The position accuracy of Global Navigation Satellite System (GNSS) modules is one the most significant factors in determining feasibility new location-based services for smartphones. Considering structure current smartphones, it impossible to apply ordinary range-domain Differential GNSS (DGNSS) method. Therefore, this paper describes and applies a DGNSS-correction projection method commercial smartphone. First, local line-of-sight unit vector calculated using elevation azimuth angle...

GNSS signals are easily blocked or degraded because of the dense presence high-rise buildings in urban areas, and positioning errors arising from reflected amount to as much hundreds meters. Various conventional techniques have been utilized resolve this problem, but applying them environments has difficult owing complexity their unpredictable nonlinear variation signal receiving environments. In study, multipath maps were generated for dynamic users at multiple positions on a road...

Multipath and non-line-of-sight (NLOS) signals are the major causes of poor accuracy a global navigation satellite system (GNSS) in urban areas. Despite wide usage GNSS populated areas, it is difficult to suggest generalized method because multipath errors user-specific cannot be eliminated by differential (DGNSS) or real-time kinematic technique (RTK). This paper introduces estimation mitigation which considers compensation for time offset between constellations. It also presents...

As the necessity of location information closely related to everyday life has increased, use global navigation satellite systems (GNSS) gradually increased in populated urban areas. Contrary high and expectation GNSS areas, performance is easily degraded by multipath errors due high-rise buildings very difficult guarantee. Errors signals reflected buildings, i.e., non-line-of-sight (NLOS) errors, are major cause poor accuracy Unlike other error sources, signal error, which a user-dependent...

A differential global positioning system (DGPS) is one of the most widely used augmentation systems for a low-cost L1 (1575.42 MHz) single-frequency GPS receiver. The accuracy receiver decreases because spatial decorrelation between reference station (RS) DGPS and users. Hence, network real-time kinematic (RTK) solution to reduce error in current system. Among various RTK methods, Flächen Korrektur parameter (FKP) complement DGPS, its concept configuration are simple size additional data...

Owing to the high demand for drone operation in high-elevation masked areas, it is necessary develop a more effective method of transmitting and applying Satellite-Based Augmentation System (SBAS) messages drones. This study proposes an onboard module including correction conversion, integrity information calculation, fast initialization requests, which can enable application online SBAS operation. The proposed system not only improves position accuracy with timely proper protection levels...

Global Navigation Satellite Systems (GNSS) are used to provide accurate position, navigation, and time (PNT) information users in various sectors of our society including transportation. Augmentation systems such as differential GNSS (DGNSS), real-time kinematics (RTK), Precise Point Positioning (PPP) improve the performance, providing reliable measurements from its reference station is very crucial. To ensure safe PNT solutions, code carrier must be monitored for potential faults or a...

The current L1 Legacy SBAS provides satellite orbit and clock corrections, as well ionospheric delay for single-frequency users. Although Dual-Frequency Multi-Constellation (DFMC) SBAS, which augments multi-constellation GNSS using the L5 signal, has recently been standardized, number of receivers supporting is lower than that those L2, both significantly smaller L2 (European Global Navigation Satellite Systems Agency 2018). This study proposes a method enables users dual-frequency to...

Real-Time Kinematics (RTK) is a technology that provides high-accuracy coordinates from centimeters to millimeters employing differential techniques GNSS carrier phase measurements. It has been widely used, particularly in the surveying field. Traditionally, RTK method employed primarily high-cost survey-grade receivers and antennas. Previously , high cost of equipment, ranging thousands tens dollars, limited specific fields such as land structure deformation monitoring where investment...

This letter introduces a GNSS/altimeter tightly coupled (TC) integration algorithm that combines barometric altitude measurements with GNSS observations to determine 3-D positions. By transforming into Earth-centered Earth-fixed (ECEF) coordinates, novel TC equation is derived. enables accurate positioning only three satellites and one measurement, overcoming the limitations of conventional techniques. A semi-indoor experiment for various smartphones was conducted validate proposed method,...

This paper presents a means of carrier phase cycle slip detection for an inertial-aided global positioning system (GPS), which is based on consideration the satellite geometry. An integrated navigation solution incorporating tightly coupled time differenced (TDCP) and inertial (INS) used to detect slips. Cycle-slips are detected by comparing satellite-difference (SD) time-difference (TD) measurements obtained from GPS satellites with range estimated solution. Additionally geometry...

The Hatch filter is a code-smoothing technique that uses the variation of carrier phase. It can effectively reduce noise pseudo-range with very simple construction, but it occasionally causes an ionosphere-induced error for low-lying satellites. Herein, we propose optimal single-frequency (SF) divergence-free satellite-based augmentation system (SBAS) message to ionospheric divergence and applies smoothing constant its window width. According data-processing results, overall performance...

