A5011756635- Ionosphere and magnetosphere dynamics
- Geophysics and Gravity Measurements
- GNSS positioning and interference
- Meteorological Phenomena and Simulations
- Precipitation Measurement and Analysis
- Atmospheric aerosols and clouds
- Solar and Space Plasma Dynamics
- Geomagnetism and Paleomagnetism Studies
- Soil Moisture and Remote Sensing
- Spacecraft and Cryogenic Technologies
- Aerospace Engineering and Energy Systems
- Radiomics and Machine Learning in Medical Imaging
- Ocean Waves and Remote Sensing
- Tropical and Extratropical Cyclones Research
- Climate variability and models
- Astro and Planetary Science
Institute of Space Sciences
2016-2025
Consejo Superior de Investigaciones Científicas
2020-2025
Institut d'Estudis Espacials de Catalunya
2019-2025
Jet Propulsion Laboratory
2018-2020
Abstract This study presents, for the first time ever, occulting signals of Global Navigation Satellite Systems (GNSSs) acquired at two polarizations from a Low Earth Orbiter, and it shows that they sense heavy precipitation. The data sets are obtained early stages Radio Occultation Heavy Precipitation experiment aboard PAZ satellite, launched in February 2018 activated May 2018. Preliminary calibration algorithms applied to remove other systematic effects, resulting vertical profiles...
Abstract. A novel radio occultation (RO) technique, polarimetric RO (PRO), has recently been developed to measure differential phase shift together with traditional products such as temperature and moisture. PRO observations have shown be associated the vertical structure of cloud hydrometeors. With this unique measurement capability, soundings could potentially used evaluate model microphysics. This study compared WRF simulations three typhoon cases in 2019 2021, initialized ERA5 NCEP FNL...
Abstract. Polarimetric radio occultations (PROs) of the Global Navigation Satellite System are able to characterize precipitation structure and intensity. Prior studies have shown relationship between water vapor pressure columns, known as “precipitation pickup.” Less is about vertical distributions temperature moisture globally within precipitating scenes measured from space. This work uses cluster analysis PRO explore how – combined into refractivity relate variables. We evaluate ability...
Abstract Global Navigation Satellite System (GNSS) Polarimetric Radio Occultations (PRO) is an extension of the traditional Occultation (RO) technique that collects two linear and orthogonal polarization components occulting GNSS signals in order to retrieve precipitation information along with standard RO thermodynamic products. This has already been demonstrated ROHP experiment aboard PAZ satellite, a large platform launched 2018. In early 2023, Spire first three nanosatellites capable...
The Polarimetric Radio Occultation (PRO) technique involves tracking signals emitted by navigation satellites (GPS, Galileo, Beidou…) from a Low Earth Orbit (LEO) satellite as it rises or sets behind the Earth’s limb. This method extends capabilities of standard (RO) employing two orthogonal linear polarizations—horizontal (H) and vertical (V)—thereby providing relevant information about atmospheric hydrometeors. Furthermore, traditional RO products...
A Global Navigation Satellite System (GNSS) radio occultation (RO) experiment is being accommodated in the Spanish low Earth orbiter for Observation PAZ. The RO payload will provide globally distributed vertical thermodynamic profiles of atmosphere suitable to be assimilated into weather numerical prediction models. Ground Segment services U.S. National Oceanographic and Atmospheric Administration standard-RO processing by University Corporation Research (USA) available under best effort...
The Global Precipitation Measurement (GPM) Dual-Frequency Radar (DPR) (Ku- and Ka-band, or 14 35 GHz) provides the capability to resolve precipitation structure under moderate heavy conditions. In this manuscript, use of near-coincident observations between GPM CloudSat Profiling (CPR) (W-band, 94 are demonstrated extend representing light rain cold-season from DPR passive microwave constellation sensors. These unique triple-frequency data have opened up applications related precipitation,...
© 2024 American Meteorological Society. This is an Author Accepted Manuscript distributed under the terms of default AMS reuse license. For information regarding and general copyright information, consult Copyright Policy (www.ametsoc.org/PUBSReuseLicenses). Corresponding author: F. Joseph Turk, jturk@jpl.nasa.gov
This study presents a new retrieval approach for obtaining wind speeds from CyGNSS level-1 observables. Unlike other existing approaches, (1) this one is variational technique that based on physical forward model, (2) it uses uncalibrated bin raw counts observables, (3) the geophysical information content comes only pixel of broader delay-Doppler map, finest achievable resolution in products over sea, and (4) calibrates them against track-wise polynomial adjustments to background numerical...
There is currently a gap in satellite observations of the moisture structure during heavy precipitation conditions, since infrared and microwave sounders cannot sense water-vapour near surface presence intense precipitation. Conversely, Global Navigation Satellite System (GNSS) radio occultations (RO) can profile with high precision vertical resolution, but indicate directly. Polarimetric RO (PRO) measurements have been proposed as method to characterize rain GNSS RO, by measuring...
The sensitivity of PAZ's Polarimetric Radio Occultation (PRO) observations to horizontally oriented frozen particles is assessed using coincident measurements from the Global Precipitation Measurement (GPM) core satellite's radiometer GPM Microwave Imager (GMI) and ancillary information Cloudsat. difference between horizontal vertical polarizations GMI observed radiances at 166 GHz, indicative particles, compared with PAZ differential phase shift observations. A clear positive trend...
