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On the Problem of Double-Filtering in PPP-RTK

Khodabandeh, A. (author), Teunissen, P.J.G. (author), Psychas, D. (author)

To obtain single-receiver Global Navigation Satellite System (GNSS) parameter solutions, the PPP-RTK user-filter combines measurements with time-correlated corrections that are separately computed by the filter of an external provider. The consequence of exercising such double-filtering is that the Kalman filter’s standard assumption of...

journal article 2023

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Ambiguity-Fixing in Frequency-Varying Carrier Phase Measurements: Global Navigation Satellite System and Terrestrial Examples

Khodabandeh, A. (author), Teunissen, P.J.G. (author)

Carrier phase signals are considered among the key observations in global navigation satellite systems (GNSSs) and several other high-precision interferometric measurement systems. However, these ultra-precise measurements are not fully exploited when the integerness of their inherent ambiguities is discarded during the estimation process....

journal article 2023

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Recent advances and perspectives in GNSS PPP-RTK

Hou, P. (author), Zha, Jiuping (author), Liu, Teng (author), Zhang, Baocheng (author)

Precise point positioning-real-time kinematic (PPP-RTK), otherwise known as integer ambiguity resolution-enabled precise pointing positioning, has attracted much attention in recent years and has become state-of-the-art in the global navigation satellite system (GNSS) high-precision positioning community. This work reviews several PPP-RTK...

journal article 2023

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Fast and reliable multi-GNSS precise point positioning with integer ambiguity resolution

Psychas, D.V. (author)

Precise Point Positioning (PPP) is a Global Navigation Satellite Systems (GNSS) modelling and processing method that provides single-receiver users with high positioning accuracy anywhere on the globe, without the explicit dependence on reference receivers. The realization of PPP is based on undifferenced code and phase measurements, a priori...

doctoral thesis 2022

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Impact and mitigation of neglecting PPP-RTK correctional uncertainty

Psychas, D.V. (author), Khodabandeh, Amir (author), Teunissen, P.J.G. (author)

The corrections needed to realize integer ambiguity resolution-enabled precise point positioning (PPP-RTK) at a single-receiver user are often treated as if they are deterministic quantities. The present contribution aims to study and analyze the effect the neglected uncertainty of these corrections, which are subject to time delay, has on...

journal article 2022

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PPP–RTK theory for varying transmitter frequencies with satellite and terrestrial positioning applications

Teunissen, P.J.G. (author), Khodabandeh, A. (author)

In this contribution, we generalize PPP–RTK theory by allowing the transmitters to transmit on different frequencies. The generalization is based on the integer-estimability theory of Teunissen (A new GLONASS FDMA model. GPS Solutions, 2019). As the theory and associated algorithms provided are generally applicable, they apply to satellite...

journal article 2022

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On vectorial integer bootstrapping implementations in the estimation of satellite orbits and clocks based on small global networks

Massarweh, L. (author), Strasser, Sebastian (author), Mayer-Gürr, Torsten (author)

The estimation of satellite orbits and clocks plays a central role in different Global Navigation Satellite System (GNSS) domains, e.g. precise positioning or time transfer. Such products can be computed in the process of Orbit Determination and Time Synchronization (ODTS), which relies on a network of ground-based stations, well distributed...

journal article 2021

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Flight-Test Evaluation of Integer Ambiguity Resolution Enabled PPP

Ma, H. (author), Verhagen, S. (author), Psychas, D.V. (author), Monico, João Francisco Galera (author), Marques, Haroldo Antonio (author)

The technology of integer ambiguity resolution-enabled precise-point-positioning (also referred to as PPP-AR) has been proven capable of providing comparable accuracy, efficiency, and productivity to long-baseline real-time kinematic positioning (RTK) during the last decade. Commercial PPP-AR services have been provided by different...

journal article 2021

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Best integer equivariant estimation for elliptically contoured distributions

Teunissen, P.J.G. (author)

This contribution extends the theory of integer equivariant estimation (Teunissen in J Geodesy 77:402–410, 2003) by developing the principle of best integer equivariant (BIE) estimation for the class of elliptically contoured distributions. The presented theory provides new minimum mean squared error solutions to the problem of GNSS carrier...

journal article 2020

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Precision analysis of partial ambiguity resolution-enabled PPP using multi-GNSS and multi-frequency signals

Psychas, D.V. (author), Verhagen, S. (author), Teunissen, P.J.G. (author)

A single-receiver integer ambiguity resolution-enabled precise point positioning (PPP-RTK) user experiences a long convergence time when the rather weak single-constellation dual-frequency ionosphere-float model is used. Nowadays, the rapid development of Global Navigation Satellite Systems (GNSS) provides a multitude of available satellites...