Xiaomi Mi8 with a Broadcom BCM47755 chip, an Android smartphone that supports multi-constellation (GPS, GLONASS, Galileo, BeiDou, and QZSS) dual-frequency (L1/E1 L5/E5), was launched in May 2018. Unlike previously released smartphones, it technically expected to provide robust precise positioning fast ambiguity resolution, which led many researchers be overly optimistic about the applicability of high-accuracy techniques such as real-time kinematic (RTK) systems point (PPP) smartphones. The...

This paper proposes a method that combines compact real-time kinematic (RTK) and reference station (RS) networking techniques, shows this approach can reduce both the temporal spatial decorrelation error. The RTK compatibility with all conventional network systems, i.e., Master-Auxiliary Concept (MAC), Virtual Reference Stations (VRS), Flächen-Korrektur Parameter (FKP), is examined theoretically in paper. To prove not only valid, but also helpful to system, field test was held using one hour...

Most Differential Global Positioning System (DGPS) correction formats are based on range information, and thus typical DGPS systems can be implemented only message-readable or raw observable-providing devices. There is no other way to improve an already-calculated position than a ‘block shift technique’, which has very limited applicability. This paper suggests algorithm project measurement directly domain data without requiring pseudorange data. By post-processing methodology, we evaluated...

The Hatch filter is a code-smoothing technique using integrated carrier phase observations. It an easy that non-experts can use to reduce receiver noise on the pseudorange. This paper suggests new algorithm for optimal whose smoothing window width varies adaptively depending regional, diurnal and seasonal ionospheric variation satellite elevation angle. We consider both quiet storm conditions of ionosphere. Using well-known model, conservative boundary value statistics function angle, this...

The unmanned aerial vehicle (UAV) market has expanded following the Fourth Industrial Revolution. However, limitations persist, particularly flight duration and operation range due to battery constraints. To overcome these limitations, combining UAVs with other moving vehicles been proposed, approaches typically rely on camera information. narrowing field of view during landing process platforms can cause target exit camera's limited range, necessitating a restart land process, which is...

The range rate correction (RRC) was useful in reducing the latency error of pseudo-range (PRC), and data baud rate. With selective availability (SA) removed, temporal variations corrections are much smaller, so issue has been raised as to whether RRC term is still necessary. We provide results on PRC variation that account for seasonal, diurnal, regional differences atmosphere receiver noise statistics. concluded setting zero would help reduce error, supported this conclusion by static...

Currently operating satellite-based augmentation systems (SBASs) provide an service that improves global positioning system (GPS) performance at 250 bps via the L1 signal. Despite their efficiency, existing SBASs cannot support other navigation satellite (GNSSs) owing to narrow bandwidth, which prevents us from taking advantage of multi-constellation GNSS positioning. This paper proposes concept single-frequency (SFMC) SBAS, enables legacy SBAS up four or five constellations with minimal...

In Network RTK (Real-Time Kinematic) positioning, the multiple corrections from reference stations, which constitute a network, are interpolated for user location through appropriate interpolation models. There exist various methods to model spatial decorrelation errors tropospheric and ionospheric delay, main contributors of corrections. Since delay is largely affected by height differences, heights stations should be considered when selecting methods. This work provides comparative...

The performance of global navigation satellite system (GNSS) receivers in dynamic modes is mostly assessed using results obtained from independent maneuvering vehicles along similar trajectories at different times due to limitations receivers, payload, space, and power moving vehicles. However, such assessments do not ensure valid evaluation because the same GNSS signal environment cannot be ensured a test session irrespective how accurately it mimics original session. In this study, we...

The rate of total electron contents (ROT) calculated from global navigation satellite system (GNSS) observables has mainly been used as a quantity that can be averaged into an ROT index (ROTI), which is unable to detect small-scale, fast-moving disturbances. In this study, we demonstrate unique signature on time series estimate the horizontal velocity and dimension irregularities when GNSS signals propagate through ionospheric (IIs). This was achieved by estimating lags durations signatures...

This paper describes the work that won third place in Google Smartphone Decimeter Challenge 2023-2024 (GSDC 2023-2024), held from September 2023 to May 2024. provided dynamic smartphone GNSS and IMU data for 196 different drive routes, offering a wider variety of chipsets compared previous GSDC 2021 2022 competitions. The goal competition was obtain accurate position information using measurements, which are characterized by high noise low quality commercial receivers. allowed use various...

A single station-based positioning system, known as Mosaic/DME, is introduced. This new system has been designed for the Alternative PNT (APNT) solution to air services it acts a backup navigation in case of GNSS outage. The Mosaic/DME station consisting conventional DME and multiple pseudolites. operated using two-way round signals range measurements, with pseudolites broadcasting one-way continuous carrier phase measurements. receiver aircraft receives both calculates its own position...