## Double Difference(双差)研究综述

Double Difference 双差 - Several vegetation indices (VIs) that focus on the spectral absorption of specific pigments were also tested: Normalized Difference Vegetation Indices (NDVI)-like ratios, Double Difference (DD)-like Ratios and Simple Ratios (SR).^{[1]}After that, the double differences between FY-3D MWTS and S-NPP ATMS and the theoretical observations in FY-3D MWTS channels are calculated.

^{[2]}We present three different schemes currently used to perform time-lapse inversions and compare these three methods: parallel, sequential and double difference.

^{[3]}Double differences (DD) seismic data are widely used to define elasticity distribution in the Earth's interior, and its variation in time.

^{[4]}Theoretical derivation and experimental verification indicate that the residual error in double difference of carrier phase measurements is proportional to the frequency deviation between PLs and the time deviation between receivers.

^{[5]}Multipath is one of the major error sources in high-precision GNSS positioning since it cannot be mitigated by double differences or corrected by empirical models.

^{[6]}The method of double difference is used to study the two rounds of purchase restriction policies, that is, in 2010, the first round of purchase restriction policies promulgated by local governments from 20111 and the second round of purchase restrictions promulgated in 2016 have their respective effects on residential commercial housing prices and price growth rates.

^{[7]}This study takes the anti-corruption campaign of the 18th CPC National Congress in China as an exogenous impact, using the data of heavy polluting enterprises in Shanghai and Shenzhen A-share manufacturing industry over 2008–2018 and the local level data to build a double difference (DID) model, which proves that anti-corruption can increase the quality of enterprise environmental information disclosure significantly.

^{[8]}Structural equation modeling (SEM) and double difference (DD) models were used to estimate pre-COVID-19 to initial COVID-19 pandemic period change (2019–2020) in cannabis use (monthly, weekly, daily) compared to 2018 to 2019 change to adjust for age-related effects.

^{[9]}The Ka-band hardware delay is calibrated by taking the double difference between ISL-centralized clock and the Multi-satellite Precise Orbit Determination clock.

^{[10]}In an effort to improve the reliability of multi-UAV relative navigation, an autonomous integrity monitoring method is proposed with a fusion of double differenced GNSS pseudoranges and Ultra Wide Band (UWB) ranging units.

^{[11]}A possible technique able to identify a GNSS spoofing attack is a dual-antenna method based on the analysis of the dispersion of the double differences (D3) of carrier-phase measurements.

^{[12]}This study takes the anti-corruption campaign of the 18th CPC National Congress in China as an exogenous impact build a double difference (DID) model, proving that anti-corruption can increase the quality of enterprise environmental information disclosure significantly.

^{[13]}Comparing the UCV results with precise point positioning (PPP), the root mean square (RMS) of the double differences for the TL-PTB, TL-USNO and USNO-PTB links are 0.

^{[14]}METHODS We compared data before and after policy implementation using double difference (DD) and triple difference (DDD) analyses.

^{[15]}The next method to relocate the event location is Double Difference (DD) algorithm.

^{[16]}Due to their locations, double difference is an appropriate method for their comparison and Aqua MODIS is one of good references.

^{[17]}Furthermore, TEHN GNSS observations are processed with CSRS-PPP, which is based on Precise Point Positioning (PPP) algorithm, and OPUS, which is based on double difference (DD) algorithm, to compare between these two techniques in terms of station velocity estimation and Earth deformation.

^{[18]}The main contribution of this paper is the derivation of measurement models for the raw GNSS measurements based on the MEKF error state, taking into account antenna lever arms and explicitly including the difference in measurement time between the receivers in the measurement model for double differenced carrier phase.

^{[19]}In multi-GNSS cases, two types of Double Difference (DD) ambiguity could be formed including an intra-system ambiguity and an inter-system ambiguity, which are identified as the DD ambiguity between satellites from the same and from different GNSS systems, respectively.

^{[20]}So, the common-clock is adopted in more than two GNSS receivers and the carrier phase single difference can get the same technical effects as the double difference.

^{[21]}More specifically, we investigate the utilization of GNSS observables in the following four categories for range measurement: 1) absolute positions of the vehicles provided by GNSS receivers; 2) raw code pseudoranges; 3) single difference of the raw code pseudoranges; and 4) double difference of the raw code pseudoranges.

