25 research outputs found

    Comparison of three methods for materials identification and mapping with imaging spectroscopy

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    We are comparing three methods of mapping analysis tools for imaging spectroscopy data. The purpose of this comparison is to understand the advantages and disadvantages of each algorithm so others would be better able to choose the best algorithm or combinations of algorithms for a particular problem. The three algorithms are: (1) the spectralfeature modified least squares mapping algorithm of Clark et al (1990, 1991): programs mbandmap and tricorder; (2) the Spectral Angle Mapper Algorithm(Boardman, 1993) found in the CU CSES SIPS package; and (3) the Expert System of Kruse et al. (1993). The comparison uses a ground-calibrated 1990 AVIRIS scene of 400 by 410 pixels over Cuprite, Nevada. Along with the test data set is a spectral library of 38 minerals. Each algorithm is tested with the same AVIRIS data set and spectral library. Field work has confirmed the presence of many of these minerals in the AVIRIS scene (Swayze et al. 1992)

    Characterizing the Mineralogy of Potential Lunar Landing Sites

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    Many processes active on the early Moon are common to most terrestrial planets, including the record of early and late impact bombardment. The Moon's surface provides a record of the earliest era of terrestrial planet evolution, and the type and composition of minerals that comprise a planetary surface are a direct result of the initial composition and subsequent thermal and physical processing. Lunar mineralogy seen today is thus a direct record of the early evolution of the lunar crust and subsequent geologic processes. Specifically, the distribution and concentration of specific minerals is closely tied to magma ocean products, lenses of intruded or remelted plutons, basaltic volcanism and fire-fountaining, and any process (e.g. cratering) that might redistribute or transform primary and secondary lunar crustal materials. The association of several lunar minerals with key geologic processes is illustrated in Figure 1. The geologic history of potential landing sites on the Moon can be read from the character and context of local mineralogy

    An enhanced tilted-angle acoustic tweezer for mechanical phenotyping of cancer cells

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    Acoustofluidic devices becomes one of the emerging and versatile tools for many biomedical applications. Most of the previous acoustofluidic devices are used for cells manipulation, and the few devices for cell phenotyping with a limitation in throughput. In this study, an enhanced tilted-angle (ETA) acoustofluidic device is developed and applied for mechanophenotyping of live cells. The ETA Device consists of an interdigital transducer which is positioned along a microfluidic channel. An inclination angle of 5° is introduced between the interdigital transducer and the liquid flow direction. The pressure nodes formed inside the acoustofluidic field in the channel deflect the biological cells from their original course in accordance with their mechanical properties, including volume, compressibility, and density. The threshold power for fully converging the cells to the pressure node is used to calculate the acoustic contrast factor. To demonstrate the ETA device in cell mechanophenotyping, and distinguishing between different cell types, further experimentation is carried out by using A549 (lung cancer cells), MDB-MA-231 (breast cancer cells), and leukocytes. The resulting acoustic contrast factors for the lung and breast cancer cells are different from that of the leukocytes by 27.9% and 21.5%, respectively. These results suggest this methodology can successfully distinguish and phenotype different cell types based on the acoustic contrast factor

    Calibration of NEON\u27s Airborne Imaging Spectrometers

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    The National Ecological Observatory Network (NEON) is a continental-scale ecological observation facility currently under construction by the National Science Foundation (NSF). NEON’s mission is to enable understanding and forecasting of the impacts of land-use change and invasive species by providing the infrastructure and consistent methodologies for the collection of continental-scale ecological data. The Airborne Observation Platform (AOP) will play a unique role in scaling individual in-situ measurements collected by NEON to those collected by external satellite-based remote sensing systems. The airborne payload consists of the NEON Imaging Spectrometer (NIS), a waveform LIDAR, and a high-resolution digital camera integrated into a Twin Otter aircraft. Three payloads on separate aircraft will provide coverage of 20 NEON core sites and 40 relocatable sites as well as targets of opportunity and PI-driven science. A key component of the NEON design is the consistent calibration of the airborne instruments to provide reliable and accurate scientific data over the full lifetime of the NEON observatory. The NEON Sensor Test Facility provides the facilities for the laboratory calibration of the AOP instrumentation. This work examines efforts at improving the spectral and radiometric calibration of the NIS in the NEON Sensor Test Facility. Recent work has focused on the traceability and uncertainty of the radiometric and spectral calibration and stability of the calibration from lab to operations. NIST FEL standards are utilized as the radiometric calibration standard and transferred to an integrating sphere through precision transfer radiometers. Wavelength calibration is tied to elemental line sources combined with a scanning monochromator to measure the spectral response functions. To verify the operational stability during acquisitions, a quality check algorithm has been developed to assess the raw NIS data prior to ingestion into the NEON processing framework. The work presented here also examines recent advances in characterizing the level of stray light in the NIS data. A first-order correction is currently being developed and tested on data acquisitions collected during normal operations to assess the impact on higher-level data products. Further research and level of effort will depend on the results of the testing

