Assessment of Dual Frequency GNSS Observations from a Xiaomi Mi 8 Android Smartphone and Positioning Performance Analysis

On May 2018 the world’s first dual-frequency Global Navigation Satellite System (GNSS) smartphone produced by Xiaomi equipped with a Broadcom BCM47755 chip was launched. It is able to receive L1/E1/ and L5/E5 signals from GPS, Galileo, Beidou, and GLONASS (GLObal NAvigation Satellite System) satellites. The main aim of this work is to achieve the phone’s position by using multi-constellation, dual frequency pseudorange and carrier phase raw data collected from the smartphone. Furthermore, the availability of dual frequency raw data allows to assess the multipath performance of the device. The smartphone’s performance is compared with that of a geodetic receiver. The experiments were conducted in two different scenarios to test the smartphone under different multipath conditions. Smartphone measurements showed a lower C/N0 and higher multipath compared with those of the geodetic receiver. This produced negative effects on single-point positioning as showed by high root mean square error (RMS). The best positioning accuracy for single point was obtained with the E5 measurements with a DRMS (horizontal root mean square error) of 4.57 m. For E1/L1 frequency, the 2DRMS was 5.36 m. However, the Xiaomi Mi 8, thanks to the absence of the duty cycle, provided carrier phase measurements used for a static single frequency relative positioning with an achieved 2DRMS of 1.02 and 1.95 m in low and high multipath sites, respectively.

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Performance Evaluation of the CNAV Broadcast Ephemeris

Journal of Navigation ◽

10.1017/s037346331900016x ◽

2019 ◽

Vol 72 (5) ◽

pp. 1331-1344

Author(s):

Ahao Wang ◽

Junping Chen ◽

Yize Zhang ◽

Jiexian Wang ◽

Bin Wang

Keyword(s):

Global Navigation Satellite System ◽

Single Point ◽

Satellite Orbit ◽

Satellite System ◽

Single Frequency ◽

Navigation Satellite ◽

Dual Frequency ◽

Navigation Message ◽

Global Navigation ◽

Global Navigation Satellite

The new Global Positioning System (GPS) Civil Navigation Message (CNAV) has been transmitted by Block IIR-M and Block IIF satellites since April 2014, both on the L2C and L5 signals. Compared to the Legacy Navigation Message (LNAV), the CNAV message provides six additional parameters (two orbit parameters and four Inter-Signal Correction (ISC) parameters) for prospective civil users. Using the precise products of the International Global Navigation Satellite System Service (IGS), we evaluate the precision of satellite orbit, clock and ISCs of the CNAV. Additionally, the contribution of the six new parameters to GPS Single Point Positioning (SPP) is analysed using data from 22 selected Multi-Global Navigation Satellite System Experiment (MGEX) stations from a 30-day period. The results indicate that the CNAV/LNAV Signal-In-Space Range Error (SISRE) and orbit-only SISRE from January 2016 to March 2018 is of 0·5 m and 0·3 m respectively, which is improved in comparison with the results from an earlier period. The ISC precision of L1 Coarse/Acquisition (C/A) is better than 0·1 ns, and those of L2C and L5Q5 are about 0·4 ns. Remarkably, ISC correction has little effect on the single-frequency SPP for GPS users using civil signals (for example, L1C, L2C), whereas dual-frequency SPP with the consideration of ISCs results have an accuracy improvement of 18·6%, which is comparable with positioning accuracy based on an ionosphere-free combination of the L1P (Y) and L2P (Y) signals.

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Implementation of a Dual-Frequency GLONASS and GPS L1 C/A Software Receiver

Journal of Navigation ◽

10.1017/s0373463309990476 ◽

2010 ◽

Vol 63 (2) ◽

pp. 269-287 ◽

Cited By ~ 4

Author(s):

S. Abbasian Nik ◽

M. G. Petovello

Keyword(s):

Global Navigation Satellite System ◽

Critical Role ◽

Satellite System ◽

Navigation Satellite ◽

Dual Frequency ◽

Software Receiver ◽

The Public ◽

Global Navigation ◽

Global Navigation Satellite

These days, Global Navigation Satellite System (GNSS) technology plays a critical role in positioning and navigation applications. Use of GNSS is becoming more of a need to the public. Therefore, much effort is needed to make the civilian part of the system more accurate, reliable and available, especially for the safety-of-life purposes. With the recent revitalization of Russian Global Navigation Satellite System (GLONASS), with a constellation of 20 satellites in August 2009 and the promise of 24 satellites by 2010, it is worthwhile concentrating on the GLONASS system as a method of GPS augmentation to achieve more reliable and accurate navigation solutions.

