## 4 Conclusions  
The modelling results show that when the television multiscan operates in the analogue mode at the LZ width exceeding the volt aperture \(VA\geq 8U_{0}\), the video signal is of a trapezoidal shape, and at the decrease of the zone width to the moment of its disappearance--of a bell shape.  
It is shown that for small objects (corresponding to narrow light zones), the moments of the change of the sign of the second derivative of the video signal do not correspond to the boundaries of this zone due to the smearing-out of the video signal by its volt aperture, which does not provide a high accuracy of the measurements of the geometric parameters of these objects.  
The mechanism is considered to be the video signal formation based on the multiscan impulse response, which is defined as an elementary video signal from an infinitely narrow light zone--from one discrete photodiode cell of the multiscan.  
It is established that the convolution of the signal of the rectangular profile of a light zone with the impulse response explains the smearing-out of the video signal edges; in this case, the smearing-out value is fully determined by the impulse response and does not depend on the zone width.  
A method is offered for the full reconstruction of the rectangular profile of a light zone (including a narrow one) in the developed noise-proof optoelectronic measuring device based on a multiscan with the use of spatio-structural parameters, where the light zone profile width corresponds to the extent of illumination--brightness, and it's coordinate--centroid.  
It is shown that the subtraction of the impulse response dissipation from the video signal dissipation permits taking into account the value of the video signal smearing-out with high accuracy at the estimation of the light zone width, in correspondence with the property of the additive accumulation of dissipation.  
It is established that the use of the spatio-structural model of a video signal allows for widening the sphere of application of the multiscan-based optoelectronic devices for the tasks of highly-accurate control and measurement of the geometric parameters of small objects. However, the issues of increasing the accuracy of measurements of structural elements' dimensions in noisy graphic images using SSPs have not been sufficiently investigated.  
In the future, we can use other techniques such as holographic interferometry [32; 33], or machine vision system with MATLAB [32], Edge Directions [34], and using logic models and sensors [35].  
Conceptualization, M.Y.A., Y.K.S. and A.I.K.; methodology, M.Y.A., A.A.M. and I.O.A.; formal analysis, M.Y.A. and A.I.K.; writing--original draft preparation, Y.K.S., I.O.A. and A.A.M.; writing--review and editing, V.T and I.K.; supervision, I.K., M.S. and M.Y.A.; funding acquisition, V.T. and M.S. All authors have read and agreed to the published version of the manuscript.  
This article was funded by the University of \(\hat{\text{Z}}\)lima project 313011 ASY4 - \"Strategic implementation of additive technologies to strengthen the intervention capacities of emergencies caused by the COVID-19 pandemic\".  
Not applicable.  
The data presented in this study are available on request from the corresponding author.  
The authors declare no conflict of interest.