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Harnessing CPF Hyperspectral Radiances to Homogenize Earth Observing Systems

Homogenization across Earth observing systems is essential for ensuring consistency in geophysical retrievals over time and enabling the construction of long-term climate records. As the first SI Traceable Satellite (SITSat) for the reflected solar, the CLARREO Pathfinder (CPF) will provide high-accuracy spectrally resolved benchmark measurements of Earth-reflected solar radiation, serving as a standardized in-orbit reference for other reflected solar (RS) instruments. The CPF intercalibration team has developed a state-of-the-art method to intercalibrate the RS channels of the VIIRS instrument onboard the NOAA-20 satellite using CPF benchmark measurements, aiming for a methodology uncertainty of 0.3-0.6% (1-sigma). To achieve this stringent accuracy, the CPF team has devised strategies to mitigate the effects of spatial, spectral, polarization, and angular disparities between the intercalibration footprints of CPF and VIIRS. Despite nearly identical instrument designs, the three VIIRS instruments currently in operation onboard SNPP, NOAA-20, and NOAA-21 platforms exhibit systematic radiometric biases up to 8%. Although each VIIRS sensor’s calibration is independent and traceable to standards maintained by NIST, there is significant concern within the community about which VIIRS sensor most accurately represents the absolute radiometric scale. The precise intercalibration between CPF and NOAA-20 VIIRS will reveal the absolute radiometric accuracy of VIIRS. This accuracy can then be extended to other RS sensors, including MODIS and other VIIRS sensors, via vicarious methods. The 3-nm spectral sampling of CPF measurements will enable users to quantify scene-dependent spectral biases between sensors, thereby aiding in establishing both spectral and radiometric homogenization across these platforms. The CPF mission overview, along with details of its intercalibration capabilities and homogenization approaches, will be discussed at the meeting.

Raj Bhatt↗

NASA NTRS2012

U.S. Government Open Internet Access to Sub-meter Satellite Data

The National Geospatial-Intelligence Agency (NGA) has contracted United States commercial remote sensing companies GeoEye and Digital Globe to provide very high resolution commercial quality satellite imagery to federal/state government agencies and those projects/people who support government interests. Under NextView contract terms, those engaged in official government programs/projects can gain online access to NGA's vast global archive. Additionally, data from vendor's archives of IKONOS-2 (IK-2), OrbView-3 (OB-3), GeoEye-1 (GE-1), QuickBird-1 (QB-1), WorldView-1 (WV-1), and WorldView-2 (WV-2), sensors can also be requested under these agreements. We report here the current extent of this archive, how to gain access, and the applications of these data by Earth science investigators to improve discoverability and community use of these data. Satellite commercial quality imagery (CQI) at very high resolution (< 1 m) (here after referred to as CQI) over the past decade has become an important data source to U.S. federal, state, and local governments for many different purposes. The rapid growth of free global CQI data has been slow to disseminate to NASA Earth Science community and programs such as the Land-Cover Land-Use Change (LCLUC) program which sees potential benefit from unprecedented access. This article evolved from a workshop held on February 23rd, 2012 between representatives from NGA, NASA, and NASA LCLUC Scientists discussion on how to extend this resource to a broader license approved community. Many investigators are unaware of NGA's archive availability or find it difficult to access CQI data from NGA. Results of studies, both quality and breadth, could be improved with CQI data by combining them with other moderate to coarse resolution passive optical Earth observation remote sensing satellites, or with RADAR or LiDAR instruments to better understand Earth system dynamics at the scale of human activities. We provide the evolution of this effort, a guide for qualified user access, and describe current to potential use of these data in earth science.

Neigh, Christopher S. R>↗

NASA NTRS2014

Griffith Saponite as an Analog for Clay Minerals at Yellowknife Bay in Gale Crater, Mars: A Marker for Low-temperature Hydrothermal Processes

