A review of methods for mitigating ionospheric artifacts in differential SAR interferometry

Interferometric synthetic aperture radar(InSAR)has been widely used to measure ground displacements related to geophysical and anthropic activities over the past three decades.Satellite SAR systems use microwave signals that interact with the ionosphere when they travel through it during the imaging processes.In this context,ionospheric variations can significantly contaminate SAR imagery,which in turn affects spaceborne InSAR measurements.This bias also leads to a decrease in the coherence and accuracy of InSAR measurements,especially for the low-frequency SAR systems.In this paper,we give an overview of the latest methods for mitigating the ionospheric contributions in InSAR,including Faraday rotation method,azimuth shift method,and range split-spectrum method,and only focus on the single pair of InSAR interferograms.The current challenges and future perspectives are outlined at the end of this paper.

Market-Led Development Under the Government Regulation in Urban Renewal:New Thoughts in the Urban Renewal Planning of Shenzhen in the 13th Five-Year Plan Period

An urban renewal mode of"government guidance and marketized operation"has been established in Shenzhen City according to the Measures for Urban Renewal in Shenzhen promulgated in 2009,which has formed a fully marketized renewal mode.However,from the development in the 12th Five-Year Plan period,it can be seen that a number of problems had emerged,such as an imbalanced renewal structure,overload of the maximum capacity,shortage of supporting facilities,and a lack of coordination,which had resulted in a low efficiency of the urban renewal.In view that little attention has been paid to planning coordination and public interests in the renewal process,some new thoughts,characterized by market-led and government-regulated balanced development,is proposed in the urban renewal planning of Shenzhen in the 13th Five-Year Plan period.It emphasizes that,while insisting on the principle of"market-led development,"the government should change its role from"active nonintervention"to"active regulation,"and adopt specific measures such as implementing renewal coordination planning,strengthening renewal zoning control,establishing early warning mechanisms,and improving the configuration standards for supporting facilities.

Spatial Humanities and Geo-computation for Social Sciences:Advances and Applications

Humanities and Social Sciences(HSS) are undergoing the transformation of spatialization and quantification. Geo-computation, with geoinformatics(including RS: Remote Sensing;GIS: Geographical Information System;GNSS: Global Navigation Satellite System), provides effective computational and spatialization methods and tools for HSS. Spatial Humanities and Geo-computation for Social Sciences(SH&GSS) is a field coupling geo-computation, and geoinformatics, with HSS. This special issue accepted a set of contributions highlighting recent advances in methodologies and applications of SH&GSS, which are related to sentiment spatial analysis from social media data, emotional change spatial analysis from news data, spatial analysis of social media related to COVID-19, crime spatiotemporal analysis, “double evaluation” for Land Use/Land Cover(LUCC), Specially Protected Natural Areas(SPNA) analysis, editing behavior analysis of Volunteered Geographic Information(VGI), electricity consumption anomaly detection, First and Last Mile Problem(FLMP) of public transport, and spatial interaction network analysis for crude oil trade network. Based on these related researches, we aim to present an overview of SH&GSS, and propose some future research directions for SH&HSS.

A data-driven method for feature assessment of historical settlements: A case study of Northeast Hubei, China

Formulating criteria for the assessment system of historic settlements is challenging due to complex geographical conditions and evaluator knowledge limitations, leading to subjective bias in the assessment process. To address this issue, this study proposes a data-driven method for assessing the features of historical settlements to carry out scientific and refined assessment and result analysis. Focusing on Northeast Hubei as the study area, this paper selects 3 historical settlements for validation and analysis. The results of the study show that (1) the data-driven method expands the methodological chain of assessing historical settlement features, and improves the assessment efficiency and scientificity of the assessment results by applying it to the new assessment process;(2) Through comparing the assessment results of the validation cases and data samples, the study establishes a comprehensive quantitative ranking of the assessment of historical settlement features and identifies the main influencing factors, thus enhancing the precision of result analysis;(3) By comparing the resulting assessment framework with the current assessment system, this study confirms the advantages of the proposed framework in identifying nuanced features and aligning with geographical conditions, thereby verifying the effectiveness of the data-driven method.

Activation of sulfite by ferric ion for the degradation of 2,4,6-tribromophenol with the addition of sulfite in batches

In this work,the removal of 2,4,6-tribromophenol(TBP)by ferric ion-activated sulfite[Fe(Ⅲ)/S(Ⅳ)]process was systematically investigated with determining the intermediate products and evaluating the influences of some operational conditions and water matrices.Our results show that batching addition of S(Ⅳ)benefits the S(Ⅳ)utilization efficiency and TBP removal,with SO_(4)^(-)being the primary reactive radical accounting for TBA degradation.The maximum TBP removal in the Fe(Ⅲ)/S(Ⅳ)process was observed at pH 4.0 and oxygen is essential in this process.With increasing Fe(Ⅲ)and S(Ⅳ)dosages from 0.05 and 0.1 mmol/L to 0.2 and 2.0 mmol/L,respectively,TBP removal followed trends of first increase then decrease.As the acute toxicity of the TBP solution was significantly reduced,the Fe(Ⅲ)/S(Ⅳ)process was believed to be a good choice in the treatment of TBP.

Impact of climate change on outdoor design conditions and implications to peak loads

This study exams the impact of climate change on outdoor design conditions and peak loads of five Chinese cities over the five major climate zones for the winter and summer conditions.The design dry-bulb temperature(DDBT)and the coincident wet-bulb temperature(CWBT)for two 30-year periods;1971–2000 and 1984–2013 were analysed.It was found that the DDBT of the period 1984–2013 was higher than that of the period 1971–2000,whereas the CWBT and the corresponding outdoor enthalpy of the period 1984–2013 was lower than that of 1971–2000 at the various cumulative frequencies.This trend implies that the increment in conductive heat gain through the building envelope due to the rising temperature can be lower than the reduction in fresh air load due to the lower outdoor air enthalpy.In this case,the peak cooling loads may reduce in all five cities under study,and this is different from the widely held view that global warming will lead to more stringent outdoor design conditions,higher peak cooling loads and larger heating,ventilation and air conditioning(HVAC)plants than the current or historical status.The implications to the“free-cooling”of HVAC systems with enthalpy control are discussed as well.

Key Issues and Compiling Approach of Accessibility Design Standards:A Case Study of Shenzhen

Both practice and research of accessible design in China are still in the initial stage,while the regulations and standardization of accessibility is taking shape.Under the framework of engineering standards based on instrumental rationality,to present the core value of humanism and to define the limitations of universal design in the standards are the key issues worth discussing continuously.By comparing the standards of China and abroad,this paper attempts to clarify the approaches for compiling the Accessibility Design Standards for Shenzhen.At the same time,it provides materials for discussion by showing the difficulties and assumptions during the compilation.

Enhanced Plasmonic-Induced Absorption Using a Cascade Scheme and Its Application as Refractive-Index Sensor

In this paper,we describe a new method to improve fast-light transmission,which uses cascades.We design a simple plasmonic device that enables plasmonic-induced absorption(PIA).It consists mainly of two parallel rectangular cavities.The numerical results simulated by using the finite element method(FEM)confirm its function.The corresponding group delay-time can reach-0.146 ps for the PIA window.Based on this result,we propose a cascade device,with the dual-rectangular cavity system as building block,to improve fast-light transmission even more.The results indicate that the cascade scheme can increase the group delay-time to-0.456 ps,which means the fast-light feature is substantially enhanced compared with the non-cascading approach.The effect of the distance between two cascade resonators and other structural parameters is also investigated.Finally,we use this design concept to build a refractive-index sensor with a sensitivity of 701 nm/RIU.