24 Result(s)
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Article
Decentralized GNSS PPP-RTK
PPP-RTK, known as integer ambiguity resolution-enabled precise point positioning, requires precise satellite-related products and atmospheric corrections estimated in a global navigation satellite system (GNSS...
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Article
An ionospheric scintillation index derived from dual-frequency Doppler measurements released by geodetic GNSS receivers operating at 1 Hz
Doppler measurements are immune to cycle slips, which offers great potential for constructing the ionospheric scintillation indexes. This study proposes a new scintillation index referred to as Doppler Index ( ...
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Article
Open AccessUndifferenced and uncombined GNSS time and frequency transfer with integer ambiguity resolution
Precise point positioning (PPP) has been a competitive global navigation satellite system (GNSS) technique for time and frequency transfer. However, the classical PPP is usually based on the ionosphere-free co...
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Article
PPP-RTK: from common-view to all-in-view GNSS networks
Integer ambiguity resolution-enabled precise point positioning (PPP), otherwise known as PPP real-time kinematic (PPP-RTK), recovers the integer nature of ambiguities at a user receiver by delivering the satel...
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Article
Estimation of code observation-specific biases (OSBs) for the modernized multi-frequency and multi-GNSS signals: an undifferenced and uncombined approach
For a long time, code biases of global navigation satellite system (GNSSs) have been parameterized and presented in the differential mode, namely the commonly-known differential code biases (DCB). However, wit...
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Article
Integer-estimable FDMA model as an enabler of GLONASS PPP-RTK
PPP-RTK extends the precise point positioning (PPP) concept by incorporating the idea of integer ambiguity resolution underlying the real-time kinematic (RTK) technique, making rapid initialization and high ac...
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Article
A single-receiver geometry-free approach to stochastic modeling of multi-frequency GNSS observables
The proper choice of stochastic model is of great importance to global navigation satellite system (GNSS) data processing. Whereas extensive investigations into stochastic modeling are mainly based on the rela...
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Article
On the application of the raw-observation-based PPP to global ionosphere VTEC modeling: an advantage demonstration in the multi-frequency and multi-GNSS context
The ionospheric delay accounts for one of the major errors that the Global Navigation Satellite Systems (GNSS) suffer from. Hence, the global ionosphere Vertical Total Electron Content (VTEC) map has been an i...
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Article
An efficient undifferenced method for estimating multi-GNSS high-rate clock corrections with data streams in real time
Precise satellite clock corrections are the key elements for the implementation of Real-Time Precise Point Positioning (RTPPP). To fully promote the capability of multi-GNSS RTPPP, an efficient method is propo...
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Article
PPP-RTK based on undifferenced and uncombined observations: theoretical and practical aspects
A synthesis of two prevailing global navigation satellite system positioning technologies, namely the precise point positioning and the network-based real-time kinematic, results in the emergence of the PPP-RT...
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Article
Multi-GNSS triple-frequency differential code bias (DCB) determination with precise point positioning (PPP)
Differential code biases (DCBs) account for the most significant systematical biases when sensing the earth’s ionosphere with GNSS observations and are also important correction parameters in GNSS applications...
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Article
A modified carrier-to-code leveling method for retrieving ionospheric observables and detecting short-term temporal variability of receiver differential code biases
Sensing the ionosphere with the global positioning system involves two sequential tasks, namely the ionospheric observable retrieval and the ionospheric parameter estimation. A prominent source of error has lo...
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Article
Real-Time Precise Point Positioning (RTPPP) with raw observations and its application in real-time regional ionospheric VTEC modeling
Precise Point Positioning (PPP) is an absolute positioning technology mainly used in post data processing. With the continuously increasing demand for real-time high-precision applications in positioning, timi...
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Article
A grid-based tropospheric product for China using a GNSS network
Tropospheric delay accounts for one source of error in global navigation satellite systems (GNSS). To better characterize the tropospheric delays in the temporal and spatial domain and facilitate the safety-cr...
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Article
GPS receiver phase biases estimable in PPP-RTK networks: dynamic characterization and impact analysis
The integer ambiguity resolution enabled precise point positioning (PPP-RTK) has been proven advantageous in a wide range of applications. The realization of PPP-RTK concerns the isolation of satellite phase b...
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Article
Joint estimation of vertical total electron content (VTEC) and satellite differential code biases (SDCBs) using low-cost receivers
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...
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Article
Determination of the optimized single-layer ionospheric height for electron content measurements over China
The ionosphere effective height (IEH) is a very important parameter in total electron content (TEC) measurements under the widely used single-layer model assumption. To overcome the requirement of a large amou...
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Article
On the short-term temporal variations of GNSS receiver differential phase biases
As a first step towards studying the ionosphere with the global navigation satellite system (GNSS), leveling the phase to the code geometry-free observations on an arc-by-arc basis yields the ionospheric obser...
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Article
Multi-GNSS precise point positioning (MGPPP) using raw observations
A joint-processing model for multi-GNSS (GPS, GLONASS, BDS and GALILEO) precise point positioning (PPP) is proposed, in which raw code and phase observations are used. In the proposed model, inter-system biase...
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Article
On the estimability of parameters in undifferenced, uncombined GNSS network and PPP-RTK user models by means of \(\mathcal {S}\) -system theory
The concept of integer ambiguity resolution-enabled Precise Point Positioning (PPP-RTK) relies on appropriate network information for the parameters that are common between the single-receiver user that applie...
