scholarly journals Precise Real-Time Positioning Using Network RTK

Author(s):  
Ahmed El-Mowafy
Keyword(s):  
2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Tamer Baybura ◽  
İbrahim Tiryakioğlu ◽  
Mehmet Ali Uğur ◽  
Halil İbrahim Solak ◽  
Şeyma Şafak

Real-time kinematic (RTK) technique is important for mapping applications requiring short measure time, the distance between rover and base station, and high accuracy. There are several RTK methods used today such as the traditional RTK, long base RTK (LBRTK), network RTK (NRTK), and precise point positioning RTK (PPP-RTK). NRTK and LBRTK are popular with the advantage of the distance, the time, and accuracy. In the present study, the NRTK and LBRTK measurements were compared in terms of accuracy and distance in a test network with 6 sites that was established between 5 and 60 km. Repetitive NRTK and LBRTK measurements were performed on 6 different days in 2015-2017-2018 and additionally 4 campaigns of repetitive static measurements were carried out in this test network. The results of NRTK and LBRTK methods were examined and compared with all relevant aspects by considering the results of the static measurements as real coordinates. The study results showed that the LBRTK and NRTK methods yielded similar results at base lengths up to 40 km with the differences less than 3 cm horizontally and 4 cm vertically.


2015 ◽  
Vol 21 (4) ◽  
pp. 814-831 ◽  
Author(s):  
M. Berber ◽  
N. Arslan

Commonly used real time kinematic (RTK) network (RTK Network) techniques, i.e., MAX, I-MAX, FKP and VRS, are tested by taking monthly measurements for a year in Florida. Additionally, RTCM message versions 2 and 3 are used with I-MAX and VRS measurements. The results revealed that mostly, horizontal coordinates vary a few centimeters and generally changes in vertical coordinates are less than two decimeters. In terms of horizontal coordinates, the best results are produced by I-MAX3 method and FKP yielded the worst results. In terms of vertical coordinates, almost all results look alike; however, the best results are produced by VRS3 method. It appears that I-MAX3 performed better than I-MAX2 and VRS3 performed better than VRS2. Yet, MAX did not stand out among other techniques.


2013 ◽  
Vol 66 (3) ◽  
pp. 335-348 ◽  
Author(s):  
Weiming Tang ◽  
Xiaolin Meng ◽  
Chuang Shi ◽  
Jingnan Liu

The average inter-station distances in most established network Real Time Kinematic (RTK) systems are constrained to around 50 km. A sparse network RTK system with an average inter-station distance of up to 300 km would have many appealing advantages over a conventional one, including a significant reduction in the development and maintenance costs. The first part of this paper introduces the key approaches for sparse network RTK positioning technology. These include long-range reference baseline ambiguity resolution and real-time kinematic ambiguity resolution for the rover receivers. The proposed method for long-range kinematic ambiguity resolution can overcome the network weaknesses through three procedures: application of the interpolated corrections from the sparse network only to wide-lane combination; searching the ambiguities of wide-lane combination; and searching L1 ambiguities with wide-lane combination and ionosphere-free observables. To test these techniques, a network including ten reference stations was created from the Ordnance Survey's Network (OS NetTM) that covers the whole territory of the United Kingdom (UK). The average baseline length of this sparse network is about 300 km. To assess the positioning performance, nine rover stations situated inside and outside the network were also selected from the OS Net™. Finally, the accuracy of interpolated corrections, the positioning accuracy and the initialization time required for precise positioning were estimated and analysed. From the observed performance of each rover receiver, and the accuracy of interpolated network corrections, it can be concluded that it is feasible to use a sparse reference station network with an average inter-station distance up to 300 km for achieving similar performance to traditional network RTK positioning. The proposed approach can provide more cost-efficient use of network RTK (NRTK) positioning for engineering and environmental applications that are currently being delivered by traditional network RTK positioning technology.


2021 ◽  
Vol 14 (1) ◽  
pp. 2
Author(s):  
Pengxu Wang ◽  
Hui Liu ◽  
Zhixin Yang ◽  
Bao Shu ◽  
Xintong Xu ◽  
...  