The CheMin X-ray diffraction (XRD) instrument onboard the Mars Science Laboratory rover Curiosity in Gale Crater, Mars, discovered smectite in drill fines of the Sheepbed mudstone at Yellowknife Bay (YNB). The mudstone has a basaltic composition, and the XRD powder diffraction pattern shows smectite 02l diffraction bands peaking at 4.59 A for targets John Klein and Cumberland, consistent with tri-octahedral smectites (saponite). From thermal analysis, the saponite abundance is ~20 wt. %. Among terrestrial analogues we have studied, ferrian saponite from Griffith Park (Los Angeles, CA) gives the best match to the position of the 02l diffraction band of YNB saponites. Here we describe iron-rich saponites from a terrestrial perspective, with a focus on Griffith saponite, and discuss their implications for the mineralogy of Sheepbed saponite and its formation pathways. Iron-rich saponite: Iron-rich saponite on the Earth is recognized as a low-temperature (<100 C), authigenic alteration product of basalt [e.g., 4-16]. In the discussion that follows, we reference the position of the 02l band because it is a measure of the unit cell 'b' dimension of the octahedral layer and thus the cations (including Fe redox state) in the octahedral layer. Ordinarily, the 06l band near 1.5 A is used to determine the 'b' dimension of smectite, but this band is not accessible with MSL CheMin instrument. For reference, a ferrosaponite (i.e., Fe2+ saponite) studied by [15] has a 02l spacing of 4.72 A and Fe3+/Fe = 0.27 [15]. Samples of terrestrial ferrosaponite, however, are reported to oxidize on the timescale of days when removed from their natural environment and not protected from oxidation. The Griffith saponite is Mg-rich ferrian saponite, and sample AMNH 89172 has an 02l spacing of 4.59 A (same as the Sheepbed saponites) and Fe3+/Fe = 0.64 [3]. This similarity suggests that Sheepbed saponites are ferrian (incompletely oxidized ferrosaponite). More oxidized Griffith saponites (Fe3+/Fe > 0.90) have somewhat smaller 02l d-spacings and also show Mossbauer evidence for an XRD amorphous Fe-bearing phase (e.g., ferrihydrite, hisingerite, superparamagnetic ferric oxides, etc.). The Griffith saponite occurs as vesicle fills, as replacements of olivine, and as replacements of mesostasis (basaltic glass). Similar occurrence modes are reported elsewhere. Hisingerite has been proposed by [13] as the alteration product of ferrian saponite whose precursor by oxidation was ferrosaponite.

Morris, R.V.↗

NASA NTRS1978

Test and evaluation of 23 electric vehicles for state-of-the-art assessment

Data developed by ERDA used to evaluate the performance parameters of modern electric vehicles is presented with reference to range, acceleration, coast-down, and braking. Eight of the tested vehicles had some type of regenerative braking system, which provided range increases from 1 to 31 percent. In comparison with conventional vehicles, performance was found to be lower, and reliability poorer. Energy consumption was the same, but electric power is less damaging to the environment than hydrocarbon fuels, and does not use up an increasingly scarce resource.

Dustin, M. O.↗

NASA NTRS1982

Crustal interpretation of the MAGSAT data in the continental United States

The processing of MAGSAT scalar data to construct a crustal magnetic anomaly map over the continental U.S. involves removal of the reference field model, a path-by-path subtraction of a low order polynomial through a least-squares fit to reduce orbital offset errors, and a two dimensional spectral filtering to mitigate the spectral bias induced by the path-by-path orbital correction scheme. The resultant anomaly map shows reasonably good correlations with an aeromagnetic map derived from the project MAGNET. Prominent satellite magnetic anomalies are identified in terms of geological provinces and age boundaries. An inversion method was applied to MAGSAT data which produces both the Curie depth topography and laterally varying magnetic susceptibility of the crust. A contoured Curie depth map thus derived shows general agreements with a crustal thickness map based on seismic data.

Won, I. J.↗

NASA NTRS2001

NASA/American Cancer Society High-Resolution Flow Cytometry Project-I

BACKGROUND: The NASA/American Cancer Society (ACS) flow cytometer can simultaneously analyze the electronic nuclear volume (ENV) and DNA content of cells. This study describes the schematics, resolution, reproducibility, and sensitivity of biological standards analyzed on this unit. METHODS: Calibrated beads and biological standards (lymphocytes, trout erythrocytes [TRBC], calf thymocytes, and tumor cells) were analyzed for ENV versus DNA content. Parallel data (forward scatter versus DNA) from a conventional flow cytometer were obtained. RESULTS: ENV linearity studies yielded an R value of 0.999. TRBC had a coefficient of variation (CV) of 1.18 +/- 0.13. DNA indexes as low as 1.02 were detectable. DNA content of lymphocytes from 42 females was 1.9% greater than that for 60 males, with a noninstrumental variability in total DNA content of 0.5%. The ENV/DNA ratio was constant in 15 normal human tissue samples, but differed in the four animal species tested. The ENV/DNA ratio for a hypodiploid breast carcinoma was 2.3 times greater than that for normal breast tissue. CONCLUSIONS: The high-resolution ENV versus DNA analyses are highly reliable, sensitive, and can be used for the detection of near-diploid tumor cells that are difficult to identify with conventional cytometers. ENV/DNA ratio may be a useful parameter for detection of aneuploid populations.