^{[22]}Photoluminescence (PL) spectroscopy shows a double difference of relative intensity between shallow zinc vacancy state and deep zinc vacancy complex state in HRS and LRS.

^{[23]}The software used for data processing is MATLAB-based software and the raw data were processed using the double difference (DD) strategy to obtain optimal results.

^{[24]}In this work, an inter-comparison of their TEB measurement is performed using double difference with Aqua MODIS.

^{[25]}We establish the real signal model and the spoofing signal model, and the double differences model of pesudorange are also established.

^{[26]}The MODIS precision is also compared from the Gaussian regression of the double difference.

^{[27]}

还测试了几个关注特定色素光谱吸收的植被指数 (VI)：归一化差异植被指数 (NDVI) 类比率、双差 (DD) 类比率和简单比率 (SR)。

^{[1]}之后，计算了 FY-3D MWTS 和 S-NPP ATMS 之间的双差以及 FY-3D MWTS 通道中的理论观测值。

^{[2]}我们提出了目前用于执行延时反演的三种不同方案，并比较了这三种方法：并行、顺序和双差。

^{[3]}双差 (DD) 地震数据广泛用于定义地球内部的弹性分布及其随时间的变化。

^{[4]}理论推导和实验验证表明，载波相位测量的双差残差与PL之间的频率偏差和接收机之间的时间偏差成正比。

^{[5]}多径是高精度GNSS定位中的主要误差源之一，因为它不能通过双差来减轻或通过经验模型进行校正。

^{[6]}采用双差法 研究两轮限购政策，即2010年第一轮限购政策 地方政府于20111年和第二轮采购 2016年颁布的限制措施对住宅产生了各自的影响 商品房价格和价格增长率。

^{[7]}本研究以十八大反腐倡廉作为外生影响，利用2008-2018年沪深A股制造业重污染企业数据和地方层面数据构建双差异（DID）模型，证明反腐败可以显着提高企业环境信息披露质量。

^{[8]}与 2018 年至 2019 年相比，结构方程模型 (SEM) 和双差 (DD) 模型用于估计大麻使用（每月、每周、每天）从 COVID-19 前到最初 COVID-19 大流行期间的变化（2019-2020 年）改变以适应与年龄相关的影响。

^{[9]}Ka 波段硬件延迟通过采用 ISL 集中时钟和多卫星精确轨道确定时钟之间的双差来校准。

^{[10]}为了提高多无人机相对导航的可靠性，提出了一种融合双差分GNSS伪距和超宽带（UWB）测距单元的自主完整性监测方法。

^{[11]}一种能够识别 GNSS 欺骗攻击的可能技术是基于对载波相位测量的双差 (D3) 的色散分析的双天线方法。

^{[12]}本研究以十八大反腐倡廉为外生影响，构建双差（DID）模型，证明反腐能够显着提高企业环境信息披露质量。

^{[13]}将 UCV 结果与精确点定位 (PPP) 进行比较，TL-PTB、TL-USNO 和 USNO-PTB 链路的双差的均方根 (RMS) 为 0。

^{[14]}方法 我们使用双差 (DD) 和三差 (DDD) 分析比较了政策实施前后的数据。

^{[15]}重新定位事件位置的下一个方法是双差 (DD) 算法。

^{[16]}由于它们的位置，双差是比较合适的方法，Aqua MODIS 是很好的参考之一。

^{[17]}此外，TEHN GNSS 观测使用基于精确点定位 (PPP) 算法的 CSRS-PPP 和基于双差 (DD) 算法的 OPUS 处理，以比较这两种技术在站点速度估计方面的差异和地球变形。

^{[18]}本文的主要贡献是推导了基于 MEKF 误差状态的原始 GNSS 测量的测量模型，同时考虑了天线杠杆臂，并在双差分载波相位测量模型中明确包括了接收器之间的测量时间差异.

^{[19]}在多GNSS情况下，可以形成两种类型的双差（DD）模糊度，包括系统内模糊度和系统间模糊度，它们分别被识别为来自相同和不同GNSS系统的卫星之间的DD模糊度.

