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The SMOS, and SMAP retrievals are not only influenced by soil moisture, vegetation but also highly sensitive to surface roughness. The current retrieval algorithms use roughness models and parameterization developed at field scale to estimate soil moisture at satellite footprint. These models ignored large scale roughness features due to differences in elevation, concavity etc., observed within the...
NASA's Airborne Microwave Observatory of Sub-canopy and Subsurface (AirMOSS) project, with more than 1200 flight hours of a P-band synthetic aperture radar (SAR), was completed in September 2015. The goal of this mission was to improve the estimates of the North American Net Ecosystem Exchange (NEE) through providing high-resolution observations of root zone soil moisture (RZSM) over nine regions...
This study investigates the polarimetric decomposition of multi-angular polarimetric UAVSAR (Uninhabited Aerial Vehicle Synthetic Aperture Radar) time series, for soil moisture retrieval over the vegetated agricultural fields. The volume scattering component was respectively removed from different incidence angle data. The resulting multiple dominant surface or dihedral scattering components were...
It has been shown that the global positioning system (GPS) signal scattering for the like-wise polarization (right-hand to right-hand circular polarization (RR)) yielded 20–30 dB lower level than that for the counter-wise one (left-hand to right-hand circular polarization (LR)), thus the counter-wise polarization was preferred in application to remote sensing by GPS signal scattering. In this paper...
Plant's photosynthetic activity and transpiration are constrained by the amount of water available to them through roots (i.e. root zone soil moisture) as well as nutrient and atmospheric conditions. Therefore, to better understand the response of plants to different stress conditions, knowledge of root zone soil moisture is essential. However, current global satellites dedicated to soil moisture...
Radar range echoes of the UHF radar souder is presented to explore the lunar surface in the permanently shdaowed polar regions (PSR). Based on radiative transfer with the Euler-angles transformation, the temporal Mueller matrix to take account of all scattering mechanisms of undulated rough surface and underlying scatter media is derived. It is applied to invert the dielectric constant of PSR region...
For the multi-frequency sensors such as AMSR-E and AMSR-2, the verification results of QP model with dual-channel algorithm (QDCA) soil moisture product are not good in Genhe area. In order to obtain the long time series of soil moisture datasets and improve the accuracy of QDCA in China, this paper improved the vegetation correction method on current QDCA soil moisture algorithm. This paper incorporated...
The component soil moisture within one mixed-pixel is important for predicting soil moisture contents in eco-hydrological research in arid and semi-arid regions. The multi-angular observations of passive microwave remote sensing provide the possibility to derive mixed-pixel component soil moisture. In this study, a field experiment was carried out using a truck-mounted multi-frequency microwave radiometer...
The acquisition of area-averaged evapotranspiration (ET) over complex land surfaces is crucial to develop ET estimation models and improve the accuracy of remote sensing ET products. The Heihe Watershed Allied Telemetry Experimental Research (HiWATER) flux matrix located in Ejina oasis provided a unique opportunity to apply an aggregation scheme for area-averaged fluxes. Based on HiWATER flux matrix...
The Global Precipitation Measurement (GPM) mission Core Observatory is equipped with a dual-frequency precipitation radar (DPR) operating at frequency channel of 13.6 GHz (Ku-band) and 35.5 GHz (Ka-band). GPM-DPR's simultaneous observations at these two frequencies are compared and cross validated against measurements from ground based dual polarized radar located at Dallas — Fort Worth, USA and operated...
A new speckle reduction algorithm is presented in this paper to improve the visualization of synthetic aperture radar (SAR) images. The algorithm contains two steps. First, we propose a speckle reduction filter. This filter use different smoothing effect according to scene of sub-window. So it can maintain the details while noise suppression. Second, we propose a method to enhance the details. We...
To evaluate the performance of the Orbiting Carbon Observatory 2 (OCO-2) Lite File Product (Lite_FP) which has the highest amount of data and the highest utilization efficiency among the three products of OCO-2, we compared global atmospheric CO2 observations for 20 months (September 2014 to April 2016) with GGG2014 data from the Total Carbon Column Observing Network (TCCON). We considered the latitude...
Emerging technologies such as IoT(Internet of Things) and UAS(Unmanned Aircraft Systems) enable new observing capabilities. In particular, infrared sensing of CO2 and surface temperature with satellite infrared radiometers have been operationally used since the 1970s for atmospheric soundings, and sea/land surface temperatures, such as with NOAA's HIRS/AVHRR radiometers. Recent advances also allow...
SAR-based image thresholding can be used to detect and map open water body locations and extents. The selection of a reasonable and consistent thresholding approach can be challenging across many complex landcover types. Besides SAR acquisition characteristics, environmental factors (e.g., emergent vegetation and wind-induced roughening of the water) can cause water locally increased backscatter relative...
Linking the terrestrial water cycles, carbon cycles and energy exchange, evapotranspiration (ET), which combines the surface evaporation and plant transpiration, is a key land surface parameter in water and heat balance of land, lake or river surface, and is central to earth system science. In this study, based on the MERRA reanalysis dataset and MODIS NDVI and LAI product, a support vector machine...
This paper proposes a fast, high-precision of multi-scale C-V model (M-C-V) method for coastline extraction with SAR imagery. (1) The multi-scale technology to the traditional C-V model is introduced that reduces the image size and obtains a series of images under different spatial resolution; (2) Low-pass filter polishes small scale image sequence is used, which is easy to form the image sequence...
Aiming to solve the limitation of coarse spatial resolution of passive microwave soil moisture product, a soil moisture relationship model based on random forest method was constructed with land surface temperature (LST), normalized difference vegetation index (NDVI), and surface albedo (ALB) from MODIS products and surface soil moisture (SSM) from AMSR-E soil moisture product in the study area at...
This work presents Land Surface Temperature (LST) retrieval from Landsat-8 data using the Generalized Split-Window (GSW) algorithm. First, radiative transfer modeling experiments were conducted using the moderate spectral resolution atmospheric transmittance algorithm and computer model (MODTRAN) 4.0 fed with SeeBor V5.0 atmospheric profile database to simulate the brightness temperatures in Thermal...
Ground Penetrating Radar (GPR) is one of the most popular subsurface sensing devices and has a wide range of applications, e.g., buried object detection. In this study, Least Mean Square (LMS) approach is used to solve buried object detection problem. Point of interest located in each depth location of 2D GPR signal is estimated from previous samples by using separate 1D LMS algorithms and prediction...
This paper presents a cosine-based back-projection(CBP) algorithm for ground penetrating radar(GPR) imaging to detect underground holes. Compared with the classic back-projection imaging algorithm, the CBP algorithm provides a better performance due to better effect of clutter suppression. In the proposed algorithm, a cosine-based measure function is established to describe the similar feature between...
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