The geoid, which serves as the reference surface for heights in geosciences, is a closed surface representing the Earth’s real physical shape. In literature, various methods have been proposed for geoid determination over the years; the gravimetric approach, which relies on gravity data, is one of the most widely used. The major challenge of the gravimetric method lies in solving the convolution integral involved in the formulation, which is a computationally time-consuming process. In this paper, the parallel computation of a convolution integral is explained. Also, the gravimetric geoid determination was carried out by parallel computing using multi-threads. Hence, the speed-up graphs and numerical comparisons were performed based on the integration cap size, data density, and number of threads, separately. The experimental results demonstrate that parallel computing significantly contributes to geoid determination processes regarding the runtime. For illustration, depending on the cap size and data density, parallel computing achieves speed-ups of up to 9 and 11 times, respectively.

This study presents the development of a high-resolution local geoid model for the Perlis region, Malaysia, using a geometric approach that integrates GNSS-levelling benchmarks with Cadastral Reference Mark (CRM) data. A total of 38 GNSS-levelling benchmarks were used as reference points, while 3,725 CRMs were incorporated to significantly enhance spatial coverage for geoid modelling. Orthometric heights at the CRM points were first determined by transferring heights from the reference benchmarks using gravimetric geoid information. Subsequently, geometric geoid heights were computed from the differences between ellipsoidal and orthometric heights. Five interpolation techniques were evaluated to generate the geometric geoid surface, namely Kriging, Polynomial, Inverse Distance to a Power, Nearest Neighbour, and Moving Average. Independent validation was carried out using 21 GNSS-levelling points observed using the Real-Time Kinematic (RTK) method. The results indicate that the Inverse Distance to a Power interpolation provides the best performance, achieving a Root Mean Square Error (RMSE) of 5.47 cm. Further comparison with Malaysia’s official hybrid geoid model shows that the developed geometric geoid improves accuracy by approximately 2 cm over the study area, demonstrating its practical advantage for local height determination. The findings demonstrate that the integration of dense CRM data within a geometric geoid framework offers a cost-effective and reliable alternative for local geoid determination, particularly in regions with limited conventional levelling coverage. This approach also highlights the potential of Malaysia’s CRM database to support accurate vertical datum realisation and practical height determination applications.

Different types of gravity anomalies are engaged in geophysical and geodetic tasks. Whether they are used for regional or global applications, they require efficient calculations. All variants are based on the so-called free-air gravity anomalies. Mean free-air gravity anomalies on an equidistant grid are needed for gravity field modeling. Three possible ways of compiling mean free-air gravity anomalies are discussed in detail. One method is via simple Bouguer gravity anomalies, the second, more time-consuming method is via complete Bouguer gravity anomalies, and the third method is via topographic-isostatic reductions, which is a tedious task. In flat areas, the differences between using any of the three methods should not be significant. However, in mountainous regions, each dependency can negatively affect the interpolation process of gravity anomalies. The reduced gravity anomalies should be as smooth as possible in order to minimize the interpolation error which is inherent in the interpolation of the information in the arbitrarily distributed gravity observation points to obtain block average signals. This study investigates the effects of Bouguer and topographic-isostatic reductions on the accuracy of the mean gravity anomalies and the resulting gravimetric geoid model. The numerical results indicate that complete Bouguer approximations improve the accuracy of the geoid model by a few millimeters. Therefore, this method should be used to predict mean gravity anomalies, especially in mountainous regions, in few of the 1 cm geoid determination.

This paper assesses the accuracy and consistency of different methods for estimating the deflection of the vertical (DoV) and various geoid models in the Colorado test area. The DoVs derived from a gravimetric geoid model and several global geopotential models (GGMs) were inter-compared and validated by astrogeodetic DoVs. For the computation of global DoVs, two recent GGMs developed through data from the GOCE (The Gravity field and steady-state Ocean Circulation Explorer), GRACE (Gravity Recovery And Climate Experiment), and GOCE+GRACE satellite missions were utilized. Additionally, the astrogeodetic geoid heights were determined with the astronomical levelling method, while the gravimetric geoid heights were computed by the KTH (Swedish Royal Institute of Technology) method. The astrogeodetic, gravimetric, and GNSS-levelling geoid models were also cross-compared. The numerical results indicate that the DoVs obtained from the gravimetric geoid model are more accurate than those derived from global models. Moreover, in mountainous areas, the astrogeodetic geoid model provides a more precise solution than the other approaches.

