An experimental comparison of noise characteristics of seven high-end dual frequency GPS receiver-sets

2002 ◽  
Author(s):  
P. Bona ◽  
C. Tiberius
Keyword(s):  
Experimental Comparison ◽  
Gps Receiver ◽  
Dual Frequency ◽  
Noise Characteristics

scholarly journals GPS Receiver Position Augmentation Using Correntropy Kalman Filter in Low Latitude Terrain

2022 ◽  
Author(s):  
Sirish Kumar Pagoti ◽  
Bala Sai Srilatha Indira Dutt Vemuri ◽  
Ganesh Laveti
Keyword(s):  
Kalman Filter ◽  
Indian Subcontinent ◽  
Estimation Algorithm ◽  
Position Estimation ◽  
Gps Receiver ◽  
Dual Frequency ◽  
Low Latitude ◽  
Position Accuracy ◽  
Aircraft Landing ◽  
Gps Accuracy

If any Global Positioning System (GPS) receiver is operated in low latitude regions or urban canyons, the visibility further reduces. These system constraints lead to many challenges in providing precise GPS position accuracy over the Indian subcontinent. As a result, the standalone GPS accuracy does not meet the aircraft landing requirements, such as Category I (CAT-I) Precision Approaches. However, the required accuracy can be achieved by augmenting the GPS. Among all these issues, the predominant factors that significantly influence the receiver position accuracy are selecting a user/receiver position estimation algorithm. In this article, a novel method is proposed based on correntropy and designated as Correntropy Kalman Filter (CKF) for precise GPS applications and GPS Aided Geosynchronous equatorial orbit Augmented Navigation (GAGAN) based aircraft landings over the low latitude Indian subcontinent. The real-world GPS data collected from a dual-frequency GPS receiver located in the southern region of the Indian subcontinent (IISc), Bangalore with Lat/Long: 13.021°N/ 77.5°E) is used for the performance evaluation of the proposed algorithm. Results prove that the proposed CKF algorithm exhibits significant improvement (up to 34%) in position estimation compared to the traditional Kalman Filter.

scholarly journals An autonomous adaptive low-power instrument platform (AAL-PIP) for remote high-latitude geospace data collection

2014 ◽  
Vol 3 (2) ◽  
pp. 211-227 ◽  
Author(s):  
C. R. Clauer ◽  
H. Kim ◽  
K. Deshpande ◽  
Z. Xu ◽  
D. Weimer ◽  
...  
Keyword(s):  
Low Power ◽  
Satellite Communication ◽  
Lessons Learned ◽  
Gps Receiver ◽  
Dual Frequency ◽  
Present Generation ◽  
Magnetic Meridian ◽  
Storage Batteries ◽  
The Antarctic ◽  
Small Team

Abstract. We present the development considerations and design for ground-based instrumentation that is being deployed on the East Antarctic Plateau along a 40° magnetic meridian chain to investigate interhemispheric magnetically conjugate geomagnetic coupling and other space-weather-related phenomena. The stations are magnetically conjugate to geomagnetic stations along the west coast of Greenland. The autonomous adaptive low-power instrument platforms being deployed in the Antarctic are designed to operate unattended in remote locations for at least 5 years. They utilize solar power and AGM storage batteries for power, two-way Iridium satellite communication for data acquisition and program/operation modification, support fluxgate and induction magnetometers as well as a dual-frequency GPS receiver and a high-frequency (HF) radio experiment. Size and weight considerations are considered to enable deployment by a small team using small aircraft. Considerable experience has been gained in the development and deployment of remote polar instrumentation that is reflected in the present generation of instrumentation discussed here. We conclude with the lessons learned from our experience in the design, deployment and operation of remote polar instrumentation.

scholarly journals A System for Tracking an Autonomously Controlled Canine

2012 ◽  
Vol 65 (3) ◽  
pp. 427-444 ◽  
Author(s):  
Jeff Miller ◽  
George Flowers ◽  
David Bevly
Keyword(s):  
Fuzzy Logic Controller ◽  
Gps Receiver ◽  
Process Noise ◽  
Embedded Control ◽  
Noise Covariance Matrix ◽  
Adaptive Tuning ◽  
Noise Characteristics ◽  
Noise Covariance ◽  
Motion Characteristics ◽  
Tone Generation

This paper presents an approach for outdoor navigation of an autonomously guided canine using an embedded command module with vibration and tone generation capabilities and an embedded control suite comprised of a microprocessor, wireless radio, GPS receiver, and an Attitude and Heading Reference System. In order to determine the canine's motions, which inherently contain non-conventional noise characteristics, the sensor measurements were integrated using a specialized Extended Kalman Filter (EKF), equipped with a Fuzzy Logic controller for adaptive tuning of the Process Noise Covariance Matrix. This allowed for rejection of un-modelled canine motion characteristics which tend to corrupt accelerometer bias tracking in a standard EKF. The EKF solution provided an optimized estimate of the canine position and velocity and also proved to be effective in tracking the canine's position (within 7·5 m) and velocity (within 1·2 m/s) during simulated 10 second GPS outages.

