## 3 Discussion  
In our studies, we have presented the algorithm for real-time adjustment of the integrated GNSS, total station, and EGM vertical direction data in the geocentric coordinate system. The proposed method has two modes: sequential online adjustment of the total station positions and online adjustment of the total station observations. Both modes have been tested on data from the spatial total station traverse measurements. In order to verify the correctness of the online algorithm, the total station traverse data were also adjusted using the offline algorithm. The offline adjustment was conducted with and without including the merging points.  
Online and offline adjustment computation should be considered complementary approaches. They are an essential aspect of the assessment of surveying results, especially in issues related to displacement measurements and deformation monitoring. As demonstrated in the previous section, the accuracies offered by both procedures are comparable and utterly applicable to field measurements. Nevertheless, the main advantages of online adjustment are the ability to conduct reliable deformation monitoring and the ongoing fulfillment of the obtained measurement results for risk management purposes. In this context, attention should be paid to the problem of notifying users of risks arising from the construction and exploitation of the monitored object, as well as from various natural phenomena affecting changes in its structural geometry. Defining safety thresholds (so-called \"limit checks\") is not straightforward. This is primarily caused by the need to correctly identify a specific object and its surroundings, which in turn requires a reasonably long observation period and using multi-source data. Its integration in a standardized manner is one of the most significant theoretical challenges posed by modern geodesy.  
Moreover, ongoing technological advancement influences the constant modification of once-accepted assumptions. As a rule, data sets representing surveying results captured continuously or quasi-continuously onsite must reliably identify outlier observations and determine the influence of other error sources, be they systematic, personal, or instrumental. To this end, complementary methods using estimation and optimization procedures are becoming increasingly important. As discussed in our paper, such a need to work online encourages the development of appropriate procedures and algorithms.  
As demonstrated in the conducted studies, including information regarding the local distribution of plumb line parameters in total station surveying is expedient and desirable. To this end, total station and GNSS satellite measurements were concatenated within the EGM2008 geoid model. Such an approach unifies operating surveying instruments, driving them to be used precisely and universally. However, in the general assessment process, one should consider the specifics of the developed test network. After all, the object reveals specific features (urban, intensively built-up, and used areas) and geometrical features; the network is regular, set up following the art of measurement. We realize that depending on the altering conditions of surveys, the results may somewhat differ from those obtained in our experiment.  
Nevertheless, as already shown in the literature review, similar work has been carried out in other conditions--for example, in the mountains--giving similar results. Additionally, incorporating further data sources into the observational system should not pose significant concerns. In such a case, the vectors of unknowns and the corresponding coefficient matrices will be modified, generally increasing the size of the corresponding arrays. Theoretically, this will cause increased demand for computer processing power; however, with the current parameters of available machines and computational optimization methods, this should be a manageable challenge.