and 92.4 ?? 6.1 m.y.), Nzega (51.1 ?? 3.8 m.y.), Koffiefontein (90.0 ?? 8.2 m.y.), and Val do Queve (133.4 ?? 11.5 m.y.). In addition we report the first radiometric ages (707.9 ?? 59.6 and 705.5 ?? 61.0 m.y.) of crustal zircons from kimberlites in northwest Liberia. The fission track ages agree well with earlier age estimates. Most of the zircons examined in this study are zoned with respect to uranium but linear correlations are established (by regression analysis) between zones of variable uranium content, and within zones of constant uranium content (by analysis of variance). Concordance between the fission track method and the U/Pb technique is established and we concluded that track fading from thermal annealing has not taken place. Kimberlitic zircons dated in this study, therefore, record the time of eruption. ?? 1983.

Haggerty, S. E.; Raber, E.; Naeser, C. W.



The radiometric characterization of AMSU-B  

Microsoft Academic Search

The Advanced Microwave Sounding Unit, AMSU, is being developed to fly on the new generation of NOAA polar orbiters due to be launched in the latter half of the 1990's. The UK Meteorological Office (UKMO) are procuring the high frequency component of AMSU (AMSU-B) with five channels in the range 88-191 GHz. In order to determine the radiometric performance and

Roger W. Saunders; Timothy J. Hewison; Stephen J. Stringer; Nigel C. Atkinson



Radiometric characterization of AMSU-B  

Microsoft Academic Search

The Advanced Microwave Sounding Unit, AMSU, is being developed to fly on the new generation of NOAA polar orbiters due to be launched in the latter half of the 1990's. The U.K. Meteorological Office (UKMO) is procuring the high frequency component of AMSU (AMSU-B) with five channels in the range 88-191 GHz. In order to determine the radiometric performance and

Roger W. Saunders; Timothy J. Hewison; Stephen J. Stringer; Nigel C. Atkinson



Radiometric characterization of AMSU-B  

Microsoft Academic Search

The U.K. Meteorological Office is procuring the humidity sounding element of the Advanced Microwave Sounding Unit (i.e. AMSU-B). This consists of a five channel microwave radiometer with channels centered at 89, 150, 183+\\/- 1, 183+\\/- 3, & 183+\\/- 7 GHz with a field of view of nominally 1.1 degree(s) (i.e. 15 km footprint at nadir). To characterize the radiometric behavior

Roger W. Saunders; T. J. Hewison; N. C. Atkinson; S. J. Stringer



Radiometric Calibration of the EOS ASTER Instrument  

Microsoft Academic Search

Pre-flight and in-flight radiometric calibration plans are described for a multispectral optical imager of high spatial resolution for remote sensing of land surfaces and clouds from orbit, which will be launched in 1998 on NASA's EOS-AM1 spacecraft. The instrument named ASTER consists of three radiometers for three separate spectral regions, the visible and near-infrared radiometer (VNIR), the shortwave infrared radiometer

F. Sakuma; A. Ono



Dating Violence  


... Parents of Teens Crime, Teens, and Trauma Assault Bullying and Harassment Child Sexual Abuse Dating Violence Sexual ... Parents of Teens Crime, Teens, and Trauma Assault Bullying and Harassment Child Sexual Abuse Dating Violence Sexual ...


Radiocarbon Dating  

SciTech Connect

Radiocarbon dating can be used to determine the age of objects that contain components that were once alive. In the case of human remains, a radiocarbon date can distinguish between a crime scene and an archeological site. Documents, museum artifacts and art objects can be dated to determine if their age is correct for the historical context. A radiocarbon date does not confirm authenticity, but it can help identify a forgery.

Buchholz, B A



First Date  

Microsoft Academic Search

Studies indicate that most people begin dating around the ages of 13 to 15, but not much else is known about this important rite of passage that adolescents go through. This article reports on research designed to study the first date. The questionnaire, administered to 128 college students, asked them to respond to 15 questions about their first date when

Connie Lizotte Spreadbury



Enhanced radiometric detection of Mycobacterium paratuberculosis by using filter-concentrated bovine fecal specimens  

SciTech Connect

A commercial radiometric medium, BACTEC 12B, was modified by addition of mycobactin, egg yolk suspension, and antibiotics (vancomycin, amphotericin B, and nalidixic acid). Decontaminated bovine fecal specimens were filter concentrated by using 3-microns-pore-size, 13-mm-diameter polycarbonate filters, and the entire filter was placed into the radiometric broth. Comparison of the radiometric technique with conventional methods on 603 cattle from 9 Mycobacterium paratuberculosis-infected herds found that of 75 positive specimens, the radiometric technique detected 92% while conventional methods detected 60% (P less than 0.0005). Only 3.9% of radiometric cultures were contaminated. To measure the effect of filter concentration of specimens on the detection rate, 5 cattle with minimal and 5 with moderate ileum histopathology were sampled weekly for 3 weeks. M. paratuberculosis was detected in 33.3% of nonfiltered specimens and 76.7% of filtered specimens (P less than 0.005). Detection rates were directly correlated with the severity of disease, and the advantage of specimen concentration was greatest on fecal specimens from cattle with low-grade infections. Detection times were also correlated with infection severity: 13.4 +/- 5.9 days with smear-positive specimens, 27.9 +/- 8.7 days with feces from cows with typical subclinical infections, and 38.7 +/- 3.8 days with fecal specimens from cows with low-grade infections. Use of a cocktail of vancomycin, amphotericin B, and nalidixic acid for selective suppression of nonmycobacterial contaminants was better than the commercial product PANTA (Becton Dickinson Microbiologic Systems, Towson, Md.) only when specimens contained very low numbers of M. paratuberculosis.

Collins, M.T.; Kenefick, K.B.; Sockett, D.C.; Lambrecht, R.S.; McDonald, J.; Jorgensen, J.B. (Univ. of Wisconsin, Madison (USA))




USGS Publications Warehouse

This preliminary report examines those radiometric characteristics of the Landsat 4 Thematic Mapper (TM) that can be established without absolute calibration of spectral data. Analysis is based largely on radiometrically raw (B type) data of three daytime and two nighttime scenes; in most scenes, a set of 512 lines were examined on an individual-detector basis. Subscenes selected for uniform-radiance were used to characterize subtle radiometric differences and noise problems.

Kieffer, Hugh, H.; Eliason, Eric, M.; Chavez, Jr. , Pat, S.



Radiocarbon Dating.  

National Technical Information Service (NTIS)

The report discusses radiocarbon dating. The cosmic ray production of new atoms in matter is the basis of radiocarbon dating. In this case the atom is carbon of mass fourteen made from the most abundant atom in air -- nitrogen of mass fourteen. Radiocarbo...

W. F. Libby



A simple radiometric in vitro assay for acetylcholinesterase inhibitors  

SciTech Connect

A radiometric method for screening acetylcholinesterase inhibitors has been described. The method is based on the production of (/sup 14/C)carbon dioxide from the hydrolysis of acetylcholine. The inhibitory concentration at 50% (IC50) values for several known acetylcholinesterase inhibitors were in agreement with literature values. The new radiometric method is simple, inexpensive, and has the potential for automation.

Guilarte, T.R.; Burns, H.D.; Dannals, R.F.; Wagner, H.N. Jr.



Radiometric comparison of the LANDSAT5 TM and MSS sensors  

Microsoft Academic Search

This paper analyses the radiometric accuracy of LANDSAT-5 Thematic Mapper (TM) data and of LANDSAT-5 Multispectral Scanner (MSS) data, using concurrent TM and MSS images recorded simultaneously over the city of Montreal, Quebec, Canada. The data sets were obtained from the Canada Centre for Remote Sensing (CCRS), and have been preprocessed for geometric correction, and for radiometric 23calibration utilizing the




Dynamic Wiener filters for small-target radiometric restoration  

Microsoft Academic Search

Small-target radiometric restoration (STRR) seeks to correct imagery for the blurring effects of the sensor and allow more accurate radiometric values to be extracted. This paper describes an STRR approach suitable for imaging systems whose point-spread functions are known and slowly varying across the image. The approach features a dynamic Wiener filter based on the physical properties of the target

Russel P. Kauffman; James P. Helferty; Mark R. Blattner



Evaluating radiometric consistency between Suomi NPP VIIRS and NOAA-19 AVHRR using extended simultaneous nadir overpass in the low latitudes  

NASA Astrophysics Data System (ADS)

The Visible Infrared Imaging Radiometer Suite (VIIRS) onboard Suomi NPP has been undergoing extensive calibration/validation efforts in order to produce high quality weather and climate quality satellite data products. VIIRS absolute radiometric accuracy and consistency can be achieved by inter-comparing its measurements with other well calibrated instruments such as AQUA MODIS. VIIRS moderate resolution bands compared with matching MODIS bands at North African desert has shown that that the radiometric bias for channels M-1 through M-8 is less than 2%. VIIRS is a follow on mission for MODIS and AVHRR. In an effort to evaluate radiometric consistency of VIIRS with multi-decadal global earth observations from AVHRR, this study uses SNO-x approach to inter-compare NOAA-19 AVHRR measurements with VIIRS at North African desert over VNIR region. The radiometric consistency is evaluated and the uncertainty due to spectral differences is quantified using hyperspectral measurements from EO-1 Hyperion. In addition, the Antarctica Dome C site is used to estimate radiometric bias between AVHRR and VIIRS. AVHRR bias relative to VIIRS at Dome C is well within 0.5% for band 1 and 2% for band 2 compared to bias estimated at the desert sites using the SNO-x technique.

Uprety, Sirish; Cao, Changyong; Blonski, Slawomir; Shao, Xi




Microsoft Academic Search

Glacier fluctuations and palaeoclimatic oscillations during the Late Quaternary in Val di Rabbi (Trentino, Northern Italy) were reconstructed using a combination of absolute dating techniques ( 14 C and 10 Be) and soil chemical characterisation. Extraction and dating of the stable fraction of soil organic matter (SOM) could give valuable information about the minimum age of soil formation and contributed

Filippo Favilli; Markus Egli; Dagmar Brandova; Susan Ivy-Ochs; Peter W. Kubik; Paolo Cherubini; Wilfried Haeberli



Application of sup 40 Ar/ sup 39 Ar laser-probe and step-heating techniques to the dating of diagenetic K-feldspar overgrowths  

SciTech Connect

The feasibility of determining the age of diagenetic K-feldspar overgrowths utilizing {sup 40}Ar/{sup 39}Ar step-heating and laser-probe dating techniques was tested on samples from the Lower Cretaceous arkoses of the Angola offshore basin. A previous study of these samples combining cathodoluminescence and K/Ar dating indicated that the K-feldspar diagenetic overgrowths were 98 {plus minus} 16 Ma and the detrital cores were 516 {plus minus} 26 Ma. Detrital and diagenetic K-feldspars from the arkoses studied appear to release their Ar over similar ranges of temperature. Partial laser fusion of individual overgrown grains, using low-energy, short-duration laser pulses carefully focused on the overgrowth, yielded mixed ages, with Ar contributed through the core-overgrowth boundary is not responsible for partial degassing of the core. Rather, beam scattering along intragrain structural defects and incipient melting of the core must occur. A more successful approach involved total laser fusion of individual grains from the overgrowth concentrates, which were physically separated from their detrital core. One limitation of this approach was that because of the young age and the small size of the diagenetic feldspar, simultaneous fusion of several grains was required for accurate age determination. The authors results suggest that future investigations will greatly benefit from the use of on-line cathodoluminescence capability to reduce the possibility of contamination by detrital material and the use of a laser beam whose wavelength is strongly absorbed by diagenetic K-feldspar.

Girard, J.P. (Case Western Reserve Univ., Cleveland, OH (United States)); Onstott, T.C. (Princeton Univ., NJ (United States))



Date: 000147  

Center for Food Safety and Applied Nutrition (CFSAN)

Text Version... 1. Date: August 1,2007 2. Name of ApplicanUNotifier: ExxonMobil Chemical Company 3. Address: PO Box 3140 Edison, NJ 08818-3140 ... More results from


1. Date:  

Center for Food Safety and Applied Nutrition (CFSAN)

Text Version... 1. Date: December 18,2007 2. Name of Submitter: Siltech Corporation 3. Address: 225 Wicksteed Avenue Toronto, Ontario, CANADA M4H 1G5 ... More results from


Virtual Dating  

NSDL National Science Digital Library

This is an interactive exercise about Geologic Time. It focuses on how geologists and archaeologists determine the ages of rocks and ancient artifacts. This is a beta release of an instructional activity still under development. Virtual Dating contains two modules as well as a demonstration version. One module is Virtual Dating Isochron for rocks and minerals and the other is Virtual Dating Radiocarbon (Carbon-14). The interactive modules involve the students in exploring data and background information and answering questions as they move through the activity. An answer checking and feedback function is employed. There is also a Virtual Dating Demo if you want to do a quick run-through of the activity without answer checking enabled.

Novak, Gary



Identification of Worldwide Optimal Pseudo-Invariant Calibration Sites for Post-Launch Radiometric Calibration of Earth Observation Satellite Sensors  

Microsoft Academic Search

The primary objective of this project was to identify extremely stable sites on the Earth's surface known as Pseudo-Invariant Calibration Sites (PICS). A recently developed technique for monitoring the long term stability of earth observing satellite sensors was based on using PICS for detecting trends in the radiometric response of these instruments. In a manner analogous to using a known

Bikash Basnet



Radiometric methods for rapid diagnosis of viral infection. Report no. 4 (final). February 1, 1975January 31, 1978  

Microsoft Academic Search

Three radiometric techniques were investigated for monitoring the effects of herpes simplex virus type I and II and cytomegalovirus on the metabolism of human embryonic lung fibroblast (WI-38) monolayers. The study was based on the hypothesis that (1) early metabolic effects of virus on the cell culture can be used as an indication for the presence of virus; (2) the

H. N. Wagner; M. Tsan



A double-spike method for K-Ar measurement: A technique for high precision in situ dating on Mars and other planetary surfaces  

NASA Astrophysics Data System (ADS)

A new method for K-Ar dating using a double isotope dilution technique is proposed and demonstrated. The method is designed to eliminate known difficulties facing in situ dating on planetary surfaces, especially instrument complexity and power availability. It may also have applicability in some terrestrial dating applications. Key to the method is the use of a solid tracer spike enriched in both 39Ar and 41K. When mixed with lithium borate flux in a Knudsen effusion cell, this tracer spike and a sample to be dated can be successfully fused and degassed of Ar at <1000 °C. The evolved 40Ar?/39Ar ratio can be measured to high precision using noble gas mass spectrometry. After argon measurement the sample melt is heated to a slightly higher temperature (˜1030 °C) to volatilize potassium, and the evolved 39K/41K ratio measured by Knudsen effusion mass spectrometry. Combined with the known composition of the tracer spike, these two ratios define the K-Ar age using a single sample aliquot and without the need for extreme temperature or a mass determination. In principle the method can be implemented using a single mass spectrometer.Experiments indicate that quantitative extraction of argon from a basalt sample occurs at a sufficiently low temperature that potassium loss in this step is unimportant. Similarly, potassium isotope ratios measured in the Knudsen apparatus indicate good sample-spike equilibration and acceptably small isotopic fractionation. When applied to a flood basalt from the Viluy Traps, Siberia, a K-Ar age of 351 ± 19 Ma was obtained, a result within 1% of the independently known age. For practical reasons this measurement was made on two separate mass spectrometers, but a scheme for combining the measurements in a single analytical instrument is described. Because both parent and daughter are determined by isotope dilution, the precision on K-Ar ages obtained by the double isotope dilution method should routinely approach that of a pair of isotope ratio determinations, likely better than ±5%.

Farley, K. A.; Hurowitz, J. A.; Asimow, P. D.; Jacobson, N. S.; Cartwright, J. A.



Geometric and radiometric properties of DMC-nigeriasat-1  

NASA Astrophysics Data System (ADS)

The geometric and radiometric quality of the DMC-Nigeriasat-1, including sensor inter-calibration of datasets acquired at different dates in the year 2005, were evaluated over different targets in the UK. The purpose of this study is to test the consistency and adequacy of the DMC-Nigeriasat-1 datasets for quantitative analysis of time-series environmental change. The results show that DMC-Nigeriasat-1 has a good geometric fidelity with root mean square errors (RMSE) of less than 0.5 pixels, strong linearity and high coefficient of determination, R 2, of the sensor inter-calibration equations with mean value of 0.87, which is promising since they were statistically significant at 95% confidence level. The results obtained indicate that the DMC satellites, having the characteristics of high temporal resolution of daily revisits and spatial resolution of 32 m, may provide the first time-series datasets at medium spatial resolution for applications in climate change assessment, quantitative phenology, as well as agricultural and natural resource management.

Ogunbadewa, Ebenezer Y.



Radiometric age determination of tonsteins and stratigraphic constraints for the Lower Permian coal succession in southern Paraná Basin, Brazil  

Microsoft Academic Search

Ion microprobe (SHRIMP II) dating of zircons from tonsteins interbedded with coal seams from the Candiota and Faxinal coalfields (Early Permian, Rio Bonito Formation, Paraná Basin, Brazil) is presented. The mean ages obtained (290.6±1.5 Ma) are more precise than previously published intervals. Calibrations of chronostratigraphic data with radiometric ages show that the main coal succession from the southern Basin is constrained

Margot Guerra-Sommer; Miriam Cazzulo-Klepzig; João Orestes Schneider Santos; Léo Afraneo Hartmann; João Marcelo Ketzer; Milton Luis Laquintinie Formoso



Radiometric calibration of an airborne multispectral scanner  

NASA Astrophysics Data System (ADS)

The absolute radiometric calibration of the NS001 Thematic Mapper Simulator reflective channels was examined based on laboratory tests and in-flight comparisons to ground measurements. The NS001 data are calibrated in-flight by reference to the NS001 internal integrating sphere source. This source's power supply or monitoring circuitry exhibited greater instability in-flight during 1988-1989 than in the laboratory. Extrapolating laboratory behavior to in-flight data resulted in 7-20 percent radiance errors relative to ground measurements and atmospheric modeling. Assuming constancy in the source's output between laboraotry and in-flight resulted in generally smaller errors. Upgrades to the source's power supply and monitoring circuitry in 1990 improved its in-flight stability, though in-flight ground reflectance based calibration tests have not yet been performed.

Markham, Brian L.; Ahmad, Suraiya P.; Jackson, Ray D.; Moran, M. S.; Biggar, Stuart F.; Gellman, David I.; Slater, Philip N.



KAr dating of rocks on Mars: Requirements from Martian meteorite analyses and isochron modeling  

Microsoft Academic Search

Radiometric age dating of Martian rocks and surfaces at known locations for which crater densities can be determined is highly desirable in order to fully understand Martian history. Performing K-Ar age dating of igneous rocks on Mars by robots, however, presents technical challenges. Some of these challenges can be defined by examining Ar-Ar data acquired on Martian meteorites, and others

Donald D. BOGARD



Precision radiometric surface temperature (PRST) sensor  

NASA Astrophysics Data System (ADS)

There is a need for a Precision Radiometric Surface Temperature (PRST) measurement capability that can achieve noncontact profiling of a sample's surface temperature when heated dynamically during laser processing, aerothermal heating or metal cutting/machining. Target surface temperature maps within and near the heated spot provide critical quantitative diagnostic data for laser-target coupling effectiveness and laser damage assessment. In the case of metal cutting, this type of measurement provides information on plastic deformation in the primary shear zone where the cutting tool is in contact with the workpiece. The challenge in these cases is to measure the temperature of a target while its surface's temperature and emissivity are changing rapidly and with incomplete knowledge of how the emissivity and surface texture (scattering) changes with temperature. Bodkin Design and Engineering, LLC (BDandE), with partners Spectral Sciences, Inc. (SSI) and Space Computer Corporation (SCC), has developed a PRST Sensor that is based on a hyperspectral MWIR imager spanning the wavelength range 2-5 ?m and providing a hyperspectral datacube of 20-24 wavelengths at 60 Hz frame rate or faster. This imager is integrated with software and algorithms to extract surface temperature from radiometric measurements over the range from ambient to 2000K with a precision of 20K, even without a priori knowledge of the target's emissivity and even as the target emissivity may be changing with time and temperature. In this paper, we will present a description of the PRST system as well as laser heating test results which show the PRST system mapping target surface temperatures in the range 600-2600K on a variety of materials.

Daly, James T.; Roberts, Carson; Bodkin, Andrew; Sundberg, Robert; Beaven, Scott; Weinheimer, Jeffrey



Intraband radiometric performance of the Landsat Thematic Mappers.  

USGS Publications Warehouse

Radiometric characteristics have been examined of the Landsat-4 and Landsat-5 Thematic Mappers (TMs) that can be established without absolute calibration of spectral data. This analysis is based on radiometrically and geometrically raw (B-type) data of both uniform (flat-field) and high-contrast scenes. Subscenes selected for uniform radiance were used to characterized subtle radiometric differences and noise problems. Although the general performance of the Thematic Mappers is excellent, various anomalies that have a magnitude of a few digital levels (DN) or less are quantified. -from Authors

Kieffer, H. H.; Cook, D. A.; Eliason, E. M.; Eliason, P. T.



Radiocarbon dating accuracy improved  

NASA Astrophysics Data System (ADS)

Scientists have extended the accuracy of carbon-14 (14C) dating by correlating dates older than 8,000 years with uranium-thorium dates that span from 8,000 to 30,000 years before present (ybp, present = 1950). Edouard Bard, Bruno Hamelin, Richard Fairbanks and Alan Zindler, working at Columbia University's Lamont-Doherty Geological Observatory, dated corals from reefs off Barbados using both 14C and uranium-234/thorium-230 by thermal ionization mass spectrometry techniques. They found that the two age data sets deviated in a regular way, allowing the scientists to correlate the two sets of ages. The 14C dates were consistently younger than those determined by uranium-thorium, and the discrepancy increased to about 3,500 years at 20,000 ybp.


Hate Date  

Microsoft Academic Search

This is a story about a man who revenge dates women for hire because he thinks women are only out to hurt men. Bryce has something of an allergic reaction anytime he tries to talk to a woman unless it is under a completely false pretense, in which case he is a woman's worst nightmare: A charming, handsome, heartbreaker. His

Mike Gemme



Radiometric detection of yeasts in blood cultures of cancer patients  

SciTech Connect

During a 12-month period, 19,457 blood cultures were collected. Yeasts were isolated from 193 cultures derived from 76 cancer patients. Candida albicans or Candida tropicalis accounted for 79% of isolates. Of the three methods compared, the radiometric method required 2.9 days to become positive, blind subculture required 2.6 days, and Gram stains required 1 day. However, the radiometric method was clearly superior in detecting positive cultures, since 73% of all cultures were first detected radiometrically, 22% were detected by subculture, and only 5% were detected by Gram stain. Although 93% of the isolates were detected by aerobic culture, five (7%) isolates were obtained only from anaerobic cultures. Seven days of incubation appear to be sufficient for the radiometric detection of yeasts.

Hopfer, R.L.; Orengo, A.; Chesnut, S.; Wenglar, M.



Radiometric detection of Haemophilus in simulated blood cultures.  


The radiometric detection of various Haemophilus species was studied in simulated blood cultures and in blood culture media without added blood, but supplemented with nicotinamide-adenine dinucleotide (NAD) or hemin, or both. Haemophilus aphrophilus was the only species studied that was radiometrically detectable without added blood or NAD. All other species studied (Haemophilus influenzae, Haemophilus parainfluenzae, Haemophilus haemolyticus, and Haemophilus parahaemolyticus) required either added NAD, whole blood, or washed blood cells for growth and radiometric detection. The results of this study and extensive experience with clinical specimens show that the radiometric system is an effective means of rapidly detecting Haemophilus in blood cultures, but it is essential that it be used in conjunction with a subculture three to five days after inoculation. PMID:218444

Sadowski, G E; Robertson, R G



In-Flight Absolute Radiometric Calibration of the Thematic Mapper.  

National Technical Information Service (NTIS)

The TM multispectral scanner system was calibrated in an absolute manner before launch. To determine the temporal changes of the absolute radiometric calibration of the entire system, spectroradiometric measurements of the ground and the atmosphere were m...

K. R. Castle R. G. Holm C. J. Kastner J. M. Palmer P. N. Slater



Radiometric correction of RapidEye imagery using the on-orbit side-slither method  

NASA Astrophysics Data System (ADS)

RapidEye AG is a commercial provider of geo-spatial information products derived from Earth observation image data. The source of this data is the RapidEye constellation of five low-earth-orbit imaging satellites. Image data from satellite electro-optical sensors contains spatial artifacts such as banding and streaking that are caused by detector responsivity variations, factors related to image formation, and the space environment. This paper describes the results of a relative radiometric calibration and correction campaign that was conducted between March and July 2011 using the side-slither technique. Radiometrically uniform terrestrial scenes that included desert and snow/ice regions were imaged with a RapidEye sensor in a ninety-degree yaw orbital configuration. In this configuration each detector on the focal plane was positioned parallel to the ground-track direction thereby exposing each detector to the light reflected from the same segment of the ground. This maneuver produced a radiometrically flat-field input to the sensor so that the relative response of each detector was determined for the same exposure level. Side-slither derived detector correction parameters were then used to improve the quality of RapidEye imagery that contained noticeable spatial artifacts. A significant improvement in image correction was achieved when compared to our standard correction procedures.

Anderson, Cody; Naughton, Denis; Brunn, Andreas; Thiele, Michael



Multiangle Imaging SpectroRadiometer (MISR) ancillary radiometric product  

Microsoft Academic Search

The in-flight calibration program for the EOS-AM1 Multi- angle Imaging SpectroRadiometer (MISR) includes on-orbit calibration, characterization of instrument properties and a calibration integrity process. One of the primary activities of the in-flight radiometric calibration and characterization group responsible for the MISR calibration program at the Science Computing Facility is to produce a data file called the Ancillary Radiometric Product (ARP).

Robert M. Woodhouse; Carol J. Bruegge; Barbara J. Gaitley; Ghobad Saghri; Nadine L. Chrien



Lessons learned from the AIRS pre-flight radiometric calibration  

NASA Astrophysics Data System (ADS)

The Atmospheric Infrared Sounder (AIRS) instrument flies on the NASA Aqua satellite and measures the upwelling hyperspectral earth radiance in the spectral range of 3.7-15.4 ?m with a nominal ground resolution at nadir of 13.5 km. The AIRS spectra are achieved using a temperature controlled grating spectrometer and HgCdTe infrared linear arrays providing 2378 channels with a nominal spectral resolution of approximately 1200. The AIRS pre-flight tests that impact the radiometric calibration include a full system radiometric response (linearity), polarization response, and response vs scan angle (RVS). We re-derive the AIRS instrument radiometric calibration coefficients from the pre-flight polarization measurements, the response vs scan (RVS) angle tests as well as the linearity tests, and a recent lunar roll test that allowed the AIRS to view the moon. The data and method for deriving the coefficients is discussed in detail and the resulting values compared amongst the different tests. Finally, we examine the residual errors in the reconstruction of the external calibrator blackbody radiances and the efficacy of a new radiometric uncertainty model. Results show the radiometric calibration of AIRS to be excellent and the radiometric uncertainty model does a reasonable job of characterizing the errors.

Pagano, Thomas S.; Aumann, Hartmut H.; Weiler, Margie



Luminescence dating of last interglacial coastal deposits of Cyprus: overcoming quartz complications by elevated-temperature Infrared Stimulated Luminescence (IRSL) from feldspars.  

NASA Astrophysics Data System (ADS)

When dating samples from a coastal area of South East Cyprus it was revealed that the OSL characteristics of quartz were problematic giving highly scattered and unexpectedly low Des. Deconvolution of the CW-OSL signals showed that the most likely cause for these underestimations was due to a weak fast component, accompanied by a thermally unstable medium component. Fortunately, recent advancements in luminescence dating have made possible the use of feldspar IRSL instead. Particularly, the "post-infrared infrared stimulated luminescence", known as p-IRIR not only compensates for the problems associated with quartz but also saves all benefits of feldspar dating, such as intense signals under laboratory stimulation and considerably higher saturation levels, and additionally deals with the problem of anomalous fading. The potential application of an elevated temperature p-IRIR SAR protocol developed by Thiel et al. (2011) for feldspar is examined for seven late Pleistocene coastal aeolian and littoral samples from a coastal site in south east Cyprus. Published radiometric ages from the same site put additional significance on evaluating the effectiveness of p-IRIR dating, as independent age control on the latter remains scarce in literature to date. Indeed, p-IRIR and published radiometric ages for Cyprus are in a good agreement. Ages are in stratigraphic order assigning the formation of the studied deposits to the Last Interglacial stage. The p-IRIR dating was concluded to be a reliable technique for establishing precise and accurate chronologies and a trustworthy alternative to quartz optically stimulated luminescence (OSL) dating when the quartz luminescence characteristics are unsuitable.

Tsakalos, Evangelos; Athanassas, Constantin; Bassiakos, Yannis



The radiometric characterization of AMSU-B  

SciTech Connect

The Advanced Microwave Sounding Unit, AMSU, is being developed to fly on the new generation of NOAA polar orbiters due to be launched in the latter half of the 1990`s. The U.K. Meteorological Office (UKMO) are procuring the high frequency component of AMSU (AMSU-B) with five channels in the range 88--191 GHz. In order to determine the radiometric performance and verify the method for calibration of AMSU-B an extensive series of tests have been performed by the UKMO on the engineering and three flight models. The instruments were placed in a 3 m thermal-vacuum chamber where their temperature could be controlled over the full range expected in orbit and an Earth target and a space target could be viewed. For the first flight model the measured Ne{Delta}T values were all <1.1 K at the nominal instrument temperature using a 300 K target. Absolute calibration accuracy and linearity in response were measured to be well within the specification of 1 and 0.3 K, respectively. A small variation in the gain with scan angle was found and an empirical factor was derived to modify the inferred radiances to remove this effect. Measurements of the gain stability for each channel were also measured for simulated in-orbit conditions.

Saunders, R.W.; Hewison, T.J.; Stringer, S.J.; Atkinson, N.C. [U.K. Meteorological Office, Farnborough (United Kingdom)



Transportable high sensitivity small sample radiometric calorimeter  

SciTech Connect

A new small-sample, high-sensitivity transportable radiometric calorimeter, which can be operated in different modes, contains an electrical calibration method, and can be used to develop secondary standards, will be described in this presentation. The data taken from preliminary tests will be presented to indicate the precision and accuracy of the instrument. The calorimeter and temperature-controlled bath, at present, require only a 30-in. by 20-in. tabletop area. The calorimeter is operated from a laptop computer system using unique measurement module capable of monitoring all necessary calorimeter signals. The calorimeter can be operated in the normal calorimeter equilibration mode, as a comparison instrument, using twin chambers and an external electrical calibration method. The sample chamber is 0.75 in (1.9 cm) in diameter by 2.5 in. (6.35 cm) long. This size will accommodate most {sup 238}Pu heat standards manufactured in the past. The power range runs from 0.001 W to <20 W. The high end is only limited by sample size.

Wetzel, J.R.; Biddle, R.S.; Cordova, B.S.; Sampson, T.E.; Dye, H.R.; McDow, J.G.



A Cryogenic Radiometer for Absolute Radiometric Measurements  

NASA Astrophysics Data System (ADS)

The adoption in 1979 of a new definition of the candela, which permitted a detector-based approach to the realization of the unit, has emphasized the importance of high-accuracy absolute radiation detectors. This paper describes a new electrical-substitution absolute radiometer operating at 5 K, based on a standard commercial helium cryostat, which has been developed at NPL for optical radiant-power measurements. The principal advantages of operating the radiometer at liquid helium temperatures are that the detector can be a large, highly absorbing cavity (absorptivity 99.998%) and that exact equivalence of electrical and radiant heating can be clearly demonstrated. It will be the primary absolute detector for a new realization of the candela at NPL and will provide the basis for the development of a wider range of radiometric and spectroradiometric standards. The use of the radiometer to measure the radiant power of an intensity-stabilized laser source at the milliwatt level with an uncertainty of 4 parts in 105 is also described, together with its application in the determination of the responsivity of transfer-standard detectors, such as silicon photodiodes.

Martin, J. E.; Fox, N. P.; Key, P. J.



Blast investigation by fast multispectral radiometric analysis  

NASA Astrophysics Data System (ADS)

Knowledge regarding the processes involved in blasts and detonations is required in various applications, e.g. missile interception, blasts of high-explosive materials, final ballistics and IED identification. Blasts release large amount of energy in short time duration. Some part of this energy is released as intense radiation in the optical spectral bands. This paper proposes to measure the blast radiation by a fast multispectral radiometer. The measurement is made, simultaneously, in appropriately chosen spectral bands. These spectral bands provide extensive information on the physical and chemical processes that govern the blast through the time-dependence of the molecular and aerosol contributions to the detonation products. Multi-spectral blast measurements are performed in the visible, SWIR and MWIR spectral bands. Analysis of the cross-correlation between the measured multi-spectral signals gives the time dependence of the temperature, aerosol and gas composition of the blast. Farther analysis of the development of these quantities in time may indicate on the order of the detonation and amount and type of explosive materials. Examples of analysis of measured explosions are presented to demonstrate the power of the suggested fast multispectral radiometric analysis approach.

Devir, A. D.; Bushlin, Y.; Mendelewicz, I.; Lessin, A. B.; Engel, M.



Dating terrestrial impact events  

NASA Astrophysics Data System (ADS)

Systematic examination of dating results from various craters indicates that about 90% of the rocks affected by an impact preserve their pre-shock ages because shock and post-shock conditions are not sufficient to disturb isotopic dating systems. In the other 10% of target lithologies, various geochronometers show significant shock-induced effects. Major problems in dating impactites are caused by their non-equlibrated character. They often display complex textures, where differently shocked and unshocked phases interfinger on the sub-mm scale. Due to this, dating on whole rock samples or insufficiently pure mineral fractions often yielded ambiguous results that set broad age limits but are not sufficient to answer reliably questions such as a possible periodicity in cratering on Earth, or correlation of impact events with mass extinctions. Dating results from shock recovery experiments indicate that post-shock annealing plays the most important role in resetting isotopic clocks. Therefore, the major criterion for sample selection in and around craters is the post-shock thermal regime. Based on their different thermal evolution, the following geological impact formations can be distinguished: (1) the coherent impact melt layer, (2) allochthonous breccia deposits, (3) the crater basement, and (4) distant ejecta deposits. Samples of the coherent impact melt layer are the most suitable candidates for dating. Excellent ages of high precision can be obtained by internal Rb-Sr, and Sm-Nd isochrons, U-Pb analyses on newly crystallized accessory minerals, and K-Ar (Ar-39-Ar-40) dating of clast-free melt rocks. Fission track counting on glassy material has yielded correct ages, and paleomagnetic measurements have been successfully applied to post-Triassic craters. In the ideal case of a fast-cooling impact melt layer, all these different techniques should give identical ages. Allochthonous breccias contain shocked, unshocked, and/or glassy components in various proportions; and, hence, each of these ejecta deposits has its own individual thermal history, making sample evaluation difficult. Glassy melt particles in suevitic breccias are well suited for fission track and Ar-Ar dating. Weakly shocked material may yield reliable Ar-Ar and fission track ages, if formation temperatures were high, and cooling rates moderate. In contrast, highly shocked but rapidly cooled lithologies show only disturbed and not reset isotopic systems. For ejecta deposits and the crater wall of young craters, dating with cosmogenic nuclides is a new and powerful technique. Crater basement lithologies have a high potential in impact dating, although it has not been exploited so far. techniques are most promising, because both systems are easily reset at low temperatures. Good candidates for impact dating are long-term annealed rocks, even if shock metamorphic overprint is very weak. In addition, Ar-Ar dating dating of pseudotachylites appears promising. *In large impact structures, where high temperatures persist for long times, polymict 'footwall' breccias beneath the melt sheet are also appropriate for dating, using the isochron approach and U-Pb on accessory minerals. -Distant ejecta material have undergone very fast cooling, and the ejecta deposits have ambient formation temperatures. Among this material, tektites and impact melt glass are ideal objects for Ar-Ar and fission track impact dating. Dating on other material from distant ejecta deposits, such as U-Pb analyses on zircons, offers new possibilities. %Efforts to correlate distant ejecta with distinct craters critically depend on proper error assignment to a specific age. This aspect is illustrated on the K/T boundary example.

Deutsch, Alexander; Schaerer, Urs



U–Pb dating of detrital zircons for sediment provenance studies—a comparison of laser ablation ICPMS and SIMS techniques  

Microsoft Academic Search

New developments in U–Pb dating of zircons by laser ablation (LA) ICPMS are described and, for the first time, a direct comparison of detrital zircons dated by LA ICPMS and SIMS methods is presented. True real-time mass bias correction is made by aspirating a Tl\\/U tracer at the same time as laser ablation. The method is similar to that described

Jan Košler; Hege Fonneland; Paul Sylvester; Mike Tubrett; Rolf-Birger Pedersen



Radiometric validation of NASA's Ames Research Center's Sensor Calibration Laboratory  

SciTech Connect

The National Aeronautics and Space Administration's (NASA's) Ames Research Center's Airborne Sensor Facility (ASF) is responsible for the calibration of several airborne Earth-viewing sensor systems in support of NASA Earth Observing System (EOS) investigations. The primary artifact used to calibrate these sensors in the reflective solar region from 400 to 2500 nm is a lamp-illuminated integrating sphere source. In September 1999, a measurement comparison was made at the Ames ASF Sensor Calibration Facility to validate the radiometric scale, establish the uncertainties assigned to the radiance of this source, and examine its day-to-day repeatability. The comparison was one of a series of validation activities overseen by the EOS Calibration Program to ensure the radiometric calibration accuracy of sensors used in long-term, global, remote-sensing studies. Results of the comparison, including an evaluation of the Ames Sensor Calibration Laboratory (SCL) measurement procedures and assigned radiometric uncertainties, provide a validation of their radiometric scale at the time of the comparison. Additionally, the maintenance of the radiance scale was evaluated by use of independent, long-term, multiyear radiance validation measurements of the Ames sphere source. This series of measurements provided an independent assessment of the radiance values assigned to integrating sphere sources by the Ames SCF. Together, the measurements validate the SCF radiometric scale and assigned uncertainties over the time period from September 1999 through July 2003.

