The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Constellation of regional BDS has been completed with five Geostationary Earth Orbit (GEO) satellites, five Inclined Geosynchronous Satellite Orbit (IGSO) satellites and four Medium Earth Orbit (MEO) satellites, which can provide positioning, navigation, timing, short-message communication and other services for regional users. China's BDS continues to develop a global system in near future. In order...
In the research and precise applications of Global Navigation Satellite System(GNSS), it is often necessary to choose a reference satellite for differential combination calculation, such as Real Time Kinematic(RTK) positioning, Uncalibrated Phase Delays(UPD) solving based on between satellite difference etc. In a specific period, the more reasonable selection of the reference satellite is, the better...
In this paper, we use SLR normal point observations provided by EDC to validate AIUB zero-difference kinematic orbit of GRACE satellites. By selecting 4 representative SLR sites, they are analyzed in detail from the regularity of observed elevation angle, azimuth angle and residual value of GRACE-A/B satellites. The results show that the data quality of different SLR sites is uneven, and more than...
The users of real time kinematic(RTK) still base on basic frequency carrier for ambiguity resolution(AR) and positioning, which leads to impossibility for positioning instantaneously. However, higher timeliness instead of precision by centimeter level is in high and increasing demand in some areas. Therefore, a method of single-epoch ambiguity resolution and positioning was researched in the paper...
Rear-End Collision has been considered as one of the most frequent accidents on roadways. In recent years, Global Satellite Navigation System (GNSS) with the merit of flexible and low cost, has exhibited the great potential for the rear-end Collision Avoidance Systems (CAS) for vehicles. Nevertheless, two main issues associated with the current rear-end CAS are: 1) accessing to high accuracy vehicle...
The high-precision measurement of attitude information is of great significance to the satellites, aircraft and vehicle. How to measure the three-dimensional attitude of the carrier efficiently and accurately becomes the hotspot in the related research field. This paper proposes a new GNSS 3D attitude measurement system based on dual-antenna receiver with common clock. This system uses single-difference...
For most of the external atmosphere flight, ballistic target trajectory has special characteristics like long-time and long-range. In this paper, the ellipsoidal earth model is taken into consideration for discussing the problem of two-dimensional engagement between the target and the interceptor, where atmosphere effect is neglected. By the presentation methods of operational area and launch area...
A total of 20 stations in the North China Plain were selected. The noise variances of each station were estimated by the least squares variance component estimation method under the combination of white noise and flicker noise. The noise variances are composed of the white noise and flicker noise vectors of different components. The correlations among the different component noise vectors were then...
Common mode errors (CMEs) commonly exist in GPS coordinate time series, and it would affect the accuracy and reliability of the position and velocity of a reference station. The reduction of CME decreases the amplitude of seasonal variation and colored noise. This paper analyzes the noise of CME of 27 reference stations in the Crustal Movement Observation Network of China (CMONOC) using maximum likelihood...
This paper presents a self-calibration method for estimating receiver position errors using TDOA measurements for targets with unknown positions. The method uses two LS minimization steps to estimate the related receiver position errors. The method estimates the initial TDOA LS for the unknown target position with the measured receiver positions. A second weighted LS using the total differential of...
Satellite-based communications, navigation, surveillance and air traffic management systems (CNS/ATM) are extremely promising in future use because of its great advantages in coverage and accuracy, yet can be seriously disabled by Global Navigation Satellite System (GNSS) vulnerability factors such as satellite anomaly, ionospheric perturbation, and electromagnetic interference. To improve the reliability...
Determination of troposphere delay has always been a challenging issue in Global Navigation Satellite System (GNSS) applications, such as high precision GNSS positioning and atmospheric delay parameter estimation. In this study, an improved algorithm, named SEU, is proposed, using a modified classic model to calculate the zenith tropospheric delay. The temperature and barometric pressure in the algorithm...
Tropospheric delay is an important error source in the Global Navigation Satellite System (GNSS) positioning, navigation and timing. The global empirical models are unable to provide sufficient accuracy for the precise positioning with the increasing demand of precision. In this paper, we utilize the UNB3m model to determine accurate temperature, pressure and relative humidity which can be used to...
Seasonal variations of gravity waves over the globe in the stratosphere are investigated using radio occultation data from the Constellation Observing System for Meteorology, Ionosphere and Climate mission from September 2006 to June 2016. The global distributions of 10-year averaged seasonal means of gravity waves indicate that potential energy is large over tropical and subtropical latitudes (30°S-30°N)...
This paper addresses the problem of plug and play measurement fusion for integrated navigation system using nonlinear optimization method. We refer to multi-sensor fusion estimation as a sequential, weighted least squares problem. Using fluid re-linearization and partial state updates strategies to reduce computational burden, we propose a low cost nonlinear optimization algorithm. This algorithm...
Indoor Global Positioning System (IGPS) is one of the most commonly used methods for indoor high-precision positioning. In order to improve the accuracy of IGPS essentially, this paper studies the device error and its influence on positioning accuracy through introducing the intermediate variable named scanning angle error. The relationship between positioning accuracy, device error and scanning angle...
The traditional GNSS spoofing signals power distribution strategy only considers availability and validity in single channel mode without multiple channel mode. Therefore, a new strategy based on acquisition and tracing performance threshold is proposed. The relationship between the signal acquisition/tracking performance and carrier-to-noise ratio (C/N0) is analyzed. Then the influence of spoofing...
Global Positioning System (GPS) is widely used not only in terrestrial scenarios for positioning, navigation and timing applications, but also in various space scenarios, like orbit determination of satellites and space station in recent years. As the visibility analysis of GPS satellites would be a critical issue to be solved in the Space Service Volume (SSV) receiver preliminary design, this parameter...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.