Time Delay Changes Research Articles

Magnetic field measurement with temperature compensation based on a fiber ring microwave photonic filter and Vernier effect.

We proposed, a novel, to the best of our knowledge, magnetic field measurement with temperature compensation based on a fiber ring microwave photonic filter (FR-MPF) and a Vernier effect. The sensing head is made up by attaching the fiber Bragg grating (FBG) on the magnetostrictive material. Based on the wavelength division multiplexing, two FR-MPFs with different optical carriers can eliminate the influence of the temperature. The Linear chirped FBG (LCFBG) in the FR can transfer the magnetic field variation to the time delay change as well as the frequency shift. Two FR-MPFs with close free spectral ranges can implement the Vernier effect, which can improve the sensitivity. The experimental results show the sensitivity is 58.3 kHz/Oe and the magnification factor is 214. The proposed sensor has merits of high resolution, high sensitivity and low cross-sensitivity, which has potential applications requiring high precision detections.

Time-delay feedback control of nonlinear forced vibration of graphene/piezoelectric sandwich nanoplates under a mechanical shock

In this study, the nonlinear forced vibration of graphene/piezoelectric sandwich nanosheets under mechanical impact was investigated. For the first time, linear (displacement and velocity) and nonlinear (displacement) time-delay proportional derivative (PD) controllers were applied to graphene/piezoelectric sandwich nanosheets, and the primary/secondary resonance under different time-delay parameters were analyzed. An approximate analytical solution for the nonlinear forced vibration control equation was obtained using the multiple scale perturbation method, and the stability of graphene/piezoelectric sandwich nanosheets under primary/secondary resonance conditions was discussed using the Ross Herwitz theorem. Finally, the results of this study were compared with those of other studies. The feasibility of the research methodology was demonstrated. On this basis, the research results indicate that linear displacement delay, nonlinear displacement delay, and velocity delay parameters can suppress the unsteady vibration characteristics of the main system. And comparing the linear and nonlinear displacement time-delay, it is found that the nonlinear displacement time-delay has a greater effect on the system. Specifically, the presence of nonlinear displacement time-delay changes the vibration characteristics of the curve from hard spring characteristics to soft spring characteristics. Comparison of displacement time-delay and velocity time-delay reveals that velocity time-delay gives better control over the system. In addition, the results show that the excitation amplitude, nonlocal parameters, and external voltage enhance the nonlinear characteristics of the system under the main and superharmonic resonance conditions before the time-delay control. Subharmonic resonance conditions, the system parameters make the vibration range wider. After the time-delay control, the influence of these three factors on the system vibration is significantly reduced for the three resonance conditions, especially for the non-local parameters. The results of the study can provide guidance for active control of time delay in different types of nanodevices for engineering applications.

An Integration of Real-Time Vehicle Routing and Mobile Technology in Poultry Distribution

Handling the distribution of broilers has special attention. The distribution of poultry should be done in the shortest possible time to decrease broiler mortality rate. Real-time monitoring of poultry distribution is expected to control the stress level of poultry due to the length of travel time by limiting the delivery time window. In order to control the distribution time and distance, it is necessary to integrate vehicle routing and mobile technology. By adopting the digital twin-enabled framework model and combining it with Google APIs, web and mobile applications are generated to accommodate the real-time traveling time, vehicle capacity, and pickup-delivery activity. There is a significant change in travel distance in one delivery cycle after implementing the developed technology. The total travel distance was 493 KM decreased to 436 KM, which means a decrease of 11.5% from the initial total travel distance. In addition, there was a change in the total penalty time (delay) from 102 minutes to 85 minutes, decreasing delay time by 16.6%. This mobile technology's development can indirectly increase vehicle utilization by not overloading the vehicle capacity and reducing vehicle travel distance.