^{[20]}因此，在两个以上的GNSS接收机中采用公共时钟，载波相位单差可以获得与双差相同的技术效果。

^{[21]}更具体地说，我们研究了在以下四类中使用 GNSS 可观测物进行距离测量：1) GNSS 接收器提供的车辆的绝对位置； 2) 原始代码伪距； 3) 原始码伪距的单差； 4) 原始代码伪距的双差。

^{[22]}光致发光 (PL) 光谱显示 HRS 和 LRS 中浅锌空位状态和深锌空位复合物状态之间的相对强度的双重差异。

^{[23]}用于数据处理的软件是基于MATLAB的软件，原始数据采用双差（DD）策略进行处理以获得最佳结果。

^{[24]}在这项工作中，使用 Aqua MODIS 的双差对他们的 TEB 测量进行了相互比较。

^{[25]}我们建立了真实信号模型和欺骗信号模型，并建立了伪距双差模型。

^{[26]}MODIS 精度也从双差的高斯回归进行比较。

^{[27]}

## propensity score matching 倾向得分匹配

The Double Difference model combined with Propensity Score Matching methods were employed in the analysis.^{[1]}Therefore, we constructed a mathematical model and adopted the propensity score matching double difference method to analyze the impact and mechanism of OFDI on firms’ innovation.

^{[2]}Based on the sample data of listed companies engaged in m&a from 2008 to 2018, this paper adopts the generalized double difference model to study the impact of vBET agreement on the innovation activities of enterprises, and USES the propensity score matching method to test the robustness.

^{[3]}

分析中采用双差模型结合倾向得分匹配方法。

^{[1]}为此，我们构建数学模型，采用倾向得分匹配双差法分析OFDI对企业创新的影响及机制。

^{[2]}nan

^{[3]}

## `` narrow therapeutic

Other terms used also include "narrow therapeutic window drugs", "narrow therapeutic range", "critical anti-dose drugs" or "narrow therapeutic ratio , According to:The US Food and Drug Administration (FDA) defines a medication product as containing NTI when (a) there is less than a double difference in LD50 and medium effective dose values (ED50) or (b) there is less than a double difference in toxic concentrations Minimum (MTC) and minimum effective concentrations (MEC) in the blood and (c) safe and effective use of the drug requires careful calibration and patient monitoring 2018.^{[1]}

其他使用的术语还包括“窄治疗窗药物”、“窄治疗范围”、“临界抗剂量药物”或“窄治疗比”，根据：美国食品和药物管理局（FDA）将药物产品定义为含有 NTI当 (a) LD50 和中有效剂量值 (ED50) 的差异小于两倍时，或 (b) 血液中的最低毒性浓度 (MTC) 和最低有效浓度 (MEC) 的差异小于两倍时，以及(c) 安全有效地使用药物需要仔细校准和患者监测 2018。

^{[1]}

## Phase Double Difference

This paper puts forward a short-baseline dual-antenna BDS/MIMU integrated navigation, constructs the carrier phase double difference model of BDS (BeiDou Navigation Satellite System), and presents a 2-position initial orientation method on BDS.^{[1]}Therefore, the Doppler-aided cycle-slip detection method (DACS) is proposed to detect cycle-slips of one cycle or greater than one, and the carrier phase double difference cycle-slip detection method (CPDD) is used to detect cycle slips of a half-wavelength.

^{[2]}Then the carrier phase single difference (SD) model, instead of the carrier phase double difference (DD) model, is used to improve the pitch and roll precision of the GPS-based attitude determination system.

^{[3]}

提出了一种短基线双天线BDS/MIMU组合导航，构建了BDS（北斗卫星导航系统）载波相位双差模型，提出了一种BDS上的2位初始定向方法。

^{[1]}因此，提出了多普勒辅助周跳检测方法（DACS）来检测一个周期或大于一个周期的周跳，而载波相位双差周跳检测方法（CPDD）用于检测一个周期的周跳。一个半波长。

^{[2]}nan

^{[3]}

## Gns Double Difference

Here, we propose relative navigation based on GNSS double difference measurement to accomplish the same task, but also onto moving landing platforms or at unsurveyed locations.^{[1]}The results show that in kinematic conditions GNSS double differenced carrier phase residuals are from 2.

