ADNET Systems Inc.

Rockville, MD, United States

ADNET Systems Inc.

Rockville, MD, United States
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Kitzmiller D.,National Oceanic and Atmospheric Administration | Miller D.,National Oceanic and Atmospheric Administration | Fulton R.,National Oceanic and Atmospheric Administration | Ding F.,ADNET Systems Inc. | Ding F.,TCoombs and Associates LLC
Journal of Hydrologic Engineering | Year: 2013

This paper describes techniques used operationally by the National Weather Service (NWS) to prepare gridded multisensor (gauge, radar, and satellite) quantitative precipitation estimates (QPEs) for input into hydrologic forecast models and decisionmaking systems for river forecasting, flood and flash flood warning, and other hydrologic monitoring purposes. Advanced hydrologic prediction techniques require a spatially continuous representation of the precipitation field, and remote sensor input is critical to achieving this continuity. Although detailed descriptions of individual remote sensor estimation algorithms have been published, this review provides a summary of how the estimates from these various sources are merged into finished products. Emphasis is placed on the Weather Surveillance Radar-1988 Doppler (WSR-88D) Precipitation Processing System (PPS) and the Advanced Weather Interactive Processing System (AWIPS) Multisensor Precipitation Estimator (MPE) algorithms that utilize a combination of in situ rain gauges and remotely sensed measurements to provide a real-time suite of gridded radar and multisensor precipitation products. These two algorithm suites work in series to combine both computer-automated and human-interactive techniques, and they are used routinely at NWS field offices [river forecast centers (RFCs) and weather forecast offices (WFOs)] to support NWS's broader hydrologic missions. The resulting precipitation products are also available to scientists and engineers outside the NWS; a summary of characteristics and sources of these products is presented. © 2013 American Society of Civil Engineers.


Komatsu E.,University of Texas at Austin | Smith K.M.,Princeton University | Dunkley J.,University of Oxford | Bennett C.L.,Johns Hopkins University | And 17 more authors.
Astrophysical Journal, Supplement Series | Year: 2011

The combination of seven-year data from WMAP and improved astrophysical data rigorously tests the standard cosmological model and places new constraints on its basic parameters and extensions. By combining the WMAP data with the latest distance measurements from the baryon acoustic oscillations (BAO) in the distribution of galaxies and the Hubble constant (H0) measurement, we determine the parameters of the simplest six-parameter ACDM model. The power-law index of the primordial power spectrum is ns = 0.968 ± 0.012 (68% CL) for this data combination, a measurement that excludes the Harrison-Zel'dovich- Peebles spectrum by 99.5% CL. The other parameters, including those beyond the minimal set, are also consistent with, and improved from, the five-year results. We find no convincing deviations from the minimal model. The seven-year temperature power spectrum gives a better determination of the third acoustic peak, which results in a better determination of the redshift of the matter-radiation equality epoch. Notable examples of improved parameters are the total mass of neutrinos, Σmν < 0.58 eV (95% CL), and the effective number of neutrino species, Neff = 4.34 +0.86 -0.88 (68% CL), which benefit from better determinations of the third peak and H0. The limit on a constant dark energy equation of state parameter from WMAP+BAO+H0, without high-redshift Type Ia supernovae, is ω = -1.10 ± 0.14 (68% CL). We detect the effect of primordial helium on the temperature power spectrum and provide a new test of big bang nucleosynthesis by measuring Yp = 0.326 ±0.075 (68% CL). We detect, and show on the map for the first time, the tangential and radial polarization patterns around hot and cold spots of temperature fluctuations, an important test of physical processes at z = 1090 and the dominance of adiabatic scalar fluctuations. The seven-year polarization data have significantly improved: we now detect the temperature-E-mode polarization cross power spectrum at 21σ, compared with 13σ from the five-year data. With the seven-year temperature-B-mode cross power spectrum, the limit on a rotation of the polarization plane due to potential parity-violating effects has improved by 38% to Δα = - 1°.1 ± 1°.4(statistical) ± 1°.5(systematic) (68% CL). We report significant detections of the Sunyaev-Zel'dovich (SZ) effect at the locations of known clusters of galaxies. The measured SZ signal agrees well with the expected signal from the X-ray data on a cluster-by-cluster basis. However, it is a factor of 0.5-0.7 times the predictions from "universal profile" of Arnaud et al, analytical models, and hydrodynamical simulations. We find, for the first time in the SZ effect, a significant difference between the cooling-flow and non-cooling-flow clusters (or relaxed and non-relaxed clusters), which can explain some of the discrepancy. This lower amplitude is consistent with the lower-than-theoretically expected SZ power spectrum recently measured by the South Pole Telescope Collaboration. © 2011. The American Astronomical Society.