ЕКСПЕРИМЕНТАЛЬНЕ ДОСЛІДЖЕННЯ ТОЧНОСТІ ПРОКАТКИ НА СТАНІ 800

The purpose of the work is an experimental study of the process of square sections rolling on the rolling mill 800 to determine the influence of rolling parameters on the dimensions and length of the roll. During the study, variations in ingot mass, rolling dimensions, and rolling length were determined, regression equations and correlation coefficients were obtained for the dependence of rolling dimensions and length on the ingot mass, changes in interroll gap and time delay before the finishing stand. It was established that the ingot mass variates within significant limits - 638 kg, which is caused by the melt mass variations. Variations in the mass of the ingot within one ingot mold stool are caused by the dimensions of the ingot molds and are within 154 kg. Variations in the dimensions of the roll are carried out within the following limits: thickness - 1.0 mm, width - 0.5 mm, length - 5.3 m. The change of the interroll gap can be used to correct the length of the finished roll in a small range of lengths, if the mass variations occur within accuracy of ingot casting on one ingot mold stool. It is necessary to take additional measures to stabilize the weight of the ingot. The influence of delays in the rolling train, which occur during rolling and lead to instability of the rolling temperature regime, for this type of profiles does not significantly affect the dimensions of the cross section and the length of the roll.

High-tolerance reconfigurable MZI racetrack resonator on a 3-µm-thick SOI photonics platform

Integration of resonators impacts the utilization of the 3-µm-thick silicon-on-insulator (SOI) platform in photonics integrated circuits (PICs). We propose an integrated resonator leveraging a deep-etch silicon waveguide. Through the utilization of a tunable coupler based on multimode interferometers (MMIs), the resonator achieves high fabrication tolerance and reconfigurability. In a critical-coupling state, it serves as a filter with an extinction ratio (ER) of 23.5 dB and quality (Q) factor of 3.1×105, operating within the range of 1530–1570 nm. In an extreme over-coupling state, it functions as a large-bandwidth delay line, offering continuous change in delay time of 22 ps, nearly wavelength-independent. This work provides devices to the 3-µm-thick silicon photonics device library, enriching the potential applications of this technology platform.

Blending Efficiency and Resilience in the Performance Assessment of Urban Intersections: A Novel Heuristic Informed by Literature Review

Urban mobility underscores the vital importance of ensuring traffic efficiency on road segments, intersections, and transportation networks, especially in challenging circumstances. In this perspective, the essential approach to improving urban intersection efficiency should involve understanding critical factors for maintaining operational performance in the face of disruptions such as storms. This paper, inspired by a systematic literature review, presents a novel heuristic for evaluating urban intersection efficiency, with resilience as its guiding principle. The methodological path was designed to address the fundamental question: How can urban intersections be designed and managed to ensure efficiency and resilience in the face of disruptions? Drawing inspiration from the Highway Capacity Manual procedure, the methodological approach encompasses both pre-storm and post-storm scenarios, comparing delay times at roundabouts and signalized intersections before and after a storm. The results reveal significant changes in delay times for traffic signals, although the choice between roundabouts and signalized intersections should be context-specific, considering factors like traffic conditions, resilience requirements, and associated trade-offs. By shedding light on the interplay between intersection design, control strategies, and urban resilience, this research provides valuable insights into integrating resilience considerations into intersection performance assessment and management strategies. It also underscores how particular intersection designs can impact efficiency and recovery, essential considerations when assessing whether a road or intersection project is resilient.

Statistics for quantifying aging in time transfer system delays

Residual time delays in time transfer systems such as two-way satellite time and frequency transfer (TWSTFT), or GPS carrier phase (GPSCP) change over time. A double difference such as TWSTFT—GPSCP provides information on the changes in the relative time delays of the two systems. These changes are referred to as aging or time dispersion. A first difference statistic, RMS time interval error, TIERMS, provides the RMS time dispersion. The time deviation statistic (TDEV) or a variation on the Allan deviation (ADEV), referred to here as ADEVS, provide information on the nature of the random fluctuations in aging. This paper describes analytical and Monte Carlo techniques used to estimate the aging (time dispersion) from TDEV or ADEVS statistics, and finds that the aging can be more than a factor of four larger than TDEV or ADEVS. The use of ADEVS is recommended over TDEV since it is sensitive to time drift.

Experimental study on effects of ammonia enrichment on the thermoacoustic instability of lean premixed swirling methane flames