    Calibration of the National Ecological Observatory Network\u27s Airborne Observation Platforms

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    The National Ecological Observatory Network (NEON) is a continental-scale ecological observation facility funded by the National Science Foundation (NSF). NEON\u27s mission is to enable understanding and forecasting of the impacts of land-use change and invasive species by providing the infrastructure and consistent methodologies for the collection of continental-scale ecological data. The Airborne Observation Platform (AOP) will play a unique role by collecting regional scale remote sensing data surrounding the NEON sites. This is expected to enable scaling of individual in-situ measurements collected by NEON or others to those collected by external satellite-based remote sensing systems. The airborne payload consists of the NEON Imaging Spectrometer (NIS), a full waveform and discrete LIDAR, and a high-resolution digital camera integrated into a Twin Otter aircraft. Three payloads on separate aircraft will provide coverage of 80 plus sites located in the 20 NEON Domains as well as targets of opportunity and PI-driven science. A key component of the NEON design is the consistent calibration of the airborne instruments to provide reliable and accurate scientific data over the full lifetime of the NEON observatory. The NEON Sensor Test Facility provides the facilities for the laboratory calibration of the AOP instrumentation. This work examines the spectral and radiometric calibration of the NIS in the NEON Sensor Test Facility. Recent work has focused on the traceability and uncertainty of the radiometric and spectral calibration and stability of the calibration from lab to operations. To verify the operational stability during acquisitions, a quality check algorithm has been developed to assess the raw NIS data prior to ingestion into the NEON processing framework. In addition, routine vicarious calibration flights are scheduled to independently verify the lab-based calibration. The work presented here also examines implemented improvements in characterizing the level of stray light in the NIS data. These corrections have significantly improved the fidelity of the spectroscopic data as well as improving the overall radiometric and spectral accuracy across the typical heterogeneous scenes included in the NEON collections

    NEON Imaging Spectrometer (NIS) Calibration Updates

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    The NIS (NEON Imaging Spectrometer) is an airborne pushbroom hyperspectral instrument developed by NASA Jet Propulsion Laboratory (JPL) for the National Ecological Observation Network (NEON) and is included in all three of NEON’s Airborne Observation Platform (AOP) payloads. NEON, funded by the National Science Foundation (NSF), is a continental-scale observatory designed to collect long-term data to better understand and forecast impacts of climate change, land use change and invasive species (Kampe et al. 2010). NEON has recently completed the construction phase and is in the initial operational phase, which represents annual activities that will be repeated for the remaining 30-year lifetime of the project (Goulden et al. 2019). The AOP begun data collection in 2013, although only a small subset of NEON sites was collected. By 2018 and 2019, AOP was collecting data in 16 domains annually, representing the typical data collection scenario during the operational phase of the NEON project. NEON provides 28 data products from AOP, which are publicly available and can be freely accessed from NEON data portal: https://data.neonscience.org/home. In addition to the NIS, AOP payloads include a discrete and full-waveform lidar and a high resolution RGB camera. The NIS design is based on AVIRIS (Airborne Visible/Infrared Imaging Spectrometer) NextGen Imaging Spectrometer and measures radiant energy both in VNIR (Visible-Near Infrared) and SWIR (Shortwave Infrared) spectral region (380-2510 nm) with ~5 nm sampling and 1 mRad instantaneous field of view (IFOV) (Kuester et al. 2010). This 1 mRad IFOV leads to a ground resolution of 1m at a typical flight altitude of ~1000m. In order to ensure the accuracy of the measurements, the NIS requires stable and consistent annual calibrations (Leisso et al. 2014). Assessment of NIS calibration datasets revealed anomalies that should be characterized and corrected to improve the accuracy of NIS datasets. This presentation will briefly discuss the current status of NEON project and provides detailed description of NIS calibration improvements including: 1) characterizing NIS stray light anomalies, 2) techniques implemented to correct such anomalies, and 3) NIS stability analysis. Goulden T., B. Hass, J. Musinsky, and A. K. Shrestha, 2019, Status of NEON\u27s Airborne Observation Platform , AGU Fall Meeting, 9-13 December, 2019, San Francisco, CA, USA, Kampe T. U., B. R. Johnson, M. Kuester, and M. Keller, 2010, NEON: the first continental-scale ecological observatory with airborne remote sensing of vegetation canopy biochemistry and structure , Journal of Applied Remote Sensing 4(1), 043510 (1 March 2010). https://doi.org/10.1117/1.3361375 Kuester M. A., J.T. McCorkel, Johnson, B.R., and Kampe T.U., 2010, Radiometric Calibration Concept of Imaging Spectrometers for a long-term Ecological Remote Sensing Project Leisso N., Kampe T., Karpowicz B., 2014, Calibration of the National Ecological Observatory Network\u27s airborne imaging spectrometers , 2014 IEEE Geoscience and Remote Sensing Symposium, Quebec City, QC, 2014, pp. 2625-2628. doi: 10.1109/IGARSS.2014.694701
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