|
|
Activities of the SKPOS National Service Center
Ferianc, Martin ; Smolík, Karol
The National Service Center of the Slovak Real-time Positioning Service (SKPOS NSC) does not perform only operation of the national positioning service, management of the service users and handling of the control software. It ensures many other interesting activities, such as detailed testing of the real-time service, checking the data quality of the SKPOS reference stations, processing the SKPOS network using Bernese software, analyzing the geokinematics of Slovakia, modernization of the network by searching for suitable potential locations for new reference stations or building the so-called National Reflector Network connecting GNSS and InSAR technologies. To work with data SKPOS NSC uses commercial software, as well as its own developed applications and scripts. It also operates a website and a Facebook funpage. In addition, NSC SKPOS is an EPN operation center, which manages reference stations in Slovakia included in the permanent EUREF network (EPN), contributes with daily or weekly network coordinate solutions to the EPN Densification project. Within the E-GVAP and HUSKROUA projects, it contributes with hourly near-real-time station data to the weather forecast predictions. Besides that, it performs quality control of selected international real-time networks within the European Position Determination System (EUPOS) initiative. The post describes individual activities in detail.
|
|
|
Precise Positioning of Railway Primary System Using Gnss Technology in Operating Conditions
Bureš, Jiří ; Vystavěl, Ondřej
The paper deals with the analysis of the accuracy of the real-time GNSS measurement procedure used in railway operating conditions. The accuracy achieved in operating conditions is compared with the accuracy obtained on a calibration base using the same measurement procedure. The consistency between the accuracies of the primary system (satellite-determined) and the secondary system (terrestrially measured by the traverse method) is also discussed. The analysis includes the problem of residual inhomogeneities of the uniform transformation key when transformed to S-JTSK.
|
|
|
Use of GNSS Methods in Mapping Regional Tectonic Structures
Švábenský, Otakar ; Pospíšil, Lubomil
The article is devoted to the analysis and interpretation of geoscientific data in the area around the Rodl-Kaplice-Blanice (RKB) fault system. The RKB system, which has been active since the Proterozoic, appears as a significant interface in geological and geophysical maps. According to the occurrences of earthquake foci, the southern (central) part is also a seismically active zone. DPZ, GNSS, geophysical and geomorphological data were used to assess possible recent activity, with the main output in the form of a recent-kinematic model. The results show that the blocks on opposite sides of the RKB show diametrically different, opposite horizontal movement tendencies, the intensity of which increases towards the system of the South Bohemian Cretaceous-Tertiary basins.
|
|
|
Assessment of the Possibilities of Monitoring the Phenological State of Vegetation Based On the Qualitative Characteristics of GNSS Signals
Tomaštík, Julián
Urban environments and vegetation cover are two of the most known examples of conditions that adversely affect the reception of GNSS signals. Despite the limitations, GNSS are used for determining the position in the forests during the implementation of various activities. Quantifying the impact of such an environment is very difficult due to its complexity and variability. The purpose of our experiment is to assess the extent to which the changes in phenology (e.g. leaf fall and growth) are observable on signal characteristics (especially C/N0, multipath, cycle slips). The monitoring station for this purpose was set up in the conditions of full forest cover, while a significant feature of the experiment is the focus on low-cost and freely available solutions. The content of the paper is an introduction to the methodology of the experiment and the presentation of preliminary results obtained during the first campaign in autumn 2023.
|
|
|
Practical Aspects of Real-Time Kinematic Measurements With Topcon Hiper+ And Trimble SPS855 Receivers in the CZEPOS And TOPNET Networks
Kostelecký, Jakub
The Real-Time Kinematic method is the most commonly used Global Navigation Satellite Systems (GNSS) method for positioning in geodetic practice. Within the framework of the article, the behavior of two GNSS devices Topcon HiPer+ and Trimble SPS855 during positioning by RTK method using corrections provided by networks of permanent stations CZEPOS and TopNet is assessed. Specifically, the use of 4 types of corrections from the CZEPOS network and 4 types of corrections from the TopNet network were evaluated. The behavior of the devices is assessed both according to the time required to perform the initial initialization and the time required to average the measurement result, and also according to the RMS (root mean square) error of the vertical component of the position. The evaluation found that the Trimble SPS855 fixed faster than the Topcon HiPer+ (3.6 minutes vs. 5.7 minutes). The averaging time is slightly shorter with the Topcon HiPer+ apparatus than with the Trimble SPS855 apparatus (30 seconds vs. 37 seconds), which is mainly related to the intuitiveness of the control software in the controller. Overall, it is stated that the Topcon HiPer+ equipment is more suitable for corrections from the TopNet network, and the Trimble SPS855 equipment works better with corrections from the CZEPOS network.