Ammonia (NH3) has recently emerged as a promising carbon-free energy carrier. Further development and application of NH3 as fuel in the gas turbine industry can significantly reduce the emissions of carbon dioxide (CO2) and contribute to the achievement of a carbon–neutral society. This study experimentally examined the thermoacoustic instability characteristics of a laboratory-scaled lean premixed gas turbine model combustor operated with different NH3 blending ratios with methane (CH4). Experiments conducted under a wide range of inlet velocities and equivalence ratios suggest that NH3 concentration is critical in determining the characteristics of the instability. Specifically, when the NH3 proportion is less than 50 %, the addition of NH3 causes a mode transition of the instability. However, when the content of NH3 is greater than 50 %, it is shown that the instabilities are suppressed, indicating that the addition of a certain amount of NH3 can enhance the stability of CH4 flames. Additional analysis of flame dynamics reveals that the introduction of NH3 causes the lengthening of the flame front and weakens heat release rate fluctuations in the flame root regions. Further Proper Orthogonal Decomposition (POD) analysis of the flow field shows that the instability modes are strongly coupled with periodic vortex motions of the flow dynamics along the shear layers. Finally, the mode shifting phenomena is successfully predicted by low-order thermoacoustic network modeling. It is suggested that the change in convective time delay caused by NH3 addition is responsible for such transitions.

Inference and analysis on the evidential reasoning rule with time-lagged dependencies

Evidential reasoning rule (ER rule), benefits by the advantage in dealing with various uncertainties, is widely applied for independent evidence aggregation and multi-attribute decision making. In engineering practice, however, time-lagged correlations among multiple attributes from complex systems are often encountered, causing time-lagged dependencies among evidences generated from these attributes. To aggregate multiple pieces of time-lagged dependent evidence, an evidential reasoning rule with time-lagged dependencies, called the ER-TLD, is developed in this paper. Firstly, the calculation algorithm for the relative total time-lagged dependence coefficient (RT-TLDC) and the delay time of each attribute is proposed based on the distance correlation (dCor) method, with which nonlinear time-lagged correlations among multiple attributes can be captured. On this basis, the ER-TLD model is constructed by introducing the RT-TLDCs and delay times into the ER rule, so that multiple pieces of time-lagged dependent evidence can be effectively aggregated. Then, sensitivity analyses are conducted, and the impact of delay time change on the aggregation results is explored. Finally, the effectiveness and potential application of the proposed method are verified by one numerical example and three practical experiments. The aggregation results obtained by the ER-TLD show more rationality according to the comparative studies.

Determining electron column density fluctuations in a dominant scattering region using pulsar scintillation

ABSTRACT Density fluctuations in the ionized interstellar medium have a profound effect on radio pulsar observations, through angular scattering, intensity scintillations, and small changes in time delays from dispersion. Here we show that it is possible to recover the variations in dispersive delays that originate from a dominant scattering region using measurements of the dynamic spectrum of intensity scintillations, provided that the pulsar velocity and scattering region location are known. We provide a theoretical framework for the technique, which involves estimating the phase gradient from the dynamic spectra and integrating that gradient to obtain phase variations. It can be used to search for “extreme scattering events” (ESEs) in pulsars for which precision dispersion delay measurements are not otherwise possible, or to separate true dispersion variations from apparent variability caused by frequency-dependent pulse shape changes. We demonstrate that it works in practice by recovering an ESE in PSR J1603−7202, which is known from precision dispersion delay measurements from pulsar timing. For this pulsar, we find that the phase gradients also track the long-term variations in electron column density observed by pulsar timing, indicating that the column density variations and the scattering are dominated by the same thin scattering screen. We identify a sudden increase in the scintillation strength and magnitude of phase gradients over ∼days in 2010, indicating a compact structure. A decrease in the electron density in 2012 was associated with persistent phase gradients and preceded a period of decreased scintillation strength and an absence of scintillation arcs.

Match Zehnder interferometry and Laguerre–Gaussian fields dependent photon drag in atomic medium

The absorption, dispersion and transmission are controlled and modified with the intensities of Laguerre–Gaussian control fields in a four level cesium atomic medium. The normal and anomalous slope of dispersion are investigated for subluminal and superluminal propagation. The maximum measured value of positive/negative group index is n g =±1×107, at which, the group velocity is ±30 ms−1. The maximum delay time between the two beams at the detector without dragging is 0.414 ns and in the presence of dragging is measured to 0.44 ns. The fractional change in delay time without and in the presence of dragging Δt F is measured to ±2%. The maximum phase shift without dragging is reported to 2.6 micro radian and in the presence of dragging is investigated to ±4 micro radian. The fractional change in phase shift is reported from −200% to 50% and may be used for gravitational waves detection and other signals identification.

