Dr. Yongxiang Hu Profile

Dr. Yongxiang Hu

at NASA Langley Research Ctr

SPIE Involvement:

Author

Publications (22)

Proceedings Article | 9 August 2023 Poster

Polarization calibration using solar radiation background signal scattered from dense cirrus clouds in the visible and ultraviolet wavelength regime

Zhaoyan Liu, Yongxiang Hu, Pengwang Zhai, Shan Zeng, Mark Vaughan, Sharon Rodier, Xiaomei Lu

Proceedings Volume 12327, 123271O (2023) https://doi.org/10.1117/12.2665858

KEYWORDS: Polarization, LIDAR, Visible radiation, Ultraviolet radiation, Solar radiation, Scattering, Clouds, Calibration, Particles, Solar radiation models

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Proceedings Article | 18 October 2019 Presentation

Potential satellite mission on atmospheric dynamics for severe weather forecasts (Conference Presentation)

Bing Lin, Qilong Min, Steven Harrah, Yongxiang Hu, Roland Lawrence

Proceedings Volume 11151, 111510J (2019) https://doi.org/10.1117/12.2531710

KEYWORDS: Satellites, Meteorological satellites, Remote sensing, Radar, Oxygen, Absorption, Sensing systems, Environmental sensing, Sensors, Atmospheric sensing

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Surface air pressure is the most important atmospheric variable for atmospheric dynamics. It is regularly measured by in-situ meteorological sensors, and there are no operational capabilities that could remotely sense the pressure over the globe. The poor spatiotemporal coverage of this dynamically crucial variable is a significant observational gap in weather predictions. To improve forecasts of severe weather conditions, especially the intensity and track of tropical storms, large spatial coverage and frequent sampling of surface barometry are critically needed for numerical weather forecast models. Recent development in remote sensing techniques provides a great hope of atmospheric barometry in large spatiotemporal scales. Currently, NASA Langley Research Center tries to use the concept of Differential-absorption Barometric Radar (DiBAR) working at the 50-56 GHz O2 absorption bands to fill the observational gap. The numerical simulation shows that with this DiBAR remote sensing system, the uncertainty in instantaneous radar surface air pressure estimates can be as low as ~1 mb. Prototype instrumentation and its related laboratory, ground and airborne experiments indicate that satellite DiBAR remote sensing systems will obtain needed air pressure observations and meet or exceed the science requirements for surface air pressure fields. Observational system simulation experiments (OSSEs) for space DiBAR performance based on the existing DiBAR technology and capability show substantial improvements in tropical storm predictions, not only for the typhoon track and position but also for the typhoon intensity. Satellite DiBAR measurements will provide an unprecedented level of the prediction and knowledge on global extreme weather conditions. A space multi-frequency differential oxygen absorption radar system will fill the gap in the global observations of atmospheric air pressure, increase our knowledge in the dynamics, and significantly improve weather, especially severe weather such as typhoon and hurricane, predictions. Advanced tropical storm forecasts are expected with the studied capability. The development of the DiBAR system and associated OSSE results will be presented.

Proceedings Article | 25 May 2018 Paper

Lidars utilizing vortex laser beams

Carl Weimer, Yong Hu, Jeff Applegate, Mike Lieber, Wenbo Sun, David MacDonnell

Proceedings Volume 10631, 106310Q (2018) https://doi.org/10.1117/12.2310042

KEYWORDS: Laser scattering, LIDAR, Wavefronts, Light scattering, Spatial light modulators, Mie scattering, Finite-difference time-domain method

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Proceedings Article | 7 June 2017 Presentation

Assessment of lidar remote sensing capability of Raman water temperature from laboratory and field experiments (Conference Presentation)

Damien Josset, Weilin Hou, Wesley Goode, Silvia Matt, Yongxiang Hu

Proceedings Volume 10186, 101860Q (2017) https://doi.org/10.1117/12.2264653

KEYWORDS: LIDAR, Turbulence, Raman spectroscopy, Remote sensing, Profiling, Polarization, Raman scattering, Laser applications, Climatology, Photosynthesis