Bennett C.L.,Johns Hopkins University | Larson D.,Johns Hopkins University | Weiland J.L.,Johns Hopkins University | Jarosik N.,Princeton University | And 21 more authors.
Astrophysical Journal, Supplement Series | Year: 2013

We present the final nine-year maps and basic results from the Wilkinson Microwave Anisotropy Probe (WMAP) mission. The full nine-year analysis of the time-ordered data provides updated characterizations and calibrations of the experiment. We also provide new nine-year full sky temperature maps that were processed to reduce the asymmetry of the effective beams. Temperature and polarization sky maps are examined to separate cosmic microwave background (CMB) anisotropy from foreground emission, and both types of signals are analyzed in detail. We provide new point source catalogs as well as new diffuse and point source foreground masks. An updated template-removal process is used for cosmological analysis; new foreground fits are performed, and new foreground-reduced CMB maps are presented. We now implement an optimal C -1 weighting to compute the temperature angular power spectrum. The WMAP mission has resulted in a highly constrained ΛCDM cosmological model with precise and accurate parameters in agreement with a host of other cosmological measurements. When WMAP data are combined with finer scale CMB, baryon acoustic oscillation, and Hubble constant measurements, we find that big bang nucleosynthesis is well supported and there is no compelling evidence for a non-standard number of neutrino species (N eff = 3.84 ± 0.40). The model fit also implies that the age of the universe is t 0 = 13.772 ± 0.059 Gyr, and the fit Hubble constant is H 0 = 69.32 ± 0.80 km s-1 Mpc-1. Inflation is also supported: the fluctuations are adiabatic, with Gaussian random phases; the detection of a deviation of the scalar spectral index from unity, reported earlier by the WMAP team, now has high statistical significance (ns = 0.9608 ± 0.0080); and the universe is close to flat/Euclidean (). Overall, the WMAP mission has resulted in a reduction of the cosmological parameter volume by a factor of 68,000 for the standard six-parameter ΛCDM model, based on CMB data alone. For a model including tensors, the allowed seven-parameter volume has been reduced by a factor 117,000. Other cosmological observations are in accord with the CMB predictions, and the combined data reduces the cosmological parameter volume even further. With no significant anomalies and an adequate goodness of fit, the inflationary flat ΛCDM model and its precise and accurate parameters rooted in WMAP data stands as the standard model of cosmology. © 2013. The American Astronomical Society. All rights reserved..


Hinshaw G.,University of British Columbia | Larson D.,Johns Hopkins University | Komatsu E.,Max Planck Institute for Astrophysics | Komatsu E.,University of Tokyo | And 21 more authors.
Astrophysical Journal, Supplement Series | Year: 2013

We present cosmological parameter constraints based on the final nine-year Wilkinson Microwave Anisotropy Probe (WMAP) data, in conjunction with a number of additional cosmological data sets. The WMAP data alone, and in combination, continue to be remarkably well fit by a six-parameter ΛCDM model. When WMAP data are combined with measurements of the high-l cosmic microwave background anisotropy, the baryon acoustic oscillation scale, and the Hubble constant, the matter and energy densities, Ωb h 2, Ωc h 2, and ΩΛ, are each determined to a precision of ∼1.5%. The amplitude of the primordial spectrum is measured to within 3%, and there is now evidence for a tilt in the primordial spectrum at the 5σ level, confirming the first detection of tilt based on the five-year WMAP data. At the end of the WMAP mission, the nine-year data decrease the allowable volume of the six-dimensional ΛCDM parameter space by a factor of 68,000 relative to pre-WMAP measurements. We investigate a number of data combinations and show that their ΛCDM parameter fits are consistent. New limits on deviations from the six-parameter model are presented, for example: the fractional contribution of tensor modes is limited to r < 0.13 (95% CL); the spatial curvature parameter is limited to ; the summed mass of neutrinos is limited to ∑m ν < 0.44 eV (95% CL); and the number of relativistic species is found to lie within N eff = 3.84 ± 0.40, when the full data are analyzed. The joint constraint on N eff and the primordial helium abundance, Y He, agrees with the prediction of standard big bang nucleosynthesis. We compare recent Planck measurements of the Sunyaev-Zel'dovich effect with our seven-year measurements, and show their mutual agreement. Our analysis of the polarization pattern around temperature extrema is updated. This confirms a fundamental prediction of the standard cosmological model and provides a striking illustration of acoustic oscillations and adiabatic initial conditions in the early universe. © 2013. The American Astronomical Society. All rights reserved.