Wave Heights during Hurricane Katrina: An Evaluation of PPP and PPK Measurements of the Vertical Displacement of the GPS Antenna

2010 ◽  
Vol 27 (10) ◽  
pp. 1760-1768 ◽  
Author(s):  
L. C. Bender ◽  
S. D. Howden ◽  
D. Dodd ◽  
N. L. Guinasso
Keyword(s):  
Hurricane Katrina ◽  
Degrees Of Freedom ◽  
Vertical Motion ◽  
Vertical Displacement ◽  
Water Levels ◽  
Gps Receiver ◽  
Dual Frequency ◽  
Wave Heights ◽  
6 Degrees Of Freedom ◽  
Gps Antenna

Abstract In August 2005 the eye of Hurricane Katrina passed 49 n mi to the west of a 3-m discus buoy operated by the Central Gulf of Mexico Ocean Observing System (CenGOOS). Buoy motions were measured with a strapped-down 6 degrees of freedom accelerometer, a three-axis magnetometer, and a survey-grade GPS receiver. The significant wave heights were computed from the buoy’s accelerometer record and from the dual-frequency GPS measurements that were processed in two different ways. The first method was postprocessed kinematic (PPK) GPS, which requires another GPS receiver at a fixed known location, and the other was precise point positioning (PPP) GPS, which is another postprocessed positioning technique that yields absolute rather than differential positions. Unlike inertial measurement units, either GPS technique can be used to obtain both waves and water levels. The purpose of this note is to demonstrate the excellent reliability and accuracy of both methods for determining wave heights and periods from a GPS record. When the motion of the GPS antenna is properly understood as the motion of the buoy deck and not the true vertical motion of the sea surface, the GPS wave heights are as reliable as a strapped-down 1D accelerometer.

Acquisition Algorithm for GPS L2C Signal on Dual-Frequency Navigation Receiver

2012 ◽  
Vol 457-458 ◽  
pp. 1413-1419
Author(s):  
Bing Hou ◽  
Xiao Lin Zhang ◽  
Peng Cheng Du ◽  
Zhu Feng Xu
Keyword(s):  
Doppler Shift ◽  
Experimental Result ◽  
Gps Receiver ◽  
Dual Frequency ◽  
Acquisition Process ◽  
Speed Up ◽  
Fixed Phase ◽  
L2c Signal ◽  
Phase Relationships

The newly broadcast GPS L2C signal will be extensively used due to its superiority. In order to acquire L2C signal fast in a dual-frequency GPS receiver, this paper firstly discusses two traditional acquisition algorithms, then proposes and implements a new algorithm based on the fixed phase relationships among C/A code, CM code and CL code and the fixed relationships of Doppler shift between the L1 channel and L2 channel. The experimental result demonstrates that the new acquisition algorithm can speed up the acquisition process substantially. It also suits other dual-frequency navigation receivers.

scholarly journals Analysis of Tec Variations over Nepal Obtained from GPS Data on Geo-Magnetically Quiet and Disturbed Days of the Year 2015

2021 ◽  
Vol 7 (2) ◽  
pp. 102-109
Author(s):  
B. D. Ghimire ◽  
N. P. Chapagain ◽  
V. Basnet ◽  
B. Khadka
Keyword(s):  
Weather Prediction ◽  
Vapor Concentration ◽  
Gps Data ◽  
Electron Content ◽  
Gps Receiver ◽  
Dual Frequency ◽  
Total Electron ◽  
Gps Tec ◽  
Global Positioning ◽  
The Difference

Dual frequency Global Positioning System (GPS) receiver in two nearby stations i.e. BESI (28.228 °N, 84.739 °E) and GHER (28.375 °N, 84.739 °E) located at almost same latitude and longitude are used to measure ionospheric total electron content (TEC) for the year 2015. Since Year of 2014- 2016 have been known as most active years in terms of geomagnetic events, the year 2015 shows some abnormal results. Diurnal, monthly and seasonal variations of GPS TEC have been studied. The difference in the value of TEC is observed between quiet and disturbed days. Moreover, the correlation between GPS-data of each month with solar activities parameters such as Kp index, disturbance storm time (Dst) index, and Solar Flux index (F10.7 cm) have been studied, separately for quiet and disturbed days for each station. In case of diurnal variation, mean TEC varies from 0100 UT (LT= UT+5:45) to maximum from 0900 UT to 1100UT. The value of TEC is observed higher on quiet days than disturbed days. For seasonal variation, local seasons i.e. autumn, Spring, Summer and Winter is taken and, the value of TEC is found to be higher in Spring (March, April and May) in both stations in quiet and disturbed days. The difference in value of quiet and disturbed days of GPS-TEC explained the geomagnetic phenomena difference in these days in ionosphere. This study can be useful to calculate the water vapor concentration in the atmosphere which is useful for weather prediction and meteorological department.