NASA Center JSC↗

NASA NTRS1991

An ab initio study of the C3(+) cation using multireference methods

The energy difference between the linear 2 sigma(sup +, sub u) and cyclic 2B(sub 2) structures of C3(+) has been investigated using large (5s3p2d1f) basis sets and multireference electron correlation treatments, including complete active space self consistent fields (CASSCF), multireference configuration interaction (MRCI), and averaged coupled-pair functional (ACPF) methods, as well as the single-reference quadratic configuration interaction (QCISD(T)) method. Our best estimate, including a correction for basis set incompleteness, is that the linear form lies above the cyclic from by 5.2(+1.5 to -1.0) kcal/mol. The 2 sigma(sup +, sub u) state is probably not a transition state, but a local minimum. Reliable computation of the cyclic/linear energy difference in C3(+) is extremely demanding of the electron correlation treatment used: of the single-reference methods previously considered, CCSD(T) and QCISD(T) perform best. The MRCI + Q(0.01)/(4s2p1d) energy separation of 1.68 kcal/mol should provide a comparison standard for other electron correlation methods applied to this system.

Taylor, Peter R.↗

NASA NTRS1975

Cosmic-ray streaming and anisotropies

The paper is concerned with the differential current densities and anisotropies that exist in the interplanetary cosmic-ray gas, and in particular with a correct formulation and simple interpretation of the momentum equation that describes these on a local basis. Two examples of the use of this equation in the interpretation of previous data are given. It is demonstrated that in interplanetary space, the electric-field drifts and convective flow parallel to the magnetic field of cosmic-ray particles combine as a simple convective flow with the solar wind, and that there exist diffusive currents and transverse gradient drift currents. Thus direct reference to the interplanetary electric-field drifts is eliminated, and the study of steady-state and transient cosmic-ray anisotropies is both more systematic and simpler.

Forman, M. A.↗

NASA NTRS1975

Error magnitude estimation in model-reference adaptive systems

A second order approximation is derived from a linearized error characteristic equation for Lyapunov designed model-reference adaptive systems and is used to estimate the maximum error between the model and plant states, and the time to reach this peak following a plant perturbation. The results are applicable in the analysis of plants containing magnitude-dependent nonlinearities.

Colburn, B. K.↗

NASA NTRS1985

Heterodyne frequency measurements on N2O at 5.3 and 9.0 microns

Heterodyne frequency measurements on the 01(1)1-00(0)0 band of N2O have been made with the use of a tunable-diode laser, CO laser transfer oscillator, and a CO2 laser frequency synthesizer. A beat frequency was measured between a CO laser and tunable-diode laser whose frequency was locked to the peak of N2O absorption features. The frequency of the CO laser was simultaneously determined by neasuring the beat frequency with respect to a reference synthesized from two CO2 lasers. New rovibrational constants are given for the 01(1)1 state of N2O, which are in excellent agreement with previous results, although the band center is 4 MHz higher than in the previous measurements. A table for the line frequencies and their absolute uncertainties is given for the N2O absorption lines in the wave-number region from 1830 to 1920 kaysers. Some additional frequency measurements near the lower-frequency end of the 02(0)0-00(0)0 band have also been made with respect to a C-12)(0-18)2 laser.

Wells, J. S.↗

NASA NTRS1988

The small molecular cloud toward HD 169454

Optical absorption line observations of the B1 supergiant HD 169454 reveal the presence of an intervening translucent interstellar cloud. Millimeter wavelength observations of CO emission show that the absorption lines can be attributed to a well-defined cloud approximately 18 by 22 min in extent at the same radial velocity as the C2 and CN absorption lines. The map of the CO emission shows three large condensations and evidence of unresolved structure on smaller scales. Various procedures for determining the cloud mass are compared. The estimated mass is 7-14 M solar masses if the cloud lies at the distance (D about 125 pc) of an extended atomic cloud at the same radial velocity, and is 250-500 M solar masses if the kinematic distance (D about 750 pc) is adopted. The dynamical state of the cloud is examined. The composition and structure of the cloud are discussed with reference to detailed theoretical models and the properties of other interstellar clouds.