Vourlidas A.,U.S. Navy | Howard R.A.,U.S. Navy | Esfandiari E.,Adnet Systems Inc. | Patsourakos S.,University of Ioannina | And 2 more authors.
Astrophysical Journal | Year: 2010

The LASCO coronagraphs, in continuous operation since 1995, have observed the evolution of the solar corona and coronal mass ejections (CMEs) over a full solar cycle with high-quality images and regular cadence. This is the first time that such a data set becomes available and constitutes a unique resource for the study of CMEs. In this paper, we present a comprehensive investigation of the solar cycle dependence on the CME mass and energy over a full solar cycle (1996-2009) including the first in-depth discussion of the mass and energy analysis methods and their associated errors. Our analysis provides several results worthy of further studies. It demonstrates the possible existence of two event classes: "normal" CMEs reaching constant mass for > 10 R⊙ and "pseudo"-CMEs which disappear in the C3 field of view. It shows that the mass and energy properties of CME reach constant levels and therefore should be measured only above ∼10 R⊙. The mass density (g/R⊙ 2) of CMEs varies relatively little (< order of magnitude) suggesting that the majority of the mass originates from a small range in coronal heights. We find a sudden reduction in the CME mass in mid-2003 which may be related to a change in the electron content of the large-scale corona and we uncover the presence of a 6 month periodicity in the ejected mass from 2003 onward. © 2010. The American Astronomical Society. All rights reserved. Printed in the U.S.A.


Moran T.G.,Catholic University of America | Moran T.G.,NASA | Davila J.M.,NASA | Thompson W.T.,Adnet Systems Inc.
Astrophysical Journal | Year: 2010

We have tested the validity of the coronal mass ejection (CME) polarimetric reconstruction technique for the first time using triangulation and demonstrated that it can provide the angle and distance of CMEs to the plane of the sky. In this study, we determined the three-dimensional orientation of the CMEs that occurred on 2007 August 21 and 2007 December 31 using polarimetric observations obtained simultaneously with the Solar Terrestrial Relations Observatory/Sun Earth Connection Coronal and Heliospheric Investigation spacecraft COR1-A and COR1-B coronagraphs. We obtained the CME orientations using both the triangulation and polarimetric techniques and found that angles to the sky plane yielded by the two methods agree to within ≈ 5°, validating the polarimetric reconstruction technique used to analyze CMEs observed with the Solar and Heliospheric Observatory/Large Angle Spectrometric Coronagraph. In addition, we located the CME source regions using EUV and magnetic field measurements and found that the corresponding mean angles to the sky plane of those regions agreed with those yielded by the geometric and polarimetric methods within uncertainties. Furthermore, we compared the locations provided by polarimetric COR1 analysis with those determined from other analyses using COR2 observations combined with geometric techniques and forward modeling. We found good agreement with those studies relying on geometric techniques but obtained results contradictory to those provided by forward modeling. © 2010. The American Astronomical Society. All rights reserved.


Thomason L.W.,NASA | Moore J.R.,Science Systems And Applications Inc. | Pitts M.C.,NASA | Zawodny J.M.,NASA | Chiou E.W.,ADNET Systems Inc.
Atmospheric Chemistry and Physics | Year: 2010

Herein, we provide an assessment of the data quality of Stratospheric Aerosol and Gas Experiment (SAGE∼III) Version 4 aerosol extinction coefficient and water vapor data products. The evaluation is based on comparisons with data from four instruments: SAGE II, the Polar Ozone and Aerosol Measurement (POAM III), the Halogen Occultation Experiment (HALOE), and the Microwave Limb Sounder (MLS). Since only about half of the SAGE III channels have a direct comparison with measurements by other instruments, we have employed some empirical techniques to evaluate measurements at some wavelengths. We find that the aerosol extinction coefficient measurements at 449, 520, 755, 869, and 1021 nm are reliable with accuracies and precisions on the order of 10% in the mission's primary aerosol target range of 15 to 25 km. We also believe this to be true of the aerosol measurements at 1545 nm though we cannot exclude some positive bias below 15 km. We recommend use of the 385 nm measurements above 16 km where the accuracy is on par with other aerosol channels. The 601 nm measurement is much noisier (∼20%) than other channels and we suggest caution in the use of these data. We believe that the 676 nm data are clearly defective particularly above 20 km (accuracy as poor as 50%) and the precision is also low (∼30%). We suggest excluding this channel under most circumstances. The SAGE III Version 4 water vapor data product appears to be high quality and is recommended for science applications in the stratosphere below 45 km. In this altitude range, the mean differences with all four corroborative data sets are no bigger than 15% and often less than 10% with exceptional agreement with POAM III and MLS. Above 45 km, it seems likely that SAGE III water vapor values are increasingly too large and should be used cautiously or avoided. We believe that SAGE III meets its preflight goal of 15% accuracy and 10% precision between 15 and 45 km. SAGE III water vapor data does not appear to be affected by aerosol loading in the stratosphere.