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Characterisation of GNSS Carrier Phase Data on a Moving Zero-Baseline in Urban and Aerial Navigation

Sensors ◽

10.3390/s20144046 ◽

2020 ◽

Vol 20 (14) ◽

pp. 4046 ◽

Cited By ~ 2

Author(s):

Fabian Ruwisch ◽

Ankit Jain ◽

Steffen Schön

Keyword(s):

Global Navigation Satellite System ◽

Carrier Phase ◽

High Sensitivity ◽

Satellite System ◽

Double Difference ◽

Navigation Satellite ◽

Noise Levels ◽

Global Navigation ◽

Zero Baseline ◽

Global Navigation Satellite

We present analyses of Global Navigation Satellite System (GNSS) carrier phase observations in multiple kinematic scenarios for different receiver types. Multi-GNSS observations are recorded on high sensitivity and geodetic-grade receivers operating on a moving zero-baseline by conducting terrestrial urban and aerial flight experiments. The captured data is post-processed; carrier phase residuals are computed using the double difference (DD) concept. The estimated noise levels of carrier phases are analysed with respect to different parameters. We find DD noise levels for L1 carrier phase observations in the range of 1.4–2 mm (GPS, Global Positioning System), 2.8–4.6 mm (GLONASS, Global Navigation Satellite System), and 1.5–1.7 mm (Galileo) for geodetic receiver pairs. The noise level for high sensitivity receivers is at least higher by a factor of 2. For satellites elevating above 30 ∘ , the dominant noise process is white phase noise. For the flight experiment, the elevation dependency of the noise is well described by the exponential model, while for the terrestrial urban experiment, multipath and diffraction effects overlay; hence no elevation dependency is found. For both experiments, a carrier-to-noise density ratio (C/N 0 ) dependency for carrier phase DDs of GPS and Galileo is clearly visible with geodetic-grade receivers. In addition, C/N 0 dependency is also visible for carrier phase DDs of GLONASS with geodetic-grade receivers for the terrestrial urban experiment.

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Comparison of Multi-GNSS Time and Frequency Transfer Performance Using Overlap-Frequency Observations

Remote Sensing ◽

10.3390/rs13163130 ◽

2021 ◽

Vol 13 (16) ◽

pp. 3130

Author(s):

Pengfei Zhang ◽

Rui Tu ◽

Yuping Gao ◽

Ju Hong ◽

Junqiang Han ◽

...

Keyword(s):

Carrier Phase ◽

Satellite System ◽

Single Frequency ◽

Navigation Satellite ◽

Transfer Performance ◽

Dual Frequency ◽

Time Transfer ◽

Difference Series ◽

Frequency Transfer ◽

Global Navigation Satellite

The modernized GPS, Galileo, and BeiDou global navigation satellite system (BDS3) offers new potential for time transfer using overlap-frequency (L1/E1/B1, L5/E5a/B2a) observations. To assess the performance of time and frequency transfer with overlap-frequency observations for GPS, Galileo, and BDS3, the mathematical models of single- and dual-frequency using the carrier-phase (CP) technique are discussed and presented. For the single-frequency CP model, the three-day average RMS values of the L5/E5a/B2a clock difference series were 0.218 ns for Galileo and 0.263 ns for BDS3, of which the improvements were 36.2% for Galileo and 43.9% for BDS3 when compared with the L1/E1/B1 solution at BRUX–PTBB. For the hydrogen–cesium time link BRUX–KIRU, the RMS values of the L5/E5a/B2a solution were 0.490 ns for Galileo and 0.608 ns for BDS3, improving Galileo by 6.4% and BDS3 by 12.5% when compared with the L1/E1/B1 solution. For the dual-frequency CP model, the average stability values of the L5/E5a/B2a solution at the BRUX–PTBB time link were 3.54∙× 10−12 for GPS, 2.20 × 10−12 for Galileo, and 2.69 × 10−12 for BDS3, of which the improvements were 21.0%, 45.1%, and 52.3%, respectively, when compared with the L1/E1/B1 solution. For the BRUX–KIRU time link, the improvements were 4.2%, 30.5%, and 36.1%, respectively.

