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185 results on '"William J. Blackwell"'

1. The alternative of CubeSat-based advanced infrared and microwave sounders for high impact weather forecasting

Author

Zhenglong LI, Jun LI, Timothy J. SCHMIT, Pei WANG, Agnes LIM, Jinlong LI, Fredrick W. NAGLE, Wenguang BAI, Jason A. OTKIN, Robert ATLAS, Ross N. HOFFMAN, Sid-Ahmed BOUKABARA, Tong ZHU, William J. BLACKWELL, and Thomas S. PAGANO

Subjects
osse, cubesat, sounder, high-impact weather, Environmental sciences, GE1-350, Oceanography, GC1-1581
Abstract

The advanced infrared (IR) and microwave (MW) sounding systems have been providing atmospheric sounding information critical for nowcasting and improving weather forecasts through data assimilation in numerical weather prediction. In recent years, advanced IR and MW sounder systems are being proposed to be onboard CubeSats that are much more cost efficient than traditional satellite systems. An impact study using a regional Observing System Simulation Experiment on a local severe storm (LSS) was carried out to evaluate the alternative of using advanced MW and IR sounders for high-impact weather forecasting in mitigating the potential data gap of the Advanced Technology Microwave Sounder (ATMS) and the Cross-track Infrared Sounder (CrIS) on the Suomi-NPP (SNPP) or Joint Polar Satellite System (JPSS). It was found that either MicroMAS-2 or the CubeSat Infrared Atmospheric Sounder (CIRAS) on a single CubeSat was able to provide a positive impact on the LSS forecast, and more CubeSats with increased data coverage yielded larger positive impacts. MicroMAS-2 has the potential to mitigate the loss of ATMS, and CIRAS the loss of CrIS, on SNPP or JPSS, especially when multiple CubeSats are launched. There are several approximations and limitations to the present study, but these represent efficiencies appropriate to the principal goal of the study — gauging the relative values of these sensors.

Published
2019
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2. Climate-Quality Calibration for Low Earth-Orbit Microwave Radiometry

Author

Philip W. Rosenkranz, William J. Blackwell, and R. Vincent Leslie

Subjects
microwave radiometer calibration, gsics, intercalibration, Science
Abstract

Improvements in radiometric calibration are needed to achieve the desired accuracy and stability of satellite-based microwave-radiometer observations intended for the production of climate data records. Linearity, stability and traceability of measurements to an SI-unit standard should be emphasized. We suggest radiometer design approaches to achieve these objectives in a microwave calibration-reference instrument. Multi-year stability would be verified by comparison to radio-occultation measurements. Data from such an instrument could be used for climate studies and also to transfer its calibration to weather-satellite instruments. With the suitable selection of an orbit, a climatology of the diurnal variation in the measured parameters could be compiled, which would reduce uncertainties in climate trends inferred from earlier microwave radiometers over past decades.

Published
2020
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8. Detail Enhancement of AIRS/AMSU Temperature and Moisture Profiles Using a 3D Deep Neural Network

Author

Adam B Milstein, Joseph A Santanello Jr, and William J Blackwell

Subjects
Meteorology and Climatology
Abstract

In recent decades, spaceborne microwave and hyperspectral infrared sounding instruments have significantly benefited weather forecasting and climate science. However, existing retrievals of lower troposphere temperature and humidity profiles have limitations in vertical resolution, and often cannot accurately represent key features such as the mixed layer thermodynamic structure and the inversion at the planetary boundary layer (PBL) top. Because of the existing limitations in PBL remote sensing from space, there is a compelling need to improve routine, global observations of the PBL and enable advances in scientific understanding and weather and climate prediction. To address this, we have developed a new 3D deep neural network (DNN) which enhances detail and reduces noise in Level 2 granules of temperature and humidity profiles from the Atmospheric Infrared Sounder (AIRS)/Advanced Microwave Sounding Unit (AMSU) sounder instruments aboard NASA’s Aqua spacecraft. We show that the enhancement improves accuracy and detail including key features such as capping inversions at the top of the PBL over land, resulting in improved accuracy in estimations of PBL height.