^{[2]}

## double difference method 双差法

The double difference method was used to estimate and thus eliminate the inter-sensor bias, and a decadal diurnal correction was used to reduce the impact of different local equator crossing times on climate trends.^{[1]}The aftershocks were relocated using the double difference method.

^{[2]}By taking China’s high-speed railway (HSR) network construction as a quasi-natural experiment, this paper uses the trend score matching and double difference methods to analyse the industrial struc.

^{[3]}Relocation with the Double Difference method, using cross–correlation differential times, resulted in highly accurate locations with spatial errors ranging from a few tens to a few hundreds of meters.

^{[4]}Firstly, the double difference method (DID) was adopted to study the effect of green credit policy on enterprises from two aspects, namely the amount of loans obtained by enterprises and the financing cost.

^{[5]}We applied double difference method in order to relocate the seismic events.

^{[6]}Therefore, we constructed a mathematical model and adopted the propensity score matching double difference method to analyze the impact and mechanism of OFDI on firms’ innovation.

^{[7]}In this paper, we propose a double difference method using Doppler shift measurements of independent receivers, which does not require time synchronization and can be easily integrated on commercial off-the-shelf (COTS) receivers.

^{[8]}In this paper, intercalibration between VIRR and MODIS is performed to obtain corrected brightness temperature (BT) via double difference method, then Bayesian cloud detection and optimal estimation algorithms based on VIRR corrected BT are used to obtain Arctic VIRR SST.

^{[9]}The data are used to examine the extent to which for each type of hazard there is a difference in nightlight intensity between affected and nonaffected cells based on (i) case studies of specific disasters, and (ii) fixed effect regression models akin to the double difference method to determine any effect that the different natural hazards might have had on the nightlight value.

^{[10]}The first approach is based on a double difference method by comparison with SNPP VIIRS using observations from simultaneous nadir overpasses (SNO) with Aqua MODIS.

^{[11]}A series of robustness tests, such as synthetic control method and double difference method, show that the pilot free trade zone policy has a positive spillover effect on attracting foreign investment in the region, and the empirical conclusion is robust.

^{[12]}In this study, AMSU-A data from the National Oceanic and Atmospheric Administration’s (NOAA’s) -15, -18, and -19 satellites and the European Organization for the Exploitation of Meteorological Satellites MetOp-A/-B collected during 1998–2017 were first inter-calibrated by a double difference method to remove inter-sensor biases.

^{[13]}This study explores the inter-comparison strategy to identify the radiometric differences between SNPP and NOAA-20 CrIS along the finest spectral scale, including 1) direct comparison; and 2) the two double difference methods using infrared atmospheric sounding interferometer and radiative transfer calculations as transfer targets.

^{[14]}One method to relocate the hypocenter is the double difference method, hypocenter relocation by double difference method is expected to improve the accuracy of the hypocenter position.

^{[15]}The average treatment effect was estimated using the double difference method.

^{[16]}

采用双差法估计并消除传感器间偏差，并采用年代际日校正来减少不同局地赤道穿越时间对气候趋势的影响。

^{[1]}余震采用双差法重新定位。

^{[2]}以中国高铁网络建设为准自然实验，采用趋势得分匹配和双差法对产业结构进行分析。

^{[3]}双差法重定位，使用互相关微分时间，可以得到高度精确的位置，空间误差从几十米到几百米不等。

^{[4]}首先，采用双差法（DID）从企业获得的贷款金额和融资成本两个方面研究绿色信贷政策对企业的影响。

^{[5]}nan

^{[6]}为此，我们构建数学模型，采用倾向得分匹配双差法分析OFDI对企业创新的影响及机制。

^{[7]}在本文中，我们提出了一种使用独立接收器的多普勒频移测量的双差分方法，该方法不需要时间同步，并且可以很容易地集成在商用现货 (COTS) 接收器上。

^{[8]}本文通过VIRR与MODIS的相互标定，通过双差法获得校正亮温（BT），然后利用贝叶斯云检测和基于VIRR校正BT的最优估计算法获得北极VIRR SST。

^{[9]}根据 (i) 特定灾害的案例研究，和 (ii) 类似于双重的固定效应回归模型，这些数据用于检查每种灾害在受影响和未受影响细胞之间夜光强度差异的程度差异法来确定不同的自然灾害可能对夜灯值产生的任何影响。