|
|
|
Aplikace Galileo High Accuray Service
Kazmierski, Kamil ; Hadas, Tomasz ; Kudłacik, Iwona ; Marut, Grzegorz ; Madraszek, Szymon
Since January 2023 the Galileo High Accuracy Service (HAS) is available to registered users. Within the HAS users can retrieve clock and orbit corrections, as well as code biases for Galileo and GPS constellations. Galileo HAS covers almost the entire globe and is the next system, after the Japanese CLAS (Japanese Centimeter Level Augmentation Service) and the Chinese PPP-B2b, that provides corrections via a satellite signal. These Galileo corrections are transmitted in the Galileo E6 signal but also via the Internet stream. The official HAS Service Definition Document indicates that the positioning accuracy is better than 25 cm and better than 30 cm for horizontal and vertical components, respectively. HAS corrections can be used in difference real-time applications without Internet connection. The presented work shows the use of Galileo HAS corrections in various geoscience applications such as positioning, timing, troposphere monitoring or coseismic vibrations detection. Additionally, the quality of the transmitted HAS correction is also verified using the SISRE parameter. The computations are carried out in the in-house developed GNSS-WARP software with the Internet HAS corrections saved in the ASCII files by the BKG Ntrip Client software. The Galileo HAS corrections quality using SISRE parameter equal to 8.6 cm and 13.0 cm for GPS and Galileo respectively. The experiment with Precise Point Positioning reveal sub-decimeter and centimeters accuracy in kinematic and static approach, respectively. In terms of timing precision Galileo HAS ensure precision of single nanosecond. Zenith Tropospheric Delay estimation with the use of evaluated corrections meet the requirement of troposphere monitoring and coseismic vibrations detection was also possible.
|
|
|
Assesment of Galileo High Accuracy Service
Nosek, Jakub ; Douša, Jan ; Václavovic, Pavel ; Kala, Michael
The paper deals with the testing of the Galileo High Accuracy Service (HAS), which will be officially launched in January 2023 as part of the HAS Initial Service phase. The results of the HAS comparison with the precise GNSS product showed a high accuracy of the HAS corrections and the fulfillment of the declared accuracy. Data processing at 3 selected stations of the EUREF Permanent Network showed that the officially declared HAS accuracy (horizontal accuracy 20 cm, vertical accuracy 40 cm) is achievable, but with a longer required convergence time (kinematic processing 22 min, static processing 8 min) than the required convergence time (5 min).
|
|
|
Inovace PPK GNSS senzoru Titan v posuzování zemětřesné kinematiky
Šugar, Danijel ; Ukas, Mladen
Within the sotware package Trimble Business Center ver. 5.90 (May 2023) was released a novel PPK GNSS processor named Titan. It utilizes all available GNSS constellations bringing improvement over the previous processor. CROPOS as the national permanent GNSS network of Croatia was modernized in summer of 2019 and since than it provides observations of all available GNSS constellations, namely, the GPS, GLONASS, Galielo and BeiDou. On March 22nd 2020, the wider area of Zagreb was hit by the M5.4 earthquake. The closest GNSS station to the epicenter (approx. 9 km) was the station ZAGR in Zagreb downtown and as such it was subject to earthquake shaking. Although the kinematic effects of that earthquake have already been assessed and examined, with this approach and novel PPK GNSS processor we are attempting to provide new insights into the earthquake kinematics involving observations from several CROPOS's GNSS stations in wider area around Zagreb.
|
|
|
Real-time propojení senzorů pro navigaci
Kaczmarek, Adrian ; Rohm, Witold ; Klingbeil, Lasse ; Tchórzewski, Janusz
The development of satellite techniques in the field of precise positioning and the availability of mobile devices with a built-in multi-GNSS (Global Navigation Satellite System) receiver allow us to determine positions with better accuracy than a dozen or so years ago. At the same time, there is a growing demand from users for more and more accurate positioning while reducing the costs of the final device (e.g., a navigation system for autonomous lawn mowers). This work presents the concept of a solution that integrates different positioning techniques: gyroscopes, odometers, and GNSS using a loosely coupled Kalman filter. The sensor integration model was developed for horizontal components (2D) with simultaneous determination of azimuth and precise position. Additionally, the integration filter uses a dynamic weight matrix, the values of which are selected depending on the type of GNSS solution (FIX, FLOAT, etc.). Tests of the measurement platform were carried out under ideal conditions and in places where the horizon is obscured (passes along a high wall, under openwork steel trusses, etc.). The accuracies obtained during tests using EKF and the dynamic weight matrix are RMS 0.019 m for the North and East components. However, the accuracy of the azimuth determination was 0.59°. In addition, the presentation will present a platform concept that integrates low-cost sensors in real time.
This work was supported by Wroclaw University of Environmental and Life Sciences (Poland) under the project “POMOST” (grant no. N110/0002/22).
|
|
| |
guest ::