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Aircraft positioning using GPS/GLONASS code observations

Aircraft Engineering and Aerospace Technology ◽

10.1108/aeat-01-2019-0018 ◽

2019 ◽

Vol 92 (2) ◽

pp. 163-171 ◽

Cited By ~ 1

Author(s):

Kamil Krasuski ◽

Janusz Cwiklak ◽

Marek Grzegorzewski

Keyword(s):

Global Navigation Satellite System ◽

Single Point ◽

Satellite System ◽

Least Square ◽

Navigation Satellite ◽

Navigation Systems ◽

Protection Level ◽

Content Type ◽

Global Navigation ◽

Global Navigation Satellite

Purpose This paper aims to present the problem of the integration of the global positioning system (GPS)/global navigation satellite system (GLONASS) data for the processing of aircraft position determination. Design/methodology/approach The aircraft coordinates were obtained based on GPS and GLONASS code observations for the single point positioning (SPP) method. The numerical computations were executed in the aircraft positioning software (APS) package. The mathematical scheme of equation observation of the SPP method was solved using least square estimation in stochastic processing. In the research experiment, the raw global navigation satellite system data from the Topcon HiperPro onboard receiver were applied. Findings In the paper, the mean errors of an aircraft position from APS were under 3 m. In addition, the accuracy of aircraft positioning was better than 6 m. The integrity term for horizontal protection level and vertical protection level parameters in the flight test was below 16 m. Research limitations/implications The paper presents only the application of GPS/GLONASS observations in aviation, without satellite data from other navigation systems. Practical implications The presented research method can be used in an aircraft based augmentation system in Polish aviation. Social implications The paper is addressed to persons who work in aviation and air transport. Originality/value The paper presents the SPP method as a satellite technique for the recovery of an aircraft position in an aviation test.

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KONTRIBUSI GLOBAL NAVIGATION SATELLITE SYSTEM PADA PENENTUAN TITIK KONTROL UDARA DI METODE FOTOGRAMETRI UNMANNED AERIAL VEHICLE UNTUK PEMETAAN SKALA BESAR DI INDONESIA

Seminar Nasional Geomatika ◽

10.24895/sng.2020.0-0.1202 ◽

2021 ◽

pp. 867

Author(s):

Irwan Gumilar ◽

Deni Suwardhi ◽

Irfan Budaya ◽

Brian Bramanto ◽

Kamal Nur Fauzan

Keyword(s):