Seasonal Variations of Seismic Travel-Time Changes in Binchuan, Southwestern China, Inferred from Large Volume Air-Gun Source Array Data

AbstractActive sources, especially air-gun sources in the water reservoir, have proven to be powerful tools for detecting regional scale velocity changes. However, the water level change affects the repeatability of the air-gun waveform and, thus, affects the stability of the detection of the velocity changes. This article explores how to make full use of the air-gun signals excited at different water levels from analyzing three years of air-gun data recorded by 20 stations deployed from ∼50 m to ∼25 km from the source. At the same time, by utilizing the poroelastic model, we quantify both vertical and horizontal distances affected by the water level change. More important, supported by the strain data from one borehole strainmeter station, the influence mechanisms of the seasonal variation derived from the three years of air-gun data are also discussed. Results indicate the water level affects the main frequency of the air gun and has a strong influence on the coda wave. When the water level of the reservoir changes abruptly, the dominant effect on the derived delay time change is from the water level change. In this case, the deconvolution method can hardly eliminate the influence of the abrupt water level change. However, when the reservoir's water level changes gently, the delay time varies accordingly rather than inversely with the water level. Other reasons affect the material properties and, thus, influence the derived delay time. The modeled vertical component of poroelastic strain caused by the reservoir water level change is 1×10−7. The observed strain (4×10−7) from the strainmeter is likely associated with thermoelastic strain induced by temperature change. Our results show that although the long-term air-gun signal is affected by water level, there is still much information about changes in the subsurface that is worth mining.

Modeling analysis of combustion instability in an annular combustor equipped with circumferentially segmented perforated liner

Hazardous azimuthal thermoacoustic modes often occur in lean-premixed annular combustors. One practical control method is the application of perforated liners with bias flow. However, circumferentially uniform perforated liners are not competent to control them, because the perforated plate covered by a single azimuthally uniform backing cavity cannot provide sufficient acoustic pressure difference across the perforated plate to bring in adequate acoustic damping. In this work, we developed a three-dimensional thermoacoustic model to consider the effects of a novel passive control damper of the circumferentially segmented perforated liner. Emphasis is placed on the effects of the segmented liner on controlling the azimuthal modes. It is found that the azimuthal mode in the premixed annular combustor can be either plenum-dominant or combustor-dominant, with the frequency of the latter one larger than the former. The stabilities of the two kinds of modes behave differently with the change of time delay. The results of the lined combustor cases indicate that the circumferentially segmented perforated liner generally improves the control effectiveness compared with the circumferentially uniform perforated liner thanks to the rigid plates inserted in the backing cavity. At the locally inserted position, the rigid plate enforces a rigid boundary condition that changes the azimuthal pressure mode shape in the backing cavity. As a result, more acoustic damping through the pressure difference across the plate is produced. Symmetry-breaking effects are found if the segmentation is asymmetric or two-fold symmetric. The behavior of the splitting frequencies caused by the segmented liner is also studied, and the symmetric segmented liner turns out to be a better choice because the resulting azimuthal mode is degenerate with two equivalent suppressed growth rates. In order to further enhance the control effect, one significant effective measure is to increase the depth of the backing cavity.

Dynamic decision modeling of production and marketing in low-carbon supply chains considering delay effects.

This article deals with a dynamic decision-making model for a low-carbon supply chain which consists of a manufacturer and a platform retailer. Consideration of delay effects, a delayed differential equation for the effect of low-carbon investment efforts (LIE) in R&D and low-carbon promotional effort (LPE) on low-carbon goodwill (LG) is developed. Moreover, Hamilton's function is applied to solve the decision problem of optimal control. In the model, the differences between the agency selling and reselling patterns are analyzed by comparing LIE, LPE, LG, and net discounted profit. The commission system is a key measure for dynamic decision making on low-carbon products, while the commission rate is also an important reference point for decision making on cooperation patterns. In contrast to the findings of previous studies, this article derives specific thresholds for commissions. Furthermore, this study considers delay effects from a dynamic perspective. The findings show differences in both decentralized and centralized decision-making solutions for supply chains as the delay time changes. The proposed models are analyzed mathematically and numerical examples are illustrated to justify the feasibility of the model in reality. This study provides new insights into the choice of platform sales patterns for firms to develop agency selling and reselling partnership solutions in practice.