Jannuzi, Buell T.↗

NASA NTRS1987

Flexible structure control laboratory development and technology demonstration

An experimental structure is described which was constructed to demonstrate and validate recent emerging technologies in the active control and identification of large flexible space structures. The configuration consists of a large, 20 foot diameter antenna-like flexible structure in the horizontal plane with a gimballed central hub, a flexible feed-boom assembly hanging from the hub, and 12 flexible ribs radiating outward. Fourteen electrodynamic force actuators mounted to the hub and to the individual ribs provide the means to excite the structure and exert control forces. Thirty permanently mounted sensors, including optical encoders and analog induction devices provide measurements of structural response at widely distributed points. An experimental remote optical sensor provides sixteen additional sensing channels. A computer samples the sensors, computes the control updates and sends commands to the actuators in real time, while simultaneously displaying selected outputs on a graphics terminal and saving them in memory. Several control experiments were conducted thus far and are documented. These include implementation of distributed parameter system control, model reference adaptive control, and static shape control. These experiments have demonstrated the successful implementation of state-of-the-art control approaches using actual hardware.

Vivian, H. C.↗

NASA NTRS1995

Evaluation of Pd-Cr Wires for Strain Gage Application

A newly developed alloy, palladium-13 weight percent chromium (Pd13Cr), was identified by United Technologies Research Center under a NASA contract to be the best material for high temperature strain gage applications. An electrical resistance strain gage that can provide accurate static strain measurement to a temperature higher than that of a commercially available gage is urgently needed in aerospace and aeronautics research. A strain gage made of a 25.4 micron (1 mil) diameter Pd13Cr wire has been recently demonstrated to be usable for static strain measurements to 800 C. This compares to the 400 C temperature limit of the commercially available strain gages. The performance of the Pd-Cr gage, however, strongly depends on the quality of the Pd13Cr wire. Four batches of Pd-Cr wires purchased from three different manufacturers were therefore evaluated to determine the best source of the wire for strain gage applications. The three suppliers were Precious Metal Institute in China, Sigmund Cohn Co., and G & S Titanium, Inc. in the United States. Two batches of wires obtained from Previous Metal Institute in 1987 and 1992, respectively are referred to herein as China87 and China92 wires. The mechanical, chemical and electrical properties of these wires, both as-received and after high temperature exposures at 800 C for 50 hours were analyzed. The elastic modulus and the failure strength of the wires were evaluated using a tensile test machine equipped with a laser speckle strain measurement system. The chemical and microstructural properties of the wires were inspected using a plasma atomic emission spectrometer and a scanning electron microscope (SEM) equipped with an energy dispersive X-ray spectroscope (EDS). The electrical stability and repeatability of the wires were determined by measuring the electrical resistance of the wires during three thermal cycles to 1000 C and a ten-hour soak at 1000 C. As a result of this study, the wire which has the highest strength, the least impurities content, the best oxidation resistance and the best electrical stability will be selected for upcoming strain gage applications.

Lei, Jih-Fen↗

NASA NTRS1995

A simple method for verifying the deployment of the TOMS-EP solar arrays

The Total Ozone Mapping Spectrometer-Earth Probe (TOMS-EP) mission relies upon a successful deployment of the spacecraft's solar arrays. Several methods of verification are being employed to ascertain the solar array deployment status, with each requiring differing amounts of data. This paper describes a robust attitude-independent verification method that utilizes telemetry from the coarse Sun sensors (CSS's) and the three-axis magnetometers (TAM's) to determine the solar array deployment status - and it can do so with only a few, not necessarily contiguous, points of data. The method developed assumes that the solar arrays are deployed. Telemetry data from the CSS and TAM are converted to the Sun and magnetic field vectors in spacecraft body coordinates, and the angle between them is calculated. Deployment is indicated if this angle is within a certain error tolerance of the angle between the reference Sun and magnetic field vectors. Although several other methods can indicate a non-deployed state, with this method there is a 70% confidence level in confirming deployment as well as a nearly 100% certainty in confirming a non-deployed state. In addition, the spacecraft attitude (which is not known during the first orbit after launch) is not needed for this algorithm because the angle between the Sun and magnetic field vectors is independent of the spacecraft attitude. This technique can be applied to any spacecraft with a TAM and with CSS's mounted on the solar array(s).