Brown, Steven W.; Johnson, B. Carol; Biggar, Stuart F.; Zalewski, Edward F.; Cooper, John; Hajek, Pavel; Hildum, Edward; Grant, Patrick; Barnes, Robert A.; Butler, James J



Urease testing of mycobacteria with BACTEC radiometric instrumentation  

SciTech Connect

A total of 140 mycobacterial isolates from patients treated at Fitzsimons Army Medical Center or the National Jewish Hospital and Research Center and from animal specimens submitted to the National Veterinary Services Laboratory were tested by using a urease procedure modified for use with a BACTEC model 301. Mycobacterial suspensions were prepared by using Middlebrook 7H10 Tween broth. Of the 98 mycobacteria isolates which were urease positive utilizing standard methodology, all were positive using the radiometric procedures. Similarly, all 42 urease-negative isolates were also negative employing the new methodology. Although maximum radiometric readings were observed at 48 h, all positive strains were readily identified 24 h after inoculation without sacrificing either test sensitivity or specificity. Thus, urease testing of mycobacteria, using the modified BACTEC radiometric methodology, was as sensitive, as specific, and more rapid than conventional methods.

Damato, J.J.; Collins, M.T.; McClatchy, J.K.



Thermochronology of economic mineral deposits: dating the stages of mineralization at Panasqueira, Portugal, by high-precision 40Ar/ 39Ar age spectrum techniques on muscovite  

USGS Publications Warehouse

This study is an example of a new and powerful application of 40Ar/39Ar age spectrum dating of muscovite. It is now possible to establish time constraints necessary for solving some of the long-standing problems in economic geology. Beyond this, the unique geologic situation of Panasqueira has allowed us to quantify the thermal characteristics of muscovite. Published fluid inclusion data have been used to estimate a muscovite argon closure temperature of ~325??C during rapid cooling or short reheating and a temperature of ~270??C during slow cooling or extended reheating. Argon-loss patterns displayed by all dated muscovites resulted from reheating after original closure; the mechanism for this argon loss appears to have been argon transport by volume diffusion. Thus, 40Ar/39Ar age spectrum dating of muscovite can be used to evaluate thermal conditions controlling argon diffusion as well as age, duration, and number of episodes of mineralization. -from Authors

Snee, L. W.; Sutter, J. F.; Kelly, W. C.



A revised radiometric calibration for the Hinode/EIS instrument  

NASA Astrophysics Data System (ADS)

An assessment of the in-flight radiometric calibration of the Hinode EUV Imaging Spectrometer (EIS) is presented. This is done with the line ratio technique applied to a wide range of observations of the quiet Sun, active regions, and flares from 2006 until 2012. The best diagnostic lines and the relevant atomic data are discussed in detail. Radiances over the quiet Sun are also considered, with comparisons with previous measurements. Some departures in the shapes of the ground calibration responsivities are found at the start of the mission. These shapes do not change significantly over time, with the exception of the shorter wavelengths of the EIS short-wavelength (SW) channel, which shows some degradation. The sensitivity of the SW channel at longer wavelengths does not show significant degradation, while that of the long-wavelength (LW) channel shows a significant degradation with time. By the beginning of 2010 the responsivity of the LW channel was already lower than the values measured on the ground by a factor of two or more. A first-order correction is proposed. With this correction, the main ratios of lines in the two channels become constant to within a relative 20%, and the He ii 256 Å radiances over the quiet Sun also become constant over time. This correction removes long-standing discrepancies for a number of lines and ions, in particular those involving the strongest Fe x, Fe xiii, Fe xiv, Fe xvii, and Fe xxiv lines, where discrepancies of factors of more than two were found. These results have important implications for various EIS science analyses, in particular for measurements of temperatures, emission measures and elemental abundances. Appendices are available in electronic form at

Del Zanna, G.



Mississippi Valley-type lead-zinc deposits through geological time: Implications from recent age-dating research  

USGS Publications Warehouse

Remarkable advances in age dating Mississippi Valley-type (MVT) lead-zinc deposits provide a new opportunity to understand how and where these deposits form in the Earth's crust. These dates are summarized and examined in a framework of global tectonics, paleogeography, fluid migration, and paleoclimate. Nineteen districts have been dated by paleomagnetic and/or radiometric methods. Of the districts that have both paleomagnetic and radiometric dates, only the Pine Point and East Tennessee districts have significant disagreements. This broad agreement between paleomagnetic and radiometric dates provides added confidence in the dating techniques used. The new dates confirm the direct connection between the genesis of MVT lead-zinc ores with global-scale tectonic events. The dates show that MVT deposits formed mainly during large contractional tectonic events at restricted times in the history of the Earth. Only the deposits in the Lennard Shelf of Australia and Nanisivik in Canada have dates that correspond to extensional tectonic events. The most important period for MVT genesis was the Devonian to Permian time, which corresponds to a series of intense tectonic events during the assimilation of Pangea. The second most important period for MVT genesis was Cretaceous to Tertiary time when microplate assimilation affected the western margin of North America and Africa-Eurasia. There is a notable paucity of MVT lead-zinc ore formation following the breakup of Rodinia and Pangea. Of the five MVT deposits hosted in Proterozoic rocks, only the Nanisivik deposit has been dated as Proterozoic. The contrast in abundance between SEDEX and MVT lead-zinc deposits in the Proterozoic questions the frequently suggested notion that the two types of ores share similar genetic paths. The ages of MVT deposits, when viewed with respect to the orogenic cycle in the adjacent orogen suggest that no single hydrologic model can be universally applied to the migration of the ore fluids. However, topographically driven models best explain most MVT districts. The migration of MVT ore fluids is not a natural consequence of basin evolution; rather, MVT districts formed mainly where platform carbonates had some hydrological connection to orogenic belts. There may be a connection between paleoclimate and the formation of some MVT deposits. This possible relationship is suggested by the dominance of evaporated seawater in fluid inclusions in MVT ores, by hydrological considerations that include the need for multiple-basin volumes of ore fluid to form most MVT districts, and the need for adequate precipitation to provide sufficient topographic head for topographically-driven fluid migration. Paleoclimatic conditions that lead to formation of evaporite conditions but yet have adequate precipitation to form large hydrological systems are most commonly present in low latitudes. For the MVT deposits and districts that have been dated, more than 75% of the combined metal produced are from deposits that have dates that correspond to assembly of Pangea in Devonian through Permian time. The exceptional endowment of Pangea and especially, North America with MVT lead-zinc deposits may be explained by the following: (1) Laurentia, which formed the core of North America, stayed in low latitudes during the Paleozoic, which allowed the development of vast carbonate platforms; (2) intense orogenic activity during the assembly of Pangea created ground preparation for many MVT districts through far-field deformation of the craton; (3) uplifted orogenic belts along Pangean suture zones established large-scale migration of basin fluids; and (4) the location of Pangea in low latitudes with paleoclimates with high evaporation rates led to the formation of brines by the evaporation of seawater and infiltration of these brines into deep basin aquifers during Pangean orogenic events.

Leach, D. L.; Bradley, D.; Lewchuk, M. T.; Symons, D. T. A.; De Marsily, G.; Brannon, J.



Discrepancy between growth of Coccidioides immitis in bacterial blood culture media and a radiometric growth index  

SciTech Connect

Spherules of Coccidioides immitis grew readily after inoculation in vented trypticase soy broth, biphasic brain heart infusion media, and aerobic tryptic soy broth bottles used in a radiometric system (BACTEC). However, visible growth was not accompanied by a significant radiometric growth index. Growth of C. immitis can be visually detected in routine bacterial blood culture media while the radiometric growth index remains negative.

Ampel, N.M.; Wieden, M.A.



Potassium-argon dating  

Microsoft Academic Search

First results in an extensive programme in potassium-argon dating at Berkeley arc reported. Ultra-high-vacuum techniques have been incorporated in the argon extraction apparatus and in a new mass spectrometer especially designed for these researches. It is found that, because of these improvements, the radiogenic argon in small and young samples can be measured with precision. Analytical data for a group

R. E. Folinsbee; J. Lipson; J. H. Reynolds



A Kinetic Model for Scattered Radiometric Ages in HP/UHP Terrains Using the Western Gneiss Region of the Scandinavian Caledonides as an Example  

NASA Astrophysics Data System (ADS)

Attempts to date the "peak" of metamorphism in HP/UHP terrains are complicated by radiometric dates that scatter over significant time periods: on the order of tens of millions of years in some terrains. For example, eclogites dated by Sm-Nd mineral isochron and U-Pb zircon techniques in the Western Gneiss Region (WGR) of the Norwegian Caledonides give ages that range from 402 to 422 Ma (the oldest age is a re-determination of an eclogite previously dated at 447 Ma). Some recent studies have proposed that the older ages should be discarded and the youngest ages should taken to date the HP/UHP metamorphism that accompanied the collision of Baltica and Laurentia during the Scandian Orogeny. This interpretation implies that HP/UHP metamorphism was a discrete, short-lived event that occurred during or shortly after the achievement of peak temperatures. However, if HP/UHP conditions are achieved through the subduction of continental crust into the mantle, eclogite-facies assemblages have the potential to form throughout the interval that the crust is within the eclogite stability field, during both subduction and eduction. Recent evidence suggests that eclogitization requires the introduction of fluids or the application of strain or the action of some other catalytic process and that where these processes do not occur the rocks can persist metastably as non-eclogite facies assemblages. This means that eclogitization can occur locally, wherever and whenever fluids are introduced or strain is localized, rather than occurring coherently within a short interval throughout the entire terrene. If so, all determined ages from the WGR could be correct with each one dating the formation of eclogite-facies assemblages in a particular place at a particular time. If so, the WGR resided at depths within the eclogite facies stability field for ca. 20 m.y. A testable consequence of this model is that eclogites from the part of the slab that was subducted to the deepest levels should have both the oldest and youngest eclogites with the ages dating the entry into, and the departure from, respectively, the eclogite stability field.

Brueckner, H. K.



Thermoluminescent dating principles and application  

Microsoft Academic Search

The physical process of thermoluminescence is outlined with particular reference to the behaviour of the common crystalline minerals found in pottery, like quartz and feldspars. Though the internal radiation dosimetry of pottery is complex two experimental techniques have been developed which allow accurate pottery dating and are believed to surmount the worst of the problems discussed. Application of thermoluminescent dating

S. J. Fleming



Depth dependence of soil carbonate accumulation based on cosmogenic 36Cl dating  

Microsoft Academic Search

Indurated pedogenic carbonate layers (calcretes) are common in soils on stable surfaces in arid to semiarid climates. The morphology and composition of calcretes provide important information on the geomorphic and climatic histories of the regions where they are formed, but they have proved difficult to date with conventional radiometric methods. We report cosmogenic 36Cl-buildup ages from three fractions (leachable Cl,

Beiling Liu; Fred M. Phillips; David Elmore; Pankaj Sharma



Radiometric estimation of water vapor content over Brazil  

NASA Astrophysics Data System (ADS)

A multi-channel microwave radiometre (make: Radiometrics Corporation) is installed at Instituto Nacional de Pesquisas Espaciais-INPE, Brazil (22°S). The radiometric output of two channels of the radiometer in the form of brightness temperature at 23.834 GHz and 30 GHz, initially, were used to find out the ambient water vapor content and the non-precipitable cloud liquid water content. The necessary algorithm was developed for the purpose. The best results were obtained using the hinge frequency 23.834 GHz and 30 GHz pair having an r.m.s. error of only 2.64. The same methodology was then adopted exploiting 23.034 GHz and 30 GHz pair. In that case the r.m.s. error was 3.42. These results were then compared with those obtained over Kolkata (22°N), India, by using 22.234 GHz and 31.4 GHz radiometric data. This work conclusively suggests the use of a frequency should not be at the water vapor resonance line. Instead, while measuring the vapor content for separation of vapor and cloud liquid, one of them should be a few GHz left or right from the resonance line i.e., at 23.834 GHz and the other one should be around 30 GHz.

Karmakar, P. K.; Maiti, M.; Sett, S.; Angelis, C. F.; Machado, L. A. T.



Laboratory-based bidirectional reflectance distribution functions of radiometric tarps  

SciTech Connect

Laboratory-based bidirectional reflectance distribution functions (BRDFs) of radiometric tarp samples used in the vicarious calibration of Earth remote sensing satellite instruments are presented in this paper. The results illustrate the BRDF dependence on the orientation of the tarps' weft and warp threads. The study was performed using the GSFC scatterometer at incident zenith angles of 0 deg., 10 deg., and 30 deg.; scatter zenith angles from 0 deg. to 60 deg.; and scatter azimuth angles of 0 deg., 45 deg., 90 deg., 135 deg., and 180 deg.. The wavelengths were 485 nm, 550 nm, 633 nm, and 800 nm. The tarp's weft and warp dependence on BRDF is well defined at all measurement geometries and wavelengths. The BRDF difference can be as high as 8% at 0 deg. incident angle and 12% at 30 deg. incident angle. The fitted BRDF data show a very small discrepancy from the measured ones. New data on the forward and backscatter properties of radiometric tarps are reported. The backward scatter is well pronounced for the white samples. The black sample has well-pronounced forward scatter. The provided BRDF characterization of radiometric tarps is an excellent reference for anyone interested in using tarps for radiometric calibrations. The results are NIST traceable.

Georgiev, Georgi T.; Butler, James J



Real-time adaptive radiometric correction for imaging radars systems  

NASA Astrophysics Data System (ADS)

A new solution is given of a real time radiometric image correction that also minimizes the quantization and saturation noise introduced by the process of analog-to-digital conversion of raw data of coherent and noncoherent imaging radar systems. The implementation of this procedure was successfully performed with the experimental SAR System (E-SAR) of the DLR.

Moreira, Joao R.; Poetzsch, Winfried



Radiometric Calibration of Korean Spaceborne Microwave Radiometer DREAM  

Microsoft Academic Search

Dual-channel Radiometers for Earth and Atmosphere Monitoring (DREAM) is the Korean spaceborne microwave radiometer. It is the main payload of Science and Technology SATlleite-2(STSAT-2) and will start the mission in December 2008. In this paper, we describe the radiometric calibration of DREAM. We also present the performance results of the system-level.

Sung-Hyun Kim; Ho-Jin Lee; Nam-Won Moon; Jin-Taek Seong; Hoon Wi; Eun-Sup Sim; De-Hai Zhang; Jing-Shan Jiang; Yong-Hoon Kim



Radiometric sky temperature measurements at 35 and 89 GHz  

Microsoft Academic Search

A set of radiometric sky temperature measurements at 35 and 89 GHz is presented in the paper. The system used to make the measurements is described as well as the method used for calibration. The temperatures were measured as a function of elevation twice a day over a period of about six months. Examples of the results obtained are presented,

A. D. Sayers



Radiometric sources for the Los Alamos National Laboratory calibration Laboratory  

SciTech Connect

Los Alamos is developing a laboratory that will support state of the art calibration of moderate-aperture instrumentation (< 40 cm diameter) having high spatial and thermal resolution. Highly accurate calibration in the reflected solar and thermal infrared spectral regions are required for newly developed instrumentation. Radiometric calibration of the instrumentation requires well-characterized, extensive sources of radiation from 0.45 to 12 {mu}m. For wavelengths above 2.5 {mu}m, blackbodies having temperature control and radiometric uniformity to within 100 mK are being designed and will be radiometrically characterized at the National Institute of Standards and Technology (NIST). For the spectral range 0.45--2.5 {mu}m, a ``whitebody`` integrating sphere equipped with tungsten-halogen lamps and enclosed inside a vacuum shroud will be used; this vacuum-compatible extensive standard diffuse source utilizes well-known technology and will be characterized at NIST`s existing facilities. Characterization of instrumental contrast performance for wavelengths, {lambda}, beyond 2.5 {mu}m will utilize a recently designed absolute variable-contrast IR radiometric calibrator, and preliminary data indicate that this calibrator will perform satisfactorily. Conceptual design and status of these extensive broad-band sources and of a monochromatic source to be used for spectral calibrations will be presented.

Maier, W.B. II; Holland, R.; Bender, S.; Byrd, D.; Michaud, F.D.; Moore, S. [Los Alamos National Lab., NM (United States); O`Brian, T.R. [National Inst. of Standards and Technology, Gaithersburg, MD (United States)



Preflight Radiometric Calibration of the Orbiting Carbon Observatory  

Microsoft Academic Search

This paper describes the radiometric calibration of the original Orbiting Carbon Observatory. The calibration pro- cess required characterizing both the dark current level and gain coefficients of each instrumental channel. The dark response was characterized with extensive testing and revealed some unexpected instrument behavior. The gain coefficients were characterized via illumination of the instrument spectrometers with a laboratory- calibrated integrating

Christopher W. O'Dell; Jason O. Day; Randy Pollock; Carol J. Bruegge; Denis M. O'Brien; Rebecca Castano; Irina Tkatcheva; Charles E. Miller; David Crisp



Multivariate uranium favorability index using aerial radiometric data  

Microsoft Academic Search

Through the National Uranium Resource Evaluation (NURE) program, the Grand Junction, Colorado office of the US Department of Energy, has been conducting aerial radiometric surveys over various portions of the United States since 1974. Among other objectives, these surveys are intended to identify lithologic units favorable for uranium deposition and to indicate those areas of the country where there is

Fredric L. Pirkle; Richard J. Beckman; H. L. Jr. Fleischhauer



Data from radar images integrated with information from traditional lithologic and dating techniques improve resolution of surficial geologic units in the central Florida peninsula  

SciTech Connect

Side Looking Airborne Radar (SLAR) images provide information useful to 1:100,000-scale surficial geologic mapping across the Florida peninsula from Sarasota to Fort Pierce. The SLAR images show textural patterns, sharp gradients, and certain compositional variations that cause differences in reflectivity. Quaternary and Pliocene beach ridges and marginal marine plains, visible on SLAR images, occupy most of the eastern half of the area; the most prominent beach ridge, which was deposited during the late Pliocene or early Pleistocene, is the southern terminus of the central highlands of Florida. Other geologic features detected by radar are a change from iron-poor to moderately iron-rich soil that marks the boundary between two middle Quaternary ( ) units, oyster reefs associated with late Pleistocene bay deposits northwest of Lake Okeechobee, and permanent and ephemeral ponds that reflect the thickness of unconsolidated sediment over weathered carbonate rocks. In addition to the geomorphic and compositional information from SLAR, mineralogic, textural, and age data from drill holes and pits were used to delineate surficial geologic map units. Stratigraphic and numerical age estimates are based on molluscan biostratigraphy, uranium disequilibrium series dates on corals, [sup 87]Sr/[sup 66]Sr dates on molluscs, and [sup 14]C dates on peat and humate.

McCartan, L.; Moy, W.S.; Wingard, G.L. Owens, J.P.; Kover, A.N.; Van Valkenburg, S.G.; Mason, D.B. (Geological Survey, Reston, VA (United States))



Rapid radiometric method for determining drug susceptibility of Mycobacterium avium-intracellulare  

SciTech Connect

A rapid radiometric method for susceptibility testing of Mycobacterium avium-intracellulare to eight chemotherapeutic agents was compared with a conventional method. Results were available within 72 h by radiometric testing in contrast to 21 days by the conventional method. The radiometric and conventional methods agreed to 61% of the tests, but growth inhibition of greater than or equal to 50% was detectable only by radiometric testing in an additional 36.5% of the tests. In only 2.5% of the tests was the radiometric method unable to detect complete inhibition shown by the conventional method. Quantifiable increases in inhibition with increasing concentration of isoniazid were more frequently detectable by the radiometric method than by conventional testing. The radiometric method is a simple, rapid, and quantitative test for drug susceptibility of mycobacteria and warrants further investigation.

Yangco, B.G.; Eikman, E.A.; Solomon, D.A.; Deresinski, S.C.; Madden, J.A.



Radiometric and spectral calibrations of the Geostationary Imaging Fourier Transform Spectrometer (GIFTS) using principle component analysis  

NASA Astrophysics Data System (ADS)

The ultimate remote sensing benefits of the high resolution Infrared radiance spectrometers will be realized with their geostationary satellite implementation in the form of imaging spectrometers. This will enable dynamic features of the atmosphere's thermodynamic fields and pollutant and greenhouse gas constituents to be observed for revolutionary improvements in weather forecasts and more accurate air quality and climate predictions. As an important step toward realizing this application objective, the Geostationary Imaging Fourier Transform Spectrometer (GIFTS) Engineering Demonstration Unit (EDU) was successfully developed under the NASA New Millennium Program, 2000-2006. The GIFTS-EDU instrument employs three focal plane arrays (FPAs), which gather measurements across the long-wave IR (LWIR), short/mid-wave IR (SMWIR), and visible spectral bands. The raw GIFTS interferogram measurements are radiometrically and spectrally calibrated to produce radiance spectra, which are further processed to obtain atmospheric profiles via retrieval algorithms. The radiometric calibration is achieved using internal blackbody calibration references at ambient (260 K) and hot (286 K) temperatures. The absolute radiometric performance of the instrument is affected by several factors including the FPA off-axis effect, detector/readout electronics induced nonlinearity distortions, and fore-optics offsets. The GIFTS-EDU, being the very first imaging spectrometer to use ultra-high speed electronics to readout its large area format focal plane array detectors, operating at wavelengths as large as 15 microns, possessed non-linearity's not easily removable in the initial calibration process. In this paper, we introduce a refined calibration technique that utilizes Principle Component (PC) analysis to compensate for instrument distortions and artifacts remaining after the initial radiometric calibration process, thus, further enhance the absolute calibration accuracy. This method is applied to data collected during an atmospheric measurement experiment with the GIFTS, together with simultaneous observations by the accurately calibrated AERI (Atmospheric Emitted Radiance Interferometer), both simultaneously zenith viewing the sky through the same external scene mirror at ten-minute intervals throughout a cloudless day at Logan Utah on September 13, 2006. The PC vectors of the calibrated radiance spectra are defined from the AERI observations and regression matrices relating the initial GIFTS radiance PC scores to the AERI radiance PC scores are calculated using the least squares inverse method. A new set of accurately calibrated GIFTS radiances are produced using the first four PC scores in the regression model. Temperature and moisture profiles retrieved from the PC-calibrated GIFTS radiances are verified against radiosonde measurements collected throughout the GIFTS sky measurement period.

Tian, Jialin; Smith, William L.; Gazarik, Michael J.



On the Use of Radiometric Measurements to Estimate Atmospheric Attenuation at 100 and 300 GHz  

NASA Astrophysics Data System (ADS)

At frequencies of between 100 GHz and 30 THz, propagation conditions are severely affected by the influence of the composition and phenomena of the troposphere. This paper focuses on the use of radiometric measurements to estimate attenuation at 100 and 300 GHz, considering non-scattering scenarios, in which the main contributions are given by atmospheric gases and non-rainy clouds. These techniques allow the estimation of the absorption loss through the entire atmosphere, without the need for a signal source situated in a satellite or a high altitude aircraft. On the basis of well-accepted absorption models, the results of calculating gaseous, cloud, and total attenuation using 3-year meteorological data from Madrid, Spain, are detailed, as well as estimates of the expected values of the sky brightness temperature as measured by the radiometer. Finally, based on the results obtained, a discussion on the use of radiometric measurements at both frequencies is presented, in connection with an experimental campaign currently under preparation.

Siles, Gustavo A.; Riera, José M.; García-Del-Pino, Pedro



The origin of radiometric anomalies in petroleum basins -- A proposed mechanism  

SciTech Connect

Radiometric mapping as a petroleum exploration tool began some seven decades ago. The results reported have predominantly been positive. Nevertheless, the method lacks broad acceptance, due in part to insufficient understanding of tis technical basis. In this article, the authors address the geochemistry and physics that underlie radiometrics. The authors and others have observed repeatedly that the anomalously low radiation flux detected over petroleum basins correlates with existing subsurface hydrocarbon accumulations. Two primary factors drive this technique: (1) the earth is inherently radioactive and (2) subsurface hydrocarbon deposits markedly alter surface radiation patterns. When subsurface hydrocarbons are absent, uranium`s intrinsic migratory ability, its greater specific radioactivity, and Rn-222`s longer transit ability, cause it to be a most significant contributor to radiation detected at the surface. When hydrocarbons are present, however, geochemical interactions constrain or arrest uranium`s movement, causing the decrease in gamma flux detected over petroleum deposits. And such low radiation flux patterns are distinguishable from the random gammas observed in areas barren of hydrocarbons.

Morse, J.G.; Zinke, R. [Colorado School of Mines, Golden, CO (United States)



Radiometric method for testing susceptibility of mycobacteria to pyrazinamide in 7H12 broth  

SciTech Connect

The test of susceptibility to pyrazinamide requires an acid environment (pH less than or equal to 5.5). This, however, is not favorable to the growth of Mycobacterium tuberculosis, especially in solid agar media. To obviate this difficulty, we developed a testing method with 7H12 broth medium and based on radiometric readings of the growth. The radiometric method employed in this study (BACTEC system) provides an opportunity to detect the dynamics of growth by daily recording of the growth index, which reflects the metabolic activity of the multiplying bacteria. In our technique, M. tuberculosis isolates were initially cultivated at pH 6.8. After logarithmic growth had begun, phosphoric acid solution was added to obtain pH 5.5. When pyrazinamide was added simultaneously with the acid, the growth index of susceptible cultures decreased, whereas it continued to increase in pH 5.5 control vials and in tests with pyrazinamide-resistant strains.

Heifets, L.B.; Iseman, M.D.



Mississippi Valley-type lead-zinc deposits through geological time: implications from recent age-dating research  

Microsoft Academic Search

Remarkable advances in age dating Mississippi Valley-type (MVT) lead-zinc deposits provide a new opportunity to understand how and where these deposits form in the Earth's crust. These dates are summarized and examined in a framework of global tectonics, paleogeography, fluid migration, and paleoclimate. Nineteen districts have been dated by paleomagnetic and\\/or radiometric methods. Of the districts that have both paleomagnetic

David L. Leach; Dwight Bradley; Michael T. Lewchuk; David T. Symons; Ghislain de Marsily; Joyce Brannon



Reflectance-based radiometric calibration of multispectral Earth-observation sensors using an automated test site at Railroad Valley, Nevada  

NASA Astrophysics Data System (ADS)

Ground-based vicarious radiometric calibration is used as an independent source to monitor the temporal changes in Earth-observing sensors. The Remote Sensing Group at the University of Arizona uses the reflectance-based approach, which requires in-situ measurements of surface reflectance and atmospheric properties during a sensor overpass. The group has expanded its capabilities by developing the Radiometric Calibration Test Site (RadCaTS), which operates in the absence of ground personnel at Railroad Valley, Nevada. It is comprised of ground-viewing radiometers, which are used to determine the surface reflectance, and a Cimel Sun photometer, which is used to make atmospheric measurements. The radiative transfer code MODTRAN5 is used to determine the top-of-atmosphere spectral radiance for a given overpass. This work presents radiometric calibration results for MODIS, MISR, ASTER, and Landsat 7 ETM+, which were obtained using RadCaTS. The automated results are also compared to those obtained using in-situ techniques.

Czapla-Myers, J.; Leisso, N. P.



Millennial-scale varnish microlamination dating of late Pleistocene geomorphic features in the drylands of western USA  

NASA Astrophysics Data System (ADS)

Varnish microlamination (VML) dating is a climate-based correlative age determination technique used to correlate and date various geomorphic features in deserts. In this study, we establish a generalized late Pleistocene (18-74 ka) millennial-scale microlamination sequence in fine-grained, fast-accumulating rock varnish for the drylands of western USA, radiometrically calibrate the sequence and correlate it with the ?18O record in the GISP2 Greenland ice core. We then use this climate-correlated varnish microstratigraphy to estimate surface exposure ages for radiometrically dated late Pleistocene geomorphic features in the study region. The VML dating of debris flow deposits on the Sehoo recessional shorelines of Lake Lahontan at the Jessup embayment of central Nevada yields a minimum-limiting age of 14.95-15.95 ka, in good agreement with a calibrated 14C age of 15.22 ± 0.12 ka for the timing of the lake recession. The VML dating of a giant ejecta block on the rim of Meteor Crater in northern Arizona yields a minimum-limiting age of 49.15 ka, closely matching a thermoluminescence (TL) age of 49 ± 3 ka and slightly younger than a recently updated cosmogenic 36Cl age of 56.0 ± 2.4 ka for the meteor impact event. The VML dating of distal Q2c fan surfaces on Hanaupah Canyon alluvial fan in Death Valley, California, yields a minimum-limiting age of 73.55 ka, in accord with cosmogenic 36Cl depth-profile ages of 66 + 22/-14 ka and 72 + 24/- 20 ka for the same fan deposits. The close agreement between the VML age estimates and the independently derived radiometric ages for these geomorphic features attests to the validity and reliability of millennial-scale VML dating.To further assess its potential in desert geomorphological research, we use the VML method to study alluvial-fan responses to millennial-scale climatic changes. The VML dating of a small tributary fan in Death Valley reveals two episodes of fan aggradation, one ceasing at 73.55-86.75 ka during the dry period of the last interglacial (MIS 5a) and the other finishing at 66.15 ka during the wet period of the last glacial (MIS 4). The VML and 36Cl dating of the distal Q2c fan surfaces on Hanaupah Canyon fan reveal two episodes of large-scale fan aggradation ended at 72 + 24/- 20 ka and 73.55 ka during the wet period of MIS 4. Fanhead incision and associated within-channel or fantoe aggradation are found to take place during the relatively dry period of the glacial-to-interglacial climatic transition (12-24 ka) and the Holocene interglacial dry period (0-12 ka). These data indicate that, on the millennial to sub-Milankovitch timescale (~ 103-104 years), fan aggradation is a discrete sedimentational process under various climatic conditions. Because fan aggradation is ultimately controlled by the intensity and frequency of precipitation events — which in turn are modulated by major climatic oscillations such as Heinrich events, Dansgaard/Oeschger (DO) events, and glacial/interglacial shifts — these major climatic changes could be the pacemaker of regionally contemporaneous large-area fan segmentation.

Liu, Tanzhuo; Broecker, Wallace S.



Radiometric method for measuring the sea state  

Microsoft Academic Search

We present a method for determining sea state from the frequency of the maximum in the brightness temperature fluctuations of the thermal radiation from the sea surface. We also calculate these spectra as a function of sea state using measurements taken from aircraft. We obtain estimates of the minimum sea states resolvable by the measurement technique used here as a

A. P. Barabanov; A. N. Reznik; K. S. Stankyevich



Radiometric calibration procedures for a wideband infrared scene projector (WISP)  

NASA Astrophysics Data System (ADS)

The Wideband Infrared Scene Projector (WISP) has been undergoing development for the Kinetic-Kill Vehicle Hardware-in-the-Loop Simulator facility at Eglin AFB, Florida. In order to perform realistic tests of an infrared seeker, the radiometric output of the WISP system must produce the same response in the seeker as the real scene. In order to ensure this radiometric realism, calibration procedures must be established and followed. This paper describes calibration procedures that have been used in recent tests. The procedures require knowledge of the camera spectral response in the seeker under test. The camera is set up to operate over the desired range of observable radiances. The camera is then nonuniformity corrected (NUCed) and calibrated with an extended blackbody. The camera drift rates are characterized, and as necessary, the camera is reNUCed and recalibrated. The camera is then set up to observe the WISP system, and calibration measurements are made of the camera/WISP system.

Flynn, David S.; Marlow, Steven A.; Bergin, Thomas P.; Kircher, James R.



Rapid radiometric method for detection of Salmonella in foods  

SciTech Connect

A radiometric method for the detection of Salmonella in foods has been developed which is based on Salmonella poly H agglutinating serum preventing Salmonella from producing 14CO2 from (14C) dulcitol. The method will detect the presence or absence of Salmonella in a product within 30 h compared to 4 to 5 days by routine culture methods. The method has been evaluated against a routine culture method using 58 samples of food. The overall agreement was 91%. Five samples negative for Salmonella by the routine method were positive by the radiometric method. These may have been false positives. However, the routine method may have failed to detect Salmonella due to the presence of large numbers of lactose-fermenting bacteria which hindered isolation of Salmonella colonies on the selective agar plates.

Stewart, B.J.; Eyles, M.J.; Murrell, W.G.



SLC-off Landsat-7 ETM+ reflective band radiometric calibration  

USGS Publications Warehouse

Since May 31, 2003, when the scan line corrector (SLC) on the Landsat-7 ETM+ failed, the primary foci of Landsat-7 ETM+ analyses have been on understanding and attempting to fix the problem and later on developing composited products to mitigate the problem. In the meantime, the Image Assessment System personnel and vicarious calibration teams have continued to monitor the radiometric performance of the ETM+ reflective bands. The SLC failure produced no measurable change in the radiometric calibration of the ETM+ bands. No trends in the calibration are definitively present over the mission lifetime, and, if present, are less than 0.5% per year. Detector 12 in Band 7 dropped about 0.5% in response relative to the rest of the detectors in the band in May 2004 and recovered back to within 0.1% of its initial relative gain in October 2004.

Markham, B. L.; Barsi, J. A.; Thome, K. J.; Barker, J. L.; Scaramuzza, P. L.; Helder, D. L.



Automatic radiometric normalization with genetic algorithms and a Kriging model  

NASA Astrophysics Data System (ADS)

An automatic procedure of radiometric normalization is proposed for multi-temporal satellite image correction, with a modified genetic algorithm (GA) regression method and a spatially variant normalization model using the Kriging interpolation.The proposed procedure was tested on a synthetic altered image and an image pair from FORMOSAT-2; the results show that the GA method is more robust than the conventional PCA methods in high-resolution imaging, and that different regression-error evaluation models have different sensitivities to the linear regression parameters. A statistical comparison demonstrates that 1-km sampling spacing is able to successfully achieve the parameter spatial variation. Error validation on FORMOSAT-2 image pair shows it is a decent combination of radiometric normalization with GA estimation and a spatially variant parameter normalization model.

Liu, Shou-Heng; Lin, Ching-Weei; Chen, Yie-Ruey; Tseng, Chih-Ming



Sensor Development and Radiometric Correction for Agricultural Applications  

Microsoft Academic Search

Abstract This review,addresses,the challenges,and,progress,in sen- sor development,and,radiometric,correction,for agricul- tural applications,with,particular,emphasis,on activities within,the U.S. Department,of Agriculture (USDA) Agricul- tural Research,Service (ARS). Examples of sensor develop- ment include on-site development of sensors and platforms, participation,in cooperative,research,and,development agreements (CRADA) with commercial companies, and membership,on NASA science,teams. Examples,of progress made,in sensor radiometric,correction,suitable,for agricul- ture are presented,for both,laboratory,and,field environ- ments. The direction,of future sensor,development,includes integrated

S. Moran; G. Fitzgerald; A. Rango; C. Walthall; E. Barnes; W. Bausch; T. Clarke; C. Daughtry; J. Everitt; D. Escobar; J. Hatfield; K. Havstad; T. Jackson; N. Kitchen; W. Kustas; M. McGuire; P. Pinter; K. Sudduth; J. Schepers; T. Schmugge; P. Starks; D. Upchurch


Radiometric calibration of the three-channel imaging polarimeter  

NASA Astrophysics Data System (ADS)

Radiometric calibration is of critical importance for information quantification of imaging polarimeters. In this paper, an integral sphere which had been traced to cryogenic radiometer was used as transfer standard in our calibration facility. The linearity, uniformity, stability of our imaging polarimeter were calibrated. The combined uncertainty in the responsivity of an imaging polarimeter was about 7.5%. At last, technical proposals of reducing uncertainty budget were briefly discussed.

Zhang, Lei; Liu, Xiao-cheng; Yin, Cheng-liang; Luo, Xiao-lin; Duan, Chang-pu



Towards Core Body Temperature Measurement via Close Proximity Radiometric Sensing  

Microsoft Academic Search

Presented is a noncontact model and radiometric sensor developed to facilitate core body temperature extraction. The system has been designed as a close-proximity sensor to detect thermal emissions radiated from deep inside the human body. The radiometer uses a cavity-backed slot antenna (CBSA) designed to account for performance degradation which occurs in the near field of the human body. Tissue-simulating

Quenton Bonds; John Gerig; Thomas M. Weller; Paul Herzig



Texture-based description of ocean microwave radiometric images  

Microsoft Academic Search

This paper discusses texture analysis of high-resolution (<1-3 km) ocean microwave radiometric images (OMI). A large volume of spectral OMI was obtained with the use of a multi-channel polarimetric scanning microwave radiometer (PSR) in the fall 1997. During image processing it was found that texture of OMI can be represented by a multi-dimensional mosaic with variable brightness characteristics. A number

V. Y. Raizer; A. J. Gasiewski; J. H. Churnside



High speed radiometric measurements of IED detonation fireballs  

NASA Astrophysics Data System (ADS)

Continuum emission is predominant in fireball spectral phenomena and in some demonstrated cases, fine detail in the temporal evolution of infrared spectral emissions can be used to estimate size and chemical composition of the device. Recent work indicates that a few narrow radiometric bands may reveal forensic information needed for the explosive discrimination and classification problem, representing an essential step in moving from "laboratory" measurements to a rugged, fieldable system. To explore phenomena not observable in previous experiments, a high speed (10?s resolution) radiometer with four channels spanning the infrared spectrum observed the detonation of nine home made explosive (HME) devices in the < 100lb class. Radiometric measurements indicate that the detonation fireball is well approximated as a single temperature blackbody at early time (0 < t <~ 3ms). The effective radius obtained from absolute intensity indicates fireball growth at supersonic velocity during this time. Peak fireball temperatures during this initial detonation range between 3000.3500K. The initial temperature decay with time (t <~ 10ms) can be described by a simple phenomenological model based on radiative cooling. After this rapid decay, temperature exhibits a small, steady increase with time (10 <~ t <~ 50ms) and peaking somewhere between 1000.1500K-likely the result of post-detonation combustion-before subsequent cooling back to ambient conditions . Radius derived from radiometric measurements can be described well (R2 > 0.98) using blast model functional forms, suggesting that energy release could be estimated from single-pixel radiometric detectors. Comparison of radiometer-derived fireball size with FLIR infrared imagery indicate the Planckian intensity size estimates are about a factor of two smaller than the physical extent of the fireball.

Spidell, Matthew T.; Gordon, J. Motos; Pitz, Jeremey; Gross, Kevin C.; Perram, Glen P.



