A5008477924- Precipitation Measurement and Analysis
- Meteorological Phenomena and Simulations
- Soil Moisture and Remote Sensing
- Geophysics and Gravity Measurements
- Methane Hydrates and Related Phenomena
- Ionosphere and magnetosphere dynamics
- Climate variability and models
- COVID-19 epidemiological studies
- Advanced Vision and Imaging
- Atmospheric aerosols and clouds
- Image and Video Stabilization
- GNSS positioning and interference
- Ocean Waves and Remote Sensing
- Cryospheric studies and observations
- COVID-19 Pandemic Impacts
- Archaeology and Historical Studies
- Optical Systems and Laser Technology
- Advanced Decision-Making Techniques
- SARS-CoV-2 and COVID-19 Research
- Fire effects on ecosystems
- COVID-19 diagnosis using AI
- Health disparities and outcomes
- Advanced Measurement and Detection Methods
- Historical and Linguistic Studies
- Tropical and Extratropical Cyclones Research
Flame University
2021-2022
Indian Space Research Organisation
2012-2019
Earth System Science Interdisciplinary Center
2009-2012
University of Maryland, College Park
2009-2012
University of Central Florida
2007-2012
Passive microwave (PMW) satellite-based precipitation over land algorithms rely on physical models to define the most appropriate channel combinations use in retrieval, yet typically require considerable empirical adaptation of model for with satellite measurements. Although low-frequency channels are better suited measure emission due liquid associated rain, techniques date high-frequency, scattering-based schemes since methods limited highly variable surface background, whose radiometric...
Abstract This paper describes improvements to the Tropical Rainfall Measurement Mission (TRMM) Microwave Imager (TMI) land rainfall algorithm in version 7 (v7) of TRMM data products. The correlations between rain rates and TMI 85-GHz brightness temperatures (Tb) for convective stratiform are generated using years collocated precipitation radar (PR) data. estimating ratio is also modified. highlights both v7 continuing problems with retrievals. It demonstrated that proposed changes...
A technique for comparing spaceborne microwave radiometer brightness temperatures (Tb) is described in the context of upcoming National Aeronautics and Space Administration Global Precipitation Measurement (GPM) mission. The GPM mission strategy to measure precipitation globally with high temporal resolution by using a constellation satellite radiometers logically united core satellite, which will be non-sun-synchronous medium inclination orbit. usefulness combined product depends on...
Recent intersatellite radiometric comparisons of the Tropical Rainfall Measurement Mission Microwave Imager (TMI) with polar orbiting satellite radiometer data and modeled clear-sky radiances have uncovered a time-variable bias in TMI brightness temperatures. The is consistent source that generally cools during orbit night warms sunlight exposure. likely primary has been identified as slightly emissive parabolic antenna reflector. This paper presents an empirical temperature correction to...
Abstract This paper studies climatically important low clouds (with cloud top below 680 hPa) over the Arabian Sea using Kalpana‐1 satellite data and International Satellite Cloud Climatology Project data. Characteristics possible mechanisms behind low‐cloud formation in summer monsoon season are presented. The dominant lower tropospheric circulation during is low‐level jet (LLJ). Low predominantly found on exit portion of LLJ with decelerating winds. We postulate that moisture carried by...
This letter presents an empirical correction for a time-varying radiometric calibration error (2.5 K peak to peak) present in the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) 1B11 calibrated brightness temperature (T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">b</sub> ) data product. The T is modeled as function of spacecraft orbit position and Sun elevation above plane (solar beta angle) based on observed systematic...
This study analyzes relationships between lightning flash rate, radar reflectivity factor (reflectivity), and passive microwave brightness temperature (Tb) for convective stratiform precipitation over land using multiyear data from the Tropical Rainfall Measuring Mission (TRMM) satellite. A new index (CSI (an estimate of areal fraction)) TRMM Microwave Imager (TMI) is developed analysis. Four years TMI, Lightning Imaging Sensor (LIS), Precipitation Radar (PR) (2002–2005) are colocated...
In this study, we present a mean-of-posteriors Bayesian estimation technique for improving rain contaminated wind speed estimates from the SCATSAT-1 scatterometer, particularly at low and moderate speeds. The performance of algorithm is assessed using Version 1.1.3 data, collocated National Centre Medium Range Weather Forecasting (NCMRWF) analysis winds, measurements Advanced Scatterometer (ASCAT), buoy 6-month period April to September 2018. validation results show reduction in bias 2.6...
NASAs Global Precipitation Measurement (GPM) Mission will consist of a constellation cooperative satellites with microwave radiometers to make global rainfall measurements. It is crucial that the brightness temperature (T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">b</sub> ) measurements from these satellite be consistent each other. This may achieved by radiometric inter-comparison near-simultaneous collocated oceanic pairs satellites. In...
Abstract A prototype generic, unified land surface classification and screening methodology for Global Precipitation Measurement (GPM)-era microwave precipitation retrieval algorithms by using ancillary datasets is developed. As an alternative to the current radiometer-determined approach, new shown be promising in improving rain detection providing better surface-cover-type information. The early scheme was applied version of Goddard profiling algorithm that used Tropical Rainfall Measuring...
This study explores the application of deep learning for rainfall prediction, leveraging Spinning Enhanced Visible and Infrared Imager (SEVIRI) High rate information transmission (HRIT) data as input Operational Program on Exchange weather RAdar (OPERA) ground-radar reflectivity ground truth. We use mean 4 InfraRed frequency channels input. The radiance images are forecasted up to hours into future using a dense optical flow algorithm. A conditional generative adversarial network (GAN) model...
This study describes the process of deriving integrated water vapor (IWV) from (a) a set 18 GPS receivers that were installed at different airports across India and (b) pair located in Ahmedabad situated around 8 km apart. The Zenith Tropospheric Delay was estimated observations using GAMIT software. Further, IWV ZTD values surface temperature pressure ERA-I reanalysis as additional inputs. estimates for 1 year—March 2013 to February 2014—were compared with ECMWF Reanalysis Interim (ERA-I)...
In this manuscript, we present an analysis of COVID-19 infection incidence in the Indian state Tamil Nadu. We used seroprevalence survey data along with fatality reports from a six-month period (1 June 2020 to 30 November 2020) estimate age- and sex-specific rates (IFR) for these IFRs new infections occurring daily using published by Government found that estimates second COVID wave Nadu were broadly consistent surveys. Further, propose composite statistical model pairs k-nearest neighbours...
This paper describes an empirical correction for a time-varying radiometric calibration error present in the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI). The Tb is modeled as function of spacecraft orbit position and solar angles based on observed systematic differences between TMI 10 GHz vertically polarized (10V) channel oceanic Tb's compared to radiative transfer model with collocated numerical weather environmental parameters. technique will be implemented Version 7...
Launch pads have many cameras that record footage of the space vehicles and surrounding areas during launches. The from these is not stable due to camera vibration ignition lift-off rocket thrust. Aside making difficult watch, instabilities in background make it harder for viewers notice any debris may fallen vehicle, or other foreign objects. In this paper, we present a method automatic stabilization detection such footage. We first stabilize by registering consecutive frames subsequently...