High-accuracy geoid modelling in complex terrain such as East Malaysia requires robust DEMs, high-quality gravity observations, and realistic crustal density information. Although global models of topographic and crustal density such as UNB_TopoDens and CRUST1.0, respectively have shown promising results internationally, their applicability and impact on geoid computation in the Malaysian region remain largely unexplored. Thus, this study investigates the influence of six global DEMs (ALOS, ASTER, SRTM, FABDEM, MERIT, and NASADEM), together with density information derived from two global models namely UNB_TopoDens and CRUST1.0 on gravimetric geoid determination using the Least Squares Modification of Stokes’ Formula with Additive Corrections (LSMSA). A comprehensive gravity dataset comprising terrestrial, airborne, and marine observations was combined with the WHU-SWPU-GOGR2022S global geopotential model for long-wavelength recovery. The geoid models based on different DEMs were evaluated using 43 GNSS-levelling benchmarks, revealing that MERIT, ALOS, and ASTER show superior vertical consistency. The impact of laterally varying crustal density was then investigated through its effect on Bouguer reductions, free-air anomalies, and final geoid heights. Although the resulting geoid surfaces differ only slightly, typically within ± 0.10–0.20 m, significant enhancements occur in mountainous regions such as the interior of Sabah. GNSS validation demonstrates that variable-density geoids (UNB and CRUST1.0) achieve lower mean differences and RMSE ( 0.520 m) compared with the constant-density solution ( 0.548 m). The findings confirm that global crustal density models, while not drastically altering the geoid, contribute measurable accuracy improvements and should be incorporated in future regional vertical datum modernisation efforts for East Malaysia.

In this study, the potential of artificial neural networks (ANN) for hybrid geoid modelling was investigated, and then ANN was compared with traditional surface models. A mountainous region in central France (Auvergne test-bed) was selected as the study area due to its complex topography and availability of high-resolution gravimetric geoid model as well as homogenously distributed GNSS-levelling benchmarks. The gravimetric geoid model was adapted to the national vertical datum adopting both classical surface models (4-, 5-, and 7-parameter) and feed-forward back-propagation ANN models. The performance of the models was evaluated using Root Mean Square Errors derived from both training and test datasets. The ANN-based model achieved the best test accuracy (2.11 cm), outperforming the best parametric model (2.34 cm). While ANN models offer higher accuracy, they require greater expertise and computational resources. The numerical results highlight the potential of ANN as a viable alternative for geodetic height transformation and exhibit their effectiveness even in a mountainous area.

Ellipsoidal heights obtained from the GNSS technique cannot be directly used for the needs of engineering projects due to their dependence on the geodetic datum. In contrast, orthometric heights are physical quantities as they are related to the Earth's gravity field, making them more suitable for practical applications. The transformation between orthometric and ellipsoidal heights is achieved using the geoid height, which is obtained from a geoid model with sufficient accuracy for the region. Therefore, determining a highly accurate geoid model to be used in the transformation from ellipsoidal to orthometric heights is of great importance. Currently, in geodetic applications, the hybrid method which evaluates gravimetric and geometric geoid determination methods together has increasingly been adopted. The hybrid method is an approach that determines a high-accuracy geoid model in the national datum by correcting systematic errors of the gravimetric geoid (such as datum shifts and tilts). In this study, geoid heights at GNSS-levelling points were first obtained from the gravimetric geoid model through the inverse distance weighted interpolation method. Then, the systematic errors between the gravimetric and geometric geoids were modeled using corrective surfaces based on 4, 5, and 7 parameter models. Finally, amongthe obtained corrective surface models, the one with the lowest root mean square error was used for the hybridization process. In addition, the accuracy of the hybrid geoid model was analyzed at selected test points which were not used in hybridization. Numerical results indicate that hybrid geoid determination significantly contributes to the accuracy. Within the scope of the study, the interpolation process and hybrid geoid model generation process were coded in MATLAB software and prepared as a practical graphical user interface.

This study assesses the effect of the UNB Topographical Density Model on the accuracy of geoid determination in Sarajevo, Bosnia Herzegovina. Using the KTH method, 1020 gravimetric geoid models were developed, incorporating both constant and variable density values, simple and complete Bouguer anomalies. The study found that the model computed by the UNB Topographical Density Model and complete Bouguer anomalies achieved the highest precision, with an RMSE of 1.33 cm. The final geoid model was adjusted to the old vertical datum (Trieste height), resulting in an RMSE of 3.44 cm when tested with static GNSS points. These findings underscore the importance of incorporating variable density models for improving geoid accuracy and suggest further refinement using local geological data could enhance precision.