Koppersmith, James R.↗

NASA NTRS2008

On Certain New Methodology for Reducing Sensor and Readout Electronics Circuitry Noise in Digital Domain

NASA Hubble Space Telescope (HST) and upcoming cosmology science missions carry instruments with multiple focal planes populated with many large sensor detector arrays. These sensors are passively cooled to low temperatures for low-level light (L3) and near-infrared (NIR) signal detection, and the sensor readout electronics circuitry must perform at extremely low noise levels to enable new required science measurements. Because we are at the technological edge of enhanced performance for sensors and readout electronics circuitry, as determined by thermal noise level at given temperature in analog domain, we must find new ways of further compensating for the noise in the signal digital domain. To facilitate this new approach, state-of-the-art sensors are augmented at their array hardware boundaries by non-illuminated reference pixels, which can be used to reduce noise attributed to sensors. There are a few proposed methodologies of processing in the digital domain the information carried by reference pixels, as employed by the Hubble Space Telescope and the James Webb Space Telescope Projects. These methods involve using spatial and temporal statistical parameters derived from boundary reference pixel information to enhance the active (non-reference) pixel signals. To make a step beyond this heritage methodology, we apply the NASA-developed technology known as the Hilbert- Huang Transform Data Processing System (HHT-DPS) for reference pixel information processing and its utilization in reconfigurable hardware on-board a spaceflight instrument or post-processing on the ground. The methodology examines signal processing for a 2-D domain, in which high-variance components of the thermal noise are carried by both active and reference pixels, similar to that in processing of low-voltage differential signals and subtraction of a single analog reference pixel from all active pixels on the sensor. Heritage methods using the aforementioned statistical parameters in the digital domain (such as statistical averaging of the reference pixels themselves) zeroes out the high-variance components, and the counterpart components in the active pixels remain uncorrected. This paper describes how the new methodology was demonstrated through analysis of fast-varying noise components using the Hilbert-Huang Transform Data Processing System tool (HHT-DPS) developed at NASA and the high-level programming language MATLAB (Trademark of MathWorks Inc.), as well as alternative methods for correcting for the high-variance noise component, using an HgCdTe sensor data. The NASA Hubble Space Telescope data post-processing, as well as future deep-space cosmology projects on-board instrument data processing from all the sensor channels, would benefit from this effort.

Kizhner, Semion↗

NASA NTRS2009

Cooper-Harper Experience Report for Spacecraft Handling Qualities Applications

A synopsis of experience from the fixed-wing and rotary-wing aircraft communities in handling qualities development and the use of the Cooper-Harper pilot rating scale is presented as background for spacecraft handling qualities research, development, test, and evaluation (RDT&E). In addition, handling qualities experiences and lessons-learned from previous United States (US) spacecraft developments are reviewed. This report is intended to provide a central location for references, best practices, and lessons-learned to guide current and future spacecraft handling qualities RDT&E.

Bailey, Randall E.↗

NASA NTRS2021

Performance Assessment of the Eastern Range Mosquito Lagoon 915-MHz Doppler Radar Wind Profiler

Please find enclosed the performance assessment for the Mosquito Lagoon 915-MHz Doppler Radar Wind Profiler (DRWP). This assessment was conducted following the installation of the new DRWP systems at the Eastern Range. DRWP profiles were compared to Automated Meteorological Profiling System balloons launched from Cape Canaveral Space Force Station. Launching balloons from the DRWP site was discussed, but was determined to be unfeasible. Therefore, these results include errors due to the spatial separation of winds. Mean wind component deltas generally ranged between -1.4-2.0 m/s between the balloons and DRWP systems. Data availability at discrete altitudes ranged from 7% to 98% with the least amount of available profiles being in the upper altitude ranges between 4000 m and 5000 m as well as below 300 m. The effective vertical resolution was not able to be estimated in this study, likely due to the relatively small dataset. The results from this analysis were requested by the United States Space Force for use of the acceptance of the DRWP system and for internal EV44 reference.

meteorology↗

NASA NTRS2021

Performance Assessment of a Western Range 915-MHz Doppler Radar Wind Profiler

Please find enclosed the performance assessment for a Western Range 915-MHz Doppler Radar Wind Profiler (DRWP). This assessment was conducted following the installation of the new DRWP systems at the Western and Eastern Ranges. DRWP profiles were compared to Automated Meteorological Profiling System balloons launched from Vandenberg Space Force Base. Balloon data was collected from both normal synoptic and launch operations as well as some releases at the DRWP site. These results will include errors due to the spatial separation of winds. Root Mean Square wind speed deltas between the balloons and DRWP system mainly ranged between 1.0 and 2.3 m/s. Mean wind direction deltas mainly ranged between 10 and 28 degrees for wind speeds greater than or equal to 4 m/s. Data availability at discrete altitudes ranged from 20% to 94% with the least amount of available profiles being in the lower altitude ranges between 100 m and 500 m. The effective vertical resolution was determined to be approximately 250 m. The results from this analysis were requested by the United States Space Force for use of the acceptance of the DRWP system and for internal EV44 reference.

B J Barbre↗