A Variance Model in NRTK-Based Geodetic Positioning as a Function of Baseline Length

Abstract

<jats:p>This study examines the effect of baseline length on accuracy and precision in Network Real-Time Kinematic (NRTK) positioning and develops an experimental mathematical model to express this effect. The study also measures the performances of the Flaechen Korrektur Parameter (FKP) and Virtual Reference Stations (VRS) methods at different baseline lengths. The study makes use of the stations that form two Continuously Operating Reference Station (CORS) networks, one of which is local and the other national. Calculations were made to perform various geodetic operations, such as datum transformations between the two networks, identifications of positional velocities, and epoch shifting. BERNESE (v5.2) software was used to identify coordinate values assumed to be true based on International GNSS Service (IGS) products. No significant changes were observed in the RMSE values in baseline lengths of up to 40 km. In contrast, an average linear correlation of 69.2% was determined between precision and baseline length. Measurements were evaluated and tested using the variance model created as a function of the baseline length, in line with the aims of the study, and the results were found to be consistent. Moreover, in an examination of the Root Mean Square Error (RMSE) and precision values of the FKP and VRS measurements, no significant differences were observed. The mean differences were at the millimetre level.</jats:p>

Türkiye’de ulusal ve yerel sürekli gözlem yapan sabit GNSS istasyonları ağlarının mevcut durumu, standartlar ve farklı ağların entegrasyonu

“…Yerel CORS ağı verileri deformasyon analizi ve yapı sağlığı izleme çalışmalarında kullanılmıştır (Akpınar, Aykut, Dindar, Gürkan, & Gülal, 2017;Gümüş & Selbesoğlu, 2019). Yerel CORS ağı kullanılarak baz mesafesinin doğruluk, presizyon ve tamsayı belirsizlik çözüm oranı üzerindeki etkisi araştırılmış ve GNSS ölçmelerinde baz mesafesi ile ölçmelere ait varyans değeri arasında matematiksel bir model oluşturulmuştur (Gökdaş & Özlüdemir, 2020a). Yerel CORS ağından türetilen troposfer gecikme değerleri ile su buharı kestirimleri yapılmış ve doğrulukları analiz edilmiştir (Gökdaş & Özlüdemir, 2020b).…”

Fast and Reliable Network RTK Positioning Based on Multi-Frequency Sequential Ambiguity Resolution under Significant Atmospheric Biases

“…Corresponding to it, ionospheric delay presents significant uncertainty, especially during periods of ionospheric activity, resulting in suboptimal modeling outcomes. Ionospheric delay modeling residual can adversely affect the initialization speed, positioning accuracy, and reliability of real-time kinematic (RTK) positioning [1][2][3]. With the modernization of global navigation systems [4,5], BDS-3 and Galileo satellite systems support the broadcast of five-frequency signals.…”

Studying the Repeatability of Measurements Obtained via Network Real-Time Kinematic Positioning at Different Times of the Day

“…The performance and use of the CORS were examined based on the results obtained near or below the wooded area. In Gökdaş and Özlüdemir (2020), two CORS networks in Turkey were employed to study the effect of the FKP and VRS correction methods on accuracy and precision at different base lengths in NRTK positioning. An experimental mathematical model was developed to express this effect.…”