44 research outputs found

    GIFTS SM EDU Radiometric and Spectral Calibrations

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    The Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS) Sensor Module (SM) Engineering Demonstration Unit (EDU) is a high resolution spectral imager designed to measure infrared (IR) radiance using a Fourier transform spectrometer (FTS). The GIFTS instrument gathers measurements across the long-wave IR (LWIR), short/mid-wave IR (SMWIR), and visible spectral bands. The raw interferogram measurements are radiometrically and spectrally calibrated to produce radiance spectra, which are further processed to obtain atmospheric profiles via retrieval algorithms. This paper describes the processing algorithms involved in the calibration. The calibration procedures can be subdivided into three categories: the pre-calibration stage, the calibration stage, and finally, the post-calibration stage. Detailed derivations for each stage are presented in this paper

    Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS): Imaging and Tracking Capability

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    The geosynchronous-imaging Fourier transform spectrometer (GIFTS) engineering demonstration unit (EDU) is an imaging infrared spectrometer designed for atmospheric soundings. It measures the infrared spectrum in two spectral bands (14.6 to 8.8 microns, 6.0 to 4.4 microns) using two 128 128 detector arrays with a spectral resolution of 0.57/cm with a scan duration of approx. 11 seconds. From a geosynchronous orbit, the instrument will have the capability of taking successive measurements of such data to scan desired regions of the globe, from which atmospheric status, cloud parameters, wind field profiles, and other derived products can be retrieved. The GIFTS EDU provides a flexible and accurate testbed for the new challenges of the emerging hyperspectral era. The EDU ground-based measurement experiment, held in Logan, Utah during September 2006, demonstrated its extensive capabilities and potential for geosynchronous and other applications (e.g., Earth observing environmental measurements). This paper addresses the experiment objectives and overall performance of the sensor system with a focus on the GIFTS EDU imaging capability and proof of the GIFTS measurement concept

    GIFTS EDU Ground-based Measurement Experiment

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    Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS) Engineering Demonstration Unit (EDU) is an imaging infrared spectrometer designed for atmospheric soundings. The EDU groundbased measurement experiment was held in Logan, Utah during September 2006 to demonstrate its extensive capabilities for geosynchronous and other applications

    Mapping an atlas of tissue-specific drosophila melanogaster metabolomes by high resolution mass spectrometry

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    Metabolomics can provide exciting insights into organismal function, but most work on simple models has focussed on the whole organism metabolome, so missing the contributions of individual tissues. Comprehensive metabolite profiles for ten tissues from adult Drosophila melanogaster were obtained here by two chromatographic methods, a hydrophilic interaction (HILIC) method for polar metabolites and a lipid profiling method also based on HILIC, in combination with an Orbitrap Exactive instrument. Two hundred and forty two polar metabolites were putatively identified in the various tissues, and 251 lipids were observed in positive ion mode and 61 in negative ion mode. Although many metabolites were detected in all tissues, every tissue showed characteristically abundant metabolites which could be rationalised against specific tissue functions. For example, the cuticle contained high levels of glutathione, reflecting a role in oxidative defence; the alimentary canal (like vertebrate gut) had high levels of acylcarnitines for fatty acid metabolism, and the head contained high levels of ether lipids. The male accessory gland uniquely contained decarboxylated S-adenosylmethionine. These data thus both provide valuable insights into tissue function, and a reference baseline, compatible with the FlyAtlas.org transcriptomic resource, for further metabolomic analysis of this important model organism, for example in the modelling of human inborn errors of metabolism, aging or metabolic imbalances such as diabetes

    Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS) Engineering Demonstation Unit (EDU) Overview and Performance Summary

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    The Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS), developed for the NASA New Millennium Program (NMP) Earth Observing-3 (EO-3) mission, has recently completed a series of uplooking atmospheric measurements. The GIFTS development demonstrates a series of new sensor and data processing technologies that can significantly expand geostationary meteorological observational capability. The resulting increase in forecasting accuracy and atmospheric model development utilizing this hyperspectral data is demonstrated by the uplooking data. The GIFTS sensor is an imaging FTS with programmable spectral resolution and spatial scene selection, allowing spectral resolution and area coverage to be traded in near-real time. Due to funding limitations, the GIFTS sensor module was completed as an engineering demonstration unit that can be upgraded to flight quality. This paper reviews the GIFTS system design considerations and the technology utilized to enable a nearly two order performance increase over the existing GOES sounder and shows its capability. While not designed as an operational sensor, GIFTS EDU provides a flexible and accurate testbed for the new products the hyperspectral era will bring. Efforts to find funding to upgrade and demonstrate this amazing sensor in space are continuing

    Ultrasound-Enhanced Anodic Stripping Voltammetry Using Perfluorosulfonated Ionomer-Coated Mercury Thin-Film Electrodes

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    The high mass transport caused by ultrasonic radiation in the preconcentration of trace metal species in anodic stripping voltammetry (ASV), leads to an order of magnitude enhancement in sensitivity. A Nafion-coated mercury thin-film working electrode is placed in a specially designed small-volume sonovoltammetric cell. The preparation and curing procedure for the Nafion film on a glassy carbon electrode substrate as well as ultrasound-enhanced mercury deposition through the Nafion film are optimized. The resulting electrode assembly is stable under ultrasonic irradiation. Optical microscopy observations show the formation of closely spaced mercury droplets of micrometer dimensions under the Nafion film. The performance characteristics of ultrasound-enhanced ASV at the Nafion-coated mercury thin-film electrode are studied in detail. The detection limit obtained for lead and cadmium test species is 3 × 10-11 M (30 s preconcentration in the presence of ultrasound). A relative standard deviation of 1.2% is obtained for repetitive determinations of 10 nM Cd2+ (n = 9)
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