A Radiometric Method of Perpetuating the Unit of Light  

Microsoft Academic Search

In using the present primary standard of light-which is a full radiator held at the freezing point of platinum-to reproduce the basic unit of light, the candela, it has proved both difficult and time-consuming to achieve the required accuracy. Similar troubles with earlier material standards prompted various proposals for trying to place photometry on a radiometric basis, not requiring the

J. S. Preston



NERO: General concept of a NEO radiometric observatory  

Microsoft Academic Search

NERO (Near-Earth Objects Radiometric Observatory) is one of the six studies for possible missions dedicated to near-Earth objects, that were funded by the ESA in 2002-2003. NERO is a further development of previous studies already submitted to ESA (Sysiphos,Spaceguard-1). The general concept is that a small satellite equipped with both a CCD for visible wavelengths and an array for thermal

A. Cellino; R. Somma; L. Tommasi; R. Paolinetti; K. Muinonen; J. Virtanen; E. F. Tedesco



Prediction of the radiometric calibration coefficients of ASTER/TIR  

NASA Astrophysics Data System (ADS)

Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), on the NASA Terra satellite, has three radiometers, the VNIR, SWIR and TIR. The TIR radiometer has five bands (10 to 14) in the thermal infrared region with a spatial resolution of 90 m. These TIR bands are radiometrically calibrated by a single onboard blackbody whose temperature can be changed between 270 K and 340 K. In the normal operation mode the blackbody is kept at 270 K, and a constant coefficient in a quadratic radiometric calibration equation for each detector is adjusted at that temperature before each Earth observation. Once in 33 days the gain term can be updated by a long term calibration in which the blackbody is measured at 270, 300, 320, and 340 K. The sensor response of all bands (particularly band 12) has been degrading since the launch, and periodical updating of the gain coefficient does not fully follow the degradation, so that the calibration error on level-1 products is sometimes unacceptable. We therefore have developed approximation equations for the coefficients to predict the most reasonable radiometric calibration coefficients (RCC) at the time of the observation. This will be implemented soon in the Level-1 data processing.

Sakuma, Fumihiro; Tonooka, Hideyuki; Ohgi, Nagamitsu; Ono, Hidehiko



Application of radiometric force to microactuation and energy transformation  

NASA Astrophysics Data System (ADS)

The force that acts on a thin vane immersed in rarefied gas when a temperature gradient is imposed along or across the vane has historically been known as the Radiometric force. First observed by Fresnel in 1825, the radiometric force has regained its former popularity in recent decades due to the advent of micro-machines, where a transitional flow regime can occur at atmospheric pressures. Whether used for its force potential or simply viewed as a nuisance, this force cannot be ignored in micro-devices where thermal gradients exist. Potential applications of radiometric force now span from atomic force microscopy to astrophysics to high altitude flight. This paper describes an application of these forces to a conceptual micro-scale energy harvester, where two possible geometries of operation are described. It is shown that one configuration is significantly simpler to fabricate while the other geometry is more efficient at producing larger forces. The effect of pressure, feature separation, and feature-to-ring gap are analyzed. For consistency and the accurate treatment of the relevant flow conditions, an implementation of the SMOKE code that solves the ES BGK equation was used in all computations.

Selden, Nathaniel; Gimelshein, Natalia; Gimelshein, Sergey; Ketsdever, Andrew



Conventional and radiometric drug susceptibility testing of Mycobacterium tuberculosis complex.  

PubMed Central

A recently developed method of drug susceptibility testing of Mycobacterium tuberculosis which measures the evolution of labeled CO2 from [1-14C]palmitic acid (BACTEC 460 system) was compared to three conventional methods. The proportion method of drug susceptibility testing was the standard against which all test results were compared. Indirect drug susceptibility to isoniazid, streptomycin, rifampin, and ethambutol of 245 isolates belonging to the M. tuberculosis complex was determined. In 95% of the cases, results obtained by the radiometric method were available within 1 week, as opposed to 3 to 6 weeks needed in conventional methodology. Overall agreement was 96.4%. Specificity values ranged from 0.98 to 1.0; sensitivity values of 1.0 for rifampin, 0.96 for streptomycin, 0.91 for isoniazid, and 0.18 for ethambutol were obtained. The specificity of the absolute concentration and resistance ratio drug susceptibility testing methods were 0.99 and 1.0, respectively. The sensitivity of the former was higher than that of the radiometric method (0.99 verus 0.92), whereas that of the latter was lower (0.88 verus 0.96). Further testing indicated that the low sensitivity determined for ethambutol may be due to the choice of the critical concentration used, rather than to a shortcoming of the procedure. The radiometric method thus does not significantly differ in reliability from conventional methods of drug susceptibility testing of M. tuberculosis.

Laszlo, A; Gill, P; Handzel, V; Hodgkin, M M; Helbecque, D M



Radiometric millimetric imaging at Roke Manor Research  

NASA Astrophysics Data System (ADS)

This paper describes two systems developed by Roke Manor Research in partnership with HMG's Home Office Immigration and Nationality Directorate and which are based upon passive millimetric microwave radiometry techniques. Their purpose is to aid the detection of people concealed in curtain-sided and plastic-sided freight vehicles. The paper covers the basic physics of radiometry, the history of these developments and concludes with an account of the future directions of this work.

Hall, Jason; Harman, Martin L.



Photocarrier radiometric characterization of semiconductor silicon wafers  

NASA Astrophysics Data System (ADS)

As semiconductor devices become increasingly complex, and consequently increasingly expensive to produce, the necessity to improve yield in order to maintain profitability is continuously driving industrial manufacturers to search for more effective characterization tools. Photothermal techniques have been developed over the last several decades as a viable characterization tool for electronic materials. However, they are in general sensitive to both thermal-wave and carrier-density-wave processes in an optically excited semiconductor and these two competing signal generation mechanisms can result in compromised computational accuracy and potential ambiguity of lateral imaging of the electronic properties of a material. In this thesis photocarrier radiometry (PCR), a form of spectrally-integrated modulated room-temperature near-infrared photoluminescence, is presented as a novel non-destructive diagnostic technique for non-contact characterization of semiconductor materials. The signal generation mechanism for PCR is the IR emission and self-reabsorption of IR photons emitted by recombining photogenerated carriers created by an intensity modulated super-bandgap optical source. The IR emission intensity is proportional to the integrated carrier density profile in the sample which is modified by enhanced recombination at defects. The developed technique is utilized for the quantitative determination of the electronic transport parameters, namely recombination lifetime, diffusivity, and surface recombination velocity, and has been applied to the study of two industrially relevant characterization issues, ion implantation dose uniformity monitoring and contamination/defect imaging. The direct correlation between contamination and carrier lifetime in Si allows for generation of contamination/defect concentration images by laterally scanning the sample. The signal dependence of the PCR signal on ion implant dose in silicon is established over a broad range of industrially relevant doses. The modification of the physical structure, and the corresponding change in the electrical and optical properties of the material during ion implantation, is used to develop a model for the optoelectronic response of an ion implanted semiconductor. In addition, a two beam cross-modulation technique is developed and shown to enhance imaging contrast and resolution and to have potential application for low injection level defect imaging. In summary, a semiconductor characterization technique with multiple applications to industrially relevant metrology issues has been developed and is presented in this work.

Shaughnessy, Derrick


The landsat data continuity mission operational land imager (OLI) radiometric calibration  

Microsoft Academic Search

The Operational Land Imager (OLI) on the Landsat Data Continuity Mission (LDCM) has a comprehensive radiometric characterization and calibration program beginning with the instrument design, and extending through integration and test, on-orbit operations and science data processing. Key instrument design features for radiometric calibration include dual solar diffusers and multi-lamped on-board calibrators. The radiometric calibration transfer procedure from NIST standards

Brian L. Markham; Philip W. Dabney; Jeanine E. Murphy-Morris; Jeffrey A. Pedelty; Edward J. Knight; Geir Kvaran; Julia A. Barsi



Application of Digital Image Processing Techniques to Astronomical Imagery 1978.  

National Technical Information Service (NTIS)

Techniques for using image processing in astronomy are identified and developed for the following: (1) geometric and radiometric decalibration of vidicon-acquired spectra, (2) automatic identification and segregation of stars from galaxies; and (3) displa...

J. J. Lorre



Photothermal radiometric quantitative detection of the different degrees of demineralization of dental enamel by acid etching  

NASA Astrophysics Data System (ADS)

Photothermal radiometric (FD-PTR or PTR) signals from human teeth have been used toward detecting an artificial surface demineralization. The aim of the study is to characterize PTR signals by using controlled mineral loss from human enamel to mimic surface and subsurface dental caries. At a fixed modulation frequency, an Ar+ ion laser was used as a light source to scan across the tooth surface, and an MCT infrared detector was used for measuring the PTR signals. Several human molar teeth were etched using 37% phosphoric acid etching gel and scanned across the etched region at 30 Hz. PTR amplitude from the etched region shows that the signal decreases with increasing etching time. The PTR phase also shows the same behavior with the amplitude and better contrast between different etching times. The PTR technique could thus be used to detect early surface demineralization and may give the examiner quantitative information of the degree of demineralization in dental caries.

Jeon, R. J.; Phan, T. D. T.; Wu, A.; Kulkarni, G.; Abrams, S. H.; Mandelis, A.



Radiometric ages of laterites and constraints on long-term denudation rates in West Africa  

NASA Astrophysics Data System (ADS)

In stable cratonic regions, most tropical weathering mantles evolve over long time scales and record long-term environmental change. They may therefore also reflect tectonism and its denudation-related signals detected through apatite fission-track thermochronology, cosmogenic radionuclide dating, and the age bracketing of laterites by 40Ar/39Ar dating of potassium- and manganese-rich oxides. Based on an existing Cenozoic pedimentation model for the West African craton, this study uses the three combined radiometric methods to define rates of Cenozoic denudation. Denudation rates of <2 m/m.y. on the lateritic plateaus, in comparison to rates of 7 13 m/m.y. adjacent to them, fit ages of 45 50 Ma for late stages of bauxite development and 24 25 Ma for one phase of lateritization. Together, they support the theory implicit in the landscape model that depths of denudation in cratonic interiors are equal to, or not significantly greater than, existing elevation differences between lateritic landforms.

Gunnell, Yanni



Radioactive Dating: A Method for Geochronology.  

ERIC Educational Resources Information Center

|Gives historical background on the discovery of natural radiation and discusses various techniques for using knowledge of radiochemistry in geochronological studies. Indicates that of these radioactive techniques, Potassium-40/Argon-40 dating is used most often. (JN)|

Rowe, M. W.



Radioactive Dating: A Method for Geochronology.  

ERIC Educational Resources Information Center

Gives historical background on the discovery of natural radiation and discusses various techniques for using knowledge of radiochemistry in geochronological studies. Indicates that of these radioactive techniques, Potassium-40/Argon-40 dating is used most often. (JN)

Rowe, M. W.



Radiometric packaging of uncooled microbolometer FPA arrays for space applications  

NASA Astrophysics Data System (ADS)

INO has extensive experience in the design and fabrication of focal plane arrays (FPAs) of uncooled microbolometers. In particular, the FPA of 512×3 microbolometers, developed in collaboration with the Canadian Space Agency (CSA), has been selected for use in the NIRST (New Infrared Sensor Technology) radiometer of the SAC-D Aquarius mission. The FPA has been designed for pushbroom scanning of the Earth to provide radiometric data in the mid- and long-wave infrared for the monitoring of fires as well as thermal mapping of ocean temperature. Uncooled microbolometer detectors are suited for space applications due to their low power consumption while still exhibiting adequate performance. Furthermore, the spectral range of their response could be tuned from the mid- to the far-infrared to meet different mission requirements. In order to ensure that the detector receives only the thermal contribution from the desired target and to minimize radiometric error due to variation of the temperature of the surrounding during the measurements, a radiometric package is required. In a radiometric package the detector environment is thermally stabilized by means of a temperature controlled radiation shield. The radiation shield should also be designed to prevent stray radiation from reaching the detector. Under the Space Technology Development Program of the CSA, INO has designed, assembled and tested a radiometric package in order to characterize its performance and compatibility with the space environment. The operating spectral band is defined by the spectral characteristics of a bandpass filter placed in front of the FPA. For typical space missions, the package must pass standard environmental tests without degradation of its performance (thermal cycling from -55 to +85 °C according to MIL-STD-810, random acceleration up to 14 G RMS from 20-2000 Hz and shock up to 75 G). In order to ensure reliability in those conditions while maintaining optimum performance, an adequate selection of materials is necessary. In this paper, INO's radiometric packaging technology for uncooled microbolometer FPA's will be presented. The selection of materials will be discussed and the final choices presented based on thermal simulations and experimental data. The effects of different design parameters on the performance, such as material, shape and thickness of radiation shield and choice of adhesive have been studied. An instantaneous noise equivalent temperature difference (NETD) of ~ 20 mK was obtained under the measurement conditions (broadband LWIR, 140 ms integration time, f/1 optics, characterization in flood exposure). The design of the package reduced the contribution of environmental temperature variations on the offset of the sensor. The equivalent response of the package varied less than 0.08 °C per degree of variation of the temperature of the package. The package also showed low sensitivity to stray radiation as a result of the effectiveness of the radiation shield design. The device successfully passed the prescribed environmental tests without degradation of performance.

García-Blanco, S.; Cote, P.; Leclerc, M.; Blanchard, N.; Desroches, Y.; Caron, J.-S.; Ngo Phong, L.; Chateauneuf, F.; Pope, T.



Onboard radiometric photography of EXCEDE SPECTRAL's ejected-electron beam  

NASA Astrophysics Data System (ADS)

The details of a wide-angle camera system used in the EXCEDE SPECTRAL experiment to determine spatial distributions of energy deposition are discussed, along with the camera calibrating and film data reduction procedures. The measured column emission rate distributions within a few tens of meters from the rocket between 123 and 83 km are presented and compared wit the predictions of an independent particle transport model. Spatial distributions of emission can be assessed with the aid of unfolds from the radiometrically calibrated photographs.

Kofsky, I. L.; Sluder, R. B.; Villanucci, D. P.




Microsoft Academic Search

Investigations on the radiometric and geometric characteristics of IKONOS Geo satellite imagery and its use for orthoimage generation and 3D building reconstruction are reported. The paper first starts with an analysis of the radiometric quality of IKONOS Geo images of varying preprocessing and type, focussing on noise, edge quality and definition, and various artefacts. A noise estimation method is presented

Emmanuel Baltsavias; Maria Pateraki; Li Zhang


Blood culture cross contamination associated with a radiometric analyzer  

SciTech Connect

During a 9-day period in August 1980 in a New Jersey hospital, three pairs of consecutively numbered blood cultures from different patients were identified as positive for the same organism, for each pair, both cultures were positive in the same atmosphere, both organisms had the same sensitivities, and the second of each pair grew at least 2 days after the first and was the only positive blood culture obtained from the patient. When the hospital laboratory discontinued use of its radiometric culture analyzer for 15 days, no more consecutive pairs of positive cultures occurred. Subsequent use of the machine for 9 days with a new power unit but the original circuit boards resulted in one more similar consecutive pair (Staphylococcus epidermidis). After replacement of the entire power unit, there were no further such pairs. Examination of the machine by the manufacturer revealed a defective circuit board which resulted in inadequate needle sterilization. Laboratories which utilize radiometric analyzers should be aware of the potential for cross contamination. Recognition of such events requires alert microbiologists and infection control practitioners and a record system in the bacteriology laboratory designed to identify such clusters.

Griffin, M.R.; Miller, A.D.; Davis, A.C.



Radiometric measurement of differential metabolism of fatty acid by mycobacteria  

SciTech Connect

An assay system has been developed based on automated radiometric quantification of /sup 14/CO2 produced through oxidation of (1-/sup 14/C) fatty acids by mycobacteria. Two stains of M. tuberculosis (H37Rv and Erdman) and one of M. bovis (BCG) in 7H9 medium (ADC) with 1.0 microCi of one of the fatty acids (butyric, hexanoic, octanoic, decanoic, lauric, myristic, palmitic, stearic, oleic, linoleic and linolenic) were studied. Results previously published on M. lepraemurium (Hawaiian) were also included for comparison. Both strains of M. tuberculosis had maximum /sup 14/CO2 production from hexanoic acid. Oxidation of butyric and avid oxidation of lauric acids were also found with the H37Rv strain but not with Erdman. In contrast, /sup 14/CO2 production by M. bovis was greatest from lauric and somewhat less from decanoic acid. M. lepraemurium showed increasing oxidation rates from myristic, decanoic and lauric acids. Assimilation studies of M. tuberculosis H37Rv confirmed that most of the oxidized substrates were converted into by-products with no change in those from which no oxidation was found. These data suggest that the radiometric measurement of differential fatty acid metabolism may provide a basis of strain identification of the genus Mycobacterium.

Camargo, E.E.; Kertcher, J.A.; Larson, S.M.; Tepper, B.S.; Wagner, H.N. Jr.



Multivariate uranium favorability index using aerial radiometric data  

SciTech Connect

Through the National Uranium Resource Evaluation (NURE) program, the Grand Junction, Colorado office of the US Department of Energy, has been conducting aerial radiometric surveys over various portions of the United States since 1974. Among other objectives, these surveys are intended to identify lithologic units favorable for uranium deposition and to indicate those areas of the country where there is the greatest probability of finding new uranium deposits, including new types of deposits. The ratios of bismuth-214 loadings derived from a principal components analysis of aerial radiometric data indicate favorable areas. The ratio of the bismuth loading of the third component and the ratio of the bismuth loading of the second component to the bismuth loading of the second component to the bismuth loading of the third component yielded the best results from modeled data and NURE aerial survey data. After the ratios are obtained, the absolute value of each ratio is taken and a scattergram of one ratio versus the other is made. Formations favorable for potential uranium resources may be identified from the plot.

Pirkle, F.L.; Beckman, R.J.; Fleischhauer, H.L. Jr.



Radiometric correction of multitemporal Thematic Mapper data for use in agricultural land-cover classification and vegetation monitoring  

Microsoft Academic Search

Many remote sensing applications, especially multitemporal approaches, require radiometric corrections of image data in which radiometric normalization to standard conditions and modelistic atmospheric corrections are often considered as alternative solutions. Successful radiometric normalization depends on the availability of suitable reference targets within the scenes under considerations, which may be critical. It is demonstrated that even simplified atmospheric correction modelling can

Joachim Hill; Boris Sturm



Second Quaternary dating workshop.  

National Technical Information Service (NTIS)

The second Quaternary dating methods workshop was held at Lucas Heights and sponsored by ANSTO and AINSE. Topics covered include, isotope and thermoluminescence dating, usage of accelerator and thermal ionisation mass spectrometry in environmental studies...



Paleomagnetic dating of the most recent silicic eruptive activity at Pantelleria (Strait of Sicily)  

Microsoft Academic Search

We report on the paleomagnetism of ten sites in the products of the most recent silicic eruptive cycle of Pantelleria, Strait\\u000a of Sicily. Previously radiometrically dated at 5–10 ka, our comparison with proxies for geomagnetic field directions allows\\u000a us to narrow considerably the time window during which these eruptions occurred. The strongly peralkaline composition causes\\u000a the magmas to have low viscosities,

Fabio Speranza; Patrizia Landi; Francesca D’Ajello Caracciolo; Alessandro Pignatelli



Youth Dating Violence.  

ERIC Educational Resources Information Center

|Examines responses to the Youth Dating Violence Survey of 37 adolescents enrolled in an alternative high school program. Many reported psychological victimization in a dating relationship and over half reported perpetrating psychological abuse in a dating relationship. Many participants had also been victims of physical violence while some had…

James, William H.; West, Carolyn; Deters, Karla Ezrre; Armijo, Eduardo



Dating of Cremated Bones  

Microsoft Academic Search

ABSTRACT.When dating unburnt bone, bone collagen, the organic fraction of the bone, is used. Collagen does not survive the heat of the cremation pyre, so dating of cremated bone has been considered impossible. Structural carbonate in the mineral fraction of the bone, however, survives the cremation process. Wedeveloped a method of dating cremated bone by accelerator mass spectrometry (AMS), using

J. N. Lanting; A. T. Aerts-Bijma; J. van der Plicht



Dating as leisure  

Microsoft Academic Search

Partner selection occurs naturally and informally, but it may also be organized through commercial intermediaries facilitating mating and dating. This paper focuses on the relationship between online dating and the business cycle . We rely on monthly data covering the period from January 2004 to August 2008 on the demand for online dating in France to study whether economic recession

Véronique Flambard; Nicolas Gérard Vaillant; François-Charles Wolff



Radiometric ratio characterization for low-to-mid CPV modules operating in variable irradiance conditions  

NASA Astrophysics Data System (ADS)

In this work, a concentrating photovoltaic (CPV) design methodology is proposed which aims to maximize system efficiency for a given irradiance condition. In this technique, the acceptance angle of the system is radiometrically matched to the angular spread of the site's average irradiance conditions using a simple geometric ratio. The optical efficiency of CPV systems from flat-plate to high-concentration is plotted at all irradiance conditions. Concentrator systems are measured outdoors in various irradiance conditions to test the methodology. This modeling technique is valuable at the design stage to determine the ideal level of concentration for a CPV module. It requires only two inputs: the acceptance angle profile of the system and the site's average direct and diffuse irradiance fractions. Acceptance angle can be determined by raytracing or testing a fabricated prototype in the lab with a solar simulator. The average irradiance conditions can be found in the Typical Metrological Year (TMY3) database. Additionally, the information gained from this technique can be used to determine tracking tolerance, quantify power loss during an isolated weather event, and do more sophisticated analysis such as I-V curve simulation.

Vorndran, Shelby; Russo, Juan; Zhang, Deming; Gordon, Michael; Kostuk, Raymond


[In-flight absolute radiometric calibration of UAV multispectral sensor].  


Based on the data of the scientific experiment in Urad Front Banner for UAV Remote Sensing Load Calibration Field project, with the help of 6 hyperspectral radiometric targets with good Lambertian property, the wide-view multispectral camera in UAV was calibrated adopting reflectance-based method. The result reveals that for green, red and infrared channel, whose images were successfully captured, the linear correlation coefficients between the DN and radiance are all larger than 99%. In final analysis, the comprehensive error is no more than 6%. The calibration results demonstrate that the hyperspectral targets equipped by the calibration field are well suitable for air-borne multispectral load in-flight calibration. The calibration result is reliable and could be used in the retrieval of geophysical parameters. PMID:23427528

Chen, Wei; Yan, Lei; Gou, Zhi-Yang; Zhao, Hong-Ying; Liu, Da-Ping; Duan, Yi-Ni



New approach for the radiometric calibration of spectral imaging systems  

NASA Astrophysics Data System (ADS)

The calibration of multispectral and hyperspectral imaging systems is typically done in the laboratory using an integrating sphere, which usually produces a signal that is red rich. Using such a source to calibrate environmental monitoring systems presents some difficulties. Not only is much of the calibration data outside the range and spectral quality of data values that are expected to be captured in the field, using these measurements alone may exaggerate the optical flaws found within the system. Left unaccounted for, these flaws will become embedded in to the calibration, and thus, they will be passed on to the field data when the calibration is applied. To address these issues, we used a series of well-characterized spectral filters within our calibration. It provided us with a set us stable spectral standards to test and account for inadequacies in the spectral and radiometric integrity of the optical imager.

Kohler, David D. R.; Bissett, W. Paul; Steward, Robert G.; Davis, Curtiss O.



Radiometric calibration and SNR calculation of a SWIR imaging telescope  

SciTech Connect

Radiometric calibration of an imaging telescope is usually made using a uniform illumination sphere in a laboratory. In this study, we used the open-sky images taken during bright day conditions to calibrate our telescope. We found a dark signal offset value and a linear response coefficient value for each pixel by using three different algorithms. Then we applied these coefficients to the taken images, and considerably lowered the image non-uniformity. Calibration can be repeated during the operation of telescope with an object that has better uniformity than open-sky. Also SNR (Signal to Noise Ratio) of each pixel was calculated from the open-sky images using the temporal mean and standard deviations. It is found that SNR is greater than 80 for all pixels even at low light levels.

Yilmaz, Ozgur; Turk, Fethi; Selimoglu, Ozgur [Tubitak Uzay (Space Technologies Research Institute) ODTU Campus 06531 Ankara (Turkey)



Polarimetric scene simulation in millimeter-wave radiometric imaging  

NASA Astrophysics Data System (ADS)

This paper describes the general requirements and an approach to scene simulation in millimetre wave radiometric imaging that is based on multi faceted semitransparent layered media in the earth"s three-dimensional geometry. The driving attributes in this field are essentially the transparency of clothing for security scanning and the transparency of fog, cloud, rain and dust for all weather flight. Out-door illumination and the physics of the interaction of millimetre waves with the atmosphere and obscurants are discussed, together with the interaction of millimetre waves with multi layer material surfaces, giving rise to transmission, reflection and emission. The physics of these interactions are discussed in the context of computer graphics. These considerations enable a powerful polarimetric modelling capability to be developed that can be used to simulate all scenarios, including artificial or burst illumination, from in-doors to imaging from satellites.

Salmon, Neil A.



The importance and attainment of accurate absolute radiometric calibration  

NASA Astrophysics Data System (ADS)

The importance of accurate absolute radiometric calibration is discussed by reference to the needs of those wishing to validate or use models describing the interaction of electromagnetic radiation with the atmosphere and earth surface features. The in-flight calibration methods used for the Landsat Thematic Mapper (TM) and the Systeme Probatoire d'Observation de la Terre, Haute Resolution visible (SPOT/HRV) systems are described and their limitations discussed. The questionable stability of in-flight absolute calibration methods suggests the use of a radiative transfer program to predict the apparent radiance, at the entrance pupil of the sensor, of a ground site of measured reflectance imaged through a well characterized atmosphere. The uncertainties of such a method are discussed.

Slater, P. N.



Ground-based vicarious radiometric calibration of Terra MODIS  

NASA Astrophysics Data System (ADS)

Accurate radiometric calibration is required by Earth-observing systems to ensure that the derived data products are of the highest quality. Preflight calibration is used as a baseline to understand the system before it is launched on orbit, while post-launch calibration is used to understand changes that may have occurred due to the nature of launching an instrument into space. On-orbit radiometric calibration ensures that changes in the system, including any onboard calibration sources, can be monitored. The Remote Sensing Group at the University of Arizona has been directly involved in the ground-based vicarious calibration of both Terra and Aqua MODIS since their respective launches in 1999 and 2002. RSG personnel are present at a test site during sensor overpass, and surface reflectance and atmospheric attenuation measurements are used as inputs to a radiative transfer code to determine the top-of-atmosphere radiance for the sensor under test. In the case of Terra MODIS, a 1-km2 site at Railroad Valley, Nevada, is used as a test site. This work presents results obtained using the reflectance-based approach at RSG’s Railroad Valley test site. Results from 10 years of in situ data collection at Railroad Valley show a percent difference in the seven land spectral channels between RSG and Terra MODIS ranging from 1.6 % in channel 6 (1632 nm), to 5.1% in channel 4 (553 nm). The average percent difference for Terra MODIS’s seven land channels and RSG is 3.5%. The uncertainty is within the 3-5% predicted for ground-based vicarious calibration.

Czapla-Myers, J.; Thome, K.



Age-dating of rockslides: Methods and limitations  

NASA Astrophysics Data System (ADS)

Age-dating of deposits of catastrophic rockslides is prerequisite to unravel the potential relation between the frequency of mass-wasting events with climatic change or earthquakes. In the Alps, about 250 rockslides exceeding 106 m3 in volume are known, but the age as yet is determined only for a comparatively small number of events. For age determination of rockslide events, different methods are available (e. g. Lang et al., 1999). Radiocarbon Dating In the past few decades, rockslide deposits commonly were proxy-dated by 14C age determination of organic remnants preserved (a) in glacial, fluvio-glacial sediments overridden by the rockslide, (b) within the rockslide mass, or (c) in rockslide-dammed backwater deposits or lakes situated atop the rockslide mass. In each case, the 14C age provides a different constraint on the age of the rockslide event: in case (a), the 14C age represents a maximum age of the event; in case (b), which is quite rare, the 14C age is generally considered as a good proxy of the event age; in case (c) the 14C age represents a minimum age for the rockslide event. Unfortunately, radiocarbon dating often cannot be applied because of absence of suited deposits or exposures thereof, lack of organic remnants or of remnants suited for age-dating, and/or because determined 14C ages are substantially biased. Optically Stimulated Luminescence (OSL) Proxy-dating of rockslide events by OSL can be applied to silt- to sand-sized quartzose sediments present (a) directly below, (b) within, or (c) above/laterally aside a rockslide mass. For each case (a) to (c), the determined ages are subject to the same constraints as outlined for radiocarbon dating. Unfortunately, situations allowing for application of OSL to rockslide event dating are comparatively rare, and the resulting ages tend to have a wide error range. Surface Exposure Dating with cosmogenic radionuclides Surface exposure ages can be determined for rock samples taken from the sliding planes at the rockslide scarp, and/or taken from boulders accumulated at the surface of rockslide deposits. Surface exposure dating is the only 'direct' approach to determine the age of a rockslide event. To date, however, exposure dates are fraught with comparatively large error ranges. 234U/230Th Dating U/Th dating of diagenetic carbonate cements formed within rockslide masses represents a new method for proxy age determination. Breccias formed by precipitation of carbonate cements within rockslide deposits are fairly common. U/Th dating of the diagenetic cements can provide a good proxy of rockslide event age. U/Th ages are cementation ages, not event ages; to minimize the error, it is thus important to detect petrographically early cement, and (if necessary) to produce multiple U/Th ages from different samples. A major advantage of U/Th dating of cement is rapid, easy extraction of numerous samples of comparatively small size. Combined with other methods of numerical age determination, U/Th dating of cements in lithified rockslide deposits thus provides an indepedent check of correctness, and may enhance the overall precision of determination of event age (Ostermann et al., 2007, Prager et al., 2009). Lang, A., Moya, J., Corominas, J., Schrott, L. & Dikau, R., 1999: Classic and new dating methods for assessing the temporal occurrence of mass movements. Geomorphology, 30, 1, 33-52. Ostermann, M., Sanders, D., Prager, C. & Kramers, J. 2007: Aragonite and calcite cementation in 'boulder-controlled' meteoric environments on the Fern Pass rockslide (Austria): implications for radiometric age-dating of catastrophic mass movements. Facies, 53, 189-208. Prager, C., Ivy-Ochs, S., Ostermann, M., Synal, H.-A. & Patzelt, G. 2009: Geology and radiometric 14C-, 36Cl- and Th-/U-dating of the Fernpass rockslide (Tyrol, Austria). Geomorphology, 103, 1, 93-103. Please fill in your abstract text.

Ostermann, M.; Sanders, D.; Prager, C.



The biology behind lichenometric dating curves  

Microsoft Academic Search

Lichenometry is used to date late-Holocene terminal moraines that record glacier fluctuations. Traditionally, it relies upon\\u000a dating curves that relate diameters of the largest lichens in a population to surface ages. Although widely used, the technique\\u000a remains controversial, in part because lichen biology is poorly understood. We use size-frequency distributions of lichens\\u000a growing on well-dated surfaces to fit demographic models

Michael G. Loso; Daniel F. Doak



San bernardino cave (Italy) and the appearance of levallois technology in europe: results of a radiometric and technological reassessment.  


The introduction of Levallois technology in Europe marked the transition from the Lower to the early Middle Paleolithic. This new method of flake production was accompanied by significant behavioral changes in hominin populations. The emergence of this technological advance is considered homogeneous in the European archaeological record at the Marine isotopic stage (MIS) 9/MIS 8 boundary. In this paper we report a series of combined electron spin resonance/U-series dates on mammal bones and teeth recovered from the lower units of San Bernardino Cave (Italy) and the technological analyses of the lithic assemblages. The San Bernardino Cave has yielded the earliest evidence of Levallois production on the Italian Peninsula recovered to date. In addition to our results and the review of the archaeological record, we describe the chronological and geographical differences between European territories and diversities in terms of technological developments. The belated emergence of Levallois technology in Italy compared to western Europe corresponds to the late Italian Neanderthal speciation event. The new radiometric dates and the technological analyses of San Bernardino Cave raise the issue of the different roles of glacial refugia in the peopling and the spread of innovative flaking strategies in Europe during the late Middle Pleistocene. PMID:24146836

Picin, Andrea; Peresani, Marco; Falguères, Christophe; Gruppioni, Giulia; Bahain, Jean-Jacques



San Bernardino Cave (Italy) and the Appearance of Levallois Technology in Europe: Results of a Radiometric and Technological Reassessment  

PubMed Central

The introduction of Levallois technology in Europe marked the transition from the Lower to the early Middle Paleolithic. This new method of flake production was accompanied by significant behavioral changes in hominin populations. The emergence of this technological advance is considered homogeneous in the European archaeological record at the Marine isotopic stage (MIS) 9/MIS 8 boundary. In this paper we report a series of combined electron spin resonance/U-series dates on mammal bones and teeth recovered from the lower units of San Bernardino Cave (Italy) and the technological analyses of the lithic assemblages. The San Bernardino Cave has yielded the earliest evidence of Levallois production on the Italian Peninsula recovered to date. In addition to our results and the review of the archaeological record, we describe the chronological and geographical differences between European territories and diversities in terms of technological developments. The belated emergence of Levallois technology in Italy compared to western Europe corresponds to the late Italian Neanderthal speciation event. The new radiometric dates and the technological analyses of San Bernardino Cave raise the issue of the different roles of glacial refugia in the peopling and the spread of innovative flaking strategies in Europe during the late Middle Pleistocene.

Picin, Andrea; Peresani, Marco; Falgueres, Christophe; Gruppioni, Giulia; Bahain, Jean-Jacques



Youth dating violence.  


Adolescents' responses to the Youth Dating Violence Survey have previously been documented by the Centers for Disease Control and Prevention (1996). The present study on dating violence examined the responses of thirty-seven adolescents enrolled in an alternative high school program. Many reported psychological victimization in a dating relationship: their partners did something to make them feel jealous, damaged their possessions, said things to hurt their feelings, insulted them in front of others, tried to control them, threatened them, blamed them for bad things the dating partners did, and brought up something from the past to hurt them. In terms of perpetrating psychological abuse in a dating relationship, over half of the adolescents reported that they hurt their dating partners' feelings, insulted them in front of others, did something just to make them jealous, tried to control them, and damaged their possessions. Many of the adolescents had also been victims of physical violence in their dating relationships; they reported being scratched, slapped, slammed or held against a wall, kicked, bitten, forced to have sex, choked, and pushed, grabbed, or shoved, as well as having their arms twisted and fingers bent. Some perpetrated physical violence in dating situations, such as scratching their dating partners, hitting them with a fist or something hard, throwing something that hit their dating partners, kicking them, slapping them, physically twisting their arms, slamming or holding them against a wall, bending their fingers, biting them, choking them, and pushing, grabbing, or shoving them. The findings confirm that dating violence among adolescents is a serious health problem that needs to be addressed. PMID:11130591

James, W H; West, C; Deters, K E; Armijo, E



Aerial Radiometric and Magnetic Reconnaissance Survey of Portions of Arizona--New Mexico, Nogales Quadrangle.  

National Technical Information Service (NTIS)

The results of a high-sensitivity aerial gamma-ray spectrometer and magnetometer survey of the Nogales Quadrangle, Arizona, are presented. Statistical and geological analysis of the radiometric data revealed 47 uranium anomalies worthy of field checking a...




Technology Transfer Automated Retrieval System (TEKTRAN)

This study compares surface emissivity and radiometric temperature products derived using data collected with the MODerate resolution Imaging Spectroradiometer (MODIS) and Advanced Spaceborne Thermal Emission Reflectance Radiometer (ASTER) sensors, on the Earth Observation System (EOS) - Terra satel...


Radiometric, Electrical and Acoustic Geophysical Borehole Studies of the Loviisa Power Plant Site in 1983.  

National Technical Information Service (NTIS)

The borehole geophysical methods have been utilized on the Loviisa power plant site to resolve hydrogeological conditions. Late in 1983 radiometric, electrical and acoustic logging was performed by BPB Instruments Ltd. The types of sondes employed were ne...

P. Saksa



Sensor for Radiometric Measurements with Pyroelectric Detector and Reflecting Objective of Long Focal Length.  

National Technical Information Service (NTIS)

A sensor which permits radiometric and pyrometric measurements is described. The sensor is equipped with a cassegrain reflecting objective of long focal length. Radiation measurements are made in a chopped radiation mode at chopping frequencies between 6 ...

U. Mester W. Glockmann E. Pudelko



Aerial Radiometric and Magnetic Survey: Austin National Topographic Map, Texas Gulf Coast.  

National Technical Information Service (NTIS)

The results from an aerial radiometric and magnetic survey of the Austin National Topographic Map area of the Texas Gulf Coast are presented as multiple-parameter stacked profiles, magnetic stacked profiles, geology map, and flight base map. (ERA citation...



Aerial Radiometric and Magnetic Survey: Corpus Christi/Laredo National Topographic Map, Texas Gulf Coast.  

National Technical Information Service (NTIS)

Volume II contains flight line profile data and statistical analysis results from the aerial radiometric and magnetic survey of the Corpus Christi/Laredo National Topographic Map area of the Texas Gulf Coast. (ERA citation 04:049512)



Control in Dating Relationships.  

ERIC Educational Resources Information Center

|Examined data from national probability sample of individuals (n=244) who date to investigate thesis that individuals act to increase their level of control over others in those stages of dating relationships where control over situation has been threatened or disturbed by others either because of high conflict or lack of perspective taking.…

Stets, Jan E.



Date Palm Germplasm  

Technology Transfer Automated Retrieval System (TEKTRAN)

This book chapter reviews date palm genetic resources and their conservation. Date palm (Phoenix dactylifera) is an important food crop in the Middle East and North Africa. Its center of origin and diversity most probably is the area near Iraq/Iran. From there, it spread throughout its present range...


First-order 14C dating of Holocene molluscs  

NASA Astrophysics Data System (ADS)

The investigation of many problems in geology requires radiometric ages which need not be precise provided they are reliable and preferably cheap and quick. Such first-order ages can be determined on Holocene molluscs at 1/100 the cost of conventional 14C ages and in the space of a few hours by trapping CO 2 from the shell carbonate in an organic base for assay in a liquid scintillation counter. Using standard laboratory glassware and a counter with preset channels the technique gives ages for the last 8000 years with a standard error (2?) of 1500 years or less.