GNSS tekniğinde elde edilen elipsoidal yükseklikler, jeodezik datuma bağlı olduğu için, mühendislik projelerinin ihtiyaçları kapsamında direkt olarak kullanılamazlar. Buna karşın ortometrik yükseklikler yerin gravite alanı ile ilgili olduğu için fiziksel bir büyüklüktür ve pratik çalışmalarda kullanımı daha uygundur. Ortometrik ile elipsoidal yükseklikler arasındaki dönüşümü, bölgede var olan yeterli doğrulukta bir jeoit modelinden elde edilen jeoit yüksekliği sağlar. Dolayısıyla elipsoidal yüksekliklerden ortometrik yüksekliklere dönüşümde kullanılacak yüksek doğruluklu jeoit modelinin belirlenmesi oldukça önemlidir. Son zamanlarda, jeodezik uygulamalarda çoğunlukla gravimetrik ve geometrik jeoit belirleme yöntemlerini birlikte değerlendiren hibrit yöntem kullanılmaya başlanmıştır. Hibrit yöntem, gravimetrik jeoidin sistematik hatalarını (datum kayıklığı, dönüklük gibi) gidererek, ulusal datumda yüksek doğruluklu jeoit modeli belirleyen bir yaklaşımdır. Bu çalışmada, öncelikle gravimetrik jeoit modelinden GNSS-Nivelman noktalarında, ters uzaklıkla ağırlıklı enterpolasyon yöntemi ile jeoit yükseklikleri elde edilmiştir. Sonra gravimetrik jeoit ile geometrik jeoit arasındaki sistematik hatalar; 4, 5 ve 7 parametreli düzeltici yüzey ile modellenmiştir. Son olarak elde edilen düzeltici yüzey modellerinden karesel ortalama hatası en iyi olan model, hibritleştirme için kullanılmıştır. Ek olarak hibrit jeoit modelinin doğruluğu hibritleştirmede kullanılmayan test noktalarında analiz edilmiştir. Sayısal sonuçlar hibrit jeoit belirlemenin doğruluğa önemli katkılar sağladığını göstermektedir. Çalışma kapsamında, enterpolasyon işlemi ve hibrit jeoit model üretim süreci MATLAB yazılımında kodlanmış ve pratik bir grafik arayüz olarak hazırlanmıştır

In gravimetric geoid determination, free-air gravity anomaly is used as input data. Therefore, gravity measurements taken on the physical Earth's surface are reduced to mean sea level and referred to free-air gravity anomalies. After the reduction, free-air gravity anomalies should be interpolated to grid centres for geoid determination studies. However, since free-air gravity anomalies contain topographic effects, they create an undulating surface and are not suitable for interpolation. To eliminate topographic effects, the Bouguer plate effect is removed from the free-air gravity anomalies, resulting in Bouguer gravity anomalies. After this step, Bouguer anomalies can be interpolated to grid centre. A review of the literature shows that there are several options for the interpolation process. In this study, it was aimed to determine the most accurate approach by using different interpolation methods to see the effects of the interpolation process. The state of Colorado, USA, was selected as the study area. The minimum, maximum and average topography in the study area are 1306 m, 4372 m and 2469 m, respectively. Thus, the KTH method providing successful results in mountainous regions, was chosen as the geoid determination method. The numerical results demonstrates that the inverse distance weighting method supplies the most accurate geoid model. In addition, the inverse distance weighting geoid model was used as a reference in the study and the geoid models obtained from other interpolation methods were compared. The comparisons showed that there were significant differences between the interpolation methods in high-altitude regions.