Published
2023
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19. An Evaluation of NOAA-20 ATMS Instrument Pre-Launch and On-Orbit Performance Characterization

Author

Edward Kim, Saji Abraham, Joel Amato, William J Blackwell, Peter Cho, James Fuentes, Mark Hernquist, James Kam, R Vincent Leslie, Quanhua Liu, Cheng-Hsuan Lyu, Taichien Mao, Idahosa A Osaretin, Fabian Rodriguez-Gutierrez, Matthew Sammons, Craig Smith, Ninghai Sun, and Hu Yang

Subjects
Earth Resources And Remote Sensing
Abstract

Passive microwave sounders provide the highest-impact observations ingested by major numerical weather prediction (NWP) forecast models. The Advanced Technology Microwave Sounder (ATMS), built by Northrop Grumman, Azusa, CA, USA, is the latest operational microwave sounder series being launched by the United States to provide both temperature and water vapor soundings of the atmosphere. The first ATMS was launched on the Suomi National Polarorbiting Partnership (SNPP) satellite in 2011. This article focuses on the details of the on-orbit performance characterization of the second ATMS, which launched on November 18, 2017, on the Joint Polar Satellite System-1 (JPSS-1) satellite. After successful commissioning, JPSS-1 was renamed National Oceanic and Atmospheric Administration (NOAA)-20 (N-20). We present performance characterizations from prelaunch and postlaunch tests, including the thermal vacuum (TVAC) campaign, and postlaunch activities that contribute to the radiance data products. Significant improvements were found for reflector emissivity, 1/ f noise performance, antenna beam efficiency, inter-channel noise correlation, and scan drive bearing design. New geolocation and pointing algorithms were evaluated. The N-20 ATMS has the same channel set, polarizations, scan geometry, and calibration approach as the SNPP ATMS. The N-20 ATMS meets all performance requirements with margin.

Published
2022
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24. Time-Resolved Observations of Precipitation Structure and Storm Intensity with a Constellation of Smallsats: Level-1 Radiance Algorithm Theoretical Basis Document

Author

R Vincent Leslie, Mike DiLiberto, and William J. Blackwell

Subjects
Earth Resources And Remote Sensing
Abstract

This Algorithm Theoretical Basis Document (ATBD) describes the theoretical background of the TROPICS native radiance calibration algorithms. It also includes TROPICS payload characteristics and the algorithm’s ancillary data (i.e., data coming from sources other than the TROPICS Space Vehicle). Details of the native radiance (i.e., Level-1a antenna temperatures and Level-1b brightness temperatures) data product format can be found in the TROPICS Data User’s Guide. This ATBD information on the pre-launch testing completed to verify the algorithm. The TROPICS Data User’s Guide will contain the post-launch radiance validation.

Published
2021

43. The Need for Spectrum and the Impact on Weather Observations

Author

Robert D. Palmer, David Draper, William J. Blackwell, Pierre Kirstetter, Karen Kosiba, Stephen L. Durden, Justin G. Metcalf, Howard B. Bluestein, Ramesh R. Rao, David A. Whelan, John Y. N. Cho, Masakazu Wada, Pavlos Kollias, Jordan Gerth, Stephen English, Mark Yeary, Tian-You Yu, Matthew R. Kumjian, Scott Collis, David J. Bodine, Dusan S. Zrnic, Joshua Wurman, Xuguang Wang, and Aaron Tuttle

Subjects
Atmospheric Science, Environmental science, Spectrum (topology), Remote sensing
Published
2021

49. Initial Radiance Validation of the Microsized Microwave Atmospheric Satellite-2A

Author

Michael S. Grant, Adam B. Milstein, I. Osaretin, Angela Crews, Amelia Gagnon, Kerri Cahoy, Stephen Leroy, Michael DiLiberto, R. Vincent Leslie, William J. Blackwell, Massachusetts Institute of Technology. Department of Aeronautics and Astronautics, and Lincoln Laboratory

Subjects
Microwave radiometer, 0211 other engineering and technologies, 02 engineering and technology, Atmospheric model, Community Radiative Transfer Model, Depth sounding, Microwave imaging, Radiance, General Earth and Planetary Sciences, Environmental science, Satellite, CubeSat, Electrical and Electronic Engineering, 021101 geological & geomatics engineering, Remote sensing
Abstract

The Micro-Sized Microwave Atmospheric Satellite (MicroMAS-2A) is a 3U CubeSat that launched in January 2018 as a technology demonstration for future microwave sounding constellation missions, such as the NASA Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats (TROPICS) mission now in development. MicroMAS-2A has a miniaturized 1U 10-channel passive microwave radiometer with channels near 90, 118, 183, and 206 GHz for moisture and temperature profiling and precipitation imaging [4]. MicroMAS-2A provided the first CubeSat atmospheric vertical sounding data from orbit and to date is the only CubeSat to provide temperature and moisture sounding and surface imaging. In this paper, we analyze six segments of data collected from MicroMAS-2A in April 2018 and compare them to ERA5 reanalysis fields coupled with the Community Radiative Transfer Model (CRTM). This initial assessment of CubeSat radiometric accuracy shows biases relative to ERA5 with magnitudes ranging from 0.4 to 2.2 K (with standard deviations ranging from 0.7 to 1.2 K) for the four mid-tropospheric temperature channels and biases of 2.2 and 2.8 K (standard deviations 1.8 and 2.6 K) for the two lower tropospheric water vapor channels., NASA (Award NNX16AM73H)

Published
2021

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