Vita-Finzi, C.



Radiometric Methods of Remote Sensing of Oil Spills on Water Surfaces  

Microsoft Academic Search

We present a comparative analysis of radiometric methods of remote sensing aimed at detecting and monitoring the parameters of oil spills on water surfaces. We consider the method of radio-brightness polarization contrasts and present the results of measuring the oil-film thickness on water, obtained using a two-frequency polarization radiometer with operating frequencies 12.2 and 34 GHz. The radiometric methods of radio-brightness

V. D. Krotikov; I. N. Mordvinkin; A. S. Pelyushenko; S. A. Pelyushenko



Radiometric and signal-to-noise ratio properties of multiplex dispersive spectrometry  

SciTech Connect

Recent theoretical investigations have shown important radiometric disadvantages of interferential multiplexing in Fourier transform spectrometry that apparently can be applied even to coded aperture spectrometers. We have reexamined the methods of noninterferential multiplexing in order to assess their signal-to-noise ratio (SNR) performance, relying on a theoretical modeling of the multiplexed signals. We are able to show that quite similar SNR and radiometric disadvantages affect multiplex dispersive spectrometry. The effect of noise on spectral estimations is discussed.

Barducci, Alessandro; Guzzi, Donatella; Lastri, Cinzia; Nardino, Vanni; Marcoionni, Paolo; Pippi, Ivan



A liquid-helium-cooled absolute reference cold load for long-wavelength radiometric calibration  

Microsoft Academic Search

Design, radiometric and thermal performance, and operation of a large diameter (78 cm) liquid-helium-cooled blackbody absolute reference cold load (CL) for the calibration of microwave radiometers is described. CL provides an absolute calibration near the liquid-helium (LHe) boiling point, with total uncertainty in the radiometric temperature of less than 30 mK over the 2.5-23 cm wavelength operating range. CL was

Marc Bensadoun; Chris Witebsky; George Smoot; Giovanni de Amici; Al Kogut; Steve Levin



Concept, simulation, and instrumentation for radiometric inflight icing detection  

NASA Astrophysics Data System (ADS)

The multi-agency Flight in Icing Remote Sensing Team (FIRST), a consortium of the National Aeronautics and Space Administration (NASA), the Federal Aviation Administration (FAA), the National Center for Atmospheric Research (NCAR), the National Oceanographic and Atmospheric Administration (NOAA), and the Army Corps of Engineers (USACE), has developed technologies for remotely detecting hazardous inflight icing conditions. The USACE Cold Regions Research and Engineering Laboratory (CRREL) assessed the potential of onboard passive microwave radiometers for remotely detecting icing conditions ahead of aircraft. The dual wavelength system differences the brightness temperature of Space and clouds, with greater differences potentially indicating closer and higher magnitude Cloud Liquid Water Content (CLWC). The Air Force RADiative TRANsfer model (RADTRAN) was enhanced to assess the flight track sensing concept, and a "flying" RADTRAN was developed to simulate a radiometer system flying through simulated clouds. Neural network techniques were developed to invert brightness temperatures and obtain integrated cloud liquid water. In addition, a dual wavelength Direct-Detection Polarimeter Radiometer (DDPR) system was built for detecting hazardous drizzle drops. This paper reviews technology development to date and addresses initial polarimeter performance.

Ryerson, Charles C.; Koenig, George G.; Reehorst, Andrew L.; Scott, Forrest R.



A multi-channel radiometric profiler of temperature, humidity and cloud liquid.  

SciTech Connect

A microwave radiometer is described that provides continuous thermodynamic (temperature, water vapor, and moisture) soundings during clear and cloudy conditions. The radiometric profiler observes radiation intensity at 12 microwave frequencies, along with zenith infrared and surface meteorological measurements. Historical radiosonde and neural network or regression methods are used for profile retrieval. We compare radiometric, radiosonde, and forecast soundings and evaluate the accuracy of radiometric temperature and water vapor soundings on the basis of statistical comparison with radiosonde soundings. We find that radiometric soundings are equivalent in accuracy to radiosonde soundings when used in numerical weather forecasting. A case study is described that demonstrates improved fog forecasting on the basis of variational assimilation of radiometric soundings. The accuracy of radiometric cloud liquid soundings is evaluated by comparison with cloud liquid sensors carried by radiosondes. Accurate high-resolution three-dimensional water vapor and wind analysis is described on the basis of assimilation of simulated thermodynamic and wind soundings along with GPS slant delays. Examples of mobile thermodynamic and wind profilers are shown. Thermodynamic profiling, particularly when combined with wind profiling and slant GPS, provides continuous atmospheric soundings for improved weather and dispersion forecasting.

Ware, R.; Carpenter, R.; Guldner, J.; Liljegren, J.; Nehrkorn, T.; Solheim, F.; Vandenberghe, F.; Environmental Research; Radiometrics Corp.; Univ. Corp. for Atmospheric Research; Weather Decision Technologies Inc.; Atmospheric and Environmental Research Inc.; National Center for Atmospheric Research



Help a geochronologist  

NSDL National Science Digital Library

This activity allows students to better understand radiometric dating and absolute dating techniques by calculating radiometric ages of zircon crystals. Their calculated ages then serve as tools to practice creating graphs, interpret analytic data, and reconstruct geologic events.

Berquist, Peter J.


Radiometric Calibration of EUNIS-06 With Theoretical Predicted `Insensitive' Line Ratios  

NASA Astrophysics Data System (ADS)

The Extreme-Ultraviolet Normal-Incidence Spectrograph (EUNIS) is a sounding-rocket payload that obtains imaged high-resolution spectra of solar active and quiet-Sun regions, providing information about the corona and upper transition region. EUNIS incorporates two independent, co-pointing imaging spectrographs, one covering EUV lines between 300 and 370 Å\\ seen in first order (the longwave [LW] channel), and a second covering lines between 170 and 205 Å\\ seen in second order (the shortwave [SW] channel). Shortly after the payload's initial successful flight on 2006 April 12, a complete end-to-end radiometric calibration of its LW bandpass was carried out at the Rutherford Appleton Laboratory in England. Here we develop and apply a technique for deriving the absolute radiometric calibration of its SW bandpass from these direct LW results by means of density- and temperature-insensitive line intensity ratios. The first step is to use the EUNIS LW calibration to get absolute intensities for EUV lines recorded from solar positions along its LW slit during the 2006 flight. Then co-registered SOHO/CDS images taken within minutes of the flight are used to transfer these absolute values to solar locations observed by the EUNIS SW slit, spatially offset by about 1 arcmin. Finally, theoretical `insensitive' line ratios obtained from CHIANTI allow us to determine absolute intensities of emission lines within the EUNIS SW bandpass from those observed in its LW channel. A total of 29 ratios composed of 11 LW and 15 SW emission lines from Fe~X - Fe~XIII yield an instrumental response curve that matches very well to a relative calibration which relied on combining measurements of individual optical components. The second EUNIS flight, now scheduled for 2007 October 30, will make coordinated observations and provide similar calibration updates for Hinode/EIS. We will also present some preliminary results from the new observations. EUNIS is supported by the NASA Heliophysics Division through its Low Cost Access to Space Program in Solar and Heliospheric Physics.

Wang, T.; Brosius, J. W.; Thomas, R. J.; Rabin, D. M.



Dating and eating. Beliefs about dating foods among university students  

Microsoft Academic Search

Dating is an important courtship activity in the U.S., and food consumption is part of dating events. Students use dating scripts to guide decisions and behaviors on dates, and perform scripts on dates to construct positive impression management. This study examined how students conceptualized dating foods. A questionnaire was administered in one large university class, and data from 301 students

Dana E. Amiraian; Jeffery Sobal



MIT-EAPS Neutron Activation Analysis and Radiometric Laboratory Contribution to Geosciences: Past, Present, and Future  

SciTech Connect

The Instrumental Neutron Activation Analysis (INAA) and Radiometric Laboratory's current system is described. This laboratory has been in continuous operation for the past thirty years. A review is provided about the laboratory's analytical participation in trace element geochemical studies of the earth's upper mantle, trace impurity studies of high purity materials, the provenance study of archaeological glass beads, trace multi-element analyses of standard reference materials, the preparation of synthetic analytical standards for Neutron Activation Analysis, and providing a training course in nuclear analytical techniques for environmental samples. The multi-element analysis by INAA consists of determining elements like the rare earths La, Ce, Nd, Sm Eu, Tb, Dy, Ho, Yb, Lu, and also As, Ba, Cl, Co, Cr, Cs, Dy, Fe, Hf, Hg, K, Mn, Na, Ta, Th, U. The projected future of the laboratory is explained in terms of its resources, expertise in high precision analysis of trace impurities for the material selection that is to be used in rare event physics experiments. For example, this 'surface' laboratory can be efficiently interfaced/integrated with a deep underground low background counting facility, especially in the initial stages.

Pillalamarri, Ila [Department of Earth Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)



Absolute Radiometric Calibration Of EUNIS, And Calibration Updates For Hinode/EIS And SOHO/CDS  

NASA Astrophysics Data System (ADS)

The Extreme-Ultraviolet Normal-Incidence Spectrograph sounding rocket payload was flown in 2006 (EUNIS-06) and 2007 (EUNIS-07), each time carrying two independent imaging spectrographs covering wave bands of 300-370 Angstrom in first order and 170-205 Angstrom in second order. For each flight, the absolute radiometric response of the EUNIS long-wavelength (LW) channel was directly measured in the same facility used for pre-flight calibrations of SOHO/CDS and Hinode/EIS. The wavelength range of the EUNIS LW channel overlaps that of CDS/NIS-1, and so can provide a direct calibration update for it. The EUNIS-06 observation shows that the efficiency of CDS/NIS-1 has decreased by a factor about 1.7 compared to that of the previously implemented calibration. Here we present an update to the absolute calibration for Hinode/EIS derived with a technique that combines a direct comparison of line intensities observed in cospatial EUNIS-07 and EIS spectra, along with density- and temperature-insensitive line intensity ratios.

Wang, Tongjiang; Thomas, R. J.; Brosius, J. W.; Young, P. R.; Rabin, D. M.; Davila, J. M.



Estimating Cloud Optical Depth from Surface Radiometric Observations: Sensitivity to Instrument Noise and Aerosol Contamination.  

NASA Astrophysics Data System (ADS)

The spectral-difference algorithm of Barker and Marshak for inferring optical depth ? of broken clouds has been shown numerically to be potentially useful. Their method estimates cloud-base reflectance and ? using spectral radiometric measurements made at the surface at two judiciously chosen wavelengths. Here it is subject to sensitivity tests that address the impacts of two ubiquitous sources of potential error: instrument noise and presence of aerosol. Experiments are conducted using a Monte Carlo photon transport model, cloud-resolving model data, and surface albedo data from satellite observations. The objective is to analyze the consistency between inherent and retrieved values of ?. Increasing instrument noise, especially if uncorrelated at both wavelengths, decreases retrieved cloud fraction and increases retrieved mean ?. As with all methods that seek to infer ? using passive radiometry, the presence of aerosol requires that threshold values be set in order to discriminate between cloudy and cloud-free columns. A technique for estimating thresholds for cloudy columns is discussed and demonstrated. Finally, it was found that surface type and mean inherent ? play major roles in defining retrieval accuracy.

Beaulne, Alain; Barker, Howard W.; Blanchet, Jean-Pierre



FDA Actions to Date  

Center for Food Safety and Applied Nutrition (CFSAN)

... FDA, US Food and Drug Administration. US Food & Drug Administration. A to Z Index; Follow FDA; FDA Voice Blog. ... FDA Actions to Date. ... More results from


Teen Dating Violence  


... community. Have a history of aggressive behavior or bullying. Dating violence can be prevented when teens, families, ... STRYVE) Violence Education Tools Online (VETOViolence) Social & New Media Podcasts Badges and Buttons Injury Center Topics Saving ...


Rock Dating Gallery  

NSDL National Science Digital Library

This gallery of online resources is from the Museum's Seminars on Science, a series of distance-learning courses designed to help educators meet the new national science standards. The Rock Dating Gallery, part of the Earth: Inside and Out seminar, features illustrations from the Hall of Planet Earth, which has two informative overviews: Dating Rocks with Radioactivity and Telling Time Precisely. Stillwater Gabbro, has two images of this rock from the Stillwater Complex in Montana and a video (with a printable PDF transcript) explaining how it was dated. Stillwater Gabbro: Collecting and Dating, has a Rate of Decay Graph, a Computing the Rate of Decay video (with a printable PDF transcript), and three images: Fieldwork in Montana, Collecting a Sample for the Hall, and Vials of Crushed Rock.


The Relationship between Balancing Reactions and Reaction Lifetimes: A Consideration of the Potassium Argon Radiometric Method for Dating Minerals  

NASA Astrophysics Data System (ADS)

Knowing the mechanism for a chemical reaction means that you can also know what the products of that reaction are, how much of each product is formed, and the kinetics of product formation. Conversely, not knowing what the products are, how much of each product is formed, or the kinetics of product formation means that the mechanism of the reaction cannot be fully known. This line of thinking, commonly taught in college chemistry courses throughout the world, applies as well to nuclear decay reactions occuring in minerals. When a geochronologist determines a mineral's age by the potassium argon method, it is implied that the mechanism(s) by which 40 Ar came to be inside the mineral are known. Yet, geochronologists never identify and quantify the other products that must form in addition to 40 Ar. In fact, no one even knows what the other products are, in any mineral. One may argue that, because most of the products from the potassium argon reaction are unknown, the geochronologist cannot actually know how the 40 Ar atoms came to be inside the mineral and, hence, cannot fully know the mineral's age. Formulating and critically examining such arguments can be an important part of the education of scientists.

Howard, William A.



Laser photothermal radiometric instrument for industrial steel hardness inspection  

NASA Astrophysics Data System (ADS)

To meet the industrial demand for on-line steel hardness inspection and quality control, a non-contact, non-destructive laser photothermal radiometric instrument (HD-PTR) was developed. The instrument is equipped with a non-liquid-nitrogen-cooled HgCdZnTe (MCZT) detector, a National Instruments data acquisition card with a Dynamic System Analysis (DSA) module, and control software. A series of industrial steel samples which included automotive screws and aircraft gears (flat or curvilinear) were examined. The effective hardness case depths of these samples ranged from 0.21 mm to 1.78 mm. The results demonstrated that three measurement parameters (metrics) can be extracted when using a fast swept-sine photothermal method. These parameters include the phase minimum (or peak) frequency, fmin, the half width, W, and the area, S. It was found that they are complementary for evaluating widely different ranges of hardness case depths. fminis most suitable for large case depths, and W and S for shallower case depths.

Guo, X.; Sivagurunathan, K.; Pawlak, M.; Garcia, J.; Mandelis, A.; Giunta, S.; Milletari, S.; Bawa, S.



Early detection of RFI in SMOS radiometric measurements  

NASA Astrophysics Data System (ADS)

The SMOS mission is a European Space Agency (ESA) project aimed at global monitoring of surface Soil Moisture and Ocean Salinity from radiometric L-band observations. The single payload of the mission is MIRAS, the very first Microwave Imaging Radiometer using Aperture Synthesis ever launched into space. This work is concerned with the contamination of the data collected by MIRAS by radio frequency interferences (RFI) which degrade the performance of the mission. RFI events are evidenced and it is explained why well-known standard RFI detection methods cannot be used. Accounting for specificities of MIRAS, an early detection method tailored to SMOS measurements is presented and illustrated with data acquired with the reference radiometers during the first year of the mission. The aim of this method is not to localize nor to quantify the RFI sources but only to detect, to quantify and possibly to mitigate the corresponding RFI effects in the signals measured by these radiometers. This is done as soon as possible in the processing pipeline so that the propagation of such undesirable effects is known and under control from measurements to final products.

Anterrieu, Eric



One date, one break?  

Microsoft Academic Search

This paper demonstrates that the conventional approach of using official liberalisation dates as the only existing breakdates\\u000a could lead to inaccurate conclusions as to the effect of the underlying liberalisation policies. It also proposes an alternative\\u000a paradigm for obtaining more robust estimates of volatility changes around official liberalisation dates and\\/or other important\\u000a market events. By focusing on five East Asian

Michail Karoglou; Panicos Demetriades; Siong Hook Law



Food Product Dating  


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Magnetostratigraphic and radiometric constraints on salt formation in the Qaidam Basin, NE Tibetan Plateau  

NASA Astrophysics Data System (ADS)

The Qaidam Basin is the largest Cenozoic intermontane basin within the northeast (NE) Tibetan Plateau. It contains large amounts of nonmarine evaporite deposits formed during the Pliocene–Quaternary. Even at present, extensive salt deposits dominated by halite and potash are formed by solar-driven concentration of brine water in the basin interior, making it the most important industrial base for potash exploitation in China. The formation of salt required an arid climatic, appropriate hydrological and tectonic setting through geologic times and will do so in the future. Studying the salt formation in the Qaidam Basin will enhance our understanding of processes driven by saline lake evolution, regional climate change, and tectonic movements, not only for the setting of the Tibetan Plateau. Reliable dating is crucial for assessing the time of salt formation in Qaidam Basin and the accumulation process, yet no comprehensive scientific studies have been reported on this important issue until now. In this paper, we critically review and compile magnetostratigraphic and radiometric studies of the salt-bearing strata within seven depressions of the basin. We find that the ages of salt formation are very different in these depressions: for the Dalangtan, Yiliping, Chahansilatu, and Kunteyi depressions, first salt deposits occurred at >3.90 ± 0.02 Ma, 2.88 ± 0.04 Ma, 2.24 ± 0.01 Ma and 1.18 ± 0.02 Ma, respectively. For the Mahai, Gasikule, and Qarhan, the ages of earliest salt formation are much younger i.e., 302 ± 56 ka, 608 ± 38 ka, and 54–24 ka, respectively. However, the result from Mahai has to be considered with caution.

Wang, Jiuyi; Fang, Xiaomin; Appel, Erwin; Zhang, Weilin



Early radiometric performance assessment of the Landsat-8 Operational Land Imager (OLI)  

NASA Astrophysics Data System (ADS)

Landsat-8, the latest in the Landsat series of satellites, was launched on February 11, 2013 and carries on board the Operational Land Imager (OLI) as one of its payloads. The satellite's mission is to continue the long history of moderate resolution imaging of the Landsat program. The OLI follows the highly successful Landsat-5 and Landsat-7 in continuing to populate a global archive of Earth images that dates back to 1972. The design of the Landsat-8 instruments is a significant departure from earlier Landsats. The OLI is a pushbroom instrument; all previous recent Landsat instruments were electromechanical (whiskbroom) instruments. OLI also has two new spectral bands and refined bandpasses; the thermal imaging capability on Landsat-8 is in a separate instrument. The pushbroom design provides significantly better signal to noise performance than historically available, but at the expense of circa 70,000 detectors versus the 100 or so on previous instruments. The large focal plane and large number of detectors makes detector to detector relative calibration more challenging, increasing the propensity for banding and striping in imagery. On-board radiometric calibration devices include a shutter to measure the dark levels, a full aperture solar panel for calibration against the sun, and multiple sets of lamps for short-term stability monitoring. Early results from the on-board calibration devices indicate that the OLI is outperforming the Landsat-7 instrument in signal-to-noise ratio by an order of magnitude, consistent with pre-launch measurements. Over the first five months, the instrument is stable to within 0.7%, as measured by the lamps and solar diffuser. A relative calibration (detector-to-detector) and a linearization parameter update have been performed that reduce visible striping; with this update, the residual striping has been reduced by half in all OLI bands.

Barsi, Julia A.; Markham, Brian L.



English/Russian terminology on radiometric calibration of space-borne optoelectronic sensors  

NASA Astrophysics Data System (ADS)

The efficient use of data acquired through exo-atmospheric observations of the Earth within the framework of existing and newly planned programs requires a unique understanding of respective terms and definitions. Yet, the last large-scale document on the subject - The International Electrotechnical Vocabulary - had been published 18 years ago. This lack of a proper document, which would reflect the changes that had occurred in the area since that time, is especially detrimental to the developing international efforts aimed at global observations of the Earth from space such as the Global Earth Observations Program proposed by the U.S.A. at the 2003 WMO Congress. To cover this gap at least partially, a bi-lingual explanatory dictionary of terms and definitions in the area of radiometric calibration of space-borne IR sensors is developed. The objectives are to produce a uniform terminology for the global space-borne observations of the Earth, establish a unique understanding of terms and definitions by the radiometric communities, including a correspondence between the Russian and American terms and definitions, and to develop a formal English/Russian reference dictionary for use by scientists and engineers involved in radiometric observations of the Earth from space. The dictionary includes close to 400 items covering basic concepts of geometric, wave and corpuscular optics, remote sensing technologies, and ground-based calibration as well as more detailed treatment of terms and definitions in the areas of radiometric quantities, symbols and units, optical phenomena and optical properties of objects and media, and radiometric systems and their properties. The dictionary contains six chapters: Basic Concepts, Quantities, Symbols, and Units, Optical phenomena, Optical characteristics of surfaces and media, Components of Radiometric Systems, Characteristics of radiometric system components, plus English/Russian and Russian/Inglish indices.

Privalsky, V.; Zakharenkov, V.; Humpherys, T.; Sapritsky, V.; Datla, R.


Microwave and Millimeter Wave Forward Modeling Results from the 2004 North Slope of Alaska Arctic Winter Radiometric Experiment  

SciTech Connect

The 2004 Arctic Winter Radiometric Experiment was conducted at the North Slope of Alaska (NSA) Atmospheric Radiation Measurement (ARM) Program field site near Barrow, Alaska from March 9 to April 9, 2004. The goals of the experiment were: to study the microwave and millimeter wave radiometric response to water vapor and clouds during cold and dry conditions; to obtain data for forward model studies at frequencies ranging from 22.235 to 400 GHz, to demonstrate new Environmental Technology Laboratory's (ETL) radiometric receiver and calibration technology and to compare both radiometric and in situ measurements of water vapor.

Westwater, E.R.; Cimini, D.; Klein, M.; Leuski, V.; Mattioli, V.; Gasiewski, A.J.; Dowlatshahi, S.; Liljegren, J.S.; Lesht, B.M.; Shaw, J.A.



Linear-array apertures for in-flight dynamic solar calibration of radiometric channels for Earth radiation-budget applications.  


The zero-frequency gain of nonimaging radiometers used in Earth radiation-budget applications is usually verified by a procedure that allows the instrument to view the Sun through an appropriate attenuating aperture and then equates its response to the known attenuated solar constant. However, channel intercomparison often requires that data from a low-resolution, relatively slow instrument such as an active-cavity radiometer be compared with data from a high-resolution, fast instrument such as a scanning thermistor-bolometer radiometer. In such a case, consideration of the difference in the dynamic responses of the two channels may be important. A novel technique for in-flight measurement of the radiometric transfer function of such instruments is described and then demonstrated through the use of a high-order dynamic model of the total, wide-field-of-view, nonscanning channel of NASA's Earth Radiation Budget Experiment (ERBE). PMID:20935961

Tira, N E; Mahan, J R; Lee Iii, R B; Keynton, R J



Geostatistical analysis as applied to two environmental radiometric time series.  


This article details the results of an investigation into the application of geostatistical data analysis to two environmental radiometric time series. The data series employed consist of 99Tc values for seaweed (Fucus vesiculosus) and seawater samples taken as part of a marine monitoring program conducted on the coast of northern Norway by the Norwegian Radiation Protection Authority. Geostatistical methods were selected in order to provide information on values of the variables at unsampled times and to investigate the temporal correlation exhibited by the data sets. This information is of use in the optimisation of future sampling schemes and for providing information on the temporal behaviour of the variables in question that may not be obtained during a cursory analysis. The results indicate a high degree of temporal correlation within the data sets, the correlation for the seawater and seaweed data being modelled with an exponential and linear function, respectively. The semi-variogram for the seawater data indicates a temporal range of correlation of approximately 395 days with no apparent random component to the overall variance structure and was described best by an exponential function. The temporal structure of the seaweed data was best modelled by a linear function with a small nugget component. Evidence of drift was present in both semi-variograms. Interpolation of the data sets using the fitted models and a simple kriging procedure were compared, using a cross-validation procedure, with simple linear interpolation. Results of this exercise indicate that, for the seawater data, the kriging procedure outperformed the simple interpolation with respect to error distribution and correlation of estimates with actual values. Using the unbounded linear model with the seaweed data produced estimates that were only marginally better than those produced by the simple interpolation. PMID:12666718

Dowdall, Mark; Lind, Bjørn; Gerland, Sebastian; Rudjord, Anne Liv



Radiometric calibration and noise estimation of acousto-optic tunable filter hyperspectral imaging systems.  


The accuracy of the radiometric response of acousto-optic tunable filter (AOTF) hyperspectral imaging systems is crucial for obtaining reliable measurements. It is therefore important to know the radiometric response and noise characteristics of the hyperspectral imaging system used. A radiometric model of an AOTF hyperspectral imaging system composed of an imaging sensor radiometric model (CCD, CMOS, and sCMOS) and an AOTF light transmission model is proposed. Using the radiometric model, a method for obtaining the fixed pattern noise (FPN) of the imaging system by displacing and imaging an illuminated reference target is developed. Methods for estimating the temporal noise of the imaging system, using the photon transfer method, and for correcting FPN are also presented. Noise estimation and image restoration methods were tested on an AOTF hyperspectral imaging system. The results indicate that the developed methods can accurately calculate temporal and FPN, and can effectively correct the acquired images. After correction, the signal-to-noise ratio of the acquired images was shown to increase by 26%. PMID:23736239

Katrašnik, Jaka; Pernuš, Franjo; Likar, Boštjan



Dating and eating. Beliefs about dating foods among university students.  


Dating is an important courtship activity in the U.S., and food consumption is part of dating events. Students use dating scripts to guide decisions and behaviors on dates, and perform scripts on dates to construct positive impression management. This study examined how students conceptualized dating foods. A questionnaire was administered in one large university class, and data from 301 students were analyzed. Students were asked to name three dating foods, three foods that are not dating foods, what makes foods dating foods, and what makes foods not dating foods. Findings revealed that both common and uncommon foods were named as dating and not dating foods. Alcoholic beverages were sometimes named as dating foods. Women often named feminine foods (considered appropriate for females) as dating foods, but men were not more likely to name masculine foods (considered appropriate for males) as dating foods. Neat and easy-to-eat foods were often named as dating foods, while pungent foods and foods causing bad breath were named as not dating foods. These findings support the conception that dating scripts guide thinking about food choices to enhance impression management. Dating food choices are important for current health and as potential precursors for long-term eating relationships like marriage. PMID:19577601

Amiraian, Dana E; Sobal, Jeffery



Identification of Worldwide Optimal Pseudo-Invariant Calibration Sites for Post-Launch Radiometric Calibration of Earth Observation Satellite Sensors  

NASA Astrophysics Data System (ADS)

The primary objective of this project was to identify extremely stable sites on the Earth's surface known as Pseudo-Invariant Calibration Sites (PICS). A recently developed technique for monitoring the long term stability of earth observing satellite sensors was based on using PICS for detecting trends in the radiometric response of these instruments. In a manner analogous to using a known reflectance or radiance source in a laboratory, this method relied on the stability of the Earth's surface over time. To perform this task, the Landsat 5 Thematic Mapper (TM) sensor was used to identify the most invariant locations or PICS on the Earth's surface by monitoring the temporal stability of carefully selected ground sites on Earth. Ground sites were selected to ensure minimal surface and atmosphere change that could affect the observed reflectance, thus enabling a means to monitor the radiometric stability of space instruments. PICS mainly consist of playa (dry lakebeds), salt flats and desert sand sites located in arid regions with low probability of cloud cover, spatial homogeneity, constant surface spectral reflectance and BRDF over short and long periods of time. Potential PICS were evaluated and chosen for the study based upon their size, location, climate characteristics, and scene availability in the USGS data archive. A grid-based approach was used to determine and recommend the areas of each PICS that was considered most invariant. This approach relied on the PICS min-noise algorithm developed recently at SDSU, where the mean radiance of each grid was calculated for each scene and the grid with lowest temporal standard deviation of the mean was considered as most invariant. The Levene Test of equality of variance was used to optimize the size of worldwide PICS, and uncertainties using those optimal locations were calculated for comparison. A catalog of recommended sites was developed: seven in the Sahara Desert and one each in North America, South America, Australia, Middle East and Asia. Sahara sites exhibit uncertainties of 2% or less in VNIR and 2--3% in SWIR across most sites. Global sites exhibit uncertainties in the range of 1--5%. Finally, as a validation exercise, Landsat-7 Enhanced Thematic Mapper plus (ETM+) reflective band radiometric gain trends were estimated using the optimal locations of four worldwide PICS.

Basnet, Bikash


The Dating Game.  

ERIC Educational Resources Information Center

|Presents activities to cultivate the tendency to see special qualities in numbers that can be played on certain calendar days. Includes games on the constant of the day, Fibonacci and golden ratio dates, primes, powers, December 25, and the day of the year. (ASK)|

Zerger, Monte J.



Biodiversity of date palm  

Technology Transfer Automated Retrieval System (TEKTRAN)

The date palm (Phoenix dactylifera) is the dominant component upon which the sustainable biophysical and socio-economic structures of the oasis ecosystem are based; a fruit tree with unique nutritional, biochemical and biophysical characteristics, a rich source of aesthetic and cultural values, and ...


Date palm: Production  

Technology Transfer Automated Retrieval System (TEKTRAN)

The future of date palm, as a dioecious, monocot fruit tree largely depends on (1) developing advanced knowledge and information about the dynamics, management, and sustainability of the tree as a central component of the oasis agro-ecosystem, and (2) in-depth understanding of the genetic diversity ...


Radiocarbon Dating of Bone  

Microsoft Academic Search

SELLSTEDT et al.1 have described a method for the removal of inorganic carbonates from bone so that the residual collagen can be used as a source material for radiocarbon dating, and they conclude that this ``offers the archaeologist an elegant and versatile tool which is likely to find wide application''.

H. Barker




Microsoft Academic Search

Mites inhabiting date palms in Egypt were studied for two years (1998-2000). During this study, 16 species of mites belonging to 11 families were collected. These mites were classified according to their feeding habits into three categories: 7 species plant feeders, 6 species predacious and 3 species with miscellaneous feeding habits.

M. E. El-Halawany; M. A. Abdel-Samad; M. E. El-Naggar


NPP Visible/Infrared Imaging Radiometer Suite (VIIRS) radiometric calibration emissive bands: tested performance  

NASA Astrophysics Data System (ADS)

The Visible/Infrared Imaging Radiometer Suite (VIIRS) collects radiometric and imagery data in 22 spectral bands within the visible and infrared spectrum ranging from 0.4 to 12.5 ?m. This paper describes the radiometric uncertainty requirements for the 7 VIIRS thermal emissive bands and the calibration methodology employed to meet these requirements, including the on-board calibration subsystems and the retrieval algorithm for generating calibrated radiance from instrument data. The instrument characteristics contributing to uncertainties in retrieved radiance are presented based on results from the recently completed pre-launch test program. The final roll-up of these uncertainties relative to the absolute radiometric requirements are shown, and compared against the results obtained from the radiance retrieval algorithm exercised during thermal-vacuum testing for a NIST traceable Blackbody Calibration Source.

Johnson, Eric; Galang, Karen; Ranshaw, Courtney; Robinson, Brendan



Radiometric selective inhibition tests for differentiation of Mycobacterium tuberculosis, Mycobacterium bovis, and other mycobacteria.  

PubMed Central

In the context of a busy reference laboratory, radiometric selective inhibition tests were evaluated for rapid differentiation of Mycobacterium tuberculosis and Mycobacterium bovis and of the M. tuberculosis complex from other mycobacteria. p-Nitro-alpha-acetylamino-beta-hydroxypropiophenone at 5 micrograms and hydroxylamine hydrochloride at 62.5 and 125 micrograms per ml of 7H12 medium were used to separate the M. tuberculosis complex from other mycobacteria (MOTT bacilli). Since it is important epidemiologically to distinguish M. tuberculosis from M. bovis, susceptibility to 1 microgram of thiophene-2-carboxylic acid per ml was also determined radiometrically. By using these three agents as selective inhibitors, M. tuberculosis, M. bovis, and MOTT bacilli were differentiated with a high degree of specificity by a BACTEC radiometric procedure. Results of tests performed on clinical isolates submitted on solid medium to our reference laboratory were available within 5 days.

Gross, W M; Hawkins, J E



Lack of clinical relevance in routine final subcultures of radiometrically negative BACTEC blood culture vials  

SciTech Connect

During a 38-month period, 10,106 blood specimens were received in the laboratory for culture. These were inoculated into 26,424 vials and processed using the BACTEC radiometric detection system. Of these vials, 1,914 were eventually found to be microbiologically positive. Isolates from 836 vials were judged to be contaminants. In the remaining 1,078 vials, growth was first detected visually or radiometrically in 1,062 and by final subculture in 16. Growth from these sixteen bottles represented 12 clinically significant bacteremic episodes in as many patients. In nine of these episodes, other culture vials from the same patient were positive radiometrically. Therefore, 358 of 361 (99.2%) bacteremic episodes were detected without the benefit of routine final subcultures. The three patients whose bacteremia was missed were diagnosed clinically and placed on appropriate therapy prior to the detection of the bacteremias by final subculture.

Plorde, J.J.; Carlson, L.G.; Dau, M.E.



K-Ar dating on Mars ?  

NASA Astrophysics Data System (ADS)

Dating terrestrial magmatic and plutonic rocks is now generally performed by the argon-argon technique, based on the potassium-argon chronometer. This technique compares the 40/39 isotopic ratios of argon extracted from the sample to the one of a standard mineral in which 39 potassium has been activated into 39 argon by neutron irradiation under the same conditions as the sample to be dated. The technique is powerful as 1) it works on isotopic ratios unavailing any quantification of the mineral amount used and also its total extraction, 2) it makes it possible to date single grains ; 3) even if the analytical conditions vary in the mass spectrometer, the measured isotopic ratios remain constant ; 4) it permits to identify, from a stepwise heating, any thermal effect having affected the rock. Dating rocks on Mars is a major challenge and would be a fundamental progress in the knowledge of its formation and evolution. Argon-argon dating would be possible on bring back samples, but the analytical conditions prohibit the application of the 40Ar/39Ar technique for in situ dating on Mars. However, potassium-argon chronometer remains the most suitable method to date Martian rocks. Potassium is an element universally distributed and one of the major constituents of silicates. Considering a giga years order of magnitude for the age of rocks exposed at the surface of Mars, the natural decay from 40K has accumulated a large amount of radiogenic 40Ar, which can be easily measured after extraction from a minute volume of the mineral. On Earth, the radiogenic argon percentage accumulated in K- minerals over 1 giga years reaches more than 99.9%, which makes not necessary an accurate correction for the atmospheric contamination based on the measurement of a non radiogenic argon isotope (36Ar). Such contamination is even more negligible for Martian rocks due to the reduced atmosphere. If we now consider that the rocks on Mars were not affected by significant thermal crisis (>250°C for the concerned silicates), argon-argon dating technique appears not sine qua non (which is also true for the majority of the rocks at the Earth surface). The potassium-argon conventional technique of measurement could thus be applied, but it implies to measure separately potassium and argon, to quantify accurately the sample volume from which argon is extracted, to perform a total extraction of the gas and to calibrate the analyses making essential to ensure the steadiness of the instruments. These requirements may limit the use of the technique. But, despite these challenges, we here present an analytical system operating the potassium-argon dating for in situ measurements on Mars.

Gillot, P.; Lefèvre, J.; Chiavassa, F.; Chassefiere, E.



Measurement of the radiometric and polarization characteristics of a microgrid polarizer infrared focal plane array  

NASA Astrophysics Data System (ADS)

Remote sensing applications make use of the optical polarization characteristics of a scene to enhance target detection and discrimination. Imaging polarimeters typically utilize polarizing arrays located in front of a focal plane array as a means of extracting polarization information from the optical scene. Over the last few years, technology development efforts have resulted in FPAs that integrate the polarizer with the infrared focal plane array (FPA). This paper will report on the radiometric and polarization characterization of a micro-grid polarizer FPA from DRS Infrared Technologies, L.P. (DRS). These measurements were performed to evaluate the radiometric performance and the polarization characteristics of the FPA.

Hubbs, John E.; Gramer, Mark E.; Maestas-Jepson, Diana; Dole, Gary A.; Fetrow, Matthew; Bowers, David; Boger, James



Dating and relationship issues  

Microsoft Academic Search

Conclusions  The subject of dating and relationships for women with disabilities is one of those areas for which we have many more questions\\u000a than answers, more suggested tendencies than demonstrated patterns of variables. If research pursuits reflect social values,\\u000a it makes sense that a society that has long ignored or disdained the gender role of women with disabilities has invested little

Carol J. Gill



Date Palm Germplasm  

Microsoft Academic Search

\\u000a Date palm (Phoenix dactylifera L) belongs to the genus Phoenix which is distributed throughout the tropical and subtropical areas of South Asia and Africa. The species are dioecious and\\u000a the fruits are drupes of varying sizes. P. dactylifera apparently originated in the area near the present Iraq and Iran, was domesticated in ancient times and spread into adjacent\\u000a regions having

R. R. Krueger


Potassium-Argon Dating of Plio-Pleistocene Intrusive Rocks  

Microsoft Academic Search

THE potential of the potassium-argon technique in the dating of young rocks can be evaluated by applying it to intrusive igneous rocks which are well dated by conventional geological methods. Because of their possible interest, we are reporting the dating of two such igneous rocks. They occur at Sutter Buttes in the Sacramento Valley, forty miles north of Sacramento, California.