^{[10]}第一种方法是基于双差法，通过与 SNPP VIIRS 进行比较，使用来自 Aqua MODIS 的同时最低点立交桥 (SNO) 的观测。

^{[11]}综合控制法、双差法等一系列稳健性检验表明，自贸试验区政策对该地区吸引外资具有正向溢出效应，实证结论具有稳健性。

^{[12]}在这项研究中，来自美国国家海洋和大气管理局 (NOAA) -15、-18 和 -19 卫星以及欧洲气象卫星开发组织 MetOp-A/-B 的 AMSU-A 数据在 1998-2017 年间收集到首先通过双差法进行相互校准，以消除传感器间的偏差。

^{[13]}nan

^{[14]}双差法是震源重定位的一种方法，采用双差法进行震源重定位有望提高震源定位精度。

^{[15]}使用双差法估计平均治疗效果。

^{[16]}

## double difference model 双差模型

The double difference model is used to estimate the impact of internal audit.^{[1]}The Double Difference model combined with Propensity Score Matching methods were employed in the analysis.

^{[2]}Based on the sample data of listed companies engaged in m&a from 2008 to 2018, this paper adopts the generalized double difference model to study the impact of vBET agreement on the innovation activities of enterprises, and USES the propensity score matching method to test the robustness.

^{[3]}This paper puts forward a short-baseline dual-antenna BDS/MIMU integrated navigation, constructs the carrier phase double difference model of BDS (BeiDou Navigation Satellite System), and presents a 2-position initial orientation method on BDS.

^{[4]}From the perspective of city innovation factors, based on the double difference model, the data of 12 cities along the Datong-Xian high-speed railway in 2008-2016 were used to analyze the impact of high-speed rail opening on the innovation output of small and medium-sized cities along the line.

^{[5]}

双差模型用于估计内部审计的影响。

^{[1]}分析中采用双差模型结合倾向得分匹配方法。

^{[2]}nan

^{[3]}提出了一种短基线双天线BDS/MIMU组合导航，构建了BDS（北斗卫星导航系统）载波相位双差模型，提出了一种BDS上的2位初始定向方法。

^{[4]}从城市创新因素的角度，基于双差模型，利用2008-2016年大同高铁沿线12个城市的数据，分析高铁开通对城市创新产出的影响。沿线的中小城市。

^{[5]}

## double difference technique 双差法

The epicentral parameters obtained from double difference technique illuminated a steep seismogenic structure extending up to 8 km depth using a minimum 1-D velocity model.^{[1]}By complementarily integrating the ray-tracing based 3DMA GNSS and the double difference technique, the random errors (such as multipath and NLOS) are mitigated while eliminating the systematic errors (such as atmospheric delay and satellite clock/orbit biases) between road user.

^{[2]}A double difference technique was employed to remove the effect of changes or deficiencies in the NWP system and radiative transfer (RT) model, which can contribute to the biases.

^{[3]}Then hypocenter relocation as well as the velocity structure is inverted using double difference technique.

^{[4]}A double difference technique is proposed for calculations of enthalpies of formation of radicals.

^{[5]}

使用最小一维速度模型，从双差分技术获得的震中参数照亮了一个延伸至 8 km 深度的陡峭发震结构。

^{[1]}通过将基于射线追踪的 3DMA GNSS 与双差分技术相结合，在消除道路使用者之间的系统误差（如大气延迟和卫星时钟/轨道偏差）的同时，减少了随机误差（如多径和 NLOS）。

^{[2]}采用双差分技术来消除 NWP 系统和辐射传输 (RT) 模型中可能导致偏差的变化或缺陷的影响。

^{[3]}然后使用双差分技术对震源重定位和速度结构进行反演。

^{[4]}提出了一种用于计算自由基形成焓的双差分技术。

^{[5]}

## double difference operator 双差算子

The prime objective of this paper is to define a new double difference operator with arbitrary order via which new classes of difference double sequences are introduced.^{[1]}In this article, we intend to introduce some Tauberian theorems for fuzzy number sequences by using the de la Vallée Poussin mean and double difference operator of order r.

^{[2]}In the present paper, we introduce the concept of relative weighted almost convergence and its weighted statistical extensions in multivariate modular function spaces based on a new type fractional-order double difference operator $$\nabla ^{a,b,c}_h$$∇ha,b,c.

