A5103198174- Calibration and Measurement Techniques
- Infrared Target Detection Methodologies
- Atmospheric Ozone and Climate
- CCD and CMOS Imaging Sensors
- Physics of Superconductivity and Magnetism
- Magnetic and transport properties of perovskites and related materials
- Advanced Condensed Matter Physics
- Adaptive optics and wavefront sensing
- Remote-Sensing Image Classification
- Scientific Measurement and Uncertainty Evaluation
- Spectroscopy and Laser Applications
- Spacecraft and Cryogenic Technologies
- Optical Imaging and Spectroscopy Techniques
- Superconducting and THz Device Technology
- Photoacoustic and Ultrasonic Imaging
- Thermography and Photoacoustic Techniques
- Atmospheric aerosols and clouds
- Radiative Heat Transfer Studies
- Scientific Research and Discoveries
- Atmospheric and Environmental Gas Dynamics
- Photonic and Optical Devices
- Optical Polarization and Ellipsometry
- Geophysics and Gravity Measurements
- Thermal properties of materials
- Astronomical Observations and Instrumentation
National Institute of Standards and Technology
2012-2023
National Institute of Standards
1996-2021
Pacific Northwest National Laboratory
2005-2008
Battelle
2008
National Aeronautics and Space Administration
2008
Science Applications International Corporation (United States)
2008
Goddard Space Flight Center
2008
Optica
1997-2006
Washington State University
2006
United States Department of Commerce
1996
The Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission will provide a calibration laboratory in orbit for the purpose of accurately measuring attributing climate change. CLARREO measurements establish new change benchmarks with high absolute radiometric accuracy statistical confidence across wide range essential variables. CLARREO's inherently be verified traceable on to Système Internationale (SI) units. established by critical assessing changes Earth system model...
We report a Raman scattering investigation of superconducting gap anisotropy in single-crystal $\mathrm{Y}{\mathrm{Ba}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{7\ensuremath{-}\ensuremath{\delta}}$. Gap is investigated by studying the peak low-temperature continuum various symmetries. Roughly 35% difference energy this observed between different symmetries, suggesting presence substantial anisotropy. Anisotropy further evidenced damping behavior 340-${\mathrm{cm}}^{\ensuremath{-}1}$ Raman-active...
Polarized Raman spectra of undoped and doped ${\mathrm{La}}_{1\ensuremath{-}x}{M}_{x}{\mathrm{MnO}}_{3}$ single crystals have been studied in the temperature range from 5 to 423 K ($M=\mathrm{Sr},$ Ca). The spectral intensity is mainly related scattering by optical phonons at $q\ensuremath{\sim}0$ (for $x\ensuremath{\approx}0$) density vibrational states for $x>0.1.$ ${\mathrm{LaMnO}}_{3}$ structure distorted static Jahn-Teller effect are consistent with orthorhombic ${D}_{2h}^{16}$ space...
We describe the concept of modularity and versatility in construction a new cryogenic radiometer developed at National Institute Standards Technology. address benefits modular design development discuss some device characterizations results intercomparison.
Raman spectra of untwinned ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7}$ with ${\mathit{T}}_{\mathit{c}}$=91 K indicate a 2.2-eV resonance for incident light polarized in the CuO chain direction. The is characterized by appearance nominally forbidden phonon modes at 232 and 597 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$. Below 100 can be optically bleached if photon energy exceeds 2.2 eV. resulting induced low-temperature state metastable; upon warming crystal to T>200...
The second calibration and intercomparison of infrared radiometers (Miami2001) was held at the University Miami's Rosenstiel School Marine Atmospheric Science (RSMAS) during May–June 2001. participants were from several groups involved with validation skin sea surface temperatures land derived measurements imaging on earth observation satellites. These satellite instruments include those currently operational satellites others that will be launched within two years following workshop. There...
We describe our use of Digital Micromirror Devices (DMDs) for the performance testing, characterization, calibration, and system-level data product validation multispectral hyperspectral imaging sensors. have developed a visible Hyperspectral Image Projector (HIP), which is capable projecting any combination many different arbitrarily programmable basis spectra into each image pixel at up to video frame rates. For full HIP, we scheme whereby one DMD array used in spectrally source, produce...
A portable thermal-infrared transfer radiometer (TXR) has been developed for use in comparisons and scale verifications of sources used to calibrate (TIR) channels the National Aeronautics Space Administration's (NASA's) Earth Observing System (EOS) flight instruments. The TXR is designed measure radiance temperature large-area black-body cryogenic vacuum environments, either at Institute Standards Technology (NIST) or EOS instrument-calibration facilities. It can be operated ambient...
