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In this paper we discuss a polarimateric calibration technique applied on the Soil Moisture Active Passive (SMAP) L-band radiometer. We take advantage of the SMAP antenna rotation and varying incidence angle during pitch maneuvers performed by the spacecraft for periodic cold-sky calibration. We present initial comparisons between the polarization corrected ocean signal at various incidence angles...
The Global Precipitation Measurement (GPM) mission is a constellation-based satellite mission designed to produce unified precipitation retrievals from a constellation of available microwave radiometers [1]. The core observatory builds on the successes of the Tropical Rainfall Measuring Mission (TRMM) providing advances in satellite precipitation monitoring including a dual-frequency radar, increased...
This study inter-compares observed Ku-, X- and C-band microwave backscatter from saline 14 cm, 8 cm, and 4 cm snow covers on smooth first-year sea ice. A surface-borne multi-frequency (Ku-, X- and C-bands) polarimetric microwave scatterometer system is used near-coincident with in situ snow geophysical measurements. The study investigated differences in scatterometer observations for all three frequencies,...
This paper presents a rain rate retrieval algorithm for tropical cyclones (TCs) using passive microwave Fengyun-3B (FY-3B) MWRI brightness temperature (TB). Channel 18.7 and 36.5GHz of FY-3B/MWRI are used to implement retrieval algorithm. Two databases are constructed: one is 15,153 matchups of MWRI TB and NSIDC global swath ocean products for rain rate retrieving and another databset of 5,093 matchups...
Monitoring freeze-thaw (FT) transitions in high latitude regions are critical to enhancing our knowledge about the prediction of biogeochemical transitions, carbon dynamics, climate change, and impacts on boreal-arctic ecosystems. Since land surface emissivity depends primarily on the surface characteristics, it would contains valuable information about the surface, especially regarding freeze and...
Wideband autocorrelation radiometry (WiBAR) is a new method to remotely sense the microwave propagation time τdelay of multi-path microwave emission of low loss layered surfaces such as dry snowpack and freshwater lake icepack. The microwave propagation time τdelay through the pack yields a measure of its vertical extent; thus, this technique is a direct measurement of depth. This technique is inherently...
The Tropical Rainfall Measurements Mission (TRMM) Microwave Imager (TMI), has served as the radiometric transfer standard for the TRMM constellation radiometers for over 17 years. The final legacy processing for the TMI is in progress for the TMI 1B11 Tb Version-8 (V8), which will be released in late 2017. This paper presents a radiometric evaluation of the Tb differences between the current TMI Version-7...
In this paper we discuss the design and development of the Radiometer Digital Backend (RDB) of the CubeSat Radiometer Radio Frequency Interference Technology (CubeRRT) validation mission. We present a brief introduction of the mission and the Radio Frequency Interference (RFI) detection and mitigation algorithm. The digital backend developed for the CubeSat is presented. The digital backend has unique...
In this paper, we study the effect of layered snow in alpine regions on microwave emission at Ku and Ka bands, using both experimental data and model simulations. A recent implementation of the multi-layer dense-medium radiative transfer model (DMRT) under the quasi-crystalline approximation (ML-QCA) was used to account for the effects of snow layers on the emission from dry snow covers. Model simulation...
SnowEx is a multi-year airborne snow campaign with the primary goal of addressing the question: How much water is stored in Earth's terrestrial snow-covered regions? Year 1 (2016–17) focused on the distribution of snow-water equivalent (SWE) and the snow energy balance in a forested environment. The year 1 primary site was Grand Mesa and the secondary site was the Senator Beck Basin, both in western,...
Soil moisture at high spatial resolution is required for various land processes related studies. However, currently the resolution of passive microwave retrieved soil moisture is low. To solve this problem, a soil moisture disaggregation algorithm based on thermal inertia relationship between daily temperature change and average soil moisture modulated by vegetation conditions has been formulated...
The advanced microwave radiometer (AMR) is a critical payload on the recently launched Jason-3 mission, designed to provide the electrical range delay of the radar altimeter signal due to tropospheric water vapor and cloud liquid water [1]. The errors in the wet tropospheric path delay measurements have a direct impact on the record of global mean sea level (GMSL) and could lead to uncertainty in...
Tracking the radiometer calibration stability is very important for climate monitoring radiometers as long term accuracy of observations is needed to create reliable climate models. This presentation discusses the advantages of 3-point onboard calibration techniques over 2-point methods to track radiometer calibration stability.
This paper outlines a technical approach to generate homogeneous warm scene binary mask: SHOWmask using microwave radiometer observations. The objective is to identify homogeneous desert scenes as targets in radiometric intercalibration of multi source multi-sensor systems. In the current paper a method is developed to generate mask on continental Australia using 10 GHz and 18 GHz Vertical and Horizontal...
The Hurricane Imaging Radiometer (HIRAD) is an experimental C-band airborne microwave radiometer developed by NASA Marshall Space Flight Center (MSFC) to provide hurricane's surface wind speed and rain rate. It is intended to expand the current NOAA and US Air Force hurricane surveillance capability by extending the operational Stepped Frequency Microwave Radiometer (SFMR) measurements to a wide-swath...
In this paper we summarize the effort to enhance the SMAP radiometer data. The applied technique is based on the Backus-Gilbert theory which is the classical estimation method in microwave radiometry. We show details of our implementation and summarize the assessment of the SMAP L1C_TB_E product.
Over land the vegetation canopy affects the microwave brightness temperature by emission, scattering and attenuation of surface soil emission. The questions addressed in this study are: 1) what is the transparency of the vegetation canopy for different biomes around the Globe at the low-frequency L-band?, 2) what is the seasonal amplitude of vegetation microwave optical depth for different biomes?,...
SAR knowledge base system is a comprehensive application platform for typical objects interpretation, which includes the database of microwave scattering models, backscattering measurement data and SAR image. The paper introduces the design of the whole system and gives a detail description for each database in the system. The comprehensive knowledge rules for SAR application is developed based on...
Water is essential to our planet Earth. Knowing when, where and how precipitation falls is crucial for understanding the linkages between the Earth's water and energy cycles and is extraordinarily important for sustaining life on our planet during climate change. The Global Precipitation Measurement (GPM) Core Observatory spacecraft launched February 27, 2014, is the anchor to the GPM international...
Retrievals of falling snow from space represent an important data set for understanding the Earth's atmospheric, hydrological, and energy cycles, especially during climate change. Estimates of falling snow must be captured to obtain the true global precipitation water cycle, snowfall accumulations are required for hydrological studies, and without knowledge of the frozen particles in clouds one cannot...
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