scholarly journals Variation of Total Electron Content (TEC) in the Quite and Disturbed days and their correlation with Geomagnetic Parameters of Lamjung Station in the year of 2015

BIBECHANA ◽  
2020 ◽  
Vol 17 ◽  
pp. 123-132
Author(s):  
Basu Dev Ghimire ◽  
Narayan Prasad Chapagain ◽  
Vardhan Basnet ◽  
Karan Bhatta ◽  
Balaram Khadka
Keyword(s):  
Lower Bound ◽  
Total Electron Content ◽  
Negative Correlation ◽  
Solar Flux ◽  
Electron Content ◽  
Gps Receiver ◽  
Dual Frequency ◽  
Total Electron ◽  
Positive Correlation ◽  
Dst Index

Total Electron content is measured using a dual frequency GPS receiver in Lamgung (LMJG) Station located at 84.57° longitude and 28.17° latitude of the year 2015 as it is considered as geo-magnetically active year. In this study, diurnal variation of VTEC has been studied separately for quiet and disturbed days and, for the effective study of the case the PRN wise data of VTEC have been also used. The maximum VTEC is seen from 0700 LT to 1100 LT (LT=UT+5.45). PRN wise VTEC is studied taking the lower bound (LB) and upper bound (UB). The correlation of VTEC with Dst index, Kp index and Solar flux have been studied. Positive correlation has been found in disturbed days with Kp index and solar flux but negative correlation with Dst index. Dst index shows positive correlation in quiet days but Kp index shows negative correlation. BIBECHANA 17(2020) 123-132

scholarly journals On the Choice of the Third-Frequency Galileo Signals in Accelerating PPP Ambiguity Resolution in Case of Receiver Antenna Phase Center Errors

2020 ◽  
Vol 12 (8) ◽  
pp. 1315
Author(s):  
Shaoming Xin ◽  
Jianghui Geng ◽  
Jiang Guo ◽  
Xiaolin Meng
Keyword(s):  
Ambiguity Resolution ◽  
Convergence Time ◽  
Gps Receiver ◽  
Dual Frequency ◽  
International Gnss Service ◽  
Phase Center ◽  
Triple Frequency ◽  
Antenna Phase ◽  
Signal Combination ◽  
Antenna Phase Center

Rapid precise point positioning ambiguity resolution (PPP-AR) is of great importance to improving precise positioning efficiency. There is an expectation that Galileo multi-frequency (three or more frequencies) data processing will offer a promising way to accelerate PPP-AR. However, the performance of different combination observables out of raw Galileo multi-frequency data is still unclear, and the adverse impacts of missing receiver antenna phase center corrections have not been quantified in detail. We therefore studied uncombined Galileo PPP-AR by contrasting three typical triple-frequency combinations, which are E1/E5a/E5b, E1/E5a/E6, and E1/E5/E6 signals, using 30 days of data from 15 stations across Australia. We carried out triple-frequency PPP-AR by separately applying the official GPS receiver antenna phase centers, as currently employed in most relevant literatures, as well as the pilot Galileo receiver antenna phase centers preliminarily measured by the International GNSS Service. We found that, compared to dual-frequency (E1/E5a) PPP-AR, triple-frequency PPP-AR based on E1/E5a/E5b signals shortened the convergence time by only 7.6%, while those based on E1/E5a/E6 and E1/E5/E6 increased unexpectedly the convergence time by 17.6% and 12.7%, respectively, if the GPS receiver antenna corrections were presumed for Galileo signals. However, after using the pilot Galileo phase center corrections, triple-frequency PPP-AR based on E1/E5a/E5b, E1/E5a/E6, and E1/E5/E6 signals could speed up the convergence on average by about 16.2%, 30.3%, and 17.7%, respectively. Therefore, we demonstrate the critical impact of correct Galileo receiver antenna phase centers on multi-frequency PPP-AR convergences. Moreover, the triple-frequency signal combination E1/E5a/E6 is advantageous over others in achieving rapid triple-frequency Galileo PPP-AR.

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