搜索结果: 1-15 共查到“航空、航天科学技术 frequency”相关记录21条 . 查询时间(0.046 秒)
Extremely low frequency plasma turbulence recorded by the DEMETER satellite in the ionosphere over the Abruzzi region prior to the April 6, 2009, L’Aquila earthquake
ionosphere turbulence earthquake
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2015/8/24
The present study analyzes the low frequency fluctuations of the magnetic and electric fields prior to the earthquake with magnitude M.6.3 on April 6, 2009, in the Abruzzi region in Italy. This includ...
Analysis of a Three-Frequency GPS/WAAS Receiver to Land an Airplane
Three-Frequency GPS/WAAS Receiver Land an Airplane
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2015/6/26
This paper investigates the vertical guidance performance of a multiple frequency Global Positioning System (GPS) (L1, L2, and L5)/Wide Area Augmentation System (WAAS) receiver in the presence of incl...
Techniques for Graceful Reversion from Dual to Single Frequency WAAS
Techniques Graceful Reversion Single Frequency WAAS
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2015/6/26
This paper investigates techniques to sustain dual frequency ionosphere performance when a dual-frequency airborne user loses all but one GPS frequency while descending into the radio frequency interf...
Ionospheric Scintillation Effects on Single and Dual Frequency GPS Positioning
Ionospheric Scintillation Effects Dual Frequency GPS Positioning
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2015/6/26
The low latitude ionosphere poses a challenge to both GPS users and Satellite-Based Augmentation System(SBAS) providers. Single and dual frequency GPS receivers used in low-latitude regions can suffer...
A Prototyping Platform for Multi-Frequency GNSS Receivers
Prototyping Platform Multi-Frequency GNSS Receivers
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2015/6/26
Dennis M. Akos completed the Ph.D. degree in Electrical Engineering at Ohio University conducting his graduate research within the Avionics Engineering Center. After completing his graduation he has s...
Ionosphere Monitoring Methodology for Hybrid Dual-Frequency LAAS
Ionosphere Monitoring Methodology Hybrid Dual-Frequency LAAS
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2015/6/26
Strong ionosphere storms are a potential threat for the Local Area Augmentation System (LAAS). During these storms,very large spatial gradients of ionosphere delays might cause significant errors in u...
Evaluation of Two Types of Dual-Frequency Differential GPS Techniques under Anomalous Ionosphere Conditions
Dual-Frequency Differential GPS Techniques Ionosphere Conditions
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2015/6/26
Strong ionosphere storms are a potential threat for the Local Area Augmentation System (LAAS). During these storms,large spatial and temporal gradients of the ionosphere component on the GPS signals c...
Optimizing WAAS Accuracy/Stability For a Single Frequency Receiver
Optimizing WAAS Accuracy/Stability Single Frequency Receiver
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2015/6/26
The Wide Area Augmentation System (WAAS) provides accuracy (95%) to better than 1m in horizontal and 2m in vertical, which is quite an improvement compared to the stand-alone GPS accuracy and well wit...
A Reference Point-based Precise Relative Positioning Method Using a Single Frequency Receiver
Point-based Precise Relative Positioning Method Single Frequency Receiver
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2015/6/26
This paper investigates how to take advantage of the known position of a point at which a single frequency GPS receiver is located. Using this reference point and a single frequency receiver, a precis...
Bounding Higher Order Ionosphere Errors for the Dual Frequency GPS User
Bounding Higher Order Ionosphere Errors Dual Frequency GPS User
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2015/6/25
The advent of a second civil GPS frequency heralds a new phase of GPS performance. For single-frequency GPS users, the signal delay due to refraction through the ionosphere is the largest and most var...
On the Probability Density Function and Stability Properties for a Cross-Product Frequency-Locked Loop
Probability Density Function Stability Properties Cross-Product Frequency-Locked Loop
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2015/6/25
The frequency locked-loop (FLL) has received new attention for modern Global Navigation Satellite Systems (GNSS) receivers, especially for its performance under severe noise interference and high dyna...
Availability Benefit;Future Dual Frequency GPS Avionics;Ionospheric Scintillation
Availability Benefit Future Dual Frequency GPS