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Lidar remote sensing based on visible wavelength is one of the only way to penetrate the water surface and to obtain range resolved information of the ocean surface mixed layer at the synoptic scale. Accurate measurement of the mixed layer properties is important for ocean weather forecast and to assist the optimal deployment of military assets. Turbulence within the mixed layer also plays an important role in climate variability as it also influences ocean heat storage and algae photosynthesis (Sverdrup 1953, Behrenfeld 2010). As of today, mixed layer depth changes are represented in the models through various parameterizations constrained mostly by surface properties like wind speed, surface salinity and sea surface temperature. However, cooling by wind and rain can create strong gradients (0.5C) of temperature between the submillimeter surface layer and the subsurface layer (Soloviev and Lukas, 1997) which will manifest itself as a low temperature bias in the observations. Temperature and salinity profiles are typically used to characterize the mixed layer variability (de Boyer Montégut et al. 2004) and are both key components of turbulence characterization (Hou 2009). Recently, several research groups have been investigating ocean temperature profiling with laser remote sensing based either on Brillouin (Fry 2012, Rudolf and Walther 2014) or Raman scattering (Artlett and Pask 2015, Lednev et al. 2016). It is the continuity of promising research that started decades ago (Leonard et al. 1979, Guagliardo and Dufilho 1980, Hirschberg et al. 1984) and can benefit from the current state of laser and detector technology. One aspect of this research that has not been overlooked (Artlett and Pask 2012) but has yet to be revisited is the impact of temperature on vibrational Raman polarization (Chang and Young, 1972). The TURBulence Ocean Lidar is an experimental system, aimed at characterizing underwater turbulence by examining various Stokes parameters. Its multispectral capability in both emission (based on an optical parametric oscillator) and detection (optical filters) provide flexibility to measure the polarization signature of both elastic and inelastic scattering. We will present the characteristics of TURBOL and several results from our laboratory and field experiments with an emphasis on temperature profiling capabilities based on vibrational Raman polarization. We will also present other directions of research related to this activity.

Proceedings Article | 16 October 2015 Paper

Aerosol properties from combined oxygen A band radiances and lidar

David Winker, Peng-Wang Zhai, Yongxiang Hu

Proceedings Volume 9640, 964002 (2015) https://doi.org/10.1117/12.2195182

KEYWORDS: Aerosols, Atmospheric modeling, Oxygen, LIDAR, Absorption, Satellites, Atmospheric particles, Scattering, Spectral resolution, Computer simulations

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Proceedings Article | 19 May 2015 Paper

Ocean and polarization observations from active remote sensing: atmospheric and ocean science applications

D. Josset, W. Hou, J. Pelon, Y. Hu, S. Tanelli, R. Ferrare, S. Burton, N. Pascal

Proceedings Volume 9459, 94590N (2015) https://doi.org/10.1117/12.2181544

KEYWORDS: Clouds, Ocean optics, LIDAR, Aerosols, Liquids, Calibration, Atmospheric particles, Atmospheric optics, Water, Analytical research

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In the past few years, we have demonstrated how the surface return measured by the active instruments onboard CloudSat and CALIPSO could be used to retrieve the optical depth and backscatter phase function (lidar ratio) of aerosols and ice clouds. This methodology lead to the development of a data fusion product publicly available at the ICARE archive center using the Synergized Optical Depth of Aerosols and Ice Clouds (SODA & ICE) algorithm¹. This algorithm, also allowing to derive ocean surface wind speed, has been extended to include dense cloud surface return to analyze aerosol and cloud properties above such clouds. This low level data fusion of CALIPSO and CloudSat ocean surface echoes has been used by several researchers to explore different research paths. Among them, we can cite: • A new characterization of the lidar ratio of cirrus clouds² • The analysis of the precipitable water and development of a new Millimeter-Wave Propagation Model for the W-Band observations (EMPIRIMA³) • The analysis of the lidar ratio of sea-spray aerosols⁴, and of Aerosol multilayer lidar ratio and extinction⁵ • A contribution to the retrieval of the subsurface particulate backscatter coefficients of phytoplankton particles⁶ In this paper, we present the main features of SODA & ICE, summarizing some of the results obtained. This low level data fusion of CALIPSO and CloudSat ocean surface echoes has been used by several researchers to explore different research paths. Among them, we can cite: A new characterization of the lidar ratio of cirrus clouds² The analysis of the precipitable water and development of a new Millimeter-Wave Propagation Model for the W-Band observations (EMPIRIMA³) The analysis of the lidar ratio of sea-spray aerosols⁴, and of Aerosol multilayer lidar ratio and extinction⁵ A contribution to the retrieval of the subsurface particulate backscatter coefficients of phytoplankton particles⁶ In this paper, we present the main features of SODA & ICE, summarizing some of the results obtained.

