## What is/are Double Difference?

Double Difference - Existing research mainly focuses on single point positioning (SPP) or double difference positioning (DDP) modes.^{[1]}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).

^{[2]}After that, the double differences between FY-3D MWTS and S-NPP ATMS and the theoretical observations in FY-3D MWTS channels are calculated.

^{[3]}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.

^{[4]}Firstly, the 103 micro-earthquakes were relocated based on double difference algorithm.

^{[5]}We present three different schemes currently used to perform time-lapse inversions and compare these three methods: parallel, sequential and double difference.

^{[6]}Double differences (DD) seismic data are widely used to define elasticity distribution in the Earth's interior, and its variation in time.

^{[7]}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.

^{[8]}The interactions of OA capped iron oxide nanoparticles with solvent molecules were probed by analytical ultracentrifugation and double difference pair distribution function analysis.

^{[9]}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.

^{[10]}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.

^{[11]}Recent researches proposed an alternative method (Double Difference Combination Rule) to estimate seismic gap between structures, as this method considers the cross relation of adjacent buildings behavior during earthquakes.

^{[12]}In this study, the aftershock sequence within 8 days after the mainshock was relocated by double difference algorithm.

^{[13]}Double difference evaluations were formed by comparing the measurements minus the estimated ionosphere for one satellite against the measurements minus the estimated ionosphere for another.

^{[14]}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.

^{[15]}The double difference model is used to estimate the impact of internal audit.

^{[16]}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.

^{[17]}The aftershocks were relocated using the double difference method.

^{[18]}2, in the upper troposphere and lower stratosphere (200–20 hPa), through dual launch campaigns at the GRUAN site and using the radio occultation (RO) product and the ERA5 reanalysis from ECMWF as standards for double difference comparison.

^{[19]}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.

^{[20]}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.

^{[21]}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.

^{[22]}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.

^{[23]}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.

^{[24]}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.

^{[25]}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.

^{[26]}Based on the double difference regression analysis of gravity coefficient, it is concluded that the central attractiveness of trade between China and the rest of the world is relatively low in the past, but under the overall downward trend of trade attractiveness between China and the rest of the world, the China-EU train has significantly promoted the growth of trade in recent years, which is attractive.

^{[27]}The Ka-band hardware delay is calibrated by taking the double difference between ISL-centralized clock and the Multi-satellite Precise Orbit Determination clock.

^{[28]}The first step is to unify the time and space systems, then make full use of the multi constellation carrier phase measurements, and finally eliminate the propagation path error and satellite clock error by double difference carrier phase.

^{[29]}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.

^{[30]}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.

^{[31]}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.

^{[32]}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.

^{[33]}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.

^{[34]}The integer rounding scheme developed in this paper is an iterative process that sequentially resolves integer ambiguities, and the sequential order of the integer ambiguity resolution is based on the required averaging epochs that vary for each satellite depending on the geometry between the baseline and the double difference line-of-sight vectors.

^{[35]}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.

^{[36]}In this paper, we test the double difference full waveform inversion method on a synthetic 4D seismic data set.

^{[37]}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.

^{[38]}METHODS We compared data before and after policy implementation using double difference (DD) and triple difference (DDD) analyses.

^{[39]}The next method to relocate the event location is Double Difference (DD) algorithm.

^{[40]}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.

^{[41]}Due to their locations, double difference is an appropriate method for their comparison and Aqua MODIS is one of good references.

^{[42]}The double difference estimator showed that the fish farmers who participated in Fadama III programme had 62.

^{[43]}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).

^{[44]}The impacts of indoor NLOS and multipath are also analyzed with double difference observables.

^{[45]}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.

^{[46]}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.

^{[47]}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.

^{[48]}Double difference hypocentre relocation of aftershocks using data from rapidly deployed seismic instrumentation confirms an east-dipping rupture plane for the first event, and shows a concentration located at the northern end of the rupture where the InSAR suggests greatest vertical displacement.

^{[49]}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.

^{[50]}

## propensity score matching

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]}

## `` 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]}

## 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]}

## 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

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]}

## double difference model

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]}

## double difference technique

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]}

## double difference operator

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]}

## 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]}

## 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]}

## 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]}

## 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]}

## 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]}

## double difference algorithm

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]}