Crevasses are formed by glacier movement and the stresses within ice. Knowledge of crevasses’ distribution is critical for understanding ice shelf stability. In this study, we propose an automated crevasse extraction framework based on Sentinel-1 SAR imagery improved U-Net network. The spatial crevasses Antarctic shelves in 2020 was mapped with a resolution ~40 m, characteristics Nickerson Ice Shelf, Jelbart Amery Thwaites Glacier, Shackleton Shelf were analyzed. results indicated accuracy...

Land use/cover change (LUCC) has a crucial influence on ecosystem function, environmental and decision support. Rapid precise monitoring of land information is essential for utilization management resources. The objectives this study were to monitor Guangzhou China from 1986 2018 using remotely sensed data, analyze the correlation between artificial surface expansion gross domestic product (GDP) growth. Supervised classification was performed Random Forest classifier, overall accuracy (OA)...

An important condition for urban studies is quantitative acquisition of spatial information, e.g., three-dimensional (3-D) structural parameters buildings. Synthetic aperture radar tomography (TomoSAR) provides scene reflectivity estimation along azimuth, range, and elevation coordinates. For a small number acquisitions their irregular spacing, however, the common Fourier-based 3-D SAR-focusing approaches, even compressive sensing (CS)-based methods, bring about some imaging quality...

ABSTRACT Antarctica's response to climate change varies greatly both spatially and temporally. Surface melting impacts mass balance also lowers surface albedo. We use a 43-year record (from 1978 2020) of Antarctic snow melt seasons from space-borne microwave radiometers with machine-learning algorithm show that the onset end season are being delayed. Granger-causality analysis shows is delayed due increased heat flux ocean atmosphere at minimum sea-ice extent warming oceans. Melt...

The surface snowmelt on ice sheets in polar areas (ice of Greenland and Antarctica) is not only an important sensitive factor global climate change, but also a key that controls the climate. Spaceborne earth observation provides efficient means measuring dynamics. Based improved sheet detection algorithm several new proposed parameters for detecting dynamics were monitored analyzed by using spaceborne microwave radiometer datasets from 1978 to 2014. Our results show change intensity...

Monitoring ice-sheet snowmelt is fundamental to understanding global climate change. A simple and automated detection process critical the establishment of an monitoring system. However, different methods are based on a variety thresholding schemes using melt signals for dry wet snow; these complicate regular operation monitoring. We propose signal method developed derived from cross-gradient polarization ratio over Greenland wavelet transformation-based Antarctica. Initial results indicate...

Synthetic aperture radar tomography (TomoSAR) has been proven to be a useful way reconstruct vertical structure over forest areas with P-band images, on account of its three-dimensional imaging ability. In the case small number non-uniformly distributed acquisitions, compressive sensing (CS) is generally adopted in TomoSAR. However, performance CS depends selected hyperparameter, which closely related noise pixel. this paper, overcome limitation, we propose sparse iterative covariance-based...

Big Earth Data—big data associated with sciences—can potentially revolutionize research on climate change, sustainable development, and other issues of global concern. For example, analyzing massive amounts satellite imagery polar environments, which are sensitive to the effects provides insights into trends. This study proposes a method use Data explore changes in snowmelt over Antarctic ice sheet from 1979 2016. The uses Zernike moments observe melt area Antarctica Mann-Kendall test detect...

Microwave scatterometer measurements have been used in monitoring the snowmelt characteristics of Greenland ice sheet. The melt signals and appropriate threshold scheme are critical to detection ice-sheet snowmelt. We propose a detecting method based on diurnal variation polarization ratio (DVPR) time series. implement algorithm detect sheet using Quick Scatterometer (QuikSCAT) data. Moreover, results DVPR compared with two other snowmelts validated by automatic weather station (AWS) data...

With the implementation processes of strategies such as Guangdong-Hong Kong-Macau Greater Bay Area’s coordinated development and “Belt Road Initiative” initiative, planning policies had produced a significant influence on land use distributions in Guangzhou. In this paper, we employ nighttime light (NTL) information proxy indicator gross domestic product(GDP), future simulation model (FLUS) to simulate patterns Guangzhou from 2015 2018 2035 by incorporating policies. The results show that:...

Climate change is a cause of the expansion snowmelt phenomena in Antarctic, and shifts position wet dry snow lines have been considered as good indicators climate changes. The impacts are observable by delineation significant glacier zones. principal limitation current zone classification methods synthetic aperture radar (SAR) image that it difficult to discriminate dry-snow wet-snow zones using only single-polarimetric backscattering intensity. This study tried solve problem polarimetric...

Although satellite gravity gradient data plays a great role in determining short-wavelength part of static field model, accuracy the long-wavelength model recovered by them are poor, which leads to only few applications time-variable investigation. The reason is that some factors limit using data, including observations, measurement bandwidth (MBW) gradiometer, inclination, etc. This paper aims at analyzing influence these limitations on recovery and discusses possibility detection...

The three-dimensional (3-D) structure of forests, especially the vertical structure, is an important parameter forest ecosystem modeling for monitoring ecological change. Synthetic aperture radar tomography (TomoSAR) provides scene reflectivity estimation vegetation along elevation coordinates. Due to advantages super-resolution imaging and a small number measurements, distribution compressive sensing (DCS) inversion techniques polarimetric SAR were successfully developed applied. This paper...

The satellite gravity mission GRACE(-FO) has not yet reached its designed baseline accuracy. Previous studies demonstrated that the deficiency in sensor system or related signal processing might be responsible, which turn motivates us to keep revising data processing, typically spacecraft’s attitude. Many efforts past have been made enhance attitude modeling for GRACE, instance, latest release reprocesses by fusing angular acceleration with star camera/tracker (SC) measurements, helps reduce...

We developed a new method to monitor the ice sheet melting periods with passive microwave measurements. Our combined original brightness temperature time series those simulated by simulation software package TIMESAT in order obtain similar behaviour, but less noise. A generalized Gaussian model was used classify pixels wet and dry snow. Based on steep rise drop of series, we detected onset end Antarctic from 1988 2008. The results indicated that whole experienced deceasing during 20 years....

When using the dynamic approach to recover time-variable gravity field, reference orbit generated by perturbation model and non-conservative force observed from accelerometer should be introduced at first, then observation equations of residual range rate are established. This introduces a error instrument noise. Thus, there low-frequency errors in rate. Currently, most studies only focus on rate, neglecting influence orbit. Therefore, under condition noise including constant term 1CPR term,...

Synthetic aperture radar tomography (TomoSAR) has been proved to be able reconstruct 3D reflectance of volumetric targets, such as vegetation. It gives us an opportunity and a possibility monitor forest pest through extracting structural information the forest. In this paper, TomoSAR echo data normal are simulated with PolSAR Pro at L-band before after respectively, analysing physical geometry backscattering properties disease. Then, method used for structure is presented discussed. Finally,...

The electrostatic gravity gradiometer carried by the Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite is affected accelerometer noise other factors; hence, observation data present complex error characteristics in low-frequency domain. accuracy of recovered will be directly design filters based on gradient data. In this study, applicability various to different errors evaluated, such as 1/f orbital frequency errors. experimental results show that cascade filter...

Synthetic aperture radar tomography (TomoSAR) provides a reflectivity estimation of ground objects along elevation coordinates by using multi-baseline acquisitions on the same targets. Recently, It is well known that sparse reconstruction-based TomoSAR has been widely used in inversion since it was proposed for advantages superresolution imaging and small number measurements. In this paper, two different method: SPICE (Sparse Iterative Covariance-based Estimation)-based Compressive sensing...