^{[3]}

本文的主要目标是定义一个具有任意顺序的新双差分算子，通过该算子引入新的差分双序列类别。

^{[1]}在本文中，我们打算使用 r 阶的 de la Vallée Poussin 均值和双差算子来介绍一些模糊数列的陶伯定理。

^{[2]}nan

^{[3]}

## double difference index

However, the relationships between some existing indices (simple difference, simple ratio, normalized difference, double difference index and difference ratio indices) and EWT at the leaf level were weak and unstable for all of the 18 plant species (including 14 broadleaf, 3 shrub, and 1 liana species) at different angles under laboratory and field conditions.^{[1]}Specifically, we quantified the difference between leaf BRF and DHRF spectra measurements and evaluated the effect of specular reflection on the estimation of LCC with 20 spectral features in four categories (simple ratio, SR; modified SR, mSR; double difference index, DD and red edge position, REP).

^{[2]}Using selected vegetation indices (VIs), the medium resolution imaging spectrometer terrestrial chlorophyll index (MTCI), and the double difference index (DD), we studied the retrieval accuracy of chlorophyll content at the leaf scale under dusty environments based on a laboratory experiment and spectra simulation.

^{[3]}

然而，18个植物物种（包括14个阔叶、3个灌木和 1 种藤本植物）在实验室和野外条件下的不同角度。

^{[1]}具体来说，我们量化了叶片 BRF 和 DHRF 光谱测量之间的差异，并评估了镜面反射对 LCC 估计的影响，具有四类（简单比率，SR；修正 SR，mSR；双差指数，DD 和红色）的 20 个光谱特征边缘位置，REP）。

^{[2]}采用选定植被指数（VIs）、中分辨率成像光谱仪陆地叶绿素指数（MTCI）和双差指数（DD），基于室内试验研究了沙尘环境下叶片尺度叶绿素含量的反演精度，光谱模拟。

^{[3]}

## double difference observable

It is also proposed that the Skymask and code pseudorange double difference observable are used to label the real signal type.^{[1]}The impacts of indoor NLOS and multipath are also analyzed with double difference observables.

^{[2]}

还提出使用 Skymask 和代码伪距双差可观测值来标记真实信号类型。

^{[1]}室内 NLOS 和多径的影响也用双差观测值进行了分析。

^{[2]}

## double difference estimator

The double difference estimator showed that the fish farmers who participated in Fadama III programme had 62.^{[1]}Descriptive statistics, double difference estimator, propensity score matching (PSM) and logic model were used to analyze the data.

^{[2]}

双差估计器显示，参与 Fadama III 计划的养鱼户有 62 个。

^{[1]}描述性统计、双差估计、倾向得分匹配（PSM）和逻辑模型用于分析数据。

^{[2]}

## double difference observation

First, it builds double difference observation equation based the measurements from two satellites.^{[1]}The effect of correlations in global navigation satellite system (GNSS) double difference observation has been investigated, and it has been empirically found that such effect is small in l.

^{[2]}

首先，它基于两颗卫星的测量结果建立了双差分观测方程。

^{[1]}研究了全球导航卫星系统（GNSS）双差观测中相关性的影响，经验表明这种影响在l中很小。

^{[2]}

## double difference tomography

We applied the Enhanced Seismic Tomography method, which incorporates the Double Difference tomography and the post processing Weighted Average Method.^{[1]}In this work, we present a high-resolution 3-D crustal seismic model for the source region of the Jiuzhaigou earthquake by exploiting the arrival times of aftershocks based on double difference tomography.

^{[2]}

我们应用了增强地震层析成像方法，该方法结合了双差分层析成像和后处理加权平均方法。

^{[1]}在这项工作中，我们利用基于双差分层析成像的余震到达时间，提出了九寨沟地震震源区的高分辨率 3-D 地壳地震模型。

^{[2]}

## double difference algorithm 双差算法

Firstly, the 103 micro-earthquakes were relocated based on double difference algorithm.^{[1]}In this study, the aftershock sequence within 8 days after the mainshock was relocated by double difference algorithm.

^{[2]}

首先，基于双差算法对103次微震进行重定位。

^{[1]}本研究采用双差算法对主震后8天内的余震序列进行重定位。

^{[2]}