Filter-Less Photonic RF Image-Reject Mixing With Simultaneous Self-Interference Cancellation and Fiber Transmission

A filter-free photonic method to simultaneously realize radio frequency (RF) image-reject mixing, self-interference cancellation (SIC), and fiber transmission for in-band full-duplex (IBFD) radio-over-fiber (RoF) link is reported. The key to achieving multi-functions is the joint manipulation of fiber dispersion-induced intermediate frequency (IF) amplitude and time delay changes, which is implemented by sideband phase-shifted optical carrier suppression (SPS-OCS) modulation and frequency tuning of the optical carrier. Owing to the control of IF amplitude and delay variation introduced by fiber dispersion, simultaneous deep image rejection and SIC over wide bandwidth can be realized after fiber transmission. Since no optical filter is required, the proposed system can work at a lower frequency, featuring a large frequency tuning range. For 25 km single-mode fiber (SMF) transmission, simultaneous 20 dB SIC within 1 GHz bandwidth and 29 dB image rejection ratio (IRR) at 6.6 GHz RF frequency in the C band, 21 dB SIC and 19 dB IRR within 1 GHz bandwidth in the X band, 24 dB SIC within 1 GHz bandwidth and 20 dB IRR at 16 GHz RF frequency in the Ku band are experimentally demonstrated. Furthermore, weak SOI with various modulation formats are well recovered after the cancellation of strong interference and fiber transmission.

Fractional differential equation modeling of the HBV infection with time delay and logistic proliferation.

In this article, a fractional-order differential equation model of HBV infection was proposed with a Caputo derivative, delayed immune response, and logistic proliferation. Initially, infection-free and infection equilibriums and the basic reproduction number were computed. Thereafter, the stability of the two equilibriums was analyzed based on the fractional Routh-Hurwitz stability criterion, and the results indicated that the stability will change if the time delay or fractional order changes. In addition, the sensitivity of the basic reproduction number was analyzed to find out the most sensitive parameter. Lastly, the theoretical analysis was verified by numerical simulations. The results showed that the time delay of immune response and fractional order can significantly affect the dynamic behavior in the HBV infection process. Therefore, it is necessary to consider time delay and fractional order in modeling HBV infection and studying its dynamics.

Impact of COVID-19 pandemic on the occurrence and outcome of cardiogenic shock complicating acute myocardial infarction

Abstract Background The COVID-19 pandemic had influenced the patient's behavior and impacted the homeostasis to a pro-thrombotic niveau. Aim The study aimed to follow the impact of COVID-19 on the incidence and prognosis of cardiogenic shock complicated initially acute myocardial infarction (CS-AMI). Methods We used data entered into a large national all-comers registry of coronary intervention over five years. From 1/2016 to 12/2020, 50,745 AMI patients were included, and 2,822 (5.6%) initially had CS. Results The incidence of CS-AMI was significantly higher in the COVID period (2020) than the mean incidence in 2016–2019 (5.5% vs 6%, p=0.032). The difference was caused by significant increase of CS in acute STEMI (7.6% vs. 8.7%, p=0.011); it was 7.1% in 2016, 7.8% (2017), 7.6% (2018), 7.8% (2019), and 8.7% (2020). The CS complicated 2.3% (2016), 2.7% (2017), 2.7% (2018), 2.8% (2019), and 2.8% (2020) of NSTEMI. The observed rise in CS-STEMI incidence each month during the pandemic compared to the average incidence in non-pandemic years correlated with the substantial increase in the number of COVID infected/hospitalized (Table 1). In these months, no changes in time delay to reperfusion layout were observed in CS-STEMI patients (Table 2). Except of less frequent history of previous PCI (13.9% and 8.2%, p<0.001), we found no significant differences in the followed CS-STEMI patient characteristics in 2016–2019 and 2020; men 72.7% and 75.4% (p=0.1), mean age (SD) 66.3 (12.3)yrs and 66.3 (12.2) yrs, Diabetes 20.9% and 19.1% (p=0.2), CKD 5.4% and 5.7% (p=0.4), previous CABG 4.5 and 4.2% (p=0.5), left main disease (14.3% and 16%, p=0.5), one vessel disease 24.9% and 32.1% (p=0.9), pre-PCI TIMI flow 0 64.4% and 66.2% (p=0.6), post-PCI TIMI flow 3 76.7% and 76.9%. The COVID pandemic didn't influence the proportions of pre-hospital resuscitated CS-AMI patients (57.5% and 58.7%, p=0.6) and those on mechanical ventilation (67.8% and 68.3%, p=0.8). The 30-day mortality trend of CS-AMI was 53.7% in 2016, 51.6% (2017), 49.7% (2018), 49.3% (2019), and 47.9% (2020). And in CS-STEMI it was 50.8%, 47.1%, 46.4%, 44.1%, and 45.3% (P2019 vs. 2020 =0.8), respectively. Conclusion Data from a large national all-comer registry showed an increase in the proportion of patients admitted to hospitals with STEMI complicated by CS in the year of the COVID pandemic. The CS rise correlated with the increase in the COVID infected population. Factors other than the patient's cardiovascular risk profile or prolongation of a time delay to reperfusion influenced this trend. We suggest that the availability of health care and patient adherence may have affected the risks control. We did not observe any effect of the pandemic on CS-AMI mortality. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Health of the Czech Republic