Unmanned Aerial Vehicle ◽

Global Navigation Satellite System ◽

Satellite System ◽

Navigation Satellite ◽

Mean Square ◽

Post Processing ◽

Check Points ◽

Aerial Vehicle ◽

Global Navigation ◽

Global Navigation Satellite

Indonesia saat ini sedang melakukan pemetaan skala besar secara masif. Salah satu metode yang digunakan pada pemetaan skala besar tersebut adalah dengan menggunakan teknik fotogrametri berbasiskan Unmanned Aerial Vehicle (UAV). Saat ini, metode penentuan titik kontrol udara dengan menggunakan Global Navigation Satellite System (GNSS) banyak dilakukan untuk memimalisir jumlah titik kontrol tanah tanpa mengurangi kualitas dari produk fotogrameteri yang dihasilkan. Penelitian ini bertujuan untuk menganalisa kontribusi sistem GNSS pada penentuan titik kontrol udara untuk metode fotogrametri berbasiskan UAV. Pengukuran GNSS frekuensi ganda pada sistem UAV di wilayah Jatinangor, Bandung dan Panglipuran Bali digunakan pada penelitian ini. Panjang baseline antara titik kontrol dan rover berkisar antara 350 hingga 900 m. Penentuan posisi titik kontrol udara berbasiskan GNSS menggunakan metode Post Processing Kinematic (PPK) dengan teknik pemecahan ambiguitas fase LAMBDA Fix and Hold. Pengolahan data GNSS dilakukan dengan menggunakan beberapa kombinasi frekuensi dan sistem GNSS. Evaluasi ketelitian hasil perataan berkas menggunakan titik kontrol udara pada setiap kombinasi frekuensi dan sistem GNSS dilakukan dengan memperhatikan nilai Root Mean Square Error (RMSE) pada 20 titik cek tanah atau Independent Check Points (ICP). Berdasarkan hasil tersebut, kombinasi gelombang L1 dan L2 menggunakan sistem GPS dan BeiDou idealnya digunakan untuk pemetaan skala besar menggunakan fotogrametri UAV. Selain itu, kombinasi data GPS dan Beidou frekuensi ganda memiliki tingkat ketelitian titik kontrol udara yang terbaik dibandingkan kombinasi yang lainnya. Selain itu, kombinasi GPS dan BeiDou menggunakan hanya gelombang L1 memiliki tingkat ketelitian yang sama dibandingkan dengan GPS menggunakan gelombang L1 dan L2.

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Optimal Fault Detection and Exclusion Applied in GNSS Positioning

Journal of Navigation ◽

10.1017/s0373463313000155 ◽

2013 ◽

Vol 66 (5) ◽

pp. 683-700 ◽

Cited By ~ 9

Author(s):

Ling Yang ◽

Nathan L. Knight ◽

Yong Li ◽

Chris Rizos

Keyword(s):

Fault Detection ◽

Global Navigation Satellite System ◽

Single Point ◽

Satellite System ◽

Navigation Satellite ◽

Gnss Positioning ◽

Practical Strategy ◽

Receiver Autonomous Integrity Monitoring ◽

Global Navigation Satellite ◽

Made In

In Global Navigation Satellite System (GNSS) positioning, it is standard practice to apply the Fault Detection and Exclusion (FDE) procedure iteratively, in order to exclude all faulty measurements and then ensure reliable positioning results. Since it is often only necessary to consider a single fault in a Receiver Autonomous Integrity Monitoring (RAIM) procedure, it would be ideal if a fault could be correctly identified. Thus, fault detection does not need to be applied in an iterative sense. One way of evaluating whether fault detection needs to be reapplied is to determine the probability of a wrong exclusion. To date, however, limited progress has been made in evaluating such probabilities. In this paper the relationships between different parameters are analysed in terms of the probability of correct and incorrect identification. Using this knowledge, a practical strategy for incorporating the probability of a wrong exclusion into the FDE procedure is developed. The theoretical findings are then demonstrated using a GPS single point positioning example.

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Purwarupa Differential Global Navigation Satellite System dengan Metode Real Time Kinematik Berbasis Radio Link Type Htox

Jurnal HIDROPILAR ◽

10.37875/hidropilar.v6i1.166 ◽

2021 ◽

Vol 6 (1) ◽

pp. 8-13

Author(s):

Surono Surono ◽

Adhi Kusuma Negara ◽

Endro Sigit Kurniawan

Keyword(s):

Real Time ◽

Global Navigation Satellite System ◽

Carrier Phase ◽

Satellite System ◽

Radio Link ◽

Navigation Satellite ◽

Raw Data ◽

Link Type ◽

Global Navigation ◽

Global Navigation Satellite

Purwarupa Differential Global Navigation Satellite System bertujuan untuk meningkatkan akurasi dari receiver GNSS, dengan menambahkan referensi stasiun lokal untuk menambah informasi yang diterima dari satelit. Differential Global Navigation Satellite System ini menggunakan metode real time kinematik yang berbasiskan pada carrier phase (besaran sudut) dalam penentuan posisi data secara relatif dengan tingkat ketelitian mencapai satuan milimeter. Sistem RTK menggunakan data pengamatan fase data atau koreksi fase dikirim secara seketika dari stasiun referensi ke receiver pengguna. Hasil dari purwarupa adalah resiver GNSS geodetik berbasis radio link yang bisa diprogram agar bisa menghasilkan raw data. Pemrograman menggunakan software RTKLIB seri b33 dengan aplikasi RTKnavi untuk logging data.

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