Abstract Observationally, a major source of uncertainty in evaluation climate models arises from the difficulty obtaining globally distributed, fine scale profiles temperature, pressure and water vapor, that probe through convective precipitating clouds, boundary layer to upper levels free troposphere. In this manuscript, two-year analysis data Radio Occultations Heavy Precipitation (ROHP) polarimetric RO demonstration mission onboard Spanish PAZ spacecraft is presented. ROHP measures...
Abstract. This study describes the first experimental observations showing that hydrometeors induce polarimetric signatures in global navigation satellite system (GNSS) signals. evidence is relevant to PAZ low Earth orbiter, which will test concept and applications of GNSS radio occultation (RO) (i.e. ROs obtained with a dual-polarization antenna). A ground field campaign was carried out preparation for verify theoretical sensitivity studies on this (Cardellach et al., 2015). The main aim...
Currently, it remains a challenge to effectively monitor areas experiencing intense precipitation and the associated atmospheric conditions on global scale. This arises due limitations both active passive remote sensing methods. Apart from lack of observations in areas, quality some deteriorates when heavy is present, making difficult obtain highly accurate measurements thermodynamic parameters driving these weather events. However, there promising solution form Global Navigation Satellite...
Abstract. Polarimetric Radio Occultations (PRO) represent an augmentation of the standard Occultation (RO) technique that provides precipitation and clouds vertical information along with thermodynamic products. A combined dataset contains both PRO observable RO retrievals, resPrf, has been developed aim to foster use these unique observations fully exploit scientific implication having about cloud structures intrinsically collocated state atmosphere. This manuscript describes such detailed...
Abstract. This paper presents the calibration and validation studies for Radio Occultation Heavy Precipitation experiment aboard PAZ satellite. These studies, necessary to assess characterize noise level robustness of differential phase shift (ΔΦ) observable polarimetric radio occultations (PROs), confirm good performance capability this technique in sensing precipitation. It is shown how all predicted effects that could have an impact into PRO observables (e.g., effect metallic structures...
The climate and weather forecast predictive capability for precipitation intensity is limited by gaps in the understanding of basic cloud-convective processes. Currently, a better process lacks observational constraints, due to difficulty obtaining accurate, vertically resolved pressure, temperature, water vapor structure inside near convective clouds. This manuscript describes potential advantages collecting sequential radio occultation (RO) observations from constellation closely spaced...
Abstract. The Radio Occultations and Heavy Precipitation (ROHP) experiment aboard the Spanish PAZ satellite was deployed in 2018 with objective of demonstrating ability polarimetric radio occultation measurement (PRO) concept detecting rain (liquid-phase precipitation). Analysis these data has also demonstrated PRO to detect horizontally oriented frozen-phase precipitation. To verify observations, a global climatological comparison is performed using CloudSat (94 GHz) radar as reference for...
The Global Navigation Satellite System (GNSS) polarimetric effects on the propagation of radio occultations (ROs) are studied here. Polarimetric ROs have been suggested as a technique to detect heavy rain events using opportunity signals from GNSS satellites. systematic that hinder isolation precipitation information described and their significance separability assessed. A method relies received phase difference between polarizations is presented. dual-frequency extension capable completely...
Abstract. A positive bias at heights between 3 and 8 km has been observed when comparing the radio-occultation (RO)-retrieved refractivity with that of meteorological analyses reanalyses in cases where heavy precipitation is present. The effect RO retrievals investigated as a potential cause bias, using measurements interpolated into actual three-dimensional ray paths to calculate excess phase induced by precipitation. study consisted such extra delay removed from measurement it not. results...
Accurate representation of cloud microphysical processes in numerical weather and climate models has proven challenging, part because the highly specialized instrumentation required for diagnosing errors simulated distributions hydrometeors. Global Navigation Satellite System (GNSS) polarimetric radio occultation (PRO) is a promising new technique that sensitive to hydrometeors potential help address these challenges by providing observations are relevant larger spatial scales, especially if...
Abstract. This manuscript presents the calibration and validation studies for Radio Occultations Heavy Precipitation experiment aboard PAZ satellite. These studies, necessary to assess characterize noise level robustness of ΔΦ observable Polarimetric (PRO), confirm good performance capability this technique in sensing precipitation. It is shown how all predicted effects that could have an impact into PRO observables (e.g. effect metallic structures nearby antenna, Faraday Rotation at...
Abstract Following the successful launch of Spanish PAZ mission proof concept experiment “Radio Occultation and Heavy Precipitation with ” (ROHP- ) started operating in May 2018. The ROHP- observations demonstrated that precise measurements phase shift between horizontal vertical polarizations from Global Navigation Satellite System (GNSS) L-band signals are sensitive to oriented hydrometeors along ray paths. While this differential measurement as a function time has proven very useful,...
A new rain measurement concept will be tested aboard the Low Earth Orbiter (LEO) PAZ, (launch planned for 2016). It aims to detect and quantify intense using polarimetric phase-shift induced by droplets along GNSS radio occultation's rays. Due integral nature of measurement, intensity extension are difficult untangle. The work presented here applies tomographic techniques reconstruct precipitation structure from integrated measurement. technique shows capability retrieving simple structures...
Abstract Analyses of the thermodynamics precipitating clouds are mostly based on localized in situ campaigns or, more globally, weather analyses and reanalyses. This work presents a comparison to satellite observations radiometeorological method that shows how layers inside coincide with underestimates amount water vapor. The thermodynamic information from is extracted using observed radio occultation (RO) refractivity profiles without requiring analysis input, thus reducing analysis‐induced...