PROJEÇÃO DA FADIGA E AS ALTERAÇÕES NEUROMUSCULARES PROVOCADAS EM DISTINTAS ATIVIDADES FÍSICAS

ABSTRACT Introduction: Athletes’ muscles can be weakened by fatigue caused by excessive activity. This limitation compromises their functional capacity and professional performance. The competition's performance correlates positively with muscular quality of function. The changes analysis caused by different athletic activities in muscle contraction by noninvasive tensiomyography reflects the functional state of the muscles. Still, no experiments are adapted to verify the fatigue risk level. Objective: Verify the possible relationship between exercise and neuromuscular fatigue using noninvasive tensiomyography. Methods: 90 athletes were randomly selected in weightlifting, badminton, and athletics sports. Maximum radial displacement, contraction, delay, duration, and relaxation time indices were collected. Muscle fatigue detection was based on the empirical mode decomposition modeling method with the Rogers sensitivity fluctuation rate. All values were collected in the rectus femoris muscle before and after the exercises. They were statistically treated and compared (P<0.05). Results: All athletes showed a decline in maximum radial displacement values after exercise. It reveals that their muscles are in a considerable state of tension, especially in the track and field group (from 8.57±3.42mm to 5.43±2.14mm). However, the slightest change in delay time was observed in the weightlifting group (16.21±4.15ms initial versus 18.34±3.27ms final). Conclusion: Through tensiomyography technology, it is possible to obtain a relationship between exercise and neuromuscular fatigue, analyzing the physical activity effects in a noninvasive way. Evidence Level II; Therapeutic Studies - Investigating the result.

Temperature characterizations of silica asymmetric Mach-Zehnder interferometer chip for quantum key distribution

Quantum key distribution (QKD) system based on passive silica planar lightwave circuit (PLC) asymmetric Mach–Zehnder interferometers (AMZI) is characterized with thermal stability, low loss and sufficient integration scalability. However, waveguide stresses, both intrinsic and temperature-induced stresses, have significant impacts on the stable operation of the system. We have designed silica AMZI chips of 400 ps delay, with bend waveguides length equalized for both long and short arms to balance the stresses thereof. The temperature characteristics of the silica PLC AMZI chip are studied. The interference visibility at the single photon level is kept higher than 95% over a wide temperature range of 12 °C. The delay time change is 0.321 ps within a temperature change of 40 °C. The spectral shift is 0.0011~nm/0.1 °C. Temperature-induced delay time and peak wavelength variations do not affect the interference visibility. The experiment results demonstrate the advantage of being tolerant to chip temperature fluctuations.

A Wideband Microwave Holography Methodology for Reflector Surface Measurement of Large Radio Telescopes

Most reflector surface holographic measurements of a large radio telescope utilize a geostationary satellite as the signal source. The shortcoming is that those measurements could only be done at a limited elevation angle due to the satellite’s relatively stationary state. This paper proposed a new wideband microwave holographic measurement method based on radio sources to achieve full-elevation-angle measurement with small size reference antenna. In theoretical derivation, the time delay and phase change due to path length and device difference between the antenna under test and reference antenna are compensated first. Then the correct method of wideband holography effect, which is because of antenna pattern differing under different wavelengths when receiving a wideband signal, is presented. To verify the proposed methodology, a wideband microwave holographic measurement system is established, the data processing procedure is illustrated, and the reflector surface measurement experiments on a 40 m radio telescope at different elevation angles are conducted. The result shows that the primary reflector surface root-mean-square at around elevation angles of 28°, 44°, 49°, and 75° are respectively 0.213 mm, 0.170 mm, 0.188 mm, and 0.199 mm. It is basically consistent with the real data, indicating that the proposed wideband microwave holography methodology is feasible.