Garniss H. Curtis; Joseph Lipson; Jack F. Evernden



From romance to rocket science: speed dating in higher education  

Microsoft Academic Search

This article is the first comprehensive review of speed dating in the tertiary sector. While speed dating has its origins as a networking technique to connect singles, it has only more recently made its way into the academy. Since 2005 universities world-wide have begun to adopt speed dating protocols as a tool for building research culture. An extensive review of

Olav Muurlink; Cristina Poyatos Matas



From Romance to Rocket Science: Speed Dating in Higher Education  

ERIC Educational Resources Information Center

|This article is the first comprehensive review of speed dating in the tertiary sector. While speed dating has its origins as a networking technique to connect singles, it has only more recently made its way into the academy. Since 2005 universities world-wide have begun to adopt speed dating protocols as a tool for building research culture. An…

Muurlink, Olav; Poyatos Matas, Cristina



Dendrochemical Dating of Tephra Layers  

NASA Astrophysics Data System (ADS)

Dating eruptions in the past 1000 years can be difficult with 14C, as production rates have varied. Tree-ring dating has been used, with eruptions presumably causing thin rings. We are developing a dendrochemical dating technique that may give more confidence to such dates. When a tephra is deposited, soil chemistry may change and many components of the glassy matrix are mobile and available for leaching into the soil and, hence, to plants. If some components were scarce prior to the eruption, the content in tree rings may increase and serve as a chemical marker of the eruption onset. LA-ICP-MS analysis of tree cores allows earlywood from each ring to be analyzed. We are currently investigating whether acid dissolution will produce similar results and precision with small sample sizes. The 1943-1952 CE eruption of Paricutin, Michoacan, Mexico, deposited a thick tephra in a conifer forest. Analyses of tree cores show that pre-eruption P concentrations of a few ppm increased an order of magnitude within the first two years after the onset of the eruption and then dropped steadily during the rest of the eruption to 10-15 ppm, which was then maintained for decades. Ca and Sr dropped during the eruption but rebounded immediately afterward. These three elements appear immobile in the wood, as steep compositional gradients occur across rings. The Paricutin tephra has 0.2-0.4 wt% P2O5. Analyses of soils and tephra obtained by the Bray method (a weak HCl leaching intended to mimic leaching in slightly acid soils) yield values of 2-17 ppm available phosphorus, fairly high values for this area. The Sunset Crater eruption near Flagstaff, Arizona, was dated at 1064 CE based on the onset of thin tree rings in three beams from structures at Wupatki village, 20 km north of the volcano. Our analyses of this wood show pronounced increases in P, Ca, Sr, Mg, and Mn in the early 1080s CE. Currently, we are investigating Jeffrey pine reaction to the mid-1600s CE Cinder Cone eruption at Lassen Volcanic National Park, California.

Ort, M. H.; Sheppard, P. R.; Speakman, J.; Anderson, K. A.; Elson, M. D.; Siebe G., C.



Landsat-7 ETM+: 12 years on-orbit reflective-band radiometric performance  

USGS Publications Warehouse

The Landsat-7 ETM+ sensor has been operating on orbit for more than 12 years, and characterizations of its performance have been ongoing over this period. In general, the radiometric performance of the instrument has been remarkably stable: 1) noise performance has degraded by 2% or less overall, with a few detectors displaying step changes in noise of 2% or less; 2) coherent noise frequencies and magnitudes have generally been stable, though the within-scan amplitude variation of the 20 kHz noise in bands 1 and 8 disappeared with the failure of the scan line corrector and a new similar frequency noise (now about 18 kHz) has appeared in two detectors in band 5 and increased in magnitude with time; 3) bias stability has been better than 0.25 DN out of a normal value of 15 DN in high gain; 4) relative gains, the differences in response between the detectors in the band, have generally changed by 0.1% or less over the mission, with the exception of a few detectors with a step response change of 1% or less; and 5) gain stability averaged across all detectors in a band, which is related to the stability of the absolute calibration, has been more stable than the techniques used to measure it. Due to the inability to confirm changes in the gain (beyond a few detectors that have been corrected back to the band average), ETM+ reflective band data continues to be calibrated with the prelaunch measured gains. In the worst case, some bands may have changed as much as 2% in uncompensated absolute calibration over the 12 years.

Markham, B. L.; Haque, M. O.; Barsi, J. A.; Micijevic, E.; Helder, D. L.; Thome, K. J.; Aaron, D.; Czapla-Myers, J. S.



Aerial radiometric and magnetic survey: Marysvale detail survey, Richfield National Topographic Map sheet, Utah. Volume II. Radiometric multi-variable stacked profile data. Final report  

SciTech Connect

The results of the analyses of a systematic airborne gamma radiation and total magnetic survey for the area identified as Marysvale, located in southwestern Utah, is presented in Volumes I-IV of this report. The airborne data gathered is reduced by ground computer facilities to yield profile plots of the equivalent uranium, thorium and potassium gamma radiation intensities, the ratios of these intensities, the total gamma radiation counting rate and the earth's residual magnetic field intensity. Profile plots of the aircraft's altitude above the earth's surface, the ambient temperature and pressure, and the magnetic field data measured by a base station magnetometer is presented also. An evaluation of the distribution of the radiometric data in terms of its established geochemical map units, which were derived via geochemical analysis methods, for the entire survey area has been prepared and is included. The determination of the geochemical units presented has been established principally from the analysis of the radiometric and magnetic contour maps and, more importantly, the multi-variate analysis map. A general description of the area, including descriptions of the various geologic and geochemical units, is included within the text. Volume II contains the 10-variable radiometric stacked profile data for the entire survey area.

Not Available



Dating gold deposition in a Carlin-type gold deposit using Rb/Sr methods on the mineral galkhaite  

NASA Astrophysics Data System (ADS)

Significant effort has been expended in an attempt to date hydrothermal activity that generated Carlin-type gold deposits (CTDs) in the Great Basin of Nevada. Thus far, these efforts have been only partially successful, because the relationship(s) between the dated mineral and hydrothermal activity are equivocal in many cases. Galkhaite, a trace component of at least four CTDs in Nevada, contains significant amounts of Rb and virtually no Sr, making it an ideal candidate for radiometric dating. At the Getchell deposit, galkhaite is paragenetically late, but clearly associated with gold mineralization. Our data place gold mineralization at Getchell at 39.0 ± 2.1 Ma. This is the first unequivocally gold-related date produced for any of the Carlin-type systems. Galkhaite also has been reported at the Carlin, Rodeo, and Betze deposits and is likely present in other CTDs in Nevada. This mineral may provide a solution to the conundrum of dating of CTDs.

Tretbar, David R.; Arehart, Greg B.; Christensen, John N.



Radiometric Ages for Seamounts from the Easter-Salas y Gomez-Nazca Hotspot Track  

NASA Astrophysics Data System (ADS)

The Easter-Salas y Gomez volcanic lineament is an east-west swath of isolated seamounts and coalesced ridges that merges at its eastern end with the southern end of the NE-SW trending Nazca Ridge. All morphologic aspects of this province are consistent with its origin as a hotspot track, with a plate motion change at the time of the inflection at the southern end of the Nazca Ridge. However, the first report of radiometric dating from dredged rocks from several seamounts showed young ages along the whole lineament, denying an age-progressive distribution required by the hotspot model. Instead, a "hot line" origin was proposed (Bonatti et al., 1977). New mapping and dredging during the R/V Revelle DRIFT 6 expedition (2001) revealed detailed volcanic morphology and has provided rocks from ˜30 previously unsampled seamounts. We report here crystallization ages for these volcanoes, based on 40Ar-39Ar incremental heating of whole rocks, feldspar and groundmass separates. Contrary to the previous work (based on K-Ar whole rock ages) we find a systematic increase in ages from west to east, continuing northeast along the Nazca Ridge, from 2 to 27 Ma, in agreement with the hotspot model. This age progression seems to fit best with a current hotspot location close to Salas y Gomez, rather than Easter Island. We next compare the seamount ages with the age of underlying ocean crust, inferred from seafloor magnetic anomaly identification (Naar et al., this session) to determine the position of the hotspot relative to the spreading ridge through time. With the exception of a short interval around 12 Ma the hotspot lay several hundred km to the east of the East Pacific Rise. Finally, we compare the observed age distribution with those predicted from fixed Pacific basin hotspots (Hawaii, Louisville), and models that predict inter-hotspot motion (Steinberger, 2002). The new age distribution, with hotspot located near Salas y Gomez, is most consistent with fixed (or only very slowly moving) hotspots for the last 27 Ma.

Duncan, R. A.; Naar, D. F.; Pyle, D. G.; Russo, C. J.



Not only Chauvet: Dating Aurignacian rock art in Altxerri B Cave (northern Spain).  


The discovery and first dates of the paintings in Grotte Chauvet provoked a new debate on the origin and characteristics of the first figurative Palaeolithic art. Since then, other art ensembles in France and Italy (Aldène, Fumane, Arcy-sur-Cure and Castanet) have enlarged our knowledge of graphic activity in the early Upper Palaeolithic. This paper presents a chronological assessment of the Palaeolithic parietal ensemble in Altxerri B (northern Spain). When the study began in 2011, one of our main objectives was to determine the age of this pictorial phase in the cave. Archaeological, geological and stylistic evidence, together with radiometric dates, suggest an Aurignacian chronology for this art. The ensemble in Altxerri B can therefore be added to the small but growing number of sites dated in this period, corroborating the hypothesis of more complex and varied figurative art than had been supposed in the early Upper Palaeolithic. PMID:24012252

González-Sainz, C; Ruiz-Redondo, A; Garate-Maidagan, D; Iriarte-Avilés, E



Differential absorption techniques and radiometric satellite calibration for measuring air-sea interactions  

Microsoft Academic Search

The transfer of heat and gas between ocean and atmosphere is a critical parameter for coupled climate models. Surface measurements of these transfers are difficult, expensive, prone to large errors, and based on parameters measured alongside the interface. Although temperature profiles inside the interface itself (topmost millimeter) control air-sea heat flux, measurement of these gradients with fine-wire thermistors is difficult

W. McKeown



Radiometric survey for exploration of hydrothermal alteration in a volcanic area  

Microsoft Academic Search

A radiometric survey on a sector of the Lipari volcanic island particularly affected by argillification due to hydrothermal processes was carried out. Preliminarily, on the basis of a wide set of field measurements over unaltered outcrops U and K distribution maps were obtained. The concentration of these radioelements increases with the degree of magma differentiation; the U and K content

P. Chiozzi; V. Pasquale; M. Verdoya



Redesign of 5 mm Wavelength Radiometric Measurement Instrument for Flight Aboard OV1-86.  

National Technical Information Service (NTIS)

A 5mm Radiometric Instrument was designed to insure component reliability and to provide compatibility with the OV1-86 Satellite. This radiometer was designed to measure temporal and geographic variations in the 60 GHz emission from the earth's atmopheric...

W. M. Caton



Radiometric performance of the CERES broadband radiometers on the Terra and Aqua spacecraft  

Microsoft Academic Search

The Clouds and the Earth's Radiant Energy System (CERES) is the only program currently measuring the global Earth Radiation Budget (ERB) from space. Two CERES units are located on the EOS Terra platform and two more are placed on the EOS Aqua satellite. Each of the four operational CERES instruments uses three broadband radiometric scanning telescopes: the shortwave (SW 0.3

Kory J. Priestley; G. Louis Smith; Susan Thomas; Grant Matthews; Z. Peter Szewczyk



Radiometric detection of spread-spectrum signals in noise of uncertain power  

Microsoft Academic Search

The standard analysis of the radiometric detectability of a spread-spectrum signal assumes a background of stationary, white Gaussian noise whose power spectral density can be measured very accurately. This assumption yields a fairly high probability of interception, even for signals of short duration. By explicitly considering the effect of uncertain knowledge of the noise power density, it is demonstrated that

Alexander Sonnenschein; PHILIP M. FISHMAN



Spectral absorption coefficient measured in situ in the North Sea with a marine radiometric spectrometer system  

Microsoft Academic Search

A submersible marine radiometric spectrometer system, capable of simultaneous measurements of the in situ spectral and angular properties of the underwater oceanic light field, is used to determine spectral inherent optical properties of marine waters. The inversion methods used to convert the sampled light field measurements into estimates of spectral absorption are presented and sample results for three water types

Eon O'Mongain; Daniel Buckton; Stuart Green; Martina Bree; Karl Moore; Roland Doerffer; Sean Danaher; Hans Hakvoort; John Kennedy; Jürgen Fischer; Frank Fell; Dimitris Papantoniou; Martin McGarrigle



An SVM Classification of Tree Species Radiometric Signatures Based on the Leica ADS40 Sensor  

Microsoft Academic Search

This paper focuses on the use of multispectral mea- surements to classify remotely sensed radiance and reflectance information into three tree species, Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst.), and birch (Betula pubescens Ehrh., Betula pendula Roth), using a Support Vector Machine (SVM) algorithm. The features used for the classifier are radiometric involving different viewing

Ville Heikkinen; Ilkka Korpela; Timo Tokola; Eija Honkavaara; Jussi Parkkinen



A 60GHz Multifrequency Radiometric Sensor for Detecting Clear Air Turbulence in the Troposphere  

Microsoft Academic Search

The temperature profile in a horizontal path forward of an aircraft canbe sensed with a multichannel 5-mm passive radiometric receivingsystem. The characteristic signature of the multichannel radiometricoutput as a function of time would provide a measure of the range tothe region of temperature discontinuity forward of the aircraft.Applicability to clear air turbulence (CAT) detection is predicatedon the assumption that temperature

George Haroules; Wilfred Brown



The Seasat scanning multichannel microwave radiometer (SMMR): Radiometric calibration algorithm development and performance  

Microsoft Academic Search

Radiometric calibration algorithms for processing Seasat scanning multichannel microwave radiometer (SMMR) flight data are presented. An equation is derived which accounts for losses and reradiation in the microwave components and nonlinearities in the radiometer. The application of pre-launch calibration data to this derivation is described. A performance evaluation of the post-launch operation of the algorithm is presented, indicating temperature resolution

P. Swanson; A. Riley



Adjustments to the MODIS Terra radiometric calibration and polarization sensitivity in the 2010 reprocessing  

NASA Astrophysics Data System (ADS)

The Moderate-Resolution Imaging Spectroradiometer (MODIS) on NASA's Earth Observing System (EOS) satellite Terra provides global coverage of top-of-atmosphere (TOA) radiances that have been successfully used for terrestrial and atmospheric research. The MODIS Terra ocean color products, however, have been compromised by an inadequate radiometric calibration at the short wavelengths. The Ocean Biology Processing Group (OBPG) at NASA has derived radiometric corrections using ocean color products from the SeaWiFS sensor as truth fields. In the R2010.0 reprocessing, these corrections have been applied to the whole mission life span of 10 years. This paper presents the corrections to the radiometric gains and to the instrument polarization sensitivity, demonstrates the improvement to the Terra ocean color products, and discusses issues that need further investigation. Although the global averages of MODIS Terra ocean color products are now in excellent agreement with those of SeaWiFS and MODIS Aqua, and image quality has been significantly improved, the large corrections applied to the radiometric calibration and polarization sensitivity require additional caution when using the data.

Meister, Gerhard; Franz, Bryan A.



Landsat: radiometric and topographic correction of satellite imagery (R package)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Most Geographic Information System software includes routines for atmospheric and topograhic correction of satellite imagery such as that taken by Landsat. Radiometric correction is an active area of research, and new, improved methods are rarely if ever available for testing and application. The R...


Aerial Radiometric and Magnetic Survey: Houston National Topographic Map, Texas Gulf Coast.  

National Technical Information Service (NTIS)

Volume 1 contains the results from an aerial radiometric and magnetic survey of the Houston National Topographic Map area. Each map line was flown in an east-west direction with a maximum length of 120 miles, and each tie line was flown in a north-south d...



Research on methods of spectral calibration and radiometric calibration of the windowing Fourier transform imaging spectrometer  

NASA Astrophysics Data System (ADS)

Spectral calibration and radiometric calibration is an important part in the data processing of the windowing Fourier transform imaging spectrometer, it can ensure that the spectral curve output from spectrometer are more closely to target spectrum. The main idea of spectral calibration is using a monochromatic source whose wavelength is known, in the same way, radiometric calibration can be achieved by using radiation source whose radiation characteristic is known. In this paper, we propose a set of methods of spectral calibration and radiometric calibration. In order to carry out spectral calibration, we use monocharomator to scan several sample points near the position of every spectral channel of imaging spectrometer, and then we employ Gaussian fitting function to determine the central wavelength and bandwidth of every spectral channel. In order to carry out radiometric calibration, we employ panchromatic light source and integrating sphere, at the position of every spectral channel of imaging spectrometer, we measure the response ability of spectrometer to radiation. The calibration accuracy is carefully analyzed. Experimental results show that calibration accuracy meet the given requirements.

Zhang, Lei; Gao, Jiao Bo; Zhao, Yu Jie; Luo, Yan Ling; Xiao, Xiang Guo; Zhang, Fang



Dating martian climate change  

NASA Astrophysics Data System (ADS)

Geological evidence indicates that low-latitude polygonally-patterned grounds on Mars, generally thought to be the product of flood volcanism, are periglacial in nature and record a complex signal of changing climate. By studying the martian surface stratigraphically (in terms of the geometrical relations between surface landforms and the substrate) rather than genetically (by form analogy with Earth), we have identified dynamic surfaces across one-fifth of martian longitude. New stratigraphical observations in the Elysium-Amazonis plains have revealed a progressive surface polygonisation that is destructive of impact craters across the region. This activity is comparable to the climatically-driven degradation of periglacial landscapes on Earth, but because it affects impact craters—the martian chronometer—it can be dated. Here, we show that it is possible to directly date this activity based on the fraction of impact craters affected by polygon formation. Nearly 100% of craters (of all diameters) are superposed by polygonal sculpture: considering the few-100 Ma age of the substrate, this suggests that the process of polygon formation was active within the last few million years. Surface polygonisation in this region, often considered to be one of the signs of young, 'plains-forming' volcanism on Mars, is instead shown to postdate the majority of impact craters seen. We therefore conclude that it is post-depositional in origin and an artefact of thermal cycling of near-surface ground ice. Stratigraphically-controlled crater counts present the first way of dating climate change on a planet other than Earth: a record that may tell us something about climate change on our own planet. Parallel climate change on these two worlds—an ice age Mars coincident with Earth's glacial Quaternary period—might suggest a coupled system linking both. We have previously been unable to generalise about the causes of long-term climate change based on a single terrestrial example—with the beginnings of a chronology for climate change on our nearest planetary neighbour, we can.

Page, David P.; Balme, Matthew R.; Grady, Monica M.



Potassium-Argon Dates on Basaltic Rocks  

Microsoft Academic Search

The applicability of the K-Ar dating to basalts is being studied. The ; Palisades Diabase sill and its related basalt flows were chosen as the geological ; units for the study. Argon and most of the potassium analyses were made by the ; isotope dilution technique. Some of the potassium analyses were carried out by ; flame photometry. lt was

G. P. Erickson; J. Laurence Kulp



Radiocarbon dating of ancient rock paintings  

SciTech Connect

This report presents progress made on a technique for {sup 14}C dating pictographs. A low-temperature oxygen plasma is used coupled with high-vacuum technologies to selectively remove C-containing material in the paints without contamination from inorganic carbon from rock substrates or accretions.

Ilger, W.A.; Hyman, M.; Rowe, M.W. [Texas A and M Univ., College Station, TX (United States). Dept. of Chemistry; Southon, J. [Lawrence Livermore National Lab., CA (United States)



Radiocarbon dating of ancient rock paintings.  

National Technical Information Service (NTIS)

This report presents progress made on a technique for C-14 dating pictographs. A low-temperature oxygen plasma is used coupled with high-vacuum technologies to selectively remove C-containing material in the paints without contamination from inorganic car...

W. A. Ilger M. Hyman M. W. Rowe J. Southon



Radiometric age determinations and their interpretations phenomena in the Menderes Massif (western Anatolia-Turkey)  

NASA Astrophysics Data System (ADS)

Radiometric isotope applications in geosciences have been enormously improving during the last decade. Most of these applications were also performed in the entire Turkey by various researchers. From southern to northern part of the Menderes Massif (western Anatolia), 40Ar-39Ar mica; Rb-Sr whole rock, mica; K-Ar whole rock, mica; U-Pb zircon isotope dilution; 207Pb-206Pb single zircon evaporation; apatite, zircon fission tracks, and Th-Pb monazite techniques are commonly applied methods. Most of the age determinations and their interpretations in the Menderes Massif were or are still used to evidence the geodynamic nature of the region with its bordered paleogeography. Last 20 years, nearly, most of the age data in the massif conflict with the well-known stratigraphical and lithological features and still preserve its debate. Moreover, individual age techniques were not properly interpreted or performed within their parameters (closure temperatures, related mineral equilibrium, metamorphic conditions…etc.). Particularly, most popular age determination methods of 40Ar/39Ar mistakenly interpreted as cooling ages instead of neo-crystallization ages. Similarly, Rb-Sr mica ages could easily demonstrate open chemical behavior related to the fluid interactions and present the timing of last fluid circulation events instead of cooling ages. The age data obtained from massif were interpreted without any consideration of the widespread Oligo-Miocene magmatic activity in the northern Menderes Massif, Neogene volcanism, and graben structures in western Anatolia. This study aims to present and summarize new (U-Pb-ID, 207Pb-206Pb single zircon evaporation, Rb-Sr mica) and previously obtained age data from northern and southern Menderes Massif in comparison with literature to better understanding of the age interpretations within their geological limits and related mineral features. Our results in comparison with previously published age data in their detailed stratigraphical features indicate that obtained youngest ages (c.20-25 Ma), which were previously interpreted as the cooling of the massif, are still questionable, and they are more likely representing the timing of fluid circulation events and/or resetting of their related isotopic systems.

Erdogan, B.; Hasozbek, A.; Akay, E.; Gungor, T.; Satir, M.; Siebel, W.



Microwave Radiometric Investigations of Mine Subsidence in Rock Springs, Wyoming.  

National Technical Information Service (NTIS)

The investigations were performed in two areas where mapping techniques are needed for locating abandoned coal mines and subsidence-prone areas. Microwave surveys were conducted specifically to map the overburden moisture distribution resulting from the s...

A. T. Edgerton F. Ruskey D. Williams



Field determination of optimal dates for the discrimination of invasive wetland plant species using derivative spectral analysis  

USGS Publications Warehouse

Mapping invasive plant species in aquatic and terrestrial ecosystems helps to understand the causes of their progression, manage some of their negative consequences, and control them. In recent years, a variety of new remote-sensing techniques, like Derivative Spectral Analysis (DSA) of hyperspectral data, have been developed to facilitate this mapping. A number of questions related to these techniques remain to be addressed. This article attempts to answer one of these questions: Is the application of DSA optimal at certain times of the year? Field radiometric data gathered weekly during the summer of 1999 at selected field sites in upstate New York, populated with purple loosestrife (Lythrum salicaria L.), common reed (Phragmites australis (Cav.)) and cattail (Typha L.) are analyzed using DSA to differentiate among plant community types. First, second and higher-order derivatives of the reflectance spectra of nine field plots, varying in plant composition, are calculated and analyzed in detail to identify spectral ranges in which one or more community types have distinguishing features. On the basis of the occurrence and extent of these spectral ranges, experimental observations suggest that a satisfactory differentiation among community types was feasible on 30 August, when plants experienced characteristic phenological changes (transition from flowers to seed heads). Generally, dates in August appear optimal from the point of view of species differentiability and could be selected for image acquisitions. This observation, as well as the methodology adopted in this article, should provide a firm basis for the acquisition of hyperspectral imagery and for mapping the targeted species over a broad range of spatial scales. ?? 2005 American Society for Photogrammetry and Remote Sensing.

Laba, M.; Tsai, F.; Ogurcak, D.; Smith, S.; Richmond, M. E.



Violence in Adolescent Dating Relationships  

ERIC Educational Resources Information Center

|Beginning with a definition of dating and dating violence among adolescents, this article explores the factors which impact such violence. It concludes with a review of two school-based prevention/intervention programs (Safe Dates and The Youth Relationships Project). (Contains 1 table.)|

Jouriles, Ernest N.; Platt, Cora; McDonald, Renee



Childhood Maltreatment and Date Rape  

Microsoft Academic Search

Women college students who reported unwanted sexual experiences judged to constitute date rape were compared with controls who reported no rape. Compared to controls, the date-rape group had significantly higher scores on a measure of overall childhood stress and maltreatment and scored significantly higher on the principal subscale of that measure, which assesses negative home environment\\/neglect. Date rape participants were




A criticism of standard TL dating technology  

NASA Astrophysics Data System (ADS)

Results of experimental research on TL kinetic processes in natural quartz are presented from the viewpoint of application in geochronology of Quaternary sediments. All regularities revealed are entirely confirmed by the classical theory of luminescence of crystalline phosphors. The main conclusions obtained demonstrate that conventional views concerning the processess of accumulation and registration of age information in the standard technology of TL dating are erroneous. The final result of the conducted research was the development of a new dating technique which is free from the shortcomings revealed.

Shlukov, A. I.; Shakhovets, S. A.; Voskovskaya, L. T.; Lyashenko, M. G.



Nist role in radiometric calibrations for remote sensing programs at NASA, NOAA, DOE and DOD  

NASA Astrophysics Data System (ADS)

The Optical Technology Division (OTD) at the National Institute of Standards and Technology (NIST) has been actively involved in providing calibration support to establish SI traceable measurement support for the National Aeronautic and Space Administration (NASA) Earth Observing System (EOS) radiometric sensors. Specialized transfer standard radiometers traceable to the NIST spectroradiometric scales were built; they cover the visible and infrared spectral range up to 10 ?m. An example of this effort has been the calibration support provided for the NASA's SeaWiFS program. The OTD has also developed the Thermal Infrared Transfer Radiometer (TXR) for NASA's EOS program, and measurements are planned at the calibration facilities for the High Resolution Dynamics Limb Sounder (HIRDLS) and the Tropospheric Emission Spectrometer (TES) that will fly on the Aura spacecraft. The TXR was used for the end-to-end radiometric calibration of a chamber at Los Alamos in support of DOE remote sensing programs. Plans also call for the TXR to be used in a feasibility test of calibration support for the National Oceanic and Atmospheric Administration (NOAA) Geostationary Operational Environmental Satellite (GOES) program. The need to calibrate the performance of sensors for missile defense prompted the Ballistic Missile Defense Organization (BMDO) of the Department of Defense (DOD) to sponsor the development of the Low Background Infrared Calibration Facility (LBIR) at NIST. The LBIR facility has been providing calibration of blackbodies and detectors to BMDO/DOD missile test facilities for over ten years. Internationally, OTD has been actively participating in the intercomparisons with other national standard laboratories in the measurement of SI traceable radiometric quantities. The requirements for global warming and climate change studies show the need for high accuracy data from remote sensing platforms. This translates into the need for long term radiometric calibration support for space-based sensors during the course of the mission. As a possibility to provide real time radiometric calibration support for a variety of missions, we will explore the future prospects of deploying SI traceable transfer standard radiometers on the International Space Station or other such platforms. Such a program would allow for recoverable instruments that could be periodically intercompared with the absolute radiometric standards in the laboratory and thereby provide long term measurement assurance for space based radiometry.

Parr, A. C.; Datla, R. U.



Analysis of Airborne Radiometric Data. Volume 2. Description, Listing, and Operating Instructions for the Code DELPHI/MAZAS. Final Report.  

National Technical Information Service (NTIS)

The computer code DELPHI is an interactive English language command system for the analysis of airborne radiometric data. The code includes modules for data reduction, data simulation, time filtering, data adjustment and graphical presentation of the resu...

M. Sperling D. C. Shreve



Radiometric method for pyrazinamide susceptibility testing of Mycobacterium tuberculosis in egg-yolk-enriched BACTEC 12A medium  

SciTech Connect

A radiometric method for testing the susceptibility of Mycobacterium tuberculosis to pyrazinamide in egg-yolk-enriched 12A medium (pH 5.5) is described. We obtained 100% agreement between the 7H10 agar method with 25 microgram of pyrazinamide per ml and the modified radiometric method with a drug concentration of 50 microgram/ml in tests of 90 clinical isolates.

Woodley, C.L.; Smithwick, R.W.



Enhancements to the radiometric calibration facility for the Clouds and the Earth's Radiant Energy System (CERES) instruments  

NASA Astrophysics Data System (ADS)

Enhancements which have been made in the Radiometric Calibration Facility (RCF) of the CERES payload are described. These include narrow field blackbody and wide field of view blackbody sources, an active cavity radiometer, and a shortwave reference source. They permit the RCF to calibrate the CERES instruments to better than +/- 0.5 percent absolute radiometric accuracy in the 3.5 to above 50 micron wavelength region and to +/- 1.0 percent in the 0.3-3.5 micron region.

Folkman, Mark A.; Jarecke, Peter J.; Darnton, Lane A.



PARADIS: Physical 802.11 Device Identification with Radiometric Signatures  

Microsoft Academic Search

This paper describes a technique that identifies an ieee 802.11 frame's source network interface card through passive radio-frequency analysis. Our approach, called paradis, leverages minute imperfections of transmitter hardware that are acquired at manufacture and are present even in other- wise identical nics. These imperfections are transmitter- specific and manifest themselves as artifacts of the emitted signals. We measure artifacts

Vladimir Brik; Suman Banerjee; Marco Gruteser; Sangho Oh


Fundamentals of gamma-ray measurements and radiometric analyses  

Microsoft Academic Search

There are four primary modes of radioactive decay. All can be measured using various types of detectors and are the basis of many analytical techniques and much of what we know about the nucleus and its structure. Alpha particle emission occurs mostly in heavy nuclei of atomic number, Z, greater than 82 like Po, Ra, Th, and U, etc. Beta




Evaluation of rapid radiometric method for drug susceptibility testing of Mycobacterium tuberculosis  

SciTech Connect

A total of 106 isolates of Mycobacterium tuberculosis were tested for drug susceptibility by the conventional 7H11 plate method and by a new rapid radiometric method using special 7H12 liquid medium with /sup 14/C-labeled substrate. Results obtained by the two methods were compared for rapidity, sensitivity, and specificity of the new test method. There was 98% overall agreement between the results obtained by the two methods. Of a total of 424 drug tests, only 8 drug results did not agree, mostly in the case of streptomycin. This new procedure was found to be rapid, with 87% of the tests results reportable within 4 days and 98% reportable within 5 days as compared to the usual 3 weeks required with the conventional indirect susceptibility test method. The results of this preliminary study indicate that the rapid radiometric method seems to have the potential for routine laboratory use and merits further investigations.

Siddiqi, S.H.; Libonati, J.P.; Middlebrook, G.



Initial on-orbit radiometric calibration of the Suomi NPP VIIRS reflective solar bands  

NASA Astrophysics Data System (ADS)

The on-orbit radiometric response calibration of the VISible/Near InfraRed (VISNIR) and the Short-Wave InfraRed (SWIR) bands of the Visible/Infrared Imager/Radiometer Suite (VIIRS) aboard the Suomi National Polar-orbiting Partnership (NPP) satellite is carried out through a Solar Diffuser (SD). The transmittance of the SD screen and the SD's Bidirectional Reflectance Distribution Function (BRDF) are measured before launch and tabulated, allowing the VIIRS sensor aperture spectral radiance to be accurately determined. The radiometric response of a detector is described by a quadratic polynomial of the detector's digital number (dn). The coefficients were determined before launch. Once on orbit, the coefficients are assumed to change by a common factor: the F-factor. The radiance scattered from the SD allows the determination of the F-factor. In this Proceeding, we describe the methodology and the associated algorithms in the determination of the F-factors and discuss the results.

Lei, Ning; Wang, Zhipeng; Fulbright, Jon; Lee, Shihyan; McIntire, Jeff; Chiang, Kwofu; Xiong, Xiaoxiong



Effect of osmotic stabilizers on radiometric detection of cell wall-damaged bacteria.  

PubMed Central

The effect of osmotic stabilizers on the 14CO2-dependent radiometric detection of cell wall-damaged Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa was studied in BACTEC 14C-labeled blood culture medium. The organisms were previously exposed to cefamandole or carbenicillin at 63 to 80% of the minimum inhibitory concentrations. The addition of 10% sucrose, 2.2% glycerol, and 2.2% ethylene glycol to the medium failed to reduce the time required for detection and diminished the amounts of 14CO2 released by the growing cultures. Viable counts made after 4 to 7 h of incubation showed a decreased culture density in osmotically stabilized media as compared with saline or Ficoll controls. Sucrose and Ficoll had little or no inhibitory effect on 14CO2 evolution by P. aeruginosa. The osmotic stabilizers tested did not seem to improve the survival of the bacterial inoculum and failed to increase the sensitivity of the radiometric system of detection.

Martinez, O V; Malinin, T I



Direct antimicrobial drug susceptibility testing of Mycobacterium tuberculosis by the radiometric method  

SciTech Connect

Direct-drug-susceptibility tests were performed on clinical specimens positive for acid-fast bacilli by either Ziehl-Neelsen or fluorochrome staining. The results of conventional agar dilution and a modified radiometric (BACTEC) method were compared. A total of 580 smear-positive specimens were tested by the BACTEC method at three separate sites. Three hundred and seventy-seven of these were culture positive for M. tuberculosis, and 343 (91%) yielded acceptable direct-susceptibility-test results. We used the conventional method to determine that 343 of 519 smear-positive specimens were culture positive for M. tuberculosis, and 212 (62%) produced acceptable results within 3 wks. Conventional results were reported in 3-4 wks, while the time required to obtain results with the BACTEC method ranged from 5 to 21 days (average 11.5 days). Results indicate that the radiometric method provides reportable results more frequently with time savings as compared to the conventional method.

Libonati, J.P.; Stager, C.E.; Davis, J.R.; Siddiqi, S.H.



Utility of Radiometric–aerodynamic Temperature Relations for Heat Flux Estimation  

Microsoft Academic Search

In many land-surface models using bulk transfer (one-source) approaches, the application of radiometric surface temperature\\u000a observations in energy flux computations has given mixed results. This is due in part to the non-unique relationship between\\u000a the so-called aerodynamic temperature, which relates to the efficiency of heat exchange between the land surface and overlying\\u000a atmosphere, and a surface temperature measurement from a

William P. Kustas; Martha C. Anderson; John M. Norman; Fuqin Li



KRMS (K-band Radiometric Mapping System) SSM\\/I validation March 1988 quick look report  

Microsoft Academic Search

The primary objective of this mission was to provide high-resolution passive microwave imagery in support of the NASA SSM\\/I sea ice algorithm verification program. Four flights were flown, originating from Eielson AFB, Fairbanks, Alaska, over the Chukchi Sea, the Beaufort Sea, and the Bering Sea. The Ka-band Radiometric Mapping System (KRMS) was flown from 6 to 14 March 1988. Data

L. Dennis Farmer; Duane T. Eppler; Bruce Heydlauff; David Olsen



Prelaunch and in-flight radiometric calibration of the Atmospheric Infrared Sounder (AIRS)  

Microsoft Academic Search

With 2378 infrared spectral channels ranging in wavelength from 3.7-15.4 ?m, the Atmospheric Infrared Sounder (AIRS) represents a quantum leap in spaceborne sounding instruments. Each channel of the AIRS instrument has a well-defined spectral bandshape and must be radiometrically calibrated to standards developed by the National Institute of Standards and Technology. This paper defines the algorithms, methods, and test results

Thomas S. Pagano; Hartmut H. Aumann; Denise E. Hagan; Kenneth Overoye



A new automatic system for angular measurement and calibration in radiometric instruments.  


This paper puts forward the design, construction and testing of a new automatic system for angular-response measurement and calibration in radiometric instruments. Its main characteristics include precision, speed, resolution, noise immunity, easy programming and operation. The developed system calculates the cosine error of the radiometer under test by means of a virtual instrument, from the measures it takes and through a mathematical procedure, thus allowing correcting the radiometer with the aim of preventing cosine error in its measurements. PMID:22319320

Marquez, Jose Manuel Andujar; Bohórquez, Miguel Ángel Martínez; Garcia, Jonathan Medina; Nieto, Francisco Jose Aguilar



Radiometric performance results of the Juno ultraviolet spectrograph (Juno-UVS)  

Microsoft Academic Search

We describe the radiometric performance and ground calibration results of the Juno mission's Ultraviolet Spectrograph (Juno-UVS) flight model. Juno-UVS is a modest power (9.0 W) ultraviolet spectrograph based on the Alice instruments now in flight aboard the European Space Agency's Rosetta spacecraft, NASA's New Horizons spacecraft, and the LAMP instrument aboard NASA's Lunar Reconnaissance Orbiter. Its primary job will be

Michael W. Davis; G. Randall Gladstone; Thomas K. Greathouse; David C. Slater; Maarten H. Versteeg; Kristian B. Persson; Gregory S. Winters; Steven C. Persyn; John S. Eterno



Radiometric performance results of the Juno ultraviolet spectrograph (Juno-UVS)  

NASA Astrophysics Data System (ADS)

We describe the radiometric performance and ground calibration results of the Juno mission's Ultraviolet Spectrograph (Juno-UVS) flight model. Juno-UVS is a modest power (9.0 W) ultraviolet spectrograph based on the Alice instruments now in flight aboard the European Space Agency's Rosetta spacecraft, NASA's New Horizons spacecraft, and the LAMP instrument aboard NASA's Lunar Reconnaissance Orbiter. Its primary job will be to characterize Jupiter's UV auroral emissions and relate them to in situ particle measurements.

Davis, Michael W.; Gladstone, G. Randall; Greathouse, Thomas K.; Slater, David C.; Versteeg, Maarten H.; Persson, Kristian B.; Winters, Gregory S.; Persyn, Steven C.; Eterno, John S.