Proceedings Article | 10 December 2014 Paper

Estimation of particulate organic carbon in the ocean from space-based polarization lidar measurements

Xiaomei Lu, Yongxiang Hu

Proceedings Volume 9261, 92610Z (2014) https://doi.org/10.1117/12.2076612

KEYWORDS: LIDAR, Polarization, Satellites, MODIS, Carbon, In situ metrology, Algorithm development, Backscatter, Spatial resolution, Error analysis

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SPIE Journal Paper | 14 October 2014

Accuracy of land surface elevation from CALIPSO mission data

Xiaomei Lu, Yongxiang Hu

OE, Vol. 54, Issue 03, 031102, (October 2014) https://doi.org/10.1117/12.10.1117/1.OE.54.3.031102

KEYWORDS: Field emission displays, LIDAR, Satellites, Vegetation, Radar, Optical engineering, Data centers, Pulsed laser operation, Earth sciences, Clouds

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Proceedings Article | 9 June 2014 Paper

High-speed on-board data processing for science instruments

Jeffrey Beyon, Tak-Kwong Ng, Bing Lin, Yongxiang Hu, Wallace Harrison

Proceedings Volume 9080, 90800L (2014) https://doi.org/10.1117/12.2050358

KEYWORDS: Data processing, Commercial off the shelf technology, Field programmable gate arrays, Data archive systems, Digital signal processing, Algorithm development, Signal processing, Carbon dioxide, Aerosols, LIDAR

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Proceedings Article | 27 September 2013 Paper

CALIOP receiver transient response study

Xiaomei Lu, Yongxiang Hu, Zhaoyan Liu, Shan Zeng, Charles Trepte

Proceedings Volume 8873, 887316 (2013) https://doi.org/10.1117/12.2033589

KEYWORDS: LIDAR, Receivers, Linear filtering, Backscatter, Sensors, Clouds, Aerosols, Signal detection, Polarization, Satellites

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Proceedings Article | 20 May 2013 Paper

Ice sheet surface elevation retrieval from CALIPSO lidar measurements

Xiaomei Lu, Yongxiang Hu

Proceedings Volume 8731, 87310Z (2013) https://doi.org/10.1117/12.2026617

KEYWORDS: LIDAR, Clouds, Atmospheric particles, Satellites, Pulsed laser operation, Earth's atmosphere, Climatology, Aerosols, Profiling, Earth observing sensors

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Proceedings Article | 8 June 2012 Paper

Exact first order scattering correction for vector radiative transfer in coupled atmosphere and ocean systems

Peng-Wang Zhai, Yongxiang Hu, Damien Josset, Charles Trepte, Patricia Lucker, Bing Lin

Proceedings Volume 8364, 83640A (2012) https://doi.org/10.1117/12.920767

KEYWORDS: Scattering, Light scattering, Radiative transfer, Electroluminescent displays, Ocean optics, Atmospheric optics, Atmospheric corrections, Photons, Polarization, Atmospheric modeling

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Proceedings Article | 24 October 2011 Paper

A super-resolution laser altimetry concept

Xiaomei Lu, Yongxiang Hu, Charles Trepte, Yuesong Jiang

Proceedings Volume 8286, 82860B (2011) https://doi.org/10.1117/12.912946

KEYWORDS: LIDAR, Pulsed laser operation, Data modeling, Super resolution, Linear filtering, Profiling, Backscatter, Sensors, Receivers, Field emission displays

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Proceedings Article | 9 June 2011 Paper