The BeiDou navigation satellite system (BDS-3) has been deployed and provides positioning, navigation, and timing (PNT) services for users all over the world. On the basis of BDS-2 system signals, BDS-3 adds B1C, B2a, B2b, and other signals to realize compatibility and interoperability with other global navigation satellite systems (GNSS). Network real-time kinematic (RTK) technology is an important real-time regional high-precision GNSS positioning technology. Combined with the network RTK high-precision service platform software developed by the author’s research group and the measured data of a provincial continuously operating reference station (CORS) in Hubei, this paper preliminarily evaluates the network RTK service performance under the new signal system of BDS-3. The results show that single BDS-3 adopts the new signal combination (B1C+B2a) and transition signal combination (B1I+B3I) when providing virtual reference station (VRS) services, the RTK fixation rate of the terminal is above 95%, and the horizontal and elevation accuracies are within 1cm and 2 cm, respectively, which meets the requirements of providing high-precision network RTK services by a single BDS-3 system. In addition, the positioning accuracy of BDS-2 is relatively poor, while the accuracy of BDS-3 is better than global positioning systems (GPS) and BDS-2. The combined processing effect of the B1I+B3I transition signal of BDS-2/3 is optimal, the accuracy of E and N directions is better than 0.5 cm, and the accuracy of U direction is better than 1.5 cm. It can be seen from the atmosphere correction accuracy, regional error modeling accuracy, and network RTK terminal positioning accuracy that the service effect of the B1C+B2a combination is slightly better than that of the B1I+B3I combination. When a single BDS-3 constellation provides network RTK services, it is recommended to use the B1C+B2a combination as the main frequency solution, and when the BDS-2/3 constellation provides service, it is recommended to use the B1I+B3I combination as the main frequency solution.


2013 ◽  
Vol 446-447 ◽  
pp. 1601-1605
Author(s):  
Eun Soo Lee ◽  
Sung Ho Cho ◽  
Dae Yong Um

The purpose of this Study is to analyze the accuracy of a network RTK GPS, by performing taping, triangulation & Network RTK (Real Time Kinematic) GPS observation on certain measuring points and comparing all locational data based on the calculational & geometric solution method. The deviation in the measured length & coordinate between the steel tape and the Network RTK GPS was within 2cm while the deviation in the measured coordinate between the triangulation and the Network RTK GPS was within 3cm. With the fact that the performance of the taping or the triangulation is less sensitive to its surroundings taken into consideration, it could be concluded that an average locational accuracy of most Network RTK GPS processes in Korea was within 3cm.


Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2437 ◽  
Author(s):  
Ying Xu ◽  
Wu Chen

Network Real Time Kinematic (NRTK) positioning with instantaneous ambiguity resolution (AR) is currently one of the most popular techniques for real-time precise positioning using Global Navigation Satellite Systems (GNSS) carrier phase observations. Although NRTK has been successfully applied in many fields in surveying and navigation, the initialization speed, accuracy, and ambiguity successfully fixed rate of NRTK in urban areas (Hong Kong, for instance) would be significantly affected by blocked satellite signals. To address these problems and analyze the performance of GPS/BDS dual/triple-frequency NRTK in urban areas, we developed a new Hong Kong GNSS Network RTK Service Platform. Based on this platform, the performance of NRTK in urban areas was examined through a series of experiments. The results showed that: (1) The initialization time of the NRTK varied with the number of the visible satellite and the quality of the observation. (2) Centimeter-level NRTK service could be provided for users over Hong Kong using the Hong Kong GNSS Network RTK Service Platform. (3) In urban areas, GPS/BDS NRTK services for static, walking, and driving users significantly improved the ambiguity successfully fixed rate of the NRTK service when compared with that using the GPS signal alone. The NRTK ambiguity successfully fixed rate in Hong Kong was better than 99% in good environment. In typical urban environment, the RTK ambiguity successfully fixed rate with GPS/BDS was 33.4–72.4%, which was about 12.7–32.4% with GPS only. (4) BDS triple-frequency observation improved the initialization speed and positioning accuracy of RTK in Hong Kong.


2015 ◽  
Vol 14 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Martin Raška ◽  
Jiří Pospíšil

In this paper we have made a brief study of RTK precision to estimate possibilities of network RTK using CZEPOS for purposes of geotechnic monitoring of landslides in real time. In this paper we describe a testing methodology, which resulted in estimation of point-position precision and describing minimal detectable positional change. Based on our results it is concluded that displacements could be detected with centimetre accuracy even with short-period observations.


1979 ◽  
Vol 44 ◽  
pp. 41-47
Author(s):  
Donald A. Landman

This paper describes some recent results of our quiescent prominence spectrometry program at the Mees Solar Observatory on Haleakala. The observations were made with the 25 cm coronagraph/coudé spectrograph system using a silicon vidicon detector. This detector consists of 500 contiguous channels covering approximately 6 or 80 Å, depending on the grating used. The instrument is interfaced to the Observatory’s PDP 11/45 computer system, and has the important advantages of wide spectral response, linearity and signal-averaging with real-time display. Its principal drawback is the relatively small target size. For the present work, the aperture was about 3″ × 5″. Absolute intensity calibrations were made by measuring quiet regions near sun center.


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