Gravimetrik jeoit belirlemede girdi verisi olarak serbest hava (free-air) gravite anomalisi kullanılmaktadır. Bu nedenle fiziksel yeryüzünde ölçülen gravite büyüklükleri, ortalama deniz seviyesine indirgenir ve serbest hava anomalisi olarak adlandırılır. Bu indirgemeden sonra serbest gravite anomalileri, jeoit belirleme çalışmaları için grid merkezlerine enterpole edilmelidir. Ancak, serbest gravite anomalileri, topografik etkileri içerdiği için dalgalı bir yüzey oluşturmaktadır ve enterpolasyona elverişli değildir. Topografik etkileri ortadan kaldırmak amacıyla Bouguer plakası etkisi, serbest hava gravite anomalilerinden çıkarılır. Sonuçta Bouguer gravite anomalileri elde edilir. Bundan sonra Bouguer anomalileri grid merkezlerine enterpole edilebilir. Literatür incelendiğinde enterpolasyon sürecinde birçok seçenek vardır. Bu çalışmada enterpolasyon sürecinin etkilerini görmek amacıyla farklı enterpolasyon yöntemleri kullanılarak en doğru yaklaşımın belirlenmesi hedeflenmiştir. Çalışma sahası olarak Amerika Birleşik Devletleri’nin Colorado eyaleti seçilmiştir. Sahada topoğrafyanın minimum, maksimum ve ortalama yüksekliği sırasıyla 1306 m, 4372 m ve 2469 m’dir. Bu nedenle, jeoit belirleme yöntemi olarak dağlık alanlarda başarılı sonuç veren KTH yöntemi tercih edilmiştir. Sayısal sonuçlar ters mesafe ağırlık yönteminin en yüksek doğruluklu jeoidi verdiği belirlenmiştir. Ayrıca çalışmada ters mesafe ağırlıklı jeoit modeli referans alınarak diğer enterpolasyon yöntemleri ile elde edilen jeoit modelleri karşılaştırılmıştır. Karşılaştırmalar, yüksek bölgelerde enterpolasyon yöntemleri arasında kayda değer farklar olduğunu göstermiştir.

This study focuses on analysing the impact of deterministic modifications of the Stokes kernel and terrain correction methods for precise geoid determination using the Stokes-Helmert method over a sophisticated topography. Three deterministic modification methods of Stokes’s kernel (Wong-Gore, Vaníček-Kleusberg, and Featherstone-Evans-Olliver) are tried to minimize the truncation error emanating from the non-availability of gravity data all over the Earth by utilizing two independent satellite only global geopotential models. In parallel to the modified Stokes kernel functions, two terrain correction techniques, i.e., spatial-spectral combined method with mass-prisms and spatial method with mass-cylinders, have also been examined to assess their combined effects on geoid heights over the Konya Closed Basin in Türkiye. The developed geoid models are validated with GNSS-levelling data and inter-compared pixel-wise. The numerical results show that although the overall statistical values depict consistent precision for various combinations of TCs, Stokes kernel modifiers, and GGMs, a holistic validation-comparison analysis reveals significant variations in view of the cm-precise geoid.

In geoid determination studies, the main goal is to create a geoid model with an accuracy of 1 centimeter. Solving this goal in the fastest and most practical way makes it easier to implement some engineering problems. For this reason, the methods used to determine the geoid are being developed day by day. The Stokes-Helmert approach is one of the classical geoid modeling options. If the topography is not handled carefully in the solution of the boundary value problem, it is an obstacle to achieving the desired goal. In the final stage of the StokesHelmert approach, the exact geoid height is obtained by calculating the PITE (Primary Indirect Topographic Effect). The density change causes a significant difference in the PITE's calculation and, therefore, in the geoid heights. To see this difference, it is enough to use the digital elevation model and the crustal density model. In geosciences studies related to topography, the density value is usually taken as an average of 2.67 g/cm3. However, this value varies in some regions, approaching 20%. Such a ratio, which can be observed in the density change, affects the values obtained from the PITE calculation at the decimetre level. In this study, the effect of density change on PITE will be examined. In this way, an important contribution will be made to the centimeter accuracy geoid determination studies in our country. The PITE values depend on the height and density of the calculation point. As a result of numerical application, the density change gives PITE values between -43 cm and -1 cm, while under constant density these values are between -39 cm and 39 cm.