Topographic mapping flash lidar for multiple scattering, terrain, and forest mapping

Tanya Ramond, Eileen Saiki, Carl Weimer, Jeff Applegate, Yongxiang Hu, Thomas Delker, Lyle Ruppert, Brian Donley

Proceedings Volume 8037, 803710 (2011) https://doi.org/10.1117/12.884145

KEYWORDS: LIDAR, Clouds, Multiple scattering, Backscatter, Receivers, Calibration, Aerospace engineering, Laser scattering, Scattering, Oscillators

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Proceedings Article | 26 October 2010 Paper

The CALIPSO Mission: results and progress

Dave Winker, Yong Hu, Michael Pitts, Melody Avery, Brian Getzewich, Jason Tackett, Chieko Kittaka, Zhaoyan Liu, Mark Vaughan

Proceedings Volume 7832, 78320B (2010) https://doi.org/10.1117/12.864901

KEYWORDS: Clouds, Aerosols, Climatology, LIDAR, Satellites, Atmospheric modeling, Environmental sensing, Backscatter, Ocean optics, Pulsed laser operation

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Proceedings Article | 25 October 2007 Paper

An assessment of the on-orbit performance of the CALIPSO wide field camera

Michael Pitts, Larry Thomason, Yongxiang Hu, David Winker

Proceedings Volume 6745, 67450K (2007) https://doi.org/10.1117/12.737377

KEYWORDS: MODIS, Clouds, Reflectivity, Calibration, LIDAR, Cameras, Satellites, Image segmentation, Aerosols, Polarization

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Proceedings Article | 29 August 2005 Paper

Study of ice cloud properties using infrared spectral data

Ping Yang, Heli Wei, Yong-Keun Lee, Jianguo Niu, Hung-Lung Huang, Bryan Baum, YongXiang Hu, Jun Li

Proceedings Volume 5890, 589004 (2005) https://doi.org/10.1117/12.620147

KEYWORDS: Clouds, Particles, Absorption, Infrared radiation, Crystals, MODIS, Near field, Scattering, Radiative transfer, Finite-difference time-domain method

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Proceedings Article | 18 August 2005 Paper

Can polarization aid in the remote sensing of dust and smoke?

David Flittner, Yongxiang Hu

Proceedings Volume 5888, 58880S (2005) https://doi.org/10.1117/12.618037

KEYWORDS: Aerosols, Polarization, Atmospheric particles, Scattering, Absorption, Near ultraviolet, Ozone, Remote sensing, Light scattering, Atmospheric modeling

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Proceedings Article | 30 November 2004 Paper

Cloud and aerosol studies using combined CPL and MAS data

Mark Vaughan, Sharon Rodier, Yongxiang Hu, Matthew McGill, Robert Holz

Proceedings Volume 5571, (2004) https://doi.org/10.1117/12.565586

KEYWORDS: Clouds, Aerosols, LIDAR, Algorithm development, MODIS, Satellites, Detection and tracking algorithms, Data fusion, Radar, Climate change

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Proceedings Article | 4 November 2004 Paper

Fully automated analysis of space-based lidar data: an overview of the CALIPSO retrieval algorithms and data products

Mark Vaughan, Stuart Young, David Winker, Kathleen Powell, Ali Omar, Zhaoyan Liu, Yongxiang Hu, Chris Hostetler

Proceedings Volume 5575, (2004) https://doi.org/10.1117/12.572024

KEYWORDS: Aerosols, Clouds, LIDAR, Backscatter, Feature extraction, Scattering, Signal attenuation, Atmospheric particles, Optical properties, Atmospheric modeling

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Proceedings Article | 14 October 2004 Paper

Radiative properties of ice crystals within cirrus clouds: application to remote sensing

Ping Yang, Heli Wei, Hung-Lung Huang, Bryan Baum, Yong Hu, K. Liou, Michael Mishchenko

Proceedings Volume 5548, (2004) https://doi.org/10.1117/12.557320

KEYWORDS: Clouds, Particles, Crystals, Atmospheric particles, Atmospheric optics, Data modeling, Atmospheric modeling, Remote sensing, Infrared radiation, Scattering

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