Studies of 19.5 GHz sky radiometric temperature: Measurements and applications  

Microsoft Academic Search

Using a single-frequency ground-based microwave radiometer with steerable horn antenna at frequency 19.5 GHz, we measure sky radiometric temperature over the Taiwan area during the period May 1997 to September 1999. Statistics indicate that for more than 80% of the time, in the absence of surface precipitation, the brightness temperature is above 27 K. Different elevation angle observations show that

Shuen-Peng Shih; Yen-Hsyang Chu



Landsat5 TM and Landsat7 ETM+ absolute radiometric calibration using the reflectance-based method  

Microsoft Academic Search

The reflectance-based method of vicarious calibration has been used for the absolute radiometric calibration of the Landsat series of sensors since the launch of Landsat-4. The reflectance-based method relies on ground-based measurements of the surface reflectance and atmospheric conditions at a selected test site nearly coincident with the imaging of that site by the sensor of interest. The results of

Kurtis J. Thome; Dennis L. Helder; D. Aaron; James D. Dewald



Radiometric Sensors as a Non-invasive Approach to Health Monitoring  

Microsoft Academic Search

“Radiometric Sensors as a Non-invasive Approach to Health Monitoring”\\u000aAuthor: Scott F Muir\\u000a(University of South Florida WAMI Research Group)\\u000aIn the healthcare industry, the ability to monitor the health of patients in real time has become a major focus to ensure proper and quality treatment; an example of one of the preferred methods for achieving this goal involves non-invasive

Scott F Muir



Radiometric, noise, and spatial characterization of the wideband infrared scene projector  

NASA Astrophysics Data System (ADS)

The Wideband Infrared Scene Projector (WISP) has been undergoing development for the AF Research Laboratory Kinetic Kill Vehicle Hardware-in-the-loop Simulator facility (KHILS) at Eglin AFB, FL. Numerous characterization measurements defining array dynamic range, spectral output, temporal response and nonuniformity have been performed and reported on in the past. This paper addresses the measurements and analyses performed to characterize the radiometric, spatial, and temporal noise errors induced by the array on a unit under test (UUT). An Amber camera was used as the UUT. The Amber camera spectral, spatial and radiometric response characteristics were measured. The camera spatial and temporal noises were measured by observing an extended blackbody. Similar measurements were then made on the WISP/UUT system by projecting uniform scenes. The WISP spatial and radiometric responses and the WISP-induced spatial and temporal noise were determined from the measurements. Although the measurements are unique to the UUT adopted, the WISP contribution to the system noise-equivalent temperature difference (NEDT) was determined. The spatial noise measurements provided data for validating a spatial noise model described in a companion paper. The measurements and models are useful for analyzing future measurements and predicting the impact of WISP on various test articles.

Marlow, Steven A.; Flynn, David S.; Kircher, James R.



On-orbit radiometric calibration of SWIR bands of TANSO-FTS onboard GOSAT  

NASA Astrophysics Data System (ADS)

The Greenhouse gases Observing SATellite (GOSAT) was launched on 23 January 2009 to monitor global distributions of carbon dioxide and methane. The Thermal And Near-infrared Sensor for carbon Observation-Fourier Transform Spectrometer (TANSO-FTS) onboard GOSAT measures the short-wavelength infrared (SWIR) spectra. Radiometric accuracy directly influences the accuracy of the retrieved greenhouse gas concentrations. From a 2.5-yr retrieval analysis of GOSAT data, we found that the minimum of the mean-squared value of the residuals (the difference between observed and fitted spectra) and the radiance adjustment factor (one of the ancillary parameters to be retrieved with the gas concentrations for adjusting the radiance level between the bands) changed with time, possibly due to inaccurate degradation correction. In this study, the radiometric degradation of TANSO-FTS was evaluated from the on-orbit solar calibration data and modeled as a function of time and wavenumber for each spectral band. The radiometric degradation of TANSO-FTS Band 1 (centered at 0.76 ?m) after the launch was found to be about 4 to 6%, varying with wavenumber, whereas the other two bands (Band 2: 1.6 ?m and Band 3: 2.0 ?m) showed about 1% degradation and small wavenumber dependency. When we applied the new degradation model in the retrieval analysis, the above-mentioned issues disappeared.

Yoshida, Y.; Kikuchi, N.; Yokota, T.



On-orbit radiometric calibration of SWIR bands of TANSO-FTS onboard GOSAT  

NASA Astrophysics Data System (ADS)

The Greenhouse gases Observing SATellite (GOSAT) was launched on 23 January 2009 to monitor global distributions of carbon dioxide and methane. The Thermal And Near-infrared Sensor for carbon Observation-Fourier Transform Spectrometer (TANSO-FTS) onboard GOSAT measures short-wavelength infrared (SWIR) spectrum, and its radiometric accuracy directly influences the accuracy of the retrieved greenhouse gas concentrations. From a 2.5-yr retrieval analysis of GOSAT data, we found that the minimum of the mean-squared value of the residuals (the difference between observed and fitted spectra) and the radiance adjustment factor (one of the ancillary parameter to be retrieved with the gas concentrations for adjusting the radiance level between the bands) changed with time, possibly due to inaccurate degradation correction. In this study, the radiometric degradation of TANSO-FTS was evaluated from the on-orbit solar calibration data and modeled as a function of time and wavenumber for each spectral band. The radiometric degradation of TANSO-FTS Band 1 (centered at 0.76 ?m) after the launch was evaluated to be about 4 to 6%, varying with wavenumber, whereas the other two bands (Band 2: 1.6 ?m and Band 3: 2.0 ?m) showed about 1% degradation and small wavenumber dependency. When we applied the new degradation model in the retrieval analysis, the above-mentioned issues disappeared.

Yoshida, Y.; Kikuchi, N.; Yokota, T.



Validation analysis of the thermal and radiometric integrity of RIT's synthetic image generation model, DIRSIG  

NASA Astrophysics Data System (ADS)

The digital imaging and remote sensing laboratory's image generation model (DIRSIG) was validated in the long wave infrared (LWIR, 8 - 13.3 micrometers ) and midwife infrared (MWIR, 3 - 5 micrometers ) pass bands. Truth data was collected for all components of the thermal and radiometric submodels including a complete set of meteorological and radiometric data. Truth temperatures were collected using a bank of thermistors and truth radiance images were collected with calibrated InSb (MWIR) and HgCdTe (LWIR) detectors. Sensor spectral response functions were also included in the radiometric analysis. Relative error contributions to the total temperature/radiance digital count were investigated for each component in the multi-spectral model. Largest contributions were found to be wind speed, air temperature, visible emissivity, and fractional sky exposure for the thermal model and atmospheric transmission, temperature, and emissivity for the radiance model. An overall comparison of truth and synthetic images yields rms errors of as low as 1.8 degree(s)C actual temperature and 5 degree(s)C (LWIR) and 6 degree(s)C (MWIR) apparent temperature.

Mason, John E.; Schott, John R.; Rankin-Parobek, Donna



Calculation of new absolute radiometric keydata for sciamachy based on existing NASA sphere measurement  

NASA Astrophysics Data System (ADS)

The SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) has been launched in March 2002 on board the European environmental satellite ENVISAT. First comparisons of radiances and irradiances measured by SCIAMACHY with independent sources indicate an error in the absolute radiometric calibration, which has a strong impact on the quality of most level-1 data products. To overcome this problem, an extensive analysis of the radiometric on-ground calibration measurements of SCIAMACHY has been performed, and a new procedure has been developed to recalculate some of the radiometric key data from existing end-to-end measurements. These calculations were primarily based on a subset of NASA sphere measurements, performed for SCIAMACHY's radiance and irradiance verification during the OPTEC 5 period in 1999/2000. This integrating sphere is a 20" diameter internally illuminated sphere coated with BaSO4 . It has a long history of providing accurate absolute radiances for NASA's SBUV2 and TOMS programs and has also been used for the validation of the GOME absolute radiance calibration. The derived new SCIAMACHY key data show a significant difference to the on-ground ambient measured and calculated Bi-directional Reflectance Distribution Function (BRDF) keydata of SCIAMACHY's Elevation Scan Mirror Diffuser (ESM-Diffuser). First tests with in-flight measurements show a significant improvement of the quality of the level-1 data products when using these new key data. An improvement of the quality of level-2 data products is also expected.

Gerilowski, K.; Noel, S.; Janz, S.; Burrows, J. P.


Simultaneous observations of aerosols, clouds, and radiometric fluxes using light-weight autonomous UAVs  

NASA Astrophysics Data System (ADS)

The Maldives Air Campaign (MAC) demonstrated a novel application of stacked autonomous unmanned aerial vehicles (AUAVs) for atmospheric science research; see abstract by Ramanathan et al. in this session. Simultaneous observations from three AUAVs of aerosols, clouds and radiometric fluxes provide insight into aerosol-cloud interactions and subsequent effects on cloud radiative properties. Ground-based measurements of cloud condensation nuclei (CCN) also quantify the cloud-nucleating ability of the boundary layer aerosols. During the experiment, long-range transport of aerosols from the Arabian Peninsula and India was observed and its impact of cloud physical and radiometric properties has been detected. To accomplish this campaign, aerosol, cloud, radiometric instruments, and an integrated data acquisition system have been miniaturized with a total payload weight and power less than 5 kg and 50 W, respectively. The AUAV payloads are mission-specific and outfitted to perform a defined set of measurements depending on the scientific goals. These measurements include aerosol concentration, aerosol size distribution, aerosol absorption, cloud drop concentration and size distribution, solar radiation fluxes (visible and broadband), atmospheric turbulence, temperature, pressure, and relative humidity. The data collected during the MAC campaign has been validated using standard calibration routines in conjunction with comparisons to ground- based instruments in both laboratory and in situ (in aircraft) settings. All instruments have been thoroughly tested and calibrated prior to deployment.

Roberts, G.; Ramanathan, V.; Corrigan, C.; Ramana, M.; Nguyen, H.



On-orbit radiometric stability assessment of MODIS thermal emissive bands with lunar observation  

NASA Astrophysics Data System (ADS)

The MODIS thermal emissive bands (TEB) are radiometrically calibrated on-orbit on a scan-by-scan basis, with reference to an aboard blackbody operated at 290 K for Terra MODIS and at 285 K for Aqua MODIS. The quality of the calibration can be evaluated with independent thermal sources at other temperatures. As a spectrally, spatially and radiometrically stable source, the Moon has become more important to the on-orbit calibration of space-borne spectral sensors that have regular lunar observation capability. MODIS is scheduled to observe the Moon on a nearly monthly basis at approximately the same lunar phase angle through its space view port. In this paper, the long-term stability of MODIS TEB radiometric calibration is assessed through the multi-year trends of the brightness temperatures (BT) of the lunar surface retrieved from the scheduled lunar observation. The highest lunar surface temperature is approximately 390 K, higher than the saturation temperatures of most TEB. For the non-saturated bands, the trending is based on the BT of the hottest area of the Moon. For the partially saturated bands, the trending is based on the BT difference of the unsaturated matching pixels between the band and a non-saturated reference band, given the fact that all MODIS bands are spatially registered. Overall, the trends have been stable throughout MODIS lifetime. The results also prove that the Moon can be used as a source to monitor the stability of the thermal bands.

Wang, Zhipeng; Xiong, Xiaoxiong (Jack); Chen, Hongda; Madhavan, Sriharsha



Long-Term Radiometric Performance of the SCIAMACHY Quartz Tungsten Halogen Lamp  

NASA Astrophysics Data System (ADS)

The SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) is part of the atmospheric chemistry payload of ESA? Environmental Satellite ENVISAT. Since 2002, SCIAMACHY provides the amount and global distribution of various atmospheric constituents relevant in the contexts of ozone chemistry, air pollution and climate change. Originally designed for a 5-year mission, the SCIAMACHY instrument is still working well and ready for the planned mission extension until 2010 or even further. Calibration and monitoring of the instrument performance are a pre-requisite for a continuously high data product quality. Here, results from the monitoring of the optical performance of the SCIAMACHY instrument are presented. Emphasis is placed on the investigation of the performance of the SCIAMACHY internal Quartz Tungsten Halogen (QTH) lamp. This type of lamp has been used for monitoring the radiometric performance of an UV-VIS-SWIR Earth observation sensor over mission lifetime for the first time. The analysis of regular in-flight measurements has shown the radiometric stability of the SCIAMACHY QTH lamp over time especially in the visible/NIR spectral range. Lamps of this type are therefore considered as useful components for further space-borne spectroscopic missions, as they provide a relatively cheap and reliable mean for (at least relative) radiometric calibration and monitoring.

Noël, S.; Bramstedt, K.; Bovensmann, H.; Burrows, J. P.; Gottwald, M.; Krieg, E.



Designing an in-flight airborne calibration site using experience from vicarious radiometric satellite calibration  

NASA Astrophysics Data System (ADS)

Laboratory calibration of electro-optical sensors is preferably complemented by regular in-flight verification. This checks whether the lab calibration parameters remain valid or recalibration is necessary. In-flight verification can be achieved by vicarious calibration using in-flight measurements of calibration targets. We intend to identify and design a set of suitable radiometric calibration targets. For this, we borrow from expertise gained with the PROBA-V satellite calibration system, which uses multiple vicarious methods relying on diverse natural on-ground targets. Besides reflectance based calibration using ground measurements, the PROBA-V calibration methods are unproven for use in airborne calibration. The selected targets should be suitable for the calibration of both multispectral and hyperspectral imagers. We start from general requirements for radiometric targets and investigate their applicability to airborne calibration. From this we identify two possible sets of natural calibration sites in Belgium. One set, located in the Campine region, contains small water bodies and sandy lakesides. Another set is located in the Westhoek region near the Belgian coast. It offers better suitable water bodies, as well as sandy areas, grass fields and dark targets. Airborne calibration lends itself to the use of smaller artifical targets. We propose to complement the natural targets with a portable target consisting of agricultural nets with different densities. The definition of sets of calibration targets, both natural and artificial can facilitate the investigation of the usability of vicarious targets and method for inflight radiometric verification.

Livens, Stefan; Debruyn, Walter; Sterckx, Sindy; Reusen, Ils



New method of aerial and surface radiometric prospecting for oil, gas  

SciTech Connect

A new petroleum exploration method has been developed using surface and aerial gamma-ray spectral measurements. Formerly troublesome lithologic and environmental variables are suppressed by correcting potassium and uranium readings using a process of thorium normalization. Normalized potassium shows characteristic low concentrations above petroleum deposits. Normalized uranium shows higher values than normalized potassium over petroleum and generally lower values elsewhere. These anomalies are attributed to effects of microbial consumption of microseeping light hydrocarbons. Preliminary tests in two basins in Australia showed positive correlation between radiometrically favorable areas and known oil and gas regions. Ground-based gamma-ray spectral measurements found the same types of potassium and uranium anomalies over all 12 fields evaluated. Since 1988, research of surface radiometric data coupled with soil gas hydrocarbon and soil magnetic susceptibility surveys has resulted in discovery of three oil and gas fields in Concho County, Tex. The paper describes thorium normalization, the aerial radiometric databases, surface gamma ray spectral measurements, aerial gamma ray data, data processing, results from various fields, and the relation of anomalies to petroleum.

Saunders, D.F.; Burson, K.R.; Branch, J.F.; Thompson, C.K. (Recon Exploration Inc., Dallas, TX (United States))



Dating violence and girls in the juvenile justice system.  


The purpose of this study is to explore the prevalence and associated behaviors of dating violence among a population of girls in the juvenile justice system. A sample of 590 girls from an urban juvenile justice system completed a questionnaire assessing attitudes and self-efficacy about and occurrence of dating violence. The analysis developed a random effect model to determine a risk profile for dating violence. The strongest predictors of dating violence were (a) initial sexual experience at age 13 or earlier, (b) unwillingness of initial sexual experience, (c) drug use, and (d) low self-efficacy about preventing dating violence. The high prevalence of dating violence and associated behaviors among participants suggests the importance of implementing primary prevention programs to assist preteen girls in delaying initial sexual intercourse and in learning techniques to prevent dating violence. PMID:18768739

Kelly, Patricia J; Cheng, An-Lin; Peralez-Dieckmann, Esther; Martinez, Elisabeth



New radiometric and petrological constraints on the evolution of the Pichincha volcanic complex (Ecuador)  

NASA Astrophysics Data System (ADS)

Fieldwork, radiometric (40Ar/39Ar and 14C) ages and whole-rock geochemistry allow a reconstruction of eruptive stages at the active, mainly dacitic, Pichincha Volcanic Complex (PVC), whose eruptions have repeatedly threatened Quito, most recently from 1999 to 2001. After the emplacement of basal lavas dated at ˜1100 to 900 ka, the eruptive activity of the old Rucu Pichincha volcano lasted from ˜850 ka to ˜150 ka before present (BP) and resulted in a 15 × 20 km-wide edifice, which comprises three main building stages: (1) A lower stratocone (Lower Rucu, ˜160 km3 in volume) developed from ˜850 to 600 ka; (2) This edifice was capped by a steeper-sided and less voluminous cone (the Upper Rucu, 40-50 km3), the history of which started 450-430 ka ago and ended around 250 ka with a sector collapse; (3) A smaller (8-10 km3) but more explosive edifice grew in the avalanche amphitheatre and ended Rucu Pichincha's history about 150 ka ago. The Guagua Pichincha volcano (GGP) was developed from 60 ka on the western flank of Rucu with four growth stages separated by major catastrophic events. (1) From ˜60 to 47 ka, a basal effusive stratocone developed, terminating with a large ash-and-pumice flow event. (2) This basal volcano was followed by a long-lasting dome building stage and related explosive episodes, the latter occurring between 28-30 and 22-23 ka. These first two stages formed the main GGP (˜30 km3), a large part of which was removed by a major collapse 11 ka BP. (3) Sustained explosive activity and viscous lava extrusions gave rise to a new edifice, Toaza (4-5 km3 in volume), which in turn collapsed around 4 ka BP. (4) The ensuing amphitheatre was partly filled by the ˜1-km3 Cristal dome, which is the historically active centre of the Pichincha complex. The average output rate for the whole PVC is 0.29 km3/ka. Nevertheless, the chronostratigraphic resolution we obtained for Lower Rucu Pichincha and for the two main edifices of Guagua Pichincha (main GGP and Toaza), leads to eruptive rates of 0.60-0.65 km3/ka during these construction stages. These output rates are compared to those of other mainly dacitic volcanoes from continental arcs. Our study also supports an overall SiO2 and large-ion lithophile elements enrichment as the PVC develops. In particular, distinctive geochemical signatures indicate the involvement of a new magma batch at the transition between Rucu and Guagua. At the GGP, the same phenomenon occurs at each major collapse event marking the onset of the ensuing magmatic stage. Since the 11-ka-BP collapse event, this magmatic behaviour has led to increasingly explosive activity. Four explosive cycles of between 100 and 200 years long have taken place at the Cristal dome in the past 3.7 ka, and repose intervals between these cycles have tended to decrease with time. As a consequence, we suggest that the 1999-2001 eruptive period may have initiated a new eruptive cycle that might pose a future hazard to Quito (˜2 million inhabitants).

Robin, Claude; Samaniego, Pablo; Le Pennec, Jean-Luc; Fornari, Michel; Mothes, Patricia; van der Plicht, Johannes




Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey



Ice Core Dating Software for Interactive Dating of Ice Cores  

Microsoft Academic Search

Scientists involved in ice core dating are well familiar with the problem of identification and recording the depth of annual signals using stable isotopes, glaciochemistry, ECM (electrical conductivity), DEP (dielectric properties) and particle counter data. Traditionally all parameters used for ice core dating were plotted as a function of depth, printed and after years were marked on the paper, converted

A. V. Kurbatov; P. A. Mayewski; B. S. Abdul Jawad



Dating volcanic and related sediments by luminescence methods: a review  

NASA Astrophysics Data System (ADS)

Applications of luminescence dating of geological materials have undergone extensive development and refinement since 1974 when Wintle first attempted to date volcanic lava using thermoluminescence (TL). Today, luminescence techniques are potentially highly useful methods for dating volcanic and related materials and events over timescales ranging from 10 2 to 10 6 years. While luminescence approaches generally do not possess the precision afforded by techniques such as 40Ar/ 39Ar and 14C methods, they offer a useful alternative approach with advantages in terms of age range and scope of material. Although the application of luminescence methods has in some cases been successfully described, a comprehensive study outlining and defining protocols for routine luminescence dating of volcanic materials has not been forthcoming. This review surveys previous attempts to develop luminescence techniques to date volcanic products and discusses the state of knowledge of the luminescence behaviour of the four principal materials currently used for luminescence dating of volcanic events. Particular attention is paid to the red luminescence emissions, primarily because of previous successes in using Red Thermoluminescence (RTL) of quartz and feldspar for dating volcanic products, for which the upper age limit may extend beyond a million years. Proposals are made for future research directions; these include: technological developments in the measurement of optically stimulated red luminescence, the systematic characterization of RTL and optically stimulated red luminescence as key luminescence parameters in volcanic quartz, feldspar, glass and polymineral sample fractions, and optimization of luminescence dating methods to define a comprehensive protocol for routine dating of volcanic materials.

Fattahi, Morteza; Stokes, Stephen



Advances in carbon dating using high energy mass spectrometers  

Microsoft Academic Search

In spite of carbon dating being over thirty years old and the fact that in that period many thousands of dates have been produced, the conventional counting technique still suffers from certain drawbacks. Comparatively large samples are required, the time for an analysis is long, and the signal-to-background ratios obtainable are low. Recent work in a number of laboratories has

E. T. Hall



Using accelerator mass spectrometry for radiocarbon dating of textiles  

Microsoft Academic Search

Since 1981 we have operated an NSF Accelerator Mass Spectrometry (AMS) Facility at the University of Arizona. The AMS method allows us to use very small samples of carbon, <1 mg for radiocarbon dating in contrast to earlier counting techniques. This has opened a vast array of applications of radiocarbon dating that was difficult to do before AMS because of




Color image processing for date quality evaluation  

NASA Astrophysics Data System (ADS)

Many agricultural non-contact visual inspection applications use color image processing techniques because color is often a good indicator of product quality. Color evaluation is an essential step in the processing and inventory control of fruits and vegetables that directly affects profitability. Most color spaces such as RGB and HSV represent colors with three-dimensional data, which makes using color image processing a challenging task. Since most agricultural applications only require analysis on a predefined set or range of colors, mapping these relevant colors to a small number of indexes allows simple and efficient color image processing for quality evaluation. This paper presents a simple but efficient color mapping and image processing technique that is designed specifically for real-time quality evaluation of Medjool dates. In contrast with more complex color image processing techniques, the proposed color mapping method makes it easy for a human operator to specify and adjust color-preference settings for different color groups representing distinct quality levels. Using this color mapping technique, the color image is first converted to a color map that has one color index represents a color value for each pixel. Fruit maturity level is evaluated based on these color indices. A skin lamination threshold is then determined based on the fruit surface characteristics. This adaptive threshold is used to detect delaminated fruit skin and hence determine the fruit quality. The performance of this robust color grading technique has been used for real-time Medjool date grading.

Lee, Dah Jye; Archibald, James K.



Night sky radiometric measurements during follow-on-evaluation testing of AN/PVS-7 (A, B) at Fort Benning, Georgia  

NASA Astrophysics Data System (ADS)

The characterization of the lighting conditions during field testing on night vision intensifier systems requires more information than can be obtained by a photometer. The Follow-on-Evaluation (FOE) testing of AN/PVS-7 Night Vision Goggles at Fort Benning, GA (Oct. 1986 to Dec. 1986) required a radiometric characterization of the nighttime spectral content in the region encompassing that of the generation two and generation three image intensifier photocathodes (400 to 920nm) used in the goggles. A night sky radiometer (NSR) measuring system was designed and fabricated by the Center for Night Vision and Electro-Optics for the purpose of characterizing the night sky spectral content during the FOE test. This report discusses the design features of the NSR, its measuring techniques, and the results of the night sky conditions during the FOE test at Fort Benning.

Stefanik, Raymond J.



Egalitarian Daters\\/Traditionalist Dates  

Microsoft Academic Search

This study replicates and expands Rose and Frieze's (1989) research, which found that young adults' scripts for dating maintain the traditional dominant\\/subordinate relationship between the sexes. In a 1993 study, Rose and Frieze looked at actual, rather than hypothetical, dates and reported essentially the same finding. The authors used Rose and Frieze's 1989 design with a larger sample and found




Radiocarbon Dating (December 21, 2007).  

National Technical Information Service (NTIS)

Radiocarbon dating can be used to determine the age of objects that contain components that were once alive. In the case of human remains, a radiocarbon date can distinguish between a crime scene and an archeological site. Documents, museum artifacts and ...

B. A. Buchholz



Radiocarbon Dating: An Annotated Bibliography.  

ERIC Educational Resources Information Center

|This selective annotated bibliography covers various sources of information on the radiocarbon dating method, including journal articles, conference proceedings, and reports, reflecting the most important and useful sources of the last 25 years. The bibliography is divided into five parts--general background on radiocarbon, radiocarbon dating

Fortine, Suellen


Date Rape: Who's to Blame?  

Microsoft Academic Search

This study will investigate the effect of alcohol and potential gender differences in the attribution of blame and responsibility in instances of date rape. One hundred and sixty seven undergraduate students at the University of New Hampshire participated in a survey to examine the relationship between perceived intoxication and the attribution of responsibility in a date rape scenario. Participants responded

Carolyn Kaulbach; Nicole Bach


Recent atmospheric lead deposition recorded in an ombrotrophic peat bog of Great Hinggan Mountains, Northeast China, from 210Pb and 137Cs dating.  


Radioactive markers are useful in dating lead deposition patterns from industrialization in peat archive. Peat cores were collected in an ombrotrophic peat bog in the Great Hinggan Mountains in Northeast China in September 2008 and dated using (210)Pb and (137)Cs radiometric techniques. The mosses in both cores were examined systematically for dry bulk density, water and ash content. Lead also was measured using atomic emission spectroscopy with inductively coupled plasma (ICP-AES). Both patterned peat profiles were preserved well without evident anthropogenic disturbance. Unsupported (210)Pb and (137)Cs decreased with the depth in both of the two sample cores. The (210)Pb chronologies were established using the constant rate of supply model (CRS) and are in good agreement with the (137)Cs time marker. Recent atmospheric (210)Pb flux in Great Hinggan Mountains peat bog was estimated to be 337 Bq m(-2)y(-1), which is consistent with published data for the region. Lead deposition rate in this region was also derived from these two peat cores and ranged from 24.6 to 55.8 mg m(-2)y(-1) with a range of Pb concentration of 14-262 microg g(-1). The Pb deposition patterns were consistent with increasing industrialization over the last 135-170 y, with a peak of production and coal burning in the last 50 y in Northeast China. This work presents a first estimation of atmospheric Pb deposition rate in peatlands in China and suggests an increasing trend of environmental pollution due to anthropogenic contaminants in the atmosphere. More attention should be paid to current local pollution problems, and society should take actions to seek a balance between economic development and environmental protection. PMID:20621757

Bao, K; Xia, W; Lu, X; Wang, G



Fission-track dating of volcanically derived sedimentary rocks  

SciTech Connect

Depositional ages of sedimentary rocks can be determined using fission-track single grain ages on zircons from layers of volcanic ash or bentonite, even when the layers have been contaminated by older grains. This is done by compiling an age probability distribution or age spectrum for a sample from individual grain ages. An age spectrum is a simple and unambiguous way of testing for contamination and extracting useful age information. The youngest peak in the age spectrum approximates the time of deposition. In most contaminated samples, 30 or more grains should be counted to produce a reliable spectrum. However, useful, reproducible ages can be obtained by counting less than 10 grains in samples where most of the older, contaminating grains can be removed. The few older grains that remain after removing the obviously abraded ones may then be eliminated by examining the age spectrum. Although ages determined in this way are probably not precise enough for use in defining stratigraphic boundaries, they still provide a means of obtaining an isotopic age in sediments that cannot be dated by other radiometric methods. 18 references, 3 figures, 3 tables.

Kowallis, B.J.; Heaton, J.S.; Bringhurst, K.



ESR dates for the hominid burial site of Es Skhul in Israel.  


The Middle East has been critical to our understanding of recent human evolution ever since the recovery of Neanderthal and early anatomically modern fossils from the caves of Tabun and Skhul (Mount Carmel) over 50 years ago. It was generally believed, on archaeological and morphological grounds, that middle eastern Neanderthals (such as those from Tabun, Amud and Kebara) probably dated from more than 50,000 years ago, whereas the earliest anatomically modern specimens (from Skhul and Qafzeh) probably dated from about 40,000 years. Recent thermoluminescence and electron spin resonance (ESR) determinations, however, have supported biostratigraphy in dating the Qafzeh deposits to an earlier part of the late Pleistocene, probably more than 90,000 years ago. These dates have been questioned on unspecified technical grounds, and it has also been argued that they create explanatory problems by separating the morphologically similar Qafzeh and Skhul samples by some 50,000 years, thus implying a long-term coexistence of early modern humans and Neanderthals in the area. Here we report the first radiometric dating analysis for Skhul, using ESR on bovine teeth from the hominid burial levels. Early uptake and linear uptake ages average 81 +/- 15 and 101 +/- 12 kyr respectively. These analyses suggest that the Skhul and Qafzeh samples are of a similar age and therefore it is possible that the presence of early modern humans in the area was episodic, rather than long-term during the early late Pleistocene. PMID:2541339

Stringer, C B; Grün, R; Schwarcz, H P; Goldberg, P



Radiometric analysis and radiological hazards of Chinese commercial marble  

NASA Astrophysics Data System (ADS)

The activity concentrations of 226Ra, 232Th and 40K in commercial marble materials have been determined using a NaI(Tl) ?-ray spectrometer with a matrix-inversion-based spectral stripping technique. Knowledge of radioactivity present in marble materials enables one to assess any possible radiological risks to human health. The concentrations of 226Ra, 232Th and 40K in Chinese commercial marble range from 8.4 to 157.4, 5.6 to 165.5 and 44.1 to 1352.7 Bq kg-1, respectively. The natural radionuclide concentration varied with color and production site of commercial marble. The activity concentrations of 226Ra, 232Th and 40K in white, gray, black, green and yellow marble samples are comparatively smaller than those in brown and red marble samples. The radium equivalent activity (Raeq), the external hazard index (Hex), the internal hazard index (Hin) and the annual gonadal dose equivalent were also calculated and compared with the internationally recommended values. One type of brown commercial marble (TSB) of China does not satisfy the universal standards.

Lu, Xinwei


The maximum likelihood dating of magnetostratigraphic sections  

NASA Astrophysics Data System (ADS)

In general, stratigraphic sections are dated by biostratigraphy and magnetic polarity stratigraphy (MPS) is subsequently used to improve the dating of specific section horizons or to correlate these horizons in different sections of similar age. This paper shows, however, that the identification of a record of a sufficient number of geomagnetic polarity reversals against a reference scale often does not require any complementary information. The deposition and possible subsequent erosion of the section is herein regarded as a stochastic process, whose discrete time increments are independent and normally distributed. This model enables the expression of the time dependence of the magnetic record of section increments in terms of probability. To date samples bracketing the geomagnetic polarity reversal horizons, their levels are combined with various sequences of successive polarity reversals drawn from the reference scale. Each particular combination gives rise to specific constraints on the unknown ages of the primary remanent magnetization of samples. The problem is solved by the constrained maximization of the likelihood function with respect to these ages and parameters of the model, and by subsequent maximization of this function over the set of possible combinations. A statistical test of the significance of this solution is given. The application of this algorithm to various published magnetostratigraphic sections that included nine or more polarity reversals gave satisfactory results. This possible self-sufficiency makes MPS less dependent on other dating techniques.

Man, Otakar



Relative radiometric correction of multi-temporal ALOS AVNIR-2 data for the estimation of forest attributes  

NASA Astrophysics Data System (ADS)

Relative radiometric correction methods have been widely used to correct ground illumination difference in multi-temporal satellite data. ALOS (Advanced Land Observing Satellite) data starts to play an important role in forest and carbon assessment, such as the REDD (Reducing Emissions from Deforestation and forest Degradation) program. The objective of the study was to compare three relative radiometric correction methods for five multi-temporal ALOS AVNIR-2 (Advanced Visible and Near Infrared Radiometer) images, and to examine the influence of each correction method on the estimation accuracy of forest attributes with auxiliary field inventory plot data. Both spectral features and textural features were extracted before and after radiometric correction and used in estimation procedure. All the radiometric correction methods used improved the estimation accuracy of forest stem volume at plot level, and they were MAD (multivariate alteration detection) transformation-based normalization, PCA (principle component analysis)-based correction and local radiometric correction, among which MAD transformation-based normalization exceeded others by reducing the relative RMSE by 5.75% with the ordinary least square fitting and 6.8% with the K-MSN (K-Most Similar Neighbour) method both after leave-one-out cross-validation. RMSE for only the corrected area is also calculated, in view of the small proportion of plots in that area. The result can be used to improve the visual effect of mosaics of multi-temporal ALOS scenes, and to retrieve more accurate forest estimates for national forest resources and biomass mapping.

Xu, Qing; Hou, Zhengyang; Tokola, Timo



Clouds and the Earth's Radiant Energy System (CERES): Long-wave Calibration Plan and Radiometric Test Model (RTM) Calibration Results  

NASA Astrophysics Data System (ADS)

The CERES instrument has three radiometers which operate in the short-wave (0,3 ?m to 5 ?m), the long-wave (8 ?m to 12 ?m) and total broadband (0,3 ?m to >200 ?m) spectral regions. The long-wave calibration plan for CERES provides for absolute radiometric calibration of the two CERES sensors operating in the long-wave portion of the spectrum. Ground calibration is carried out in the TRW Radiometric Calibration Facility (RCF), a cryogenic vacuum chamber with the capability to simulate radiometrically both cold space and Earth viewing conditions. Absolute calibration is made using a temperature-based radiometric scale created by a black-body radiance standard controlled at temperatures from 200 K to 320 K. In May 1992, the CERES radiometric test model (RTM), a developmental but functionally flight-like instrument, was calibrated at TRW in the RCF. This was the first end-to-end long-wave calibration of a CERES sensor and provided a test and initial validation of the long-wave calibration plan and procedures. The gain, offset, out-of-field response and spectral response were determined for each sensor. The end-to-end long-wave calibration plan is described and the RTM calibration and validation results are presented.

Jarecke, P. J.; Folkman, M. A.; Hedman, T. R.; Frink, M. E.



Ground-based microwave radiometric remote sensing of the tropical atmosphere  

SciTech Connect

A partially developed 9-channel ground-based microwave radiometer for the Department of Meteorology at Penn State was completed and tested. Complementary units were added, corrections to both hardware and software were made, and system software was corrected and upgraded. Measurements from this radiometer were used to infer tropospheric temperature, water vapor and cloud liquid water. The various weighting functions at each of the 9 channels were calculated and analyzed to estimate the sensitivities of the brightness temperature to the desired atmospheric variables. The mathematical inversion problem, in a linear form, was viewed in terms of the theory of linear algebra. Several methods for solving the inversion problem were reviewed. Radiometric observations were conducted during the 1990 Tropical Cyclone Motion Experiment. The radiometer was installed on the island of Saipan in a tropical region. The radiometer was calibrated using tipping curve and radiosonde data as well as measurements of the radiation from a blackbody absorber. A linear statistical method was applied for the data inversion. The inversion coefficients in the equation were obtained using a large number of radiosonde profiles from Guam and a radiative transfer model. Retrievals were compared with those from local, Saipan, radiosonde measurements. Water vapor profiles, integrated water vapor, and integrated liquid water were retrieved successfully. For temperature profile retrievals, however, the radiometric measurements with experimental noises added no more profile information to the inversion than that they were determined mainly by the surface pressure measurements. A method was developed to derive the integrated water vapor and liquid water from combined radiometer and ceilometer measurements. Significant improvement on radiometric measurements of the integrated liquid water can be gained with this method.

Han, Yong.



A comparison between radiometric and fluorimetric methods for measuring SSAO activity.  


Semicarbazide-sensitive amine oxidase (SSAO) metabolizes the oxidative deamination of primary aromatic and aliphatic amines. The final cytotoxic products of its catalysis contribute to diseases involving vascular degeneration. The increasing interest in measuring SSAO activity has led to the development of several different methods. Herein, we compare SSAO activity results obtained with radiometric and fluorimetric methods in 49 plasma samples. Although not interchangeable, a significant correlation was obtained between methods. Considering these limitations, the fluorimetric method might replace the radioisotopic one. PMID:23400361

Gella, Alejandro; Solé, Montse; Bolea, Irene; Ventriglia, Mariacarla; Siotto, Mariacristina; Durany, Nuria; Squitti, Rosanna; Unzeta, Mercedes




Microsoft Academic Search

A radiometric method capable of determining the activity of Ce¹⁴¹, ; Ce¹⁴³, and Ce¹⁴⁴ yields Pr¹⁴⁴ by a single m easurement with a ; BETA - gamma spectrometer is suggested. The Pr¹⁴³ in the mixture is ; determined by accumulation of Ce¹⁴³ or by subtracting from the total ; activity (of Ce¹⁴¹, Ce¹⁴³, Ce¹⁴⁴ yields Pr¹⁴⁴) measured ; with a

S. V. Belov; R. V. Zhelezkov; N. T. Polyakov; N. V. Sidorov



Radiometric traverse along the Yukon River from Fort Yukon to Ruby, Alaska, 1949  

USGS Publications Warehouse

In 1949, a radiometric traverse was made of rocks exposed along the banks of and near the Yukon River about Fort Yukon to Ruby, Alaska. Granitic rocks of Tertiary age and of Devonian or Carboniferous age and sandstone beds of Cretaceous age gave the highest readings obtained in the field. Other rock types examined were greenstone of Devonian or Carboniferous age and metamorphic rocks of Devonian and pre-Devonian age, sedimentary rocks, and liginite of Tertiary age, and alluvial deposits of Quaternary age. The most radioactive sample, from Melozitna River canyon, contained only 0.017 percent equivalent uranium.

White, Max G.; Stevens, John M.; Matzko, John J.



Towards Luminescence Dating Of Mosaic Glass  

NASA Astrophysics Data System (ADS)

The possibility of dating archaeological glass by means of luminescent techniques has been investigated in recent years, despite the difficulties of this application, mainly linked to the amorphous structure of the material. We focused in particular on mosaic glass, after the encouraging results obtained on byzantine and medieval samples. Further studies were devoted to the comprehension of the luminescent mechanisms in silica glasses, and to the investigation of the relationships between luminescence, colouring or opacifier ions and crystalline phase of the vitreous matrix. The results of a study on the dosimetric characteristics of thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) of a few medieval blue-green mosaic glasses from the San Lorenzo church (Milan) are presented, and the experimental protocols established to identify their suitability for dating are discussed.

Galli, A.; Martini, M.; Sibila, E.; Villa, I.


Support technologies involved in the development and implementation of radiometric systems for sensor calibration, characterization, and HWIL testing at AEDC  

NASA Astrophysics Data System (ADS)

The characterization, calibration, and mission simulation testing of space-based, interceptor, and air-borne sensors require a continual involvement in the development and evaluation of radiometric projection technologies. Activities at Arnold Engineering Development Center (AEDC) include Hardware in the Loop (HWIL) testing with high-fidelity complex scene-projection technologies as well as improvements in the radiometric source-calibration systems. These technologies are integrated into a low cryo-vacuum (~20 K) environment. The latest scene simulation and HWIL projection technologies are being investigated that can produce desired target temperatures and target-to-sensor ranges such that sensor mission performance can be evaluated. These technologies include multiple-band source subsystems and special spectral-tailoring methods, as well as comprehensive analysis and optical properties measurements of the components involved. Emphasis areas include the development of methodologies to test wide field of view (WFOV), polarimetric, and multi/hyperspectral radiometric imaging systems.