Jeoit belirleme çalışmalarında 1 santimetre doğruluklu jeoit modeli oluşturmak ana hedeftir. Bu hedefin en hızlı ve en pratik şekilde çözülmesi bazı mühendislik problemlerinin çözülmesini kolaylaştırmaktadır. Bu nedenle jeoit belirmek için kullanılan yöntemler gün geçtikçe geliştirilmektedir. Stokes-Helmert yaklaşımı klasik jeoit modelleme seçeneklerinden biridir. Sınır değer probleminin çözümünde topoğrafya dikkatli bir şekilde ele alınmaz ise istenen hedefe ulaşmaya engeldir. Stokes-Helmert yaklaşımının son aşamasında PITE’nin (Birincil Dolaylı Topoğrafik Etki) hesabıyla kesin jeoit yüksekliği elde edilmektedir. Yoğunluk değişimi, PITE’nin hesabında ve dolayısıyla, jeoit yüksekliklerinde anlamlı farklılığa neden olur. Bu farkı görmek için bir sayısal yükseklik modeli ve kabuk yoğunluğu modelinden yararlanmak yeterlidir. Topoğrafyayı ilgilendiren yerbilimleri çalışmalarında yoğunluk değeri genelde ortalama 2.67 gr/cm³ alınır. Ancak bu değer bazı bölgelerde %20’lere yaklaşan farklılık gösterir. Yoğunluk değişimindeki böyle bir oran PITE hesabından bulunan değerleri desimetre mertebesinde etkiler. Bu çalışmada yoğunluk değişiminin PITE üzerindeki etkisi incelenecektir. Bu sayede ülkemizde santimetre doğruluklu jeoit belirleme çalışmalarına önemli bir katkı sağlanacaktır. PITE değerleri hesap noktasının yüksekliğine ve yoğunluğuna bağlıdır. Sayısal uygulama sonucunda değişken yoğunluklu PITE değerleri -43 cm ile -1 cm arasında değişirken, sabit yoğunluk kullanıldığında bu değerler -39 cm ile -10 cm arasındadır

TUSAGA-Aktif (Türkiye Ulusal Sabit GNSS Ağı) sistemi, 168 adet sabit GNSS (Küresel Konum Belirleme Sistemleri) istasyonu ile ticari ve akademik çalışmalar için kullanıma sunulmuştur. Sistemden yüksek doğrulukta veri elde edilebilmesi, yer kabuğu hareketleri nedeniyle mühendislik yapılarında meydana gelen deformasyonların izlenmesini kolaylaştırmıştır. 30 Ekim 2020 tarihinde Ege Denizi’nde (Sisam Adası açıklarında) yerel saat ile 14.51’de aletsel büyüklüğü Ml=6.6 (Mw=6.9) olan bir deprem meydana gelmiştir. Çalışmanın amacı deprem etki alanında seçilen TUSAGA-Aktif istasyonlarında, bu deprem kaynaklı herhangi bir kabuk deformasyonu olup olmadığının incelenmesidir. Bu kapsamda AYD1, CESM, DIDI, IZMI, KIKA ve SALH istasyonlarının deformasyon yönleri ve büyüklükleri belirlenmiştir. Deprem tarihinden 15 gün önce ve 11 gün sonrasına ait RINEX (Alıcı Bağımsız Değişim Biçimi) gözlem verileri internet tabanlı GNSS servislerinden CSRS-PPP (Canadian Spatial Reference System Precise Point Positioning Service) ve OPUS’da (Online Positioning User Service) değerlendirilmiş, sonuçlar analiz edilmiştir. CSRS-PPP servisi sonuçlarına göre, kuzey yönde 57.39 mm anlamlı deformasyon miktarı ile depremden en çok CESM istasyonu etkilendiği görülmüştür. OPUS analiz servisi verilerinden de benzer sonuçlar elde edilmiştir.

Accurate geoid height determination are crucial for achieving high precision in geospatial measurements. In this context, one key challenge is accounting the density for the Earth's topography, which varies considerably across different regions. The assumption of a homogeneous crustal density value of 2.67 g/cm3 has traditionally been employed in geoid determination using Stokes' formula. However, recent studies have underscored the need to consider the actual density variations, which can deviate by up to +/- 20% from this assumed value. Such deviations can lead to substantial discrepancies in geoid height calculations, especially in regions characterized by significant topographic variations, such as mountainous areas. In this study, we address this issue by developing a local density model specifically tailored to Central Anatolia, Turkiye, using Bouguer gravity anomalies. By incorporating this refined density model, we aim to improve the accuracy of gravimetric geoid determination in the mountainous terrain of the study area. To achieve this objective, we employ the Least Squares Modification of Stokes' Formula (LSMS) approach, implemented via the LSMSSOFT software package. Through numerical analysis, our results demonstrate noteworthy geoid height differences, sometimes exceeding a few decimeters, between the local density model and the conventional homogeneous crustal model. These disparities point out the significance of considering local density variations, particularly when striving for centimeter-level accuracy in geoid determination, especially in topographically complex regions. In conclusion, this study highlights the critical impact of density variations on geoid determination and emphasizes the necessity of adopting local density models, particularly in mountainous areas.

