Acta Geodaetica et Geophysica最新文献_第4页

Picking of first arrival times on noisy ultrasonic S-wave signals for concrete and rock materials 在混凝土和岩石材料的高噪声超声波 S 波信号上提取首次到达时间

IF 1.4 4区地球科学

Acta Geodaetica et Geophysica Pub Date : 2023-10-06 DOI: 10.1007/s40328-023-00426-7

Ali Erden Babacan, Hakan Karsli, Mustafa Senkaya

{"title":"Picking of first arrival times on noisy ultrasonic S-wave signals for concrete and rock materials","authors":"Ali Erden Babacan, Hakan Karsli, Mustafa Senkaya","doi":"10.1007/s40328-023-00426-7","DOIUrl":"10.1007/s40328-023-00426-7","url":null,"abstract":"<div><p>Ultrasonic testing techniques are non-invasive and generally used in geosciences to obtain the longitudinal and shear wave velocities for either concrete or rock materials, which are essential to investigate the physical and mechanical properties of the materials. However, the accuracy and reliability of the material velocities depend on the precise reading of the first arrival time directly on the recorder. In ultrasonic testing, due to the heterogeneity of the samples and noise, it is often problematic especially to determine the S-wave first arrival time both directly on the recorder and from the recorded signal, and this process mainly depends on user experience. This study focuses on the semi-automatic picking of the first arrival time (FAT) of ultrasonic shear (S)-wave signals. For this, after an application of a band-pass filter (BP) to suppress the noise components, the cross-correlation (CC) technique using an operator signal estimated by Kolmogorov spectral factorization from the filtered signal is applied to determine the boundaries of the possible time interval of the FAT. An automatic search then reads the FAT which encounters the maximum amplitude value within the interval. The technique has been tested for synthetic and real data sets. The results show that the FAT can be picked within safe and acceptable limits within errors ± 2.0 µs and ensure that the velocities of materials such as rock and concrete will be obtained accurately. Therefore, this also provides the ability to calculate other related physical and mechanical parameters of the materials.</p></div>","PeriodicalId":48965,"journal":{"name":"Acta Geodaetica et Geophysica","volume":"58 4","pages":"631 - 648"},"PeriodicalIF":1.4,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135346894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A study of ionospheric anomaly detection before the August 14, 2021 Mw7.2 earthquake in Haiti based on sliding interquartile range method 基于滑动四分位数区间法的 2021 年 8 月 14 日海地 Mw7.2 级地震前电离层异常检测研究

IF 1.4 4区地球科学

Acta Geodaetica et Geophysica Pub Date : 2023-10-06 DOI: 10.1007/s40328-023-00425-8

Dongjie Chen, Di Meng, Fu Wang, Yanmei Gou

{"title":"A study of ionospheric anomaly detection before the August 14, 2021 Mw7.2 earthquake in Haiti based on sliding interquartile range method","authors":"Dongjie Chen, Di Meng, Fu Wang, Yanmei Gou","doi":"10.1007/s40328-023-00425-8","DOIUrl":"10.1007/s40328-023-00425-8","url":null,"abstract":"<div><p>This study focuses on the possible ionospheric anomalies before the Mw7.2 earthquake in Haiti on August 14, 2021. Based on the dual-frequency observation data of Global Navigation Satellite System (GNSS) stations and Global Ionosphere Maps (GIM) data products, the sliding interquartile range method was applied to detect and analyze the changes of ionospheric Total Electron Content (TEC) anomalies before the earthquake. The results show that the TEC anomalies over five GNSS stations show the common existence of anomalous times, which are July 28, August 1, August 2, August 7, and August 13, 2021, respectively. Combining space weather parameters and GIM, it is tentatively concluded that the TEC anomaly that appeared on August 1 (i.e., the 13th day before the earthquake) was not disturbed by geomagnetic storms and solar activity, and may be related to the breeding earthquake. An ionospheric anomaly close to 6 TECU was present near the epicenter 13 days before the earthquake, which is strongly associated with the peak variation of the equatorial anomaly. This suggests that an anomalously increased vertical electric field may have been generated before the earthquake, which in turn enhanced the “fountain effect” and created a strong northern hump.</p></div>","PeriodicalId":48965,"journal":{"name":"Acta Geodaetica et Geophysica","volume":"58 4","pages":"539 - 551"},"PeriodicalIF":1.4,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135346900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Using real GNSS data for ionospheric disturbance remote sensing associated with strong thunderstorm over Wuhan city 利用真实的全球导航卫星系统数据进行与武汉市上空强雷暴有关的电离层扰动遥感

IF 1.4 4区地球科学

Acta Geodaetica et Geophysica Pub Date : 2023-10-04 DOI: 10.1007/s40328-023-00423-w