Lowry, H. S.; Breeden, M. F.; Crider, D. H.; Steely, S. L.; Nicholson, R. A.; Labello, J. M.



Radiometric performance results of the Lunar Reconnaissance Orbiter's Lyman Alpha Mapping Project (LRO/LAMP) UV imaging spectrograph  

NASA Astrophysics Data System (ADS)

We describe the pre-flight radiometric performance and calibration results of the Lunar Reconnaissance Orbiter's Lyman Alpha Mapping Project (LRO/LAMP) flight model. LAMP is a lightweight (6.1 kg), low-power (4.5 W), ultraviolet spectrograph based on the ALICE instruments now in flight aboard the European Space Agency's Rosetta spacecraft and NASA's New Horizons spacecraft. Its primary job will be to identify and localize exposed water frost in permanently shadowed regions (PSRs), and to characterize landforms and albedos in PSRs. Detailed radiometric performance results of the LAMP flight model are presented and discussed.

Davis, Michael W.; Slater, David C.; Gladstone, G. Randall; Stern, S. Alan; Greathouse, Thomas K.; Retherford, Kurt D.; Versteeg, Maarten H.; Black, Ronald K.



Determination of U, Pu and Am isotopes in Irish Sea sediment by a combination of AMS and radiometric methods.  


Samples from a marine sediment core from the Irish Sea (54.416 N, 3.563 W) were analyzed for the isotopic composition of uranium, plutonium and americium by a combination of radiometric methods and AMS. The radiochemical procedure consisted of a Pu separation step by anion exchange, subsequent U separation by extraction chromatography using UTEVA® and finally Am separation with TRU® Resin. Additionally to radiometric determination of these isotopes by alpha spectrometry, the separated samples were also used for the determination of (236)U/(238)U and plutonium isotope ratios by Accelerator Mass Spectrometry (AMS) at the VERA facility. PMID:21316820

Srncik, M; Hrnecek, E; Steier, P; Wallner, G



[In-flight absolute radiometric calibration of UAV hyperspectral camera and its validation analysis].  


With the data in Urad Front Banner, Inner Mongolia on November 14th, 2010, hyper-spectral camera on UAV was calibrated adopting reflectance-based method. During the in-flight absolute radiometric calibration, 6 hyper-spectral radiometric gray-scale targets were arranged in the validation field. These targets' reflectances are 4.5%, 20%, 30%, 40%, 50% and 60% separately. To validate the calibration result, four extra hyper-spectral targets with sharp-edge spectrum were arranged to simulate the reflection and absorption peaks in natural objectives. With these peaks, the apparent radiance calculated by radiation transfer model and that calculated through calibration coefficients are much different. The result shows that in the first 15 bands (blue bands), errors are somewhat huge due to the noises of equipment. In the rest bands with quite even spectrum, the errors are small, most of which are less than 10%. For those bands with sharp changes in spectral curves, the errors are quite considerable, varying from 10% to 25%. PMID:22512184

Gou, Zhi-yang; Yan, Lei; Chen, Wei; Jing, Xin; Yin, Zhong-yi; Duan, Yi-ni



Sensitivity and information content of aerosol retrievals from the Advanced Very High Resolution Radiometer: radiometric factors.  


The sensitivity of aerosol optical depths tau1 and tau2 derived from the Advanced Very High Resolution Radiometer (AVHRR) channels 1 and 2, centered at lambda1 = 0.63 and lambda2 = 0.83 microm, respectively, and of an effective Angstrom exponent alpha, derived therefrom as alpha = -ln(tau1/tau2)/ln(lambda1/lambda2), to calibration uncertainties, radiometric noise, and digitization is estimated. Analyses are made both empirically (by introduction of perturbations into the measured radiances and estimation of the respective partial derivatives) and theoretically (by use of a decoupled form of the single-scattering approximation of the radiative transfer equation). The two results are in close agreement. The errors, deltataui and deltaalphai, are parameterized empirically as functions of taui, radiometric errors, and Sun and view geometry. In particular, the alpha errors change in approximately inverse proportion to tau and are comparable with, or even exceed, typical alpha signals over oceans when tau < 0.25. Their detrimental effect on the information content of the AVHRR-derived size parameter gradually weakens as tau increases. PMID:11900149

Ignatov, Alexander



Radiometric Survey in Western Afghanistan: A Website for Distribution of Data  

USGS Publications Warehouse

Radiometric (uranium content, thorium content, potassium content, and gamma-ray intensity) and related data were digitized from radiometric and survey route location maps of western Afghanistan published in 1976. The uranium content data were digitized along contour lines from 33 maps in a series entitled 'Map of Uranium (Radium) Contents of Afghanistan (Western Area),' compiled by V. N. Kirsanov and R. S. Dershimanov. The thorium content data were digitized along contour lines from 33 maps in a series entitled 'Map of Thorium Contents of Afghanistan (Western Area),' compiled by V. N. Kirsanov and R. S. Dershimanov. The potassium content data were digitized along contour lines from 33 maps in a series entitled 'Map of Potassium Contents of Afghanistan (Western Area),' compiled by V. N. Kirsanov and R. S. Dershimanov. The gamma-ray intensity data were digitized along contour lines from 33 maps in a series entitled 'Map of Gamma-Field of Afghanistan (Western Area),' compiled by V. N. Kirsanov and R. S. Dershimanov. The survey route location data were digitized along flight-lines located on 33 maps in a series entitled 'Survey Routes Location and Contours of Flight Equal Altitudes. Western Area of Afghanistan,' compiled by Z. A. Alpatova, V. G. Kurnosov, and F. A. Grebneva.

Sweeney, Ronald E.; Kucks, Robert P.; Hill, Patricia L.; Finn, Carol A.



Radiometric calibration of the telescope and ultraviolet spectrometer SUMER on SOHO  

NASA Astrophysics Data System (ADS)

The prelaunch spectral-sensitivity calibration of the solar spectrometer SUMER (Solar Ultraviolet Measurements of Emitted Radiation) is described. SUMER is part of the payload of the Solar and Heliospheric Observatory (SOHO), which begins its scientific mission in 1996. The instrument consists of a telescope and a spectrometer capable of taking spatially and spectrally highly resolved images of the Sun in a spectral range from 50 to 161 nm. The pointing capabilities, the dynamic range, and the sensitivity of the instrument allow measurements both on the solar disk and above the limb as great as two solar radii. To determine plasma temperatures and densities in the solar atmosphere, the instrument needs an absolute spectral-sensitivity calibration. Here we describe the prelaunch calibration of the full instrument, which utilizes a radiometric transfer-standard source. The transfer standard was based on a high-current hollow-cathode discharge source. It had been calibrated in the laboratory for vacuum UV radiometry of the Physikalisch-Technische Bundesanstalt by use of the calculable spectral photon flux of the Berlin electron storage ring for synchrotron radiation (BESSY)-a primary radiometric source standard.

Hollandt, Jörg; Schühle, Udo; Paustian, Wolfgang; Curdt, Werner; Kühne, Michael; Wende, Burkhard; Wilhelm, Klaus



NIST activities in support of space-based radiometric remote sensing  

NASA Astrophysics Data System (ADS)

We provide an historical overview of NIST research and development in radiometry for space-based remote sensing. The applications in this field can be generally divided into two areas: environmental and defense. In the environmental remote sensing area, NIST has had programs with agencies such as the National Aeronautical and Space Administration (NASA) and the National Oceanic and Atmospheric Administration (NOAA) to verify and improve traceability of the radiometric calibration of sensors that fly on board Earth-observing satellites. These produce data used in climate models and weather prediction. Over the years, the scope of activities has expanded from existing routine calibration services for artifacts such as lamps, diffusers, and filters, to development and off-site deployment of portable radiometers for radiance- and irradiance-scale intercomparisons. In the defense remote sensing area, NIST has had programs with agencies such as the Department of Defense (DOD) for support of calibration of small, low-level infrared sources in a low infrared background. These are used by the aerospace industry to simulate ballistic missiles in a cold space background. Activities have evolved from calibration of point-source cryogenic blackbodies at NIST to measurement of irradiance in off-site calibration chambers by a portable vacuum/cryogenic radiometer. Both areas of application required measurements on the cutting edge of what was technically feasible, thus compelling NIST to develop a state-of-the-art radiometric measurement infrastructure to meet the needs. This infrastructure has led to improved dissemination of the NIST spectroradiometric quantities.

Rice, Joseph P.; Johnson, B. Carol



Relative radiometric correction on panchromatic images of the Beijing-1 Micro-Satellite  

NASA Astrophysics Data System (ADS)

Because of the problems existing in the optimal system and data transfer equipment on the payload, which cause the nonuniformity of the irradiation response on the panchromatic camera's CCD array of Beijing-1 of Disaster Monitoring Constellation(DMC+4, launched on 10th 2005), there are several radiometric response errors on images produced by the array pushbroom scanner. Such as odd and even stripe noise, the integrated lightness difference on the left and right part image, the lightness pulse at the centre of images and so on. The curve of the radiometric response of the panchromatic camera's CCD array on the uniform light irradiation has been measured in the laboratory. But some correlative parameters are still unknown and may be changed with the space environment. This article suggest new correction methods which are based on the array response model after filtering useless stripe noise of it by a special filter. Through the experiment of simulated images, the best method combination for de-striping and eliminating the PRNU (Photoresponse non-uniformity) phenomenon in the image simultaneously was found.

Liu, Xiang; Chen, ZhengChao; Zhang, Hao; Luo, WenFei; Zhang, Xia



Radiometric calibration stability of the FIRST: a longwave infrared hyperspectral imaging sensor  

NASA Astrophysics Data System (ADS)

Emerging applications in Defense and Security require sensors with state-of-the-art sensitivity and capabilities. Among these sensors, the imaging spectrometer is an instrument yielding a large amount of rich information about the measured scene. Standoff detection, identification and quantification of chemicals in the gaseous state are fundamental needs in several fields of applications. Imaging spectrometers have unmatched capabilities to meet the requirements of these applications. Telops has developed the FIRST, a LWIR hyperspectral imager. The FIRST is based on FTIR technology to yield high spectral resolution and to enable high accuracy radiometric calibration. The FIRST, a man portable sensor, provides datacubes of up to 320x256 pixels at 0.35 mrad spatial resolution over the 8-12 ?m spectral range at spectral resolutions of up to 0.25 cm-1. The FIRST has been used in several field measurements, including demonstration of standoff chemical agent detection. One key feature of the FIRST is its ability to give calibrated measurements. The quality of the radiometric and spectral calibration will be presented in this paper. During the field measurements, the FIRST operated under changing environmental conditions while many calibration measurements were taken. In this paper, we will present the stability of the calibration of the FIRST obtained during the field campaigns.

Farley, Vincent; Chamberland, Martin; Vallières, Alexandre; Villemaire, André; Legault, Jean-François



The moon as a radiometric reference source for on-orbit sensor stability calibration  

USGS Publications Warehouse

The wealth of data generated by the world's Earth-observing satellites, now spanning decades, allows the construction of long-term climate records. A key consideration for detecting climate trends is precise quantification of temporal changes in sensor calibration on-orbit. For radiometer instruments in the solar reflectance wavelength range (near-UV to shortwave-IR), the Moon can be viewed as a solar diffuser with exceptional stability properties. A model for the lunar spectral irradiance that predicts the geometric variations in the Moon's brightness with ???1% precision has been developed at the U.S. Geological Survey in Flagstaff, AZ. Lunar model results corresponding to a series of Moon observations taken by an instrument can be used to stabilize sensor calibration with sub-percent per year precision, as demonstrated by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS). The inherent stability of the Moon and the operational model to utilize the lunar irradiance quantity provide the Moon as a reference source for monitoring radiometric calibration in orbit. This represents an important capability for detecting terrestrial climate change from space-based radiometric measurements.

Stone, T. C.



Extreme Ultraviolet Variability Experiment (EVE) Multiple EUV Grating Spectrographs (MEGS): Radiometric Calibrations and Results  

NASA Astrophysics Data System (ADS)

The NASA Solar Dynamics Observatory (SDO), scheduled for launch in early 2010, incorporates a suite of instruments including the Extreme Ultraviolet Variability Experiment (EVE). EVE has multiple instruments including the Multiple Extreme ultraviolet Grating Spectrographs (MEGS) A, B, and P instruments, the Solar Aspect Monitor (SAM), and the Extreme ultraviolet SpectroPhotometer (ESP). The radiometric calibration of EVE, necessary to convert the instrument counts to physical units, was performed at the National Institute of Standards and Technology (NIST) Synchrotron Ultraviolet Radiation Facility (SURF III) located in Gaithersburg, Maryland. This paper presents the results and derived accuracy of this radiometric calibration for the MEGS A, B, P, and SAM instruments, while the calibration of the ESP instrument is addressed by Didkovsky et al. ( Solar Phys., 2010, doi:10.1007/s11207-009-9485-8). In addition, solar measurements that were taken on 14 April 2008, during the NASA 36.240 sounding-rocket flight, are shown for the prototype EVE instruments.

Hock, R. A.; Chamberlin, P. C.; Woods, T. N.; Crotser, D.; Eparvier, F. G.; Woodraska, D. L.; Woods, E. C.



Relation of thorium-normalized surface and aerial radiometric data to subsurface petroleum accumulations  

SciTech Connect

A new exploration method has been developed using surface and aerial gamma-ray spectral measurements in prospecting for petroleum in stratigraphic and structural traps. Formerly troublesome lithologic and environmental variables are suppressed by correcting potassium and uranium readings using a new process of thorium normalization. Normalized potassium shows characteristic low concentrations above petroleum deposits. Normalized uranium shows higher values than normalized potassium over petroleum and generally lower values elsewhere. The authors attribute these anomalies to effects of microbial consumption of microseeping light hydrocarbons. Studies of National Uranium Resource Evaluation (NURE) Program aerial, gamma-ray, spectral data covering portions of six states have shown characteristic normalized potassium and uranium anomalies above 72.7 percent of 706 oil and gas fields. Additionally, an average of 27 similar untested anomalies were found for each 1,000 square mi (2,600 square km) covered. Similar aerial gamma-ray spectral data are available over large portions of potential petroleum areas of the US including Alaska and Australia. Preliminary tests in two basins in Australia showed positive correlation between radiometrically favorable areas and known oil and gas regions. Ground-based, gamma-ray, spectral measurements found the same types of potassium and uranium anomalies over all twelve fields evaluated. Since 1988, the research of surface radiometric data coupled with soil gas hydrocarbon and soil magnetic susceptibility surveys has resulted in discovery of four oil and gas fields in Concho County, Texas.

Saunders, D.F.; Burson, K.R.; Branch, J.F.; Thompson, C.K. (Recon Exploration Inc., Dallas, TX (United States))



AMS carbon-14 dating of ice: progress and future prospects  

Microsoft Academic Search

The ``sublimation technique'' for the recovery of carbon dioxide from ice samples and the conversion of the recovered carbon dioxide into graphite for AMS dating will be described, together with its use in some applications. The technique involves placing the ice sample in a carefully degassed glass vacuum system, ``cleaning'' the ice by removing the outer few millimeters by sublimation,

A. T. Wilson; D. J. Donahue



Dating of ballpoint pen ink.  


In this paper we describe a case in which a cash book, dated of the year 2000, was sent to the Forensic Science Division, Document Laboratory, Zurich Canton Police in March 2003. The questioned document was a list of 29 pages containing a consecutive handwritten numbering and dated entries (payments) made of blue ballpoint pen ink. By definition, a cash book has to be written by hand and the entries have to be made daily. The questioned document was suspected to have been written within a short period (e.g., a few hours) and backdated. The document lab was asked to determine the date of the entries of the questioned list. On one hand, we were asked, if the cash book had been kept on account consecutively during the period of one year, and on the other hand, the judges were interested in knowing, if the document could have been written in 2003 and back dated to 2000. To answer these questions, the document was examined for latent elements by electrostatic detection device (ESDA). The relative dating of the entries was performed by the quantification of the ballpoint pen ink dyes and their degradation products using HPLC. Results show that it is possible to determine the relative age of entries written by ballpoint pen within a relatively short time scale, if storage and supporting material of the different samples are the same or at least similar. PMID:15568713

Hofer, R



Evaluation of Remote Sensing Techniques for Ice-Area Classification Applied to the Tropical Quelccaya Ice Cap, Peru  

Microsoft Academic Search

Concerns of deglaciation in the Andes prompted this investigation of meth- ods to determine ice extent of glaciers from satellite imagery. Several remote sensing techniques to delineate ice cover are evaluated through application to the tropical Quelccaya Ice Cap. Each technique is applied to a single image that was previously geo- metrically and radiometrically corrected, and their results are evaluated

Todd H. Albert



The 190Pt-186Os Decay System Applied to Dating Platinum-Group Element Mineralization in Layered Intrusions, Ophiolites and Detrital Deposits  

NASA Astrophysics Data System (ADS)

Discrete platinum-group minerals (PGM) occur as accessory phases in mafic-ultamafic intrusions and ophiolitic chromitites, as well as numerous detrital deposits globally. The 190Pt-186Os decay system, measured by laser ablation MC-ICPMS (LA-MC-ICPMS) provides a useful geochronometric tool for direct dating of PGM. Here we present two examples that verify the accuracy of the technique in geologically well constrained situations and demonstrate the potential for using the 190Pt-186Os PGM method to accurately date layered mafic intrusions, ophiolitic chromitites and detrital PGM deposits. Fifty PGM grains from three different horizons within the Bushveld complex yield a Pt-Os isochron age of 2012 ± 47 Ma (2?, MSWD = 1.19, 186Os/188Osi = 0.119818 ± 0.000006). This is consistent with the published U-Pb zircon age of 2054 Ma (Scoates and Friedman, 2008). The younger PGM isochron age is not likely to be a function of difference in blocking temperatures in the different systems. Pt-Os model ages are possible in high pt grains because initial 186Os/188Os can be well constrained. Using this approach we obtained Pt-Os model ages of 2113 ± 106 Ma and 2042 ± 102 Ma for a Bushveld Pt-Fe alloy and sperrylite respectively. Detrital PGM derived from the Meratus ophiolite, southeast Borneo yield a 190Pt-186Os isochron age of 202.5 Ma ± 8.3 Ma (2?, n = 260, MSWD = 0.90, 186Os/188Osi = 0.119830 ± 0.000003), consistent with radiometric and biostratigraphic age constraints (Wakita et al., 1998). We interpret this as the age of formation of the PGM grains in during chromitite genesis in the lower oceanic lithosphere. Our combined data demonstrate the utility of the LA-MC-ICPMS method as a tool for accurate Pt-Os dating of detrital PGM as well as their igneous parent bodies. We can constrain Pt/Os fractionation at the ablation site as being < 2.5%, while within-grain heterogeneity is ultimately one of the strongest controls on isochron and single-grain ages given the partial sampling represented by laser ablation. Scoates, J.S. and Friedman, R.M. 2008. Precise age of the platiniferous Merensky reef, Bushveld Complex, South Africa, by the U-Pb zircon chemical abrasion ID-TIMS technique; Economic Geology 103, p. 465-471. Wakita, K., Miyazaki, K., Zulkarnain, I., Sopaheluwakan, J. and Sanyoto, P. 1998. Tectonic implications of new age data for the Meratus complex of south Kalimantan, Indonesia; Island Arc 7, p. 202-222.

Coggon, J. A.; Nowell, G.; Pearson, G.; Oberthür, T.; Lorand, J.; Melcher, F.; Parman, S. W.



Low energy cyclotron for radiocarbon dating  

SciTech Connect

The measurement of naturally occurring radioisotopes whose half lives are less than a few hundred million years but more than a few years provides information about the temporal behavior of geologic and climatic processes, the temporal history of meteoritic bodies as well as the production mechanisms of these radioisotopes. A new extremely sensitive technique for measuring these radioisotopes at tandem Van de Graaff and cyclotron facilities has been very successful though the high cost and limited availability have been discouraging. We have built and tested a low energy cyclotron for radiocarbon dating similar in size to a conventional mass spectrometer. These tests clearly show that with the addition of a conventional ion source, the low energy cyclotron can perform the extremely high sensitivity /sup 14/C measurements that are now done at accelerator facilities. We found that no significant background is present when the cyclotron is tuned to accelerate /sup 14/C negative ions and the transmission efficiency is adequate to perform radiocarbon dating on milligram samples of carbon. The internal ion source used did not produce sufficient current to detect /sup 14/C directly at modern concentrations. We show how a conventional carbon negative ion source, located outside the cyclotron magnet, would produce sufficient beam and provide for quick sampling to make radiocarbon dating milligram samples with a modest laboratory instrument feasible.

Welch, J.J.



Assessing screening criteria for the radiocarbon dating of bone mineral  

NASA Astrophysics Data System (ADS)

Radiocarbon dating of bone mineral (carbonate in the apatite lattice) has been the target of sporadic research for the last 40 years. Results obtained by different decontamination protocols have, however, failed to provide a consistent agreement with reference ages. In particular, quality criteria to assess bone mineral radiocarbon dating reliability are still lacking.Systematic research was undertaken to identify optimal preservation criteria for bone mineral in archeological bones. Six human long bones, originating from a single site, were radiocarbon-dated both for collagen and apatite, with the level of agreement between the dates providing an indication of exogenous carbon contamination. Several techniques (Histology, FTIR, TEM, LA-ICP-MS) were employed to determine the preservation status of each sample.Research results highlight the importance of a micro-scale approach in establishing bone preservation, in particular the use of trace element concentration profiles demonstrated its potential use as a viable sample selection criterion for bone carbonate radiocarbon dating.

Fernandes, Ricardo; Hüls, Matthias; Nadeau, Marie-Josée; Grootes, Pieter M.; Garbe-Schönberg, C.-Dieter; Hollund, Hege I.; Lotnyk, Andriy; Kienle, Lorenz



Identifying potentially active volcanoes in the Andes: Radiometric evidence for late Pleistocene-early Holocene eruptions at Volcán Imbabura, Ecuador  

NASA Astrophysics Data System (ADS)

Recent eruptions from volcanoes with no previously known historical activity in Chile and Indonesia have raised the importance of the early identification of potentially active centers for the purpose of hazard assessment. Here we bring radiometric evidence ( 14 C, 39 Ar- 40 Ar) of previously unrecognized but significant magmatic activity at partly eroded Imbabura volcano (Ecuador) in late Pleistocene to early Holocene times, on whose perimeter live more than 300,000 persons. Following an effusive stage from 50 to 30 ka with the emplacement of andesitic lava flows on different flanks of its edifice, the activity became explosive with the generation of andesitic block-and-ash flows on its eastern side, beginning at ~ 35 ka cal BP. Subsequently a flank collapse associated with a volcanic blast occurred on the volcano's SW flank at ~ 30 ka cal BP. The resulting debris avalanche and blast breccias cover an area now heavily populated around San Pablo Lake and its source was later concealed by successive dome building episodes at Huarmi which produced ~ 2.8 km 3 of silicic andesite. Renewed dome activity at the edifice's Taita summit occurred at ~ 17 ka cal BP and continued intermittently into early Holocene times, as indicated by pyroclastic flow deposits overlying a palaeosoil dated at ~ 9 ka cal BP. In summary, this study reveals an eruptive behavior characterized by a low recurrence rate but with quite large eruptions, a pattern which is also observed at other silicic volcanoes of Ecuador's Western Cordillera. It is now imperative to reconsider the origin and source of the many tephra layers catalogued in Holocene lacustrine sediments in the Imbabura area. Tephra and lava volume estimates for Imbabura volcano converted to Dense Rock Equivalent values yield a minimum magmatic output rate of 0.13 km 3 /ka in the past 35,000 years, which argues for sustained magma production for this volcano in recent geological times. The Imbabura example thus raises the question of how to improve population preparedness for volcanoes with infrequent eruptions, and how to guide authorities' decisions concerning the development of urban areas and infrastructures near presently inactive but potentially highly dangerous volcanoes.

Le Pennec, J. L.; Ruiz, A. G.; Eissen, J. P.; Hall, M. L.; Fornari, M.



Dating silk by capillary electrophoresis mass spectrometry.  


A new capillary electrophoresis mass spectrometry (CE-MS) technique is introduced for age estimation of silk textiles based on amino acid racemization rates. With an L to D conversion half-life of ~2500 years for silk (B. mori) aspartic acid, the technique is capable of dating silk textiles ranging in age from several decades to a few-thousand-years-old. Analysis required only ~100 ?g or less of silk fiber. Except for a 2 h acid hydrolysis at 110 °C, no other sample preparation is required. The CE-MS analysis takes ~20 min, consumes only nanoliters of the amino acid mixture, and provides both amino acid composition profiles and D/L ratios for ~11 amino acids. PMID:21913691

Moini, Mehdi; Klauenberg, Kathryn; Ballard, Mary



Internet dating: a British survey  

Microsoft Academic Search

Purpose – An online survey was carried out with the purpose of finding out the extent to which internet users subscribe to online dating services. The paper aims to assess users' experiences of such services and their eventual outcomes. Design\\/methodology\\/approach – Data were obtained through a self-completion online questionnaire survey posted on the website of a leading internet research agency,

Barrie Gunter



Online Dating and Conjugal Bereavement  

ERIC Educational Resources Information Center

|This study examined self-presentation in the online dating profiles of 241 widowed and 280 divorced individuals between 18 and 40 years old. A content analysis of open-ended user-generated profiles assessed the presence or absence of various themes, including the user's marital status, the backstory of their lost relationship, and whether they…

Young, Dannagal Goldthwaite; Caplan, Scott E.



Peer Group Influences on Adolescent Dating Aggression  

ERIC Educational Resources Information Center

|The peer group is a critical social context for dating and romantic relationships. Peer groups provide opportunities to meet potential dating partners and set norms for acceptable dating behaviors. This article explores how peer groups influence dating and dating aggression, as well as how they can be used in prevention efforts. It also reviews…

Connolly, Jennifer; Friedlander, Laura



Non-invasive temperature profile estimation in a lossy medium based on multi-band radiometric signals sensed by a microwave dual-purpose body-contacting antenna.  


Microwave radiometry has during the past two decades been investigated as a non-invasive scheme for measurement of subcutaneous tissue temperatures, basically for monitoring and control in hyperthermic treatment of cancer. In this effort, we test a contact-type, dual-purpose antenna with integral water bolus. To overcome conflicting optimization criteria in the integration of this thermometry technique with heat applicators exhibiting a large effective field size during superficial hyperthermia, a stacked configuration design is proposed, where the radiometer receive antenna (Archimedean spiral) is located on the front (skin) surface of the water bolus and the heating antenna (Dual-Concentric Conductor aperture) is placed on the bolus back surface. The motivation is to achieve homogeneous tissue heating simultaneously with non-invasive thermography of the target tissue under the applicator. This paper addresses the feasibility of predicting one-dimensional depth temperature profiles from multi-band brightness temperatures. The performance is investigated statistically by a Monte Carlo technique on both simulated and real heated-phantom data using up to six radiometric bands. Analysis of measured data shows that during the transient heating period in a solid lossy phantom, the inversion technique exhibits a precision (2sigmaT) and skewness (bias) of estimated compared to actual temperature profiles of better than +/-0.38 degrees C and +/-0.55 degrees C, respectively. PMID:11911486

Jacobsen, S; Stauffer, P


A method of relative radiometric correction for linear push-broom CCD Image without calibration device onboard  

Microsoft Academic Search

The obvious vertical strip and chromatic aberration exist in the raw images obtained from the linear push-broom CCD, due to the different response among CCD detectors, the odd\\/even effect raised in signal transfer and the inconsistency of electronic link outside CCD array. In this paper, one relative radiometric correction method based on dark target image to calculate the bias coefficient

Ming Yan; Zhiyong Wang; Shaoshuai He; Fei Wu; Bingyang Yu



Radiometric measurement of zenith path attenuation due to rain at 19.9 GHz at Amritsar, India  

Microsoft Academic Search

This paper describes the measurement of zenith path attenuation due to rain in winter and monsoon seasons of the year 2001 at Amritsar (31° 38' N 74° 52' E) India, using zenith looking radiometer operating at 19.9 GHz frequency. The effective rain height has been obtained from the analysis of the radiometric data and point rainfall intensity. Specific attenuation for

I. S. Hudiara; Ashok Kumar; Sarita Sharma



Radiometric calibration of IR Fourier transform spectrometers - Solution to a problem with the High-Resolution Interferometer Sounder  

Microsoft Academic Search

A calibrated Fourier transform spectrometer, known as the High-Resolution Interferometer Sounder (HIS), has been flown on the NASA U-2 research aircraft to measure the infrared emission spectrum of the earth. The primary use - atmospheric temperature and humidity sounding - requires high radiometric precision and accuracy (of the order of 0.1 and 1 C, respectively). To meet these requirements, the

Henry E. Revercomb; William L. Smith; H. Buijs; Hugh B. Howell; D. D. Laporte; L. A. Sromovsky




Microsoft Academic Search

A car-borne radiometric survey was carried out to study the distribution of radioactivity of granitic rocks in the Takanawa peninsula, Ehime prefecture. The maintenance of equipment and the dynamic character of special ratemeter system used in the car-borne survey are discussed. The effect of weathering to the radioactivity of rocks and the geometric effect in the measurement of gamma rays

Shun-ichi Sano



Soil mapping in northern Thailand based on an radiometrically calibrated Maximum likelihood approach  

NASA Astrophysics Data System (ADS)

The highlands of northern Thailand are dominated by the soil reference groups Acrisols and Alisols. The occurrence of these depends mainly on petrography and local climate gradients. The probabilistic Maximum likelihood method locally proved the potential to predict these reference soil groups. However, the available soil information is mostly nested around research stations with vast blank areas in between. Therefore more training data are required. The collection of further soil information is costly and time consuming as the access is often difficult and the determination of the reference soil groups is based on clay content, cation exchange capacity and the organic matter content, which can hardly be determined in the field. Groundbased radiometric data have shown the potential to distinguish Acrisols and Alisols. Therefore, airborne radiometric data, which are available for whole Thailand, might have the potential for regional distinction of those. The airborne data were collected in 1984-89. The sensor was mounted on an airplane flying at approximately 120m altitude, with a distance between the flight lines of approximately 1km and measurements in the flight line of approximately 50m. After orthographic correction a low pass filter (Savitzky Golay) was used for smoothing the data. Corrected output data (grey values) were calibrated and thus transferred to concentration values (K %; Th ppm, U ppm). The standard procedure for interpolation between the flight lines was bidirectional latticing (spline). After interpolation, the data can be presented as a 2D map either as single channel, binary, or ternary presentation. Initial comparisons between the petrography in the field and those ternary maps showed a potential for further subdivision of the existing geological maps. However, smoothing and data interpolation caused numerous artefacts. Therefore it is intended to focus on the primary measuring points. At least, ground measurements of gamma-ray in a limestone area with low background radiation showed different gamma-ray spectra for the respective reference soil groups, so that these points can be used as secondary training data. In conclusion, the calibration of the Maximum likelihood approach with airborne radiometric data offers a promising possibility for efficient soil mapping of larger regions in northern Thailand.

Schuler, U.; Herrmann, L.; Rangnugpit, W.; Stahr, K.



Ice Core Dating Software for Interactive Dating of Ice Cores  

NASA Astrophysics Data System (ADS)

Scientists involved in ice core dating are well familiar with the problem of identification and recording the depth of annual signals using stable isotopes, glaciochemistry, ECM (electrical conductivity), DEP (dielectric properties) and particle counter data. Traditionally all parameters used for ice core dating were plotted as a function of depth, printed and after years were marked on the paper, converted to depth vs. age time scale. To expedite this tedious and manual process we developed interactive computer software, Ice core Dating (ICD) program. ICD is written in Java programming language, and uses GPL and GPL site licensed graphic libraries. The same 3.5 Mb in size pre-compiled single jar file, that includes all libraries and application code, was successfully tested on WinOS, Mac OSX, Linux, and Solaris operating systems running Java VM version 1.4. We have followed the modular design philosophy in our source code so potential integration with other software modules, data bases and server side distributed computer environments can be easily implemented. We expect to continue development of new suites of tools for easy integration of ice core data with other available time proxies. ICD is thoroughly documented and comes with a technical reference and cookbook that explains the purpose of the software and its many features, and provides examples to help new users quickly become familiar with the operation and philosophy of the software. ICD is available as a free download from the Climate Change Institute web site ( under the terms of GNU GPL public license.

Kurbatov, A. V.; Mayewski, P. A.; Abdul Jawad, B. S.



40 CFR 63.1351 - Compliance dates.  

Code of Federal Regulations, 2013 CFR

...compliance date for existing sources for all the requirements...2013, except for the open clinker pile requirements...compliance date for new sources is February 12, 2013...compliance date for existing sources with the requirements for open clinker storage...



Corrections of size-of-source effect and distance effect in radiometric measurements of radiance.  


Many optical instruments used in quality control of the optical radiation emission level of several devices are limited by the so-called size-of-source effect (SSE) as well as the distance effect (DE) when we are dealing with very accurate measurements. Different authors have studied the SSE and DE and have proposed experimental methods that provide corrections for them. We describe a general method based on the partial coherence theory that allows us to describe and calculate the SSE and DE in any radiometric system with circular apertures. We show some experimental results that verify our proposal. Additionally, as a practical example, we present the corresponding DE and SSE correction factors for a particular geometry. PMID:15881058

Solorio-Leyva, Juan Carlos; Suárez-Romero, José Guadalupe; Cortés-Reynoso, José Germán; Hurtado-Ramos, Juan Bautista; Tepichín-Rodríguez, Eduardo



Characterization of Titan surface scenarios combining Cassini SAR images and radiometric data  

NASA Astrophysics Data System (ADS)

A great amount of data and images was provided by the radar on Cassini probe, thus opening and suggesting new scenarios about Titan's formation and evolution. An important result was the detection, among the peculiar and heterogeneous Titan's surface features, of lakes most likely constituted by liquid hydrocarbons, thus supporting the hypothesis of a methane cycle similar to water cycle on Earth.These areas, which resemble terrestrial lakes, seem to be sprinkled all over the high latitudes surrounding Titan's pole. The abundant methane in Titan's atmosphere combined with the low temperature, 94 K, lead scientists to interpret them as lakes of liquid methane or ethane. In this work, scattering models and a Bayesian inversion algorithm are applied in order to characterize lake and land surfaces. The possibility of combining the SAR data with radiometric ones on both lakes and neighboring land areas is also presented. Radar backscattering from lakes is described in terms of a double layer model, consisting of Bragg or facets scattering for the upper liquid layer and the Integral Equation Model (IEM) model for the lower solid surface. Furthermore, by means of a gravity-capillary wave model (Donelan-Pierson), the wave spectra of liquid hydrocarbons surfaces are introduced as a function of wind speed and direction. Theoretical radar backscattering coefficient values are compared with the experimental ones collected by the radar in order to estimate physical and morphological surface parameters, and to evaluate their compatibility with the expected constituents for Titan surfaces. This electromagnetic analysis is the starting point for a statistical inversion algorithm which allows determining limits on the parameters values, especially on the optical thickness and wind speed of the lakes. The physical surface parameters inferred by using the inversion algorithm are used as input for a forward radiative transfer model calculation to obtain simulated brightness temperatures. The radiometric model has been introduced to further verify the values ranges for the different parameters. In fact the same parameters derived from the radar data analysis have been used as input for the radiometric model. The comparison between the observed and computed brightness temperatures has been performed in order to address the consistency of the observations from the two instruments and to determine the coarse characteristics of the surface parameters. For both radar and radiometric data the soil medium is horizontally stratified into 2 layers. Each layer can be characterized by different absorption coefficients depending on the optical thickness, dielectric constant and physical temperature. In this algorithm, the starting point is the map of optical thickness derived from the SAR images. The simulated brightness temperature is calculated by applying the forward radiative transfer model to the optical thickness map with the same hypotheses assumed to derive it. The simulation is also carried out on the neighboring land areas by considering a double layer model including a contribution of volume scattering. Each layer is described in terms of dielectric constant values, albedo and roughness parameters with the hypothesis of water ice ammonia on layers of solid hydrocarbons and organic compounds like tholins. The analysis is applied to the areas detected on flybys 25 and 30. One important result arises from the analysis of the inverted optical thickness on deep lakes. In this case, found values of optical thickness can be considered limit values because, beyond these values, a complete attenuation can be considered. This limit value is important as it is stable even if the other parameters vary. Starting from this point, posing the condition of a complete attenuation of the second layer, i.e. fixing the value of the optical thickness, the algorithm can be used to estimate the wind speed. The retrieved values vary between 0.2 to 0.5 m/s. The first results also show a good agreement between the simulated data and the measured brightness temperature

Ventura, B.; Notarnicola, C.; Casarano, D.; Janssen, M.; Posa, F.; Cassini RADAR Science Team



Calibration of a Solar Absolute Cavity Radiometer with Traceability to the World Radiometric Reference  

SciTech Connect

This report describes the present method of establishing traceability of absolute cavity radiometers to the World Radiometric Reference (WRR) through the process employed in the International Pyrheliometer Comparisons (IPC). This method derives the WRR reduction factor for each of the participating cavity radiometers. An alternative method is proposed, described, and evaluated as a way to reduce the uncertainty in the comparison process. The two methods are compared using a sample of data from the recent IPC-VIII conducted from September 25th to October 13th, 1995 at the World Radiation Center in Davos, Switzerland. A description of absolute cavity radiometers is also included, using a PMO-6 as an example of active cavity radiometers, and a HF as an example of passive cavity radiometers.

Reda, I.



KRMS (K-band Radiometric Mapping System) SSM/I validation March 1988 quick look report  

NASA Astrophysics Data System (ADS)

The primary objective of this mission was to provide high-resolution passive microwave imagery in support of the NASA SSM/I sea ice algorithm verification program. Four flights were flown, originating from Eielson AFB, Fairbanks, Alaska, over the Chukchi Sea, the Beaufort Sea, and the Bering Sea. The Ka-band Radiometric Mapping System (KRMS) was flown from 6 to 14 March 1988. Data were collected on each of four days during this period. This report provides the flight and navigation records required to reconstruct the missions. Flight racks, compiled from the primary navigation system, indicate areas of coverage. The system logs provide the sensor settings and pertinent flight data, such as altitude and ground speed. The navigation logs provide specifics as to location of data and time of collection. A flight track chart is provided for each day's mission. Several examples of KRMS imagery are also provided.