With the progress in Global Navigation Satellite Systems (GNSS) technology, accurate geoid modelling has started to play an essential role in geodetic applications such as establishing height datum as a continuous surface model and related vertical control for infrastructure projects. Thus, numerous geoid modelling methods have been offered since 1990’s, each of them has its own algorithm and approximation theories. Classical Stokes-Helmert is one of the most well-known methods all over the world by geodetic communities. However, a user-friendly software package of the method is not publicly accessible on the Internet. Therefore, a compact and user-friendly software package “CSHSOFT” is developed and presented for scholars in this field. A fractionated programming strategy has been treated to build individual components striving high accuracy and computational efficiency for geoid heights. Subsequently, the CSHSOFT is simply tested to construct a geoid model in the mountainous area in Auvergne test-bed where several geoid modelling techniques are implemented. Afterward, the new geoid model of the region is externally evaluated by GNSS-levelling data in terms of rigorous orthometric heights. The fitting statistics of 2.75 cm and 0.36 ppm in absolute and relative height differences fairly indicate that the CSHSOFT is a vigorous tool for gravimetric geoid modelling, and can be comfortably employed for geoscientific and technical studies.

The researchers investigate some phenomena by continuously observing physical variables, i.e., time series. Nowadays, the Least-Squares Spectral Analysis (LSSA) technique has been preferred for the analysis of time series to conduct more reliable analysis. This technique uses the least-squares principle to estimate the hidden periodicities in the time series. Based on the previous investigations, LSSA gives more reasonable results in the experimental time series that have disturbing effects such as the datum shifts, linear trend, unequally spaced data and etc. The LSSA method is a unique method that can overcome these problems without preprocessing the original series. However, a practical and user-friendly software package in C programming language is not available for scientific purposes to implement the LSSA method. In this paper, we review the computational scheme of the LSSA method, then a software (LSSASOFT) package in the C programming language is developed in the view of the simplicity of the method and compatibility of all types of data. Finally, LSSASOFT is applied in two sample studies for the determining hidden periods in the synthetic data and sea level observations. Consequently, the numerical results indicate that LSSASOFT is a useful tool that can efficiently predicting hidden periodicity for the experimental time series that have disturbing effects.

Integration of land and marine vertical datums is an important aspect of geospatial reference systems. Therefore, this study has been conducted to identify an optimum approach to integrate the marine and land vertical datums. Two hybrid geoid models have been developed and fitted to the the land levelling datum at benchmark and to the tide gauge-benchmark station (TGBM). The differences between the two hybrid geoid models were computed to establish a vertical datum transformation model (VDT). Among the 305 GNSS-levelling points, 295 have been used in the hybridization process and 10 have been used for validation. Based on the comparison, the geoidal differences at the 10 points range from −7.2 to 7.0 cm while the mean and RMSE of differences are 1.3 cm and ± 4 cm, respectively. The second hybrid geoid, which was fitted to local MSL, was developed by directly adding to the offset between the gravimetric geoid and local MSL at nine TGBM stations. The result indicates that the offset derived at Tanjung Gelang is the optimum one with an RMSE of ± 0.045 m. The VDT model developed shows a transformation accuracy of approximately ± 4 cm.

We compute the first gravimetric geoid model for Bosnia and Herzegovina (BHG2022) based upon the KTH method and additive corrections. The BHG2022 is computed with the help of 34,820 terrestrial gravity points and a digital elevation model produced by the Shuttle Radar Topography Mission. The gravity data is gridded onto a 0.02 arc-degree resolution via the nearest neighbour interpolation method. ITU_GGC16 and ITG-Grace2010 models are utilised to provide long wavelengths of gravity field up to 280 and 180 maximum degree/order in the geoid computation, respectively. On the basis of an external evaluation by 609 Global Navigation Satellite System (GNSS)-levelling points homogeneously distributed over the country, the accuracy of the BHG2022 is estimated to be 5.65 cm absolutely. This is the most precise geoid model ever seen in this territory. The result highlights the significant effect of all gravity data obtained from various sources on the accuracy of the geoid model.