journal article 2020

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Distributed least-squares estimation applied to GNSS networks

Khodabandeh, A. (author), Teunissen, P.J.G. (author)

In view of the recent proliferation of low-cost mass-market receivers, the number of network receivers and GNSS users will be growing rapidly, demanding an efficient way of data processing in terms of computational power and capacity. One way of improving the computational capacity is to decentralize the underlying data processing and distribute...

journal article 2019

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GLONASS ambiguity resolution

Teunissen, P.J.G. (author), Khodabandeh, A. (author)

A new integer-estimable GLONASS FDMA model is studied and analysed. The model is generally applicable, and it shows a close resemblance with the well-known CDMA models. The analyses provide insights into the performance characteristics of the model and concern a variety of different ambiguity-resolution critical applications. This will be done...

journal article 2019

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A new GLONASS FDMA model

Teunissen, P.J.G. (author)

We introduce a new formulation of the double-differenced GLONASS FDMA model. It closely resembles that of CDMA-based systems and it guarantees the estimability of the newly defined GLONASS ambiguities. The formulation is made possible because of our defining new concept of integer-estimability and the analytical construction of a special...

journal article 2019

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Integer estimability in GNSS networks

Khodabandeh, A. (author), Teunissen, P.J.G. (author)

Estimability and S-systems are important concepts when dealing with rank-defect models. In this contribution, we generalize the concept of estimability to integer estimability and determine the necessary and sufficient conditions that need to be satisfied for parameter functions to be integer estimable. This is then worked out and applied to the...

journal article 2019

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How Abnormal Are the PDFs of the DIA Method: A Quality Description in the Context of GNSS

Zaminpardaz, Safoora (author), Teunissen, P.J.G. (author)

The DIA-method, for the detection, identification and adaptation of modeling errors, has been widely used in a broad range of applications including the quality control of geodetic networks and the integrity monitoring of GNSS models. The DIA-method combines two key statistical inference tools, estimation and testing. Through the former, one...

conference paper 2019

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Multi-GNSS PPP-RTK: From large- to Small-Scale networks

Nadarajah, Nandakumaran (author), Khodabandeh, Amir (author), Wang, Kan (author), Choudhury, Mazher (author), Teunissen, P.J.G. (author)

Precise point positioning (PPP) and its integer ambiguity resolution-enabled variant, PPP-RTK (real-time kinematic), can benefit enormously from the integration of multiple global navigation satellite systems (GNSS). In such a multi-GNSS landscape, the positioning convergence time is expected to be reduced considerably as compared to the one...

journal article 2018

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Minimal Detectable and Identifiable Biases for quality control

Imparato, D. (author), Teunissen, P.J.G. (author), Tiberius, C.C.J.M. (author)

The Minimal Detectable Bias (MDB) is an important diagnostic tool in data quality control. The MDB is traditionally computed for the case of testing the null hypothesis against a single alternative hypothesis. In the actual practice of statistical testing and data quality control, however, multiple alternative hypotheses are considered. We...

journal article 2018

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On the impact of GNSS ambiguity resolution: geometry, ionosphere, time and biases

Khodabandeh, A. (author), Teunissen, P.J.G. (author)

Integer ambiguity resolution (IAR) is the key to fast and precise GNSS positioning and navigation. Next to the positioning parameters, however, there are several other types of GNSS parameters that are of importance for a range of different applications like atmospheric sounding, instrumental calibrations or time transfer. As some of these...

journal article 2018

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Joint estimation of vertical total electron content (VTEC) and satellite differential code biases (SDCBs) using low-cost receivers

Zhang, Baocheng (author), Teunissen, P.J.G. (author), Yuan, Yunbin (author), Zhang, Hongxing (author), Li, Min (author)

Vertical total electron content (VTEC) parameters estimated using global navigation satellite system (GNSS) data are of great interest for ionosphere sensing. Satellite differential code biases (SDCBs) account for one source of error which, if left uncorrected, can deteriorate performance of positioning, timing and other applications. The...

journal article 2018

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Does RAIM with correct exclusion produce unbiased positions?

Teunissen, P.J.G. (author), Imparato, D. (author), Tiberius, C.C.J.M. (author)

As the navigation solution of exclusion-based RAIM follows from a combination of least-squares estimation and a statistically based exclusion-process, the computation of the integrity of the navigation solution has to take the propagated uncertainty of the combined estimation-testing procedure into account. In this contribution, we analyse,...

journal article 2017