Precise Positioning of Primary System of Geodetic Points by GNSS Technology in Railway Operating Conditions

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26110%2F24%3APU151348" target="_blank" >RIV/00216305:26110/24:PU151348 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.3390/app14083288" target="_blank" >https://doi.org/10.3390/app14083288</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3390/app14083288" target="_blank" >10.3390/app14083288</a>

Result language

angličtina

Original language name

Precise Positioning of Primary System of Geodetic Points by GNSS Technology in Railway Operating Conditions

Original language description

This article deals with the analysis of the accuracy of the geodetic real-time GNSS measurement procedure used in railway operating conditions in the Czech Republic. The purpose was to deter-mine to what extent the operating conditions affect the accuracy of the measurement result and whether an accuracy of standard deviation σx,y = 5 mm in the horizontal plane could be achieved. The use of geodetic GNSS equipment with an IMU unit was also tested. The accuracy obtained in op-erational conditions is compared with the accuracy obtained on a calibration base using the same measurement procedure. The consistency between the accuracy of the primary system (satel-lite-based) and the secondary system (terrestrially measured by the traverse method) is also dis-cussed. The analysis includes the issue of residual inhomogeneities of the uniform transformation key when converted to the Czech national coordinate system S-JTSK. It is shown that a homoge-neous accuracy in coordinate standard deviation better than σx,y = 5 mm can be achieved. The results indicate that the accuracy under operational conditions is two−three times worse than the accuracy achieved by the same procedure under ideal conditions on a calibration base. This is due to the non-ideal observing conditions, i.e., horizon occlusion by overlays, surrounding vegetation and multipath effects. It has been shown that the effect of multipath can be reduced by repeating short observations 3−4 h apart. Older GNSS instruments using an IMU unit in combination with an elec-tronic compass (eCompass) are at risk of a systematic bias of up to several tens of millimeters, which can be detected by rotating the antenna by 180°. The current uniform transformation key used in the Czech Republic for the conversion of GNSS coordinates into the national system has residual ge-ometric inhomogeneities (p = 0.90 to 10 mm/km, sporadically up to 20 mm/km), which metrolog-ically deteriorate the results of the calculation of the terrestriall

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

20104 - Transport engineering

Project

—

Continuities

S - Specificky vyzkum na vysokych skolach

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Applied Sciences - Basel

ISSN

2076-3417

e-ISSN

—

Volume of the periodical

13

Issue of the periodical within the volume

9

Country of publishing house

CH - SWITZERLAND

Number of pages

17

Pages from-to

1-17

UT code for WoS article

001210580800001

EID of the result in the Scopus database

2-s2.0-85192561663