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August 11–14, 2014
Conference on Characterization and
Radiometric Calibration for Remote Sensing
Monday, August 11, 2014 | 4:20 p.m.
Technical Sessions
National Standards Technology Advancement
Opportunities for communication and collaboration between national standards laboratories and the calibration community to improve
calibration technologies and methodologies.
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Calibration traceability to standards—NIST and international
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Relationship between primary, secondary, and transfer standards and applications to remote sensing
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Maintenance of a valid calibration throughout instrument life
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Activities within the community aimed at increasing the quality of our satellite based measurements
Session Chair: Joseph Rice, National Institute of Standards and Technology (NIST)
4:05
System Concept for 0.1% Spectrally Resolved Radiometric Calibration in the Solar Bands for
Earth Viewing Remote Sensors
Joe Predina – Logistikos Engineering LLC; Allan Smith, Steve Lorentz – L1 - Standards and Technology
ABSTRACT: We report on a remote sensor system architecture that has potential to improve absolute radiometric calibration accuracy in the
solar bands by a factor of 10 when compared to conventional methods that rely on solar diffusers, calibrated bulb references, detector
references, the sun or moon. We call the concept "NIST-in-Space" because it would bring the calibration accuracy of the National Institute of
Standards & Technology (NIST) into space for the first time in the solar bands (250 nm – 3000 nm). NIST-in-Space should enable future
space based remote sensors to evolve into climate class instruments that have the measurement accuracy needed to answer important
questions related to climate change and land surface changes on shorter time scales.
A small aperture solar band (250 – 3000 nm) Fourier Transform Spectrometer (FTS) is the spectrally resolving sensor in this system. The
FTS undergoes conventional calibration from a laser driven plasma white light source and black target. The plasma white light source is not
required to have any calibration traceability. A second optical source comprised of an integrating sphere driven by a multitude of light emitting
diodes (LED) becomes the primary reference. The LED sphere output radiance is short-term stabilized using monitor detectors as feedback.
Long term stability and absolute radiometric accuracy is established by an uncooled, broadband, electrical substitution radiometer that views
the LED sphere and provides a direct tie to the electrical Watt (SI). Successive views of both calibration sources by the FTS will allow the SI
traceability to be transferred from the LED sphere to the white light source at a multitude of discrete wavelengths.
A spectrally resolved 0.1% radiometric calibration uncertainty is expected for this system. This is relative to 100% earth albedo radiance
level. The system is robust against calibration degradation over decade long space missions.
4:30
Carbon Nanotube Radiometer for Cryogenic Calibrations
Solomon Woods, Julia Scherschligt, Nathan Tomlin, John Lehman – NIST
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ABSTRACT: Two teams at the National Institute of Standards and Technology (NIST) have been collaborating to develop a carbon nanotube
radiometer (CNTR) for use in high accuracy cryogenic optical calibrations. This novel device employs an absorber made from a vertically
aligned nanotube array (VANTA), which can exhibit nearly perfect absorption from visible wavelengths to the far-infrared. A molybdenum
heater and VANTA thermistor, integrated with the absorber on the same silicon substrate, allow the detector to be operated in an electricalsubstitution mode at a fixed temperature using a feedback control loop. All parts of the radiometer are fabricated using thin film techniques
and silicon micro-machining, enabling the development of highly reproducible absolute cryogenic radiometers with precisely tailored
properties. We discuss a version of the carbon nanotube radiometer designed with a thermal time constant near 1 ms, power noise floor near 1
pW, and absorber diameter of 3 mm.
4:55
Status of Low-Background Infrared Calibration Facility at NIST
Simon Kaplan, Solomon Woods, Julia Scherschligt, Joseph Rice – National Institute of Standards and Technology (NIST);
Timothy Jung, Adriaan Carter – Jung Research and Development Corp.
ABSTRACT: The Low-Background Infrared (LBIR) calibration facility at NIST provides customers in the missile defense community and
others with measurements of radiance temperature and infrared irradiance in a low-background vacuum environment that are traceable to
the national primary standard for optical power. Traceability can be established through radiance temperature measurements of users’
cryogenic blackbody sources at NIST, or by measurements of the irradiance output of cryogenic vacuum infrared test chambers by the LBIR
transfer radiometers, BXR and MDXR, in the 3 µm to 28 µm wavelength region. We discuss the status and recent developments in both of
these primary calibration areas, including the construction of a new fluid-bath cryogenic blackbody source for radiance and irradiance
calibrations. In addition, LBIR is working with others at NIST and in the infrared calibration community to develop new traceability paths for
low-level spectral irradiance and power. These development efforts include spectrally calibrated Si:As trap detectors, compact electrical
substitution radiometers based on carbon nanotube absorbers, and new capabilities to calibrate users’ cryogenic transfer radiometers at
NIST.
5:20
Ultraviolet Radiation from Some Types of Outdoor Lighting Lamps
Essam Elmoghazy, Alaa Abd-Elmageed, Sameh Reda – National Institute for Standards (NIS)
ABSTRACT: Illumination using artificial light sources is common in these days. Many manufactures are paying for the design of lamps
depending on high efficacy and low UV hazards. This research is focusing on the most useable lamps in the Egyptian markets; High Pressure
Mercury (HPM), Metal Halide (MH), and High Pressure Sodium (HPS). A set up for relative spectral power distribution based on single
monochromator and UVA silicon detector for absolute irradiance measurements are used. The absolute irradiance in (W/m2) in UVA region
of the lamps and their accompanied standard uncertainty are evaluated.
5:45
Absolute Cyogenic Radiometer Control Using Commercial Off-the-Shelf Electronics
Adriaan Carter, Timothy Jung – Jung Research and Development Corp.; Julia Scherschligt – National Institute of Standards and
Technology (NIST)
ABSTRACT: National metrology institutes around the world and other calibration facilities interested in highly precise (~±0.02% k=2), SI
traceable radiance calibrations use Absolute Cryogenic Radiometers (ACRs) to set their optical power measurement scale. An ACR system
consists of a highly absorptive optical receiver cavity that is operated around 4 K and below, and an electronics package that is used to control
and report measured power readings from the receiver cavity. There are commercial electronics specifically designed for ACR calibrations
currently available, but these complete systems can be difficult for the end-user to modify or upgrade. In addition, the Low Background Infrared
(LBIR) Facility at NIST is interested in making lower power measurements than are supported in the commercially available systems. In an
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effort to develop a research calibration system which can be easily assembled and modified, the LBIR Facility has used commercial off-theshelf (COTS) components such as AC resistance bridges and tabletop voltmeters to build up a system for ACR optical power calibrations. In
this presentation we will compare the results of the new COTS ACR electronics with those from a set of commercial ACR electronics. Optical
measurement data will be used to demonstrate the accuracy, repeatability, power range, and data acquisition time for the new calibration
system.
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