IntroductionThe range of absolute total solar irradiance (TSI) values measured by different exo-atmospheric radiometers is currently about 5 W/m 2 , which 0.35 % (3500 × 10 -6 Fig. 1) the TSI value at a distance 1 astronomical unit (AU) from Sun.This difference greater than indi-vidual standard uncertainties reported for most these instruments, and 0.02 per decade typically stated as required to understand vs. anthropogenic forcing in climate change.The discrepancy between instruments during...
Flight Center who worked on NASA/ EOS and experts at NOAA radiometric calibrations for remote sensing the last two decades.Therefore, information provided discussed happened to be specific these organizations.However, best practice guidelines are generally
Polarized Raman scattering by phonons is used to characterize thin films prepared laser ablation of La1−xCaxMnO3 targets. It was found that, in the temperature range from 6 300 K, phonon spectra La0.7Ca0.3MnO3 exhibit observable differences those bulk materials (microcrystalline ceramics and single crystals). A significant difference “as-grown” compared annealed oxygen at 800 °C. The observed peaks their linewidths an irregular dependence near Tc. correlation data with magnetization sample...
An antenna-coupled high-Tc superconducting microbolometer on a silicon substrate, operating at infrared wavelengths, is described. This detector incorporates silicon-micromachined yttria-stabilized zirconia air bridge the feed of planar lithographic antenna to simultaneously minimize thermal conductance and heat capacity bolometer. At an temperature 87.4 K, optical responsivity measured using 300-K blackbody source over 0.2–2.9 THz bandwidth 2900 V/W, noise-equivalent power (NEP) 9×10−12...
A common radiometric platform for the development of application-specific metrics to quantify performance sensors and systems is described. Using this platform, sensor system may be quantified in terms accuracy measurements standardized sets source distributions. The prototype consists spectrally programmable light sources that can generate complex spectral distributions ultraviolet, visible short-wave infrared regions radiometric, photometric colorimetric applications. In essence, a...
We have developed and demonstrated a Hyperspectral Image Projector (HIP) intended for system-level validation testing of hyperspectral imagers, including the instrument any associated spectral unmixing algorithms. HIP, based on same digital micromirror arrays used in commercial light processing (DLP*) displays, is capable projecting combination many different arbitrarily programmable basis spectra into each image pixel at up to video frame rates. use scheme whereby one array produce having...
We describe a Calibrated Hyperspectral Image Projector (CHIP) intended for radiometric testing of instruments ranging from complex hyperspectral or multispectral imagers to simple filter radiometers. The CHIP, based on the same digital mirror arrays used in commercial Digital Light Processing (DLP) displays, is capable projecting any combination as many approximately one hundred different arbitrarily programmable basis spectra per frame into each pixel instrument under test (IUT). resulting...
Detectors have historically been calibrated for spectral power responsivity at the National Institute of Standards and Technology (NIST) using a lamp-monochromator system to tune wavelength excitation source. Silicon detectors can be in visible region with uncertainties 0.1 % level. However, increase dramatically when measuring an instrument's irradiance or radiance responsivity. In addition, are even larger UV IR ranges. We will discuss new laser-based facility Spectral Irradiance Radiance...
By quenching the tetragonal phase during crystal growth of ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\delta}}}$ and then oxygenating crystals without mechanical stress, we obtain some essentially untwinned crystals. Magnetic measurements on such crystals, with fields applied along a or b axis, show anisotropy. A qualitative analysis our relaxation hysteresis data indicates that critical current density is higher than (the chain...
In this work, we describe radiometric platforms able to produce realistic spectral distributions and spatial scenes for the development of application-specific metrics quantify performance sensors systems. Using these platforms, sensor system may be quantified in terms accuracy measurements standardized sets complex source distributions. The same can also serve as a basis algorithm testing instrument comparison. consist spectrally tunable light sources (STS's) coupled with spatially...
Historically, the traceability of laboratory calibration Earth-observing satellite instruments to a primary radiometric reference scale (SI units) is responsibility each instrument builder. For NASA Earth Observing System (EOS), program has been developed using transfer radiometers, with its own radiance national metrology laboratory, independently validate radiances assigned sources builders. The EOS Project Science Office also validation for measurement onboard diffuse reflecting plaques,...
For the past several years NIST has been developing, along with collaborators, a Hyperspectral Image Projector (HIP). This scene projector produces high-resolution programmable spectra and projects them into dynamic two-dimensional images. The current digital micromirror device (DMD) based HIP prototype spatial resolution of 1024 x 768 pixels spectral range 450 nm to 2400 nm, from 2 in visible 5 short-wave infrared. It disperses light supercontinuum fiber source across two DMDs produce...