Mohamed Freeshah, Nahed Osama, Xiaohong Zhang

{"title":"Using real GNSS data for ionospheric disturbance remote sensing associated with strong thunderstorm over Wuhan city","authors":"Mohamed Freeshah, Nahed Osama, Xiaohong Zhang","doi":"10.1007/s40328-023-00423-w","DOIUrl":"10.1007/s40328-023-00423-w","url":null,"abstract":"<div><p>Acoustic-gravity waves (AGWs) generated in the lower atmosphere can cause the ionosphere’s ionized plasma. Therefore, the electromagnetic signals transmitted from the navigation and communication satellites can be distorted based on AGWs propagating to upper atmosphere height and then disturbing the ionosphere. In this work, total electron content (TEC) was derived from dense Hubei continuously operating reference stations (HBCORS) to detect the potential ionospheric disturbance associated with a severe thunderstorm that hit Wuhan city on March 2, 2018. TEC values were examined under meticulous observation for the space weather indices. Furthermore, a de-trending algorithm, the so-called numerical divergence by multiple intervals, was applied to TEC sequences to detect the ionospheric disturbance due to the event. The slant TEC (STEC) variations near the thunderstorm area had a higher amplitude content than those that were away from it. The STEC deviations (dTEC) have been compared with a non-lighting day. Our findings indicated that the dTEC was insignificant compared with the day of the event. Afterwards, regional ionosphere maps (RIMs) were modeled through the HBCORS data around Hubei province. RIMs were employed to analyze the vertical TEC (VTEC) response to the thunderstorm. VTEC responses were detected by a proposed de-trend method so-called differences from the average value. The ionosphere showed a positive response up to 2 TECU, especially in the northern part of Hubei province where the maximum VTEC amplitude variations coincided with the thunderstorm influence. The findings are tentatively interpreted by lightning-induced electric fields and AGWs.</p></div>","PeriodicalId":48965,"journal":{"name":"Acta Geodaetica et Geophysica","volume":"58 4","pages":"553 - 574"},"PeriodicalIF":1.4,"publicationDate":"2023-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135590771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Examining landslides by different geodetic deformation models: a case study on Esiroğlu-Işıklar location, Trabzon, Turkey 用不同的大地测量变形模型检查滑坡:以土耳其特拉布宗Esiroğlu-Işıklar地点为例

IF 1.4 4区地球科学

Acta Geodaetica et Geophysica Pub Date : 2023-09-01 DOI: 10.1007/s40328-023-00420-z

F. Kadi, Faruk Yildirim

引用次数: 0

PL-geoid2021: A quasigeoid model for Poland developed using geophysical gravity data inversion technique PL-geoid2021:利用地球物理重力数据反演技术开发的波兰准类地面模型

IF 1.4 4区地球科学

Acta Geodaetica et Geophysica Pub Date : 2023-08-30 DOI: 10.1007/s40328-023-00422-x

M. Trojanowicz, M. Owczarek-Wesołowska

引用次数: 0

Identification of potential seismic damage in Tanah Patah area, Bengkulu City, Indonesia 印尼明古鲁市Tanah Patah地区潜在地震破坏的识别

IF 1.4 4区地球科学

Acta Geodaetica et Geophysica Pub Date : 2023-08-29 DOI: 10.1007/s40328-023-00419-6

L. Z. Mase

引用次数: 0

Ultrasonic P-wave to ascertain the mean grain diameter of D’Euville limestone 超声纵波法测定德维尔石灰岩平均粒径

IF 1.4 4区地球科学

Acta Geodaetica et Geophysica Pub Date : 2023-08-16 DOI: 10.1007/s40328-023-00421-y

Guangxi Li, Xiang Li, Yuchao Wang

引用次数: 0

Gravity field modelling in mountainous areas by solving the nonlinear satellite-fixed geodetic boundary value problem with the finite element method 用有限元法求解非线性卫星定边值问题建立山区重力场模型

IF 1.4 4区地球科学

Acta Geodaetica et Geophysica Pub Date : 2023-08-16 DOI: 10.1007/s40328-023-00418-7

M. Macák, Z. Minarechová, R. Cunderlík, K. Mikula

引用次数: 0

Geoid model determination for the Hellenic area “Hellas Geoid 2023” 希腊地区“Hellas Geoid 2023”的大地水准面模型确定

IF 1.4 4区地球科学

Acta Geodaetica et Geophysica Pub Date : 2023-07-25 DOI: 10.1007/s40328-023-00416-9

Melissinos Paraskevas, N. Papadopoulos, D. Ampatzidis

引用次数: 1

Geodetic observations confirming land subsidence of Bandung Basin, Indonesia, and subsequent building damage 大地测量观测证实印度尼西亚万隆盆地的地面沉降和随后的建筑物损坏

IF 1.4 4区地球科学

Acta Geodaetica et Geophysica Pub Date : 2023-07-10 DOI: 10.1007/s40328-023-00417-8

I. Gumilar, T. P. Sidiq, R. Virtriana, G. Pambudi, B. Bramanto, H. Abidin

引用次数: 0