Ireland J.,ADNET Systems Inc. | Marsh M.S.,University of Central Lancashire | Kucera T.A.,NASA | Young C.A.,ADNET Systems Inc.
Solar Physics | Year: 2010

Recently observed oscillations in the solar atmosphere have been interpreted and modeled as magnetohydrodynamic wave modes. This has allowed for the estimation of parameters that are otherwise hard to derive, such as the coronal magnetic-field strength. This work crucially relies on the initial detection of the oscillations, which is commonly done manually. The volume of Solar Dynamics Observatory (SDO) data will make manual detection inefficient for detecting all of the oscillating regions. An algorithm is presented that automates the detection of areas of the solar atmosphere that support spatially extended oscillations. The algorithm identifies areas in the solar atmosphere whose oscillation content is described by a single, dominant oscillation within a user-defined frequency range. The method is based on Bayesian spectral analysis of time series and image filtering. A Bayesian approach sidesteps the need for an a-priori noise estimate to calculate rejection criteria for the observed signal, and it also provides estimates of oscillation frequency, amplitude, and noise, and the error in all of these quantities, in a self-consistent way. The algorithm also introduces the notion of quality measures to those regions for which a positive detection is claimed, allowing for simple post-detection discrimination by the user. The algorithm is demonstrated on two Transition Region and Coronal Explorer (TRACE) datasets, and comments regarding its suitability for oscillation detection in SDO are made. © 2010 Springer Science+Business Media B.V.


Thompson W.T.,Adnet Systems Inc.
Solar Physics | Year: 2013

Triangulation measurements using observations from the two Solar Terrestrial Relations Observatory (STEREO) spacecraft, combined with observations from the Solar Dynamics Observatory (SDO), are used to characterize the behavior of a prominence involved in two successive coronal mass ejections 6 - 7 December 2010. The STEREO separation at the time was 171. 6{ring operator}, which was functionally equivalent to a separation of 8. 4{ring operator}, and thus very favorable for feature co-identification above the limb. The first eruption at ≈ 14:16 UT on 6 December of the middle branch of the prominence starts off a series of magnetic reconfigurations in the right branch, which itself erupts at ≈ 2:06 UT the next day, about 12 hours after the first eruption. The cool prominence material seen at 304 Å drains back down to the surface, but a flux-rope-like magnetic structure is seen to erupt in both 195 Å by the STEREO/Extreme Ultraviolet Imager (EUVI), and in white light by the STEREO/COR1 inner coronagraph. In between the two eruptions, two different signs of helicity are seen in the measured twist of the right branch. This is interpreted to be caused by the overall prominence channel being composed of different segments with alternating helicity signs. The erupting parts on 6 and 7 December both show positive twist, but negative twist is seen in between these positive sections. Negative twist is consistent with the dextral chirality signs seen in the He ii line at 304 Å prior to both eruptions. However, during the period between the eruptions, a region of positive twist grows and replaces the region of negative twist, and finally erupts. We interpret these observations in the light of models that predict that helicity cancellation can be an important factor in the triggering of flares and coronal mass ejections. © 2013 Springer Science+Business Media Dordrecht.


Herrmann N.,ADNET Systems Inc.
Proceedings of the International Astronautical Congress, IAC | Year: 2012

The construction of a facility at an Earth-Moon Lagrange point will enable humans to mature exploration technologies and overcome the challenges of living in the cis-lunar environment. The L2 Lagrange point is an optimal staging area for future missions and would serve as a gateway to human exploration of deep space. To ensure that humans can thrive and maintain a presence at L2, it will be imperative that NASA and its partners, including private industry and international agencies, develop a sustainable strategy. Ideally, an L2 Gateway has great potential to not only serve as a staging area for exploration missions, but also as a destination for space tourism; provide opportunities for telescope construction and deployment; establish deep-space communication and navigation capabilities; provide emergency facilities for future Lunar explorers; and develop a satellite servicing station, to name a few of the myriad possibilities. Essentially, a sustained human presence in cis-lunar space could create an entirely new market with an endless number of potential customers. This vision of a thriving hub of activity in cis-lunar space will be dependent on a sustainable strategy for development. Although there is no precedent for the establishment of a deep-space gateway facility, parallels can be drawn from the development of seaports. For centuries, seaports have served as central hubs of economic activity around the world, providing efficient means of transportation of goods and services and catalyzing the development of surrounding communities. The cruise industry is also completely dependent on seaports as destinations, serving as an example for development of the space-tourism industry. In budget constrained environments and an ever- changing political landscape, seaports have been established as, or are turning to, public-private partnerships to ensure continued prosperity. This study will examine the success of public-private partnerships in the development of seaports and propose a similar model for maintaining facilities, managing stakeholders, and encouraging economic activity at L2. Additionally, this paper proposes the establishment of an international port authority to govern and regulate activities at cis-lunar destinations. Copyright © (2012) by the International Astronautical Federation.

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