STAR Seminars

STAR Science Seminars
Presenter:
Likun Wang, Riverside Technology, inc
Co-Authors: LingLiu, Katherine Lukens, Kayo Ide, Kevin Garrett, Sid Boukabara
Sponsor(s):
STAR Science Seminar Series
Remote access:
WebEx:
Event Number:     904 040 583   
Password: STARSeminar
Event address for attendees:
https://noaa-nesdis-star.webex.com/noaa-nesdis-star/j.php?MTID=mfb1864553ba631a7369c610e5bbd40c0
Audio:
       
+1-415-527-5035 US Toll
Access code: 904 040 583




Abstract:

The NOAA global observing system (GOS) contains a large variety of observing platforms, including geostationary and polar-orbiting satellites, radiosonde,aircraft, surface stations, ships, buoys, etc. Despite the comprehensiveness of the observing system, many critical gaps exist in spatial/temporal coverage,spectral coverage, and resolution. To address these gaps, the NOAA/NESDIS Technology Maturation Program funded one of projects to explore use of emerging internet platforms (such as Loon high altitude balloons and SpaceX StarLink Satellites) for hosting remote sensing instruments. This talk summarizes feasibility assessment on potentials payload hosting opportunities that can benefit NOAA GOS system, which mainly focuses on Loon platforms and also extends to recent SpaceX StarLink constellations.  

First, the Loon platform characteristics and flight dynamics are comprehensively surveyed to explore the capability and limitation for Loon as a hosting platform.  Second, by comparing GOES-16 Advanced Baseline Imager (ABI) with collocated Loon infrared thermometer measurements,we demonstrate that the Loon platform can served as a validation platform for future NOAA satellite sensors. Third, through simulation studies, observational geometry (e.g., footprint size, swath width, pointing accuracy) and weighting functions are studied for the scenarios that the Loon platform can host passive microwave instruments. More importantly, we demonstrate that balloon-based GPS radio occultation (RO) measurements can be complementary to current satellite based GPSRO systems. Efforts have been devoted to develop the capability of simulating the GPSRO slant path and bending angle from the balloon platform at~20 km, utilizing current constellation of Global Navigation Satellite Systems.Based on the calculations, the sampling characteristics and spatial and temporal coverage as well as the advantages and disadvantages are discussed.Based on this, the Observing System Simulation Experiment (OSSE) is designed to assess possible impacts on Global Forecasting System (GFS) forecasting capabilities by adding balloon-based GPSRO observations. The impacts are demonstrated and compared to those from space-based GPSRO observations. Finally,SpaceX StarLink constellation are simulated and potential hosting opportunities are discussed.
Presenter:
Dr. Likun Wang is now working in NOAA/NESDIS/STAR as a contract scientist employed by Riverside Technology, inc for Research Technology Maturation for the Exploitation of Emerging Technologies (RTMEE) Contract, including near space payload hosting platform assessment, Artificial Intelligence (AI) technology demonstration, and geostationary sounder proxy data  simulations. With more than 15 years of progressive working experiences of NOAA's satellite sensors, Dr. Likun Wang has been responsible for the pre- and post-launch calibration testing data analysis, inter-calibration for post-launch instrument monitoring and assessment, ground processing software development, configuration and calibration parameter refining, and new algorithm design and integration. He currently serves the chair of World Meteorological Organization (WMO) sponsored Global Space-based Inter-Calibration System (GSICS) infrared sensor working group. Likun Wang received his B.S. degree in atmospheric sciences and the M.S. degree in meteorology from Peking University, Beijing, China, in 1996 and 1999, respectively, and the Ph.D. degree in atmospheric sciences from University of Alaska Fairbanks, in 2004.
POC:
Stacy Bunin, stacy.bunin@noaa.gov

STAR Science Seminars
Presenter:

F. Joseph (Joe) Turk and Chi O. Ao, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 

Sponsor(s):
STAR Science Seminar Series
Remote access:
WebEx:
Event Number:     902 629 658   
Password: STARSeminar
Event address for attendees:
https://noaa-nesdis-star.webex.com/noaa-nesdis-star/j.php?MTID=me9f3b586d540b847e7aa28c848f6b3e2
Audio:
       
+1-415-527-5035 US Toll
Access code: 902 629 658


Abstract:

As stated  in the recent Decadal Survey for Earth Observations from Space, the climate and weather forecast predictive capability for precipitation intensity is limited by gaps in the understanding of basic cloud-convective processes.  This process lacks several observational constraints, one being the difficulty in obtaining the thermodynamic profile (i.e., vertically resolved pressure,temperature, and water vapor structure) in close proximity to convective clouds.  The objective of the Radio Occultations and Heavy Precipitation (ROHP) experiment, orbiting onboard the Spanish PAZ satellite since May 2018, is to demonstrate the simultaneous capability to detect heavy precipitation along the same RO ray paths used to estimate the thermodynamic profile. While conventional RO does not directly provide this capability, PRO enhances standard RO by receiving the GNSS signals in two orthogonal polarizations (“H” and “V”). Owing to hydrometeor asymmetry, the H- and V-polarized radio signals propagating through heavy precipitation will experience differential phase delays,measurable via the ROHP polarimetric antenna.

In this presentation we will discuss the on-orbit calibration and validation of the ROHP data, and present potential applications for these data in weather modeling. The ROHP calibration is performed with an extensive dataset of one year of observations, co-located with independent information from Global Precipitation Mission (GPM) precipitation products and ionospheric activity.  The validation demonstrates how the calibrated products can be used as a proxy for heavy precipitation.  The PRO signals also exhibit positive differential phase signatures well above the freezing level, indicating possible sensitivity to frozen hydrometeors and the cloud vertical structure.  This knowledge of the presence of precipitation associated with the RO observation is useful for the evaluation and diagnosis of NWP forecast models.  The use of PRO in data assimilation methods will require an observation operator that can simulate all contributions to the differential phase delay along realistic RO propagation paths, taking into account the cloud structure.
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Presenter(s):

F.J.(Joe) Turk is a radar scientist at JPL, where he has been since 2009.  From 1995-2009, he was a member of the meteorological applications group at the Naval Research Laboratory, Marine Meteorology Division, in Monterey, CA. He received his Ph.D. degree from Colorado State University, and his M.S. and B.S. degrees from Michigan Technological University, all in electrical engineering.  His work experience has covered polarimetric weather radar, satellite passive microwave and radar observations and applications, microwave radiative transfer, polarimetric RO, and airborne radar and wind lidar observations. He is a member of NASA's Precipitation Measurement Missions science team.

Chi O.Ao is a research technologist at JPL with over 15 years of experience in GNSS radio occultation (RO) receiver tracking and inversion techniques, simulation methods, data analysis, and climate applications.  He leads the RO processing and applications team from multiple missions including CHAMP and COSMIC at JPL.  He is currently the GNSS-RO Scientist of the Jason-CS/Sentinel-6mission, the Principal Investigator of the NASA Earth Science U.S. Participating Program for the ROHP-PAZ experiment, and a member of the Decadal Survey Incubation Study Team for the Planetary Boundary Layer.

POC:
Stacy Bunin, stacy.bunin@noaa.gov