Farmer, L. Dennis; Eppler, Duane T.; Heydlauff, Bruce; Olsen, David



Tower-based radiometric observations at a coastal site in the Baltic Proper  

NASA Astrophysics Data System (ADS)

An autonomous above-water radiometer was operated during the summer of 2005 on the Gustaf Dalén Lighthouse Tower (GDLT) off the Swedish coast in the Baltic Proper. Normalized water leaving radiances, LWN(?), produced from measurements performed with the autonomous system at various center-wavelengths ? in the 412 675 nm spectral range, were applied within the context of water quality monitoring and satellite ocean color validation activities. Specifically these in situ radiometric data were used to determine the chlorophyll a concentration through a regional band-ratio algorithm and to assess LWN(?) derived from top-of-atmosphere Moderate Resolution Imaging Spectroradiometer (MODIS) observations. The in situ measurements collected during a bloom occurring in July 2005 were also used to investigate the spectral and small scale temporal-spatial variability of LWN(?) in the presence of cyanobacteria.

Zibordi, G.; Strömbeck, N.; Mélin, F.; Berthon, J.-F.



Radiometric determination of trace amounts of zinc using liquid scintillation counting.  


A sensitive and selective radiometric method of substoichiometric isotope dilution analysis for the determination of trace amounts of zinc is described. The activity of (65)Zn used as a tracer in this method was measured by liquid scintillation counting and its counting efficiency was found to be 76+/-2.7%. The method is based on the extraction of the ion-association complex of zinc from thiocyanate medium at pH 7.9 using substoichiometric amount of Aliquat-336 in toluene. The method is sensitive to 20 ng of Zn(II) in an aqueous phase volume of up to 15 ml and its reliability was tested by applying it to a certified reference material-magnesium alloy and pharmaceutical samples. PMID:18967214

Sandhya, D; Subramanian, M S



Minimization of the A/D-conversion noise in imaging radar using radiometric real time correction  

NASA Astrophysics Data System (ADS)

A new solution for radiometric real time correction of radar signals is proposed which simultaneously minimizes both quantization and saturation noise in analog/digital (A/D) conversion of video signals from coherent and incoherent radar systems. The dynamic range which is restricted by the A/D converter is expanded by varying the gain of the intermediate frequency part, so that the signal variation of the conversion remains constant and independent of the distance. A procedure for calculating the amplification curve is developed. An adaptive control system determines the optimal amplification curve using the instantaneous signal output. The successful application of this procedure in the experimental SAR system of the DFVLR demonstrates that a residual signal power error in the A/D converter of less than 1 dB is attained, a level not achieved using conventional methods.

Moreira, Joao R.; Poetzsch, Winfried


Pilot study of the application of Tellus airborne radiometric and soil geochemical data for radon mapping.  


The scope for using Tellus Project airborne gamma-ray spectrometer and soil geochemical data to predict the probability of houses in Northern Ireland having high indoor radon concentrations is evaluated, in a pilot study in the southeast of the province, by comparing these data statistically with in-house radon measurements. There is generally good agreement between radon maps modelled from the airborne radiometric and soil geochemical data using multivariate linear regression analysis and conventional radon maps which depend solely on geological and indoor radon data. The radon maps based on the Tellus Project data identify some additional areas where the radon risk appears to be relatively high compared with the conventional radon maps. One of the ways of validating radon maps modelled on the Tellus Project data will be to carry out additional indoor measurements in these areas. PMID:18562054

Appleton, J D; Miles, J C H; Green, B M R; Larmour, R



Improvement of the X-ray radiometric method of lanthanides' diagnostics in soils  

NASA Astrophysics Data System (ADS)

There are scarce data on the content of lanthanides in the soils of Russia, which is explained by the difficulties in their identification. The improvement of X-ray radiometric analysis permitted us to analyze a significant group of lanthanides in soils, i.e., La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, and Dy. Methods of diagnostics are developed for different groups of lanthanides. The new procedure permitted achieving high accuracy in the measurement; the limit of the lanthanide identification in soils is equal to 2-5 mg/kg. The new procedure allows revealing the particularities of heavy lanthanides' distribution depending on the lithogenic and anthropogenic factors. The procedure is applicable for revealing the technogenic anomalies of heavy lanthanides and determining their content in soils within positive and weakly negative anomalies.

Savichev, A. T.; Vodyanitskii, Yu. N.



A Liquid-Helium-Cooled Absolute Reference Cold Load forLong-Wavelength Radiometric Calibration  

SciTech Connect

We describe a large (78-cm) diameter liquid-helium-cooled black-body absolute reference cold load for the calibration of microwave radiometers. The load provides an absolute calibration near the liquid helium (LHe) boiling point, accurate to better than 30 mK for wavelengths from 2.5 to 25 cm (12-1.2 GHz). The emission (from non-LHe temperature parts of the cold load) and reflection are small and well determined. Total corrections to the LHe boiling point temperature are {le} 50 mK over the operating range. This cold load has been used at several wavelengths at the South Pole and at the White Mountain Research Station. In operation, the average LHe loss rate was {le} 4.4 l/hr. Design considerations, radiometric and thermal performance and operational aspects are discussed. A comparison with other LHe-cooled reference loads including the predecessor of this cold load is given.

Bensadoun, M.; Witebsky, C.; Smoot, George F.; De Amici,Giovanni; Kogut, A.; Levin, S.



Radiometric characterization of ultra-bright xenon short-arc discharge lamps for novel applications  

NASA Astrophysics Data System (ADS)

The latest generations of ultra-bright Xenon short-arc discharge lamps have prodigious emissions outside the visible spectrum, primarily in the near infrared. Their brightness distributions are spatially and angularly inhomogeneous due to both the pronounced non-uniformities of the plasma arc and the substantial infrared radiation from the hot electrodes. These characteristics are fortuitously favorable for applications in photonic surgery, biomedical diagnostics, high-temperature chemical reactors and furnaces: cases where the full lamp spectrum is utilizable, and the key is reconstituting the spectral power density of the optimal regions of the lamp's plasma at a remote target. The associated optical systems must be tailored to lamp radiometric properties that are not extensively available and invariably are restricted to visible light due to their widespread use in projection systems. We present experimental measurements for the spectral, spatial and angular distributions of 150 W lamps of this genre, and relate to their ramifications for broadband high-flux applications.

Nakar, Doron; Malul, Asher; Feuermann, Daniel; Gordon, Jeffrey M.



Preliminary results of radiometric measurements of clear air and cloud brightness (antenna) temperatures at 37GHz  

NASA Astrophysics Data System (ADS)

In this paper the results of polarization measurements of clear air and clouds brightness temperatures at 37GHz are presented. The results were obtained during the measurements carried out in Armenia from the measuring complex built under the framework of ISTC Projects A-872 and A-1524. The measurements were carried out at vertical and horizontal polarizations, under various angles of sensing by Ka-band combined scatterometric-radiometric system (ArtAr-37) developed and built by ECOSERV Remote Observation Centre Co.Ltd. under the framework of the above Projects. In the paper structural and operational features of the utilized system and the whole measuring complex will be considered and discussed as well.

Arakelyan, A. K.; Hambaryan, A. K.; Arakelyan, A. A.



Radiometric and Geometric Analysis of Hyperspectral Imagery Acquired from an Unmanned Aerial Vehicle  

SciTech Connect

In the summer of 2010, an Unmanned Aerial Vehicle (UAV) hyperspectral in-flight calibration and characterization experiment of the Resonon PIKA II imaging spectrometer was conducted at the U.S. Department of Energy’s Idaho National Laboratory (INL) UAV Research Park. The purpose of the experiment was to validate the radiometric calibration of the spectrometer and determine the georegistration accuracy achievable from the on-board global positioning system (GPS) and inertial navigation sensors (INS) under operational conditions. In order for low-cost hyperspectral systems to compete with larger systems flown on manned aircraft, they must be able to collect data suitable for quantitative scientific analysis. The results of the in-flight calibration experiment indicate an absolute average agreement of 96.3%, 93.7% and 85.7% for calibration tarps of 56%, 24%, and 2.5% reflectivity, respectively. The achieved planimetric accuracy was 4.6 meters (based on RMSE).

Ryan C. Hruska; Jessica J. Mitchell; Matthew O. Anderson; Nancy F. Glenn



Radiometric calibration of an airborne CO2 pulsed Doppler lidar with a natural earth surface.  


Radiometric calibration of an airborne CO2 pulsed Doppler lidar has been accomplished with surface retroreflection signals from the White Sands National Monument, New Mexico. Two circular passes were made at altitudes of 6.3 and 9.3 km. The computed calibration factors for both altitudes are in excellent agreement with the value derived from standard ground-based measurements involving a fixed sandpaper target of known reflectance. This finding corroborates a previous study that successfully calibrated an airborne cw Doppler lidar with a variety of natural Earth surfaces. The present results indicate that relatively uniform Earth surface targets can be used for in-flight calibration of CO2 pulsed airborne and, in principal, other infrared lidars. PMID:12078677

Cutten, Dean R; Rothermel, Jeffry; Jarzembski, Maurice A; Hardesty, R Michael; Howell, James N; Tratt, David M; Srivastava, Vandana



A quantitative radiometric assay to measure mammalian cell binding to hyphae of Candida albicans.  


A rapid and reproducible assay has been developed to measure the capacity of lymphocytes to bind to Candida albicans. Lymphocytes that bound to C. albicans were either the large granular lymphocyte cell line, YT, or interleukin-2 activated lymphocytes. Lymphocyte binding was assessed as the associated radioactivity of 51Cr-labeled lymphocytes with preformed hyphae. The assay was sensitive to detection of 0.6 lymphocytes/one hyphal form at one half maximal lymphocyte binding capacity. The assay correlated well with direct microscopic assessment of lymphocyte binding to C. albicans and provided quantitative radiometric data. Although the assay was developed for the assessment of lymphocyte adhesion to C. albicans, it can be used to measure binding of other mammalian cells (e.g., polymorphonuclear leukocytes) to this fungus. In addition, the assay may be used to identify molecules involved in the adhesion of lymphocytes and other mammalian cells to C. albicans. PMID:8409462

Forsyth, C B; Mathews, H L



Sensitive radiometric assay for enkephalin convertase and other carboxypeptidase B-like enzymes  

SciTech Connect

A sensitive radiometric assay for carboxypeptidase B-like enzymes has been developed using enkephalin convertase, an enkephalin synthesizing carboxypeptidase. The assay is based on the differential solubility of /sup 3/H-labeled substrate and product in chloroform. The substrates /sup 3/H-benzoyl-Phe-Ala-Arg or /sup 3/H-benzoyl-Phe-Leu-Arg are poorly soluble in chloroform due to the charged arginine. The products of carboxypeptidase B-like activity on these substrates, /sup 3/H-benzoyl-Phe-Ala or /sup 3/H-benzoyl Phe-Leu partition quantitatively into chloroform, allowing rapid separation of product from substrate. This assay is approximately 100 times more sensitive than a similar fluorometric assay utilizing dansyl-Phe-Ala-Arg as a substrate.

Stack, G.; Fricker, L.D.; Snyder, S.H.



Rapid and sensitive measurement of PET radioligands in plasma by fast liquid chromatography/radiometric detection.  


A fast and sensitive liquid chromatographic (fast-LC) method with radiometric detection was developed and validated to analyze positron emission tomography (PET) radioligands in plasma during PET studies. The plasma samples were deproteinized with acetonitrile and the extracts were injected into the fast-LC system coupled to an on-line radioactivity detector. Under the optimum conditions, complete separation of target PET radioligands from their radioactive metabolites was achieved within the short run time of only 3.5-min. The limits of detection were 1.0-1.2 Becquerel (Bq) for (11)C and (18)F-labeled compounds. This method can successfully be applied to study the metabolism of a wide variety of PET radioligands in human and monkey plasma with higher numbers of samples to be analyzed compared to the traditional LC method. PMID:22494928

Nakao, Ryuji; Schou, Magnus; Halldin, Christer



Infrared lock-in carrierography (photocarrier radiometric imaging) of Si solar cells  

NASA Astrophysics Data System (ADS)

Modulated photocarrier radiometric (PCR) imaging (lock-in carrierography) of multicrystalline (mc) Si solar cells is introduced using a near-infrared (NIR) InGaAs camera and a spread superband gap laser beam as an optoelectronic source at low modulation frequencies (<10 Hz) or point-by-point scanning PCR imaging with a focused laser beam at high (kilohertz) frequencies. PCR images are supplemented by quantitative PCR frequency scans and compared to NIR optical reflectance, modulated electroluminescence (MEL) and modulated photovoltage (MPV) images. Noncontact PCR imaging is controlled by the photoexcited carrier diffusion wave and exhibits very similar images to contacting MEL and MPV. Among these methods it exhibits the highest contrast and sensitivity to mechanical and crystalline defects in the substrate at lock-in image frequencies in the range of the inverse recombination lifetime in the quasineutral region (bulk).

Melnikov, A.; Mandelis, A.; Tolev, J.; Chen, P.; Huq, S.



Somaclonal Variation in Date Palm  

Microsoft Academic Search

\\u000a The exploration of somaclonal variation is an approach that could provide date palm breeding programs with new genotypes.\\u000a Naturally occurring or induced variants may have superior agronomic quality and\\/or enhanced performance but could also harbor\\u000a new traits such as tolerance to drought and salinity or resistance to major diseases i.e. bayoud. This chapter summarizes\\u000a recent progress in terms of studying

A. El Hadrami; F. Daayf; S. Elshibli; S. M. Jain; I. El Hadrami


PLEIADES-HR 1A&1B image quality commissioning: innovative radiometric calibration methods and results  

NASA Astrophysics Data System (ADS)

PLEIADES is an earth observing system conducted by the French National Space Agency, CNES. It consists of two satellites launched on December 2011 (PHR-1A) and December 2012 (PHR-1B), both designed to provide optical pushbroom imagery on five spectral bands to civilian and defense users, with ground sample distance up to 70 cm. During inflight image quality commissioning, radiometric activities included inter-detector normalization coefficients computation, refocusing operations, MTF assessment and estimation of signal to noise ratios. This paper presents inflight results for both satellites. It focuses on several innovative methods that were implemented, taking advantage of the satellite platform great agility. These methods are based on processing images obtained through dedicated exotic guidance. In particular, slow-motion steering enables an efficient estimation of the instrumental noise model, since during acquisition each detector has been viewing a stable ground target along different time samples. Conversely, rotated retina guidance is used to guarantee that all different elementary detectors have successively viewed the same set of landscape samples during acquisition. Non-uniformity of detector sensitivities can then be characterized, and on-board coefficients used prior to compression can be calibrated in order to prevent vertical striping effects on operational images. Defocus control and Point Spread Function estimation can be easily obtained through processing acquisitions of stars associated to various spectral characteristics, for different adjustments of the refocusing system. All these methods allow an accurate estimation of radiometric performance on the whole range of specified spectral radiances, while drastically reducing the number of required acquisitions on natural targets.

Martin, Vincent; Blanchet, Gwendoline; Kubik, Philippe; Lacherade, Sophie; Latry, Christophe; Lebegue, Laurent; Lenoir, Florie; Porez-Nadal, Florence



Assessment of GOCI radiometric products using MERIS, MODIS and field measurements  

NASA Astrophysics Data System (ADS)

The first Geostationary Ocean Color Imager (GOCI) launched by South Korea in June 2010 constitutes a major breakthrough in marine optics remote-sensing for its capabilities to observe the diurnal cycles of the ocean. The light signal recorded at eight wavelengths by the sensor allows, after correction for Solar illumination and atmospheric effects, the retrieval of coloured biogeochemical products such as the chlorophyll, suspended sediment and coloured dissolved organic matter concentrations every hour between 9:00 am and 4:00 pm local time around the Korean peninsula. However operational exploitation of the mission needs beforehand a sound validation of first the radiometric calibration, i.e. inspection of the top-of-atmosphere reflectance, and second atmospheric corrections for retrieval of the water-leaving reflectance at sea surface. This study constitutes a contribution to the quality assessment of the GOCI radiometric products generated by the Korea Ocean Satellite Center (KOSC) through comparison with concurrent data from the MODerate-resolution Imaging Spectroradiometer (MODIS, NASA) and MEdium Resolution Imaging Spectrometer (MERIS, ESA) sensors as well as in situ measurements. These comparisons are made with spatially and temporally collocated data. We focus on Rayleigh-corrected reflectance ( ? RC ) and normalized remote-sensing marine reflectance (nRrs). Although GOCI compares reasonably well with MERIS and MODIS, what demonstrates the success of Ocean Colour in geostationary orbit, we show that the current GOCI atmospheric correction systematically masks out data over very turbid waters and needs further examination and correction for future release of the GOCI products.

Lamquin, Nicolas; Mazeran, Constant; Doxaran, David; Ryu, Joo-Hyung; Park, Young-Je



1D-VAR Retrieval of Aerosol Properties from Satellite Spectral Lidar and Radiometric Observations  

NASA Astrophysics Data System (ADS)

Aerosols play an important role in atmospheric physics and chemistry through their impact on air pollution, actinic fluxes, visibility, acid rain, and climate. Numerous atmospheric models at the urban, regional or global scale include a representation of aerosols aimed at simulating their physical and chemical properties such as their concentration, size distribution, chemical composition and state of mixture. Unfortunately these models are not well constrained by observations, which limits the possibility of accurate operational forecasts of aerosol properties at these different scales. Important progresses have been made in the observation of aerosols (in clear-sky) from space. One can measure with a good accuracy the aerosol optical depth and the Ångström exponent (a signature of aerosol size) from radiometric measurements in the visible over the ocean and to some extent over land. Active remote-sensing by lidar offer an opportunity to measure the aerosol vertical profile. In this work we use a simple 1D radiative transfer model and its adjoint to study the retrieval of the vertical profile of aerosol properties from variational assimilation of spectral lidar and radiometric measurements. The cost function is minimized using a BFGS algorithm forcing the model towards the observations. Results of this one dimensional variational assimilation (1D-VAR) scheme with synthetic satellite measurements will be presented and analyzed. In particular we will focus on the retrieval of aerosol properties such as the extinction coefficient vertical profile and size distribution of the accumulation and coarse modes. Colocated lidar and radiance data from the GLAS and MODIS instruments will be used to test the algorithm.

Huneeus, N.; Boucher, O.; Bocquet, M.; Sportisse, B.


Radiometric comparison of the primary source standard 'Metrology Light Source' to a primary detector standard  

NASA Astrophysics Data System (ADS)

The spectral radiant intensity of synchrotron radiation from electron storage rings can be calculated from basic electrodynamic relations (Schwinger equation). A storage ring can, thus, be used as a radiometric primary source standard. The Metrology Light Source (MLS), the dedicated electron storage ring of the Physikalisch-Technische Bundesanstalt, can be operated as a primary radiation source standard from the near infrared up to the soft x-ray region and its operational parameters can be adjusted and accurately measured in a wide range. The MLS electron beam current can be varied from 1 pA (one stored electron) up to 200 mA and, thus, the radiant intensity, being directly proportional to the stored current, can be varied by more than 11 decades. The electron energy, which has a large effect on the spectral shape of the spectrum, can be varied from 105 MeV up to 630 MeV. For the radiometric comparison, the total power irradiated into a well-defined solid angle was directly measured by a cryogenic radiometer as a primary detector standard and compared with the power calculated from the storage ring parameters. These measurements were performed for various electron energies in the range from 200 MeV to 630 MeV, thus varying the shape of the spectrum. For each electron energy setting, the power level was varied within the dynamic range of the cryogenic radiometer by a variation of the electron beam current. Good agreement was found for all parameter settings, thus validating the performance of the cryogenic radiometer and the storage ring parameter measurements within the related uncertainty budget.

Klein, Roman; Gottwald, Alexander; Brandt, Guido; Fliegauf, Rolf; Hoehl, Arne; Kroth, Udo; Kaser, Hendrik; Richter, Mathias; Thornagel, Reiner; Ulm, Gerhard



Monensin causes dose dependent inhibition of Mycobacterium avium subspecies paratuberculosis in radiometric culture  

PubMed Central

Background Mycobacterium avium subspecies paratuberculosis (MAP) causes a chronic wasting diarrheal disease in ruminants called Johne's disease, that is evocative of human inflammatory bowel disease (IBD). Agents used to treat IBD, called "anti-inflammatories", immuno-modulators" and "immuno-suppressants" inhibit MAP growth in culture. We concluded that, unknowingly, the medical profession has been treating MAP since sulfasalazine's introduction in 1942. Monensin, called a "Growth Enhancer" in cattle, ameliorates Johne's disease without a documented mechanism of action. We hypothesized that Monensin would inhibit MAP in culture. Methods Using the radiometric 14CO2 Bactec® system, that expresses mycobacterial growth in arbitrary growth index (GI) units, we studied the effect of Monensin on the growth kinetic of MAP isolated from humans with IBD ("Dominic", "Ben" & UCF-4) and cattle with Johne's disease (303 & ATCC 19698.) Results are expressed as percent inhibition of cumulative GI (%–?cGI). Results The positive control Clofazimine inhibits every strain tested. The negative controls Cycloheximide & Phthalimide, have no inhibition on any MAP strain. Monensin has dose dependent inhibition on every MAP strain tested. The most susceptible human isolate was UCF-4 (73% – ?cGI at 1 ?g/ml) and bovine isolate was 303 (73% – ?cGI at 4 ?g/ml.) Monensin additionally inhibits M. avium ATCC 25291 (87% – ?cGI at 64 ?g/ml) & BCG (92% – ?cGI at 16 ?g/ml). Discussion We show that in radiometric culture the "Growth Enhancer" Monensin causes dose dependent inhibition of mycobacteria including MAP. We posit that the "Growth Enhancer" effect of Monensin may, at least in part, be due to inhibition of MAP in clinical or sub-clinical Johne's disease.

Greenstein, Robert J; Su, Liya; Whitlock, Robert H; Brown, Sheldon T



Radiometric, geometric, and image quality assessment of ALOS AVNIR-2 and PRISM sensors  

USGS Publications Warehouse

The Advanced Land Observing Satellite (ALOS) was launched on January 24, 2006, by a Japan Aerospace Exploration Agency (JAXA) H-IIA launcher. It carries three remote-sensing sensors: 1) the Advanced Visible and Near-Infrared Radiometer type 2 (AVNIR-2); 2) the Panchromatic Remote-Sensing Instrument for Stereo Mapping (PRISM); and 3) the Phased-Array type L-band Synthetic Aperture Radar (PALSAR). Within the framework of ALOS Data European Node, as part of the European Space Agency (ESA), the European Space Research Institute worked alongside JAXA to provide contributions to the ALOS commissioning phase plan. This paper summarizes the strategy that was adopted by ESA to define and implement a data verification plan for missions operated by external agencies; these missions are classified by the ESA as third-party missions. The ESA was supported in the design and execution of this plan by GAEL Consultant. The verification of ALOS optical data from PRISM and AVNIR-2 sensors was initiated 4 months after satellite launch, and a team of principal investigators assembled to provide technical expertise. This paper includes a description of the verification plan and summarizes the methodologies that were used for radiometric, geometric, and image quality assessment. The successful completion of the commissioning phase has led to the sensors being declared fit for operations. The consolidated measurements indicate that the radiometric calibration of the AVNIR-2 sensor is stable and agrees with the Landsat-7 Enhanced Thematic Mapper Plus and the Envisat MEdium-Resolution Imaging Spectrometer calibration. The geometrical accuracy of PRISM and AVNIR-2 products improved significantly and remains under control. The PRISM modulation transfer function is monitored for improved characterization. ?? 2006 IEEE.

Saunier, S.; Goryl, P.; Chander, G.; Santer, R.; Bouvet, M.; Collet, B.; Mambimba, A.; Kocaman, Aksakal, S.



Large sedimentation rate in the Bengal delta: Magnetostratigraphic dating of Cenozoic sediments from northeastern Bangladesh  

NASA Astrophysics Data System (ADS)

A 4.3-km-thick section of clastic sediments of the Surma basin, northeastern Bangladesh, that is exposed along the Shari River was sampled for a magnetostratigraphic study. Miocene through Pleistocene ages have been discussed previously; however, there has been no firm dating through biostratigraphy, or radiometric or other methods. Primary paleomagnetic remanent magnetizations of normal or reversed polarity were determined for most of the 300 collected samples. On the basis of assumptions of (1) constant sedimentation rates, on average, throughout the deposition of the sedimentary sequence, (2) no major gaps in sedimentation, and (3) a fairly young (< 2 Ma) age for the topmost Dupi Tila deposits, we find good agreement between the measured profile and the geomagnetic polarity time scale if the entire sedimentary sequence is between 4.9 and 1.4 Ma in age. The Upper Marine Shales, an important seismic marker horizon, are dated as 3.5 Ma and are therefore ˜1.5 m.y. younger than previously assigned by biostratigraphic results. The Upper Marine Shales presumably correspond to the last pre-Pleistocene sea-level highstand. The dating of rock units below the Upper Marine Shales is tentative because of a large gap in exposure. The inferred sedimentation rate—and thus the rate of delta subsidence—of 1.2 m/k.y. is much larger than previously assumed; it appears to be one of the highest sedimentation rates in Earth history that was sustained for millions of years.

Worm, H.-U.; Ahmed, A. M. M.; Ahmed, N. U.; Islam, H. O.; Huq, M. M.; Hambach, U.; Lietz, J.



Heterosexual Dating Discourses Among College Students  

Microsoft Academic Search

We investigated the extent to which contemporary dating practices are characterized by traditional sexual scripts, such as the double standard, and emerging scripts of female sexual desire and male sexual integrity. One hundred sixty-two upper-division college students responded to measures about dating under two instructional conditions, one describing their dating experiences and the second their dating preferences. Both traditional and

Sabrina Starling Schleicher; Lucia Albino Gilbert



Aerial Radiometric and Magnetic Reconnaissance Survey of Portions of Arizona, Idaho, Montana, New Mexico, South Dakota and Washington. Volume 2-B. Shelby Quadrangle. Final Report.  

National Technical Information Service (NTIS)

The results of a high-sensitivity, aerial, gamma-ray spectrometer and magnetometer survey of the Shelby Quadrangle, Montana, are presented. Statistical and geological analysis of the radiometric data revealed 75 uranium anomalies worthy of field-checking ...



Postlaunch Radiometric Validation of the Clouds and the Earth's Radiant Energy System (CERES) Proto-Flight Model on the Tropical Rainfall Measuring Mission (TRMM) Spacecraft through 1999  

Microsoft Academic Search

Each Clouds and the Earth's Radiant Energy System (CERES) instrument contains three scanning thermistor bolometer radiometric channels. These channels measure broadband radiances in the shortwave (0.3-5.0 m), total (0.3->100 m), and water vapor window regions (8-12 m). Ground-based radiometric calibrations of the CERES flight models were conducted by TRW Inc.'s Space and Electronics Group of Redondo Beach, California. On-orbit calibration

Kory J. Priestley; Bruce R. Barkstrom; Robert B. Lee III; Richard N. Green; Susan Thomas; Robert S. Wilson; Peter L. Spence; Jack Paden; D. K. Pandey; Aiman Al-Hajjah



Multicenter evaluation of the fully automated Bactec MGIT 960 system for susceptibility testing of Mycobacterium tuberculosis to pyrazinamide: comparison with the radiometric Bactec 460TB system.  


One hundred and fifty clinical isolates of Mycobacterium tuberculosis were tested for susceptibility to pyrazinamide using the fully automated Bactec MGIT 960 system and the radiometric Bactec 460TB system. The overall concordance rate between MGIT 960 and radiometric system was 100% and the mean turnaround times to report the susceptibility test results were almost identical (6.37 and 6.8 days, respectively). PMID:14500027

Kontos, Fanourios; Nicolaou, Stavroula; Kostopoulos, Christos; Gitti, Zoe; Petinaki, Efthymia; Maniati, Maria; Anagnostou, Spyridoula; Raftopoulou, Aikaterini; Papageorgiou, Panagiota; Scrioubellou, Aggeliki; Tselentis, Ioannis; Maniatis, Antonios N



Impacts of spectral band difference effects on radiometric cross-calibration between satellite sensors in the solar-reflective spectral domain  

Microsoft Academic Search

In order for quantitative applications to make full use of the ever-increasing number of Earth observation satellite systems, data from the various imaging sensors involved must be on a consistent radiometric scale. This paper reports on an investigation of radiometric calibration errors due to differences in spectral response functions between satellite sensors when attempting cross-calibration based on near-simultaneous imaging of

P. M. Teillet; G. Fedosejevs; K. J Thome; John L. Barker



Pretreatment of date syrup to increase citric acid production  

Microsoft Academic Search

Pretreatment of date syrup with sulfuric acid, tricalcium phosphate, tricalcium phosphate with hydrochloric acid, potassium ferrocyanide, and EDTA to increase the production of citric acid was investigated. Among the above techniques used for the removal of heavy metals, 2% tricalcium phosphate treatment gave better results regarding citric acid concentration (55 ± 1.5 g l?1), citric acid yield (50 ± 1.5%),

T. Roukas; P. Kotzekidou



40Ar\\/39Ar dating of Apollo 12 impact spherules  

Microsoft Academic Search

We have used the 40Ar\\/39Ar isochron technique to determine ages of 81 lunar spherules from Apollo 12 soil sample 12023. Most spherules are created in meteoroid impacts, and their ages correspond to the timing of the impacts that formed them. Of the 81 impacts we have dated, most occurred in the last 500 million years. The abundance of spherules from

Jonathan Levine; Timothy A. Becker; Richard A. Muller; Paul R. Renne



Retrospective Birth Dating of Cells  

SciTech Connect

The generation of cells in the human body has been difficult to study and our understanding of cell turnover is limited. Extensive testing of nuclear weapons resulted in a dramatic global increase in the levels of the isotope {sup 14}C in the atmosphere, followed by an exponential decrease after the test ban treaty in 1963. We show that the level of {sup 14}C in genomic DNA closely parallels atmospheric levels, and can be used to establish the time point when the DNA was synthesized and cells were born. We use this strategy to determine the age of cells in the cortex of the adult human brain, and show that whereas non-neuronal cells are exchanged, occipital neurons are as old as the individual, supporting the view that postnatal neurogenesis does not take place in this region. Retrospective birth dating is a generally applicable strategy that can be used to measure cell turnover in man under physiological and pathological conditions.

L.Spalding, K; Bhardwaj, R D; Buchholz, B A; Druid, H; Frisen, J



Analysis of airborne radiometric data. Volume 2. Description, listing, and operating instructions for the code DELPHI/MAZAS. Final report  

SciTech Connect

The computer code DELPHI is an interactive English language command system for the analysis of airborne radiometric data. The code includes modules for data reduction, data simulation, time filtering, data adjustment and graphical presentation of the results. DELPHI is implemented in FORTRAN on a DEC-10 computer. This volume gives a brief set of operations instructions, samples of the output obtained from hard copies of the display on a Tektronix terminal and finally a listing of the code.

Sperling, M.; Shreve, D.C.



FDTD analysis of the radiometric temperature measurement of a bilayered biological tissue using a body-contacting waveguide probe  

Microsoft Academic Search

Radiometric signal received by an open-ended rectangular waveguide probe in direct contact with a bilayered biological tissue is analyzed by the FDTD method. A two-layer tissue model consists of an outer thin skin layer over a semi-infinite fat layer is analyzed for a X-band total power radiometer. A spherical tumor with same permittivity as, but slightly higher temperature than, the

Lin-Kun Wu; William K. Nieh



Comparison and sensitivity analysis of instruments and radiometric methods for LAI estimation: assessments from a boreal forest site  

Microsoft Academic Search

Retrievals of LAI from inversion of canopy radiometric measurements, using the Li-Cor LAI-2000 Plant Canopy Analyzer and the Decagon AccuPar Ceptometer (a linear quantum probe) were analyzed and compared. Field data were collected from 34 sites in the boreal forest of interior Alaska, and sensitivity tests were conducted to estimate the effect of a variety of measurement conditions on the

Edward J. Hyer; Scott J. Goetz



Correcting first-order errors in snow water equivalent estimates using a multifrequency, multiscale radiometric data assimilation scheme  

Microsoft Academic Search

A season-long, multiscale, multifrequency radiometric data assimilation experiment is performed to test the feasibility of snow water equivalent (SWE) estimation. Synthetic passive microwave (PM) observations at Advanced Microwave Scanning Radiometer-Earth Observing System frequencies and 25 km resolution and synthetic near infrared (NIR) narrowband albedo observations corresponding to Moderate Resolution Imaging Spectroradiometer band 5 (1230-1250 mum) and 1 km resolution are

Michael Durand; Steven A. Margulis



Identifying potentially active volcanoes in the Andes: Radiometric evidence for late Pleistocene-early Holocene eruptions at Volcán Imbabura, Ecuador  

Microsoft Academic Search

Recent eruptions from volcanoes with no previously known historical activity in Chile and Indonesia have raised the importance of the early identification of potentially active centers for the purpose of hazard assessment. Here we bring radiometric evidence (14C,39Ar–40Ar) of previously unrecognized but significant magmatic activity at partly eroded Imbabura volcano (Ecuador) in late Pleistocene to early Holocene times, on whose

J. L. Le Pennec; A. G. Ruiz; J. P. Eissen; M. L. Hall; M. Fornari



Clouds and the Earth's Radiant Energy System (CERES): Long-wave Calibration Plan and Radiometric Test Model (RTM) Calibration Results  

Microsoft Academic Search

The CERES instrument has three radiometers which operate in the short-wave (0,3 ?m to 5 ?m), the long-wave (8 ?m to 12 ?m) and total broadband (0,3 ?m to >200 ?m) spectral regions. The long-wave calibration plan for CERES provides for absolute radiometric calibration of the two CERES sensors operating in the long-wave portion of the spectrum. Ground calibration is

P J Jarecke; M A Folkman; T R Hedman; M E Frink



Clouds and the Earth's Radiant Energy System (CERES): Long-wave Calibration Plan and Radiometric Test Model (RTM) Calibration Results  

Microsoft Academic Search

The CERES instrument has three radiometers which operate in the short-wave (0,3 mum to 5 mum), the long-wave (8 mum to 12 mum) and total broadband (0,3 mum to >200 mum) spectral regions. The long-wave calibration plan for CERES provides for absolute radiometric calibration of the two CERES sensors operating in the long-wave portion of the spectrum. Ground calibration is

P. J. Jarecke; M. A. Folkman; T. R. Hedman; M. E. Frink



In-flight radiometric calibration plans for the Earth Observing System-Multi-angle Imaging SpectroRadiometer  

Microsoft Academic Search

The Multi-angle Imaging SpectroRadiometer (MISR) will fly on the EOS-AM1 spacecraft, and provide global data sets with nine discrete view directions per scene. The instrument's radiometric scale is achieved by use of detector standards. On-orbit, photodiodes measure reflected light from solar-illuminated deployable Spectralon panels. The cameras simultaneously view the panels, providing the needed calibration data inputs. Other calibration methodologies include

Carol Bruegge; Robert Woodhouse; David Diner



High performance spectroradiometer for very accurate radiometric calibrations and testing of blackbody sources and EO test equipment  

Microsoft Academic Search

In the late eighties CI Systems pioneered the radiometric calibration and testing of electro-optical infrared test equipment1,2 by using its advanced in-house developed infrared spectroradiometer (the SR 5000), applied to measurements of signatures of military objects and long path atmospheric spectral transmission. Technological advances of frame rates, temperature resolution, spatial resolution, widened spectral ranges and other performance parameters of Forward

Dario Cabib; Amir Gil; R. A. Buckwald



Aerosol, cloud, and radiometric measurements with small autonomous unmanned aerial vehicles  

NASA Astrophysics Data System (ADS)

The AUAV (autonomous unmanned aerial vehicle) project is a part of the Atmospheric Brown Clouds project. It has been designed to allow for routine vertical profile measurements of aerosols and clouds using AUAVs above ground-based observatories in the Indo-Pacific Ocean region. The current scientific payloads consist of optical particle counters, condensation particle counters, cloud droplet probes, aethelometers, upward and downward facing pyranometers, and temperature-relative humidity sensors. Aerosol, cloud and radiometric instruments have been miniaturized with a total payload weight and power less than 5 kg and 50 W, respectively. Demonstration flights at the Yuma Proving Grounds, AZ show the potential for small AUAVs in atmospheric studies. The flights were performed on two aircraft, which flew autonomously up to 3000 m above sea level (asl) along programmed flight tracks. The aircraft flew in stacked formation for part of the flights. Once the aircraft were stacked (550 and 2100 m asl), the projected distances were less than 50 m - which translates to less than a 1.5 sec latency between the aircraft. Vertical profiles show a constant 8 K km-1 lapse rate and increasing relative humidity with altitude. At 2000 m asl (1600 m above ground level), an aerosol layer is evident in the total aerosol concentration profile (NCN = 2000 cm-3); relative humidity also increased by 10% in this layer. No such increase in 0.3 ?m aerosol (NOPC) is visible at 2000 m asl, suggesting transport from an urban center. Back trajectories indicate air masses originated from south and west across central Baja California, Mexico. Aerosol concentrations are fairly constant at 1000 cm-3 throughout the profile indicating a well-mixed boundary layer. Spikes in aerosol concentrations are a result of sampling the aircrafts' exhaust. The vertical profiles show that spikes occurred at levels where the aircraft maintained level, repeating holding patterns. The cloud droplet probe was flown; however, due to the flight ceiling, the aircraft was not allowed to ascend into the cloud base. The pyranometers performed well during straight and level portions of the flight as the autopilot maintained a level platform (pitch and roll) to within a degree. Circular tracks (at 2 miles diameter) cause oscillations in the aircraft's pitch and constantly bank the aircraft 3 to 4 degrees. Hence, a larger radius or long straight and level legs need to be used for radiometric measurements. We will also include data from three stacked aircraft flights to be conducted in November, to sample the boundary layer, clouds and cloud top layers simultaneously.

Ramanathan, V.; Roberts, G.; Corrigan, C.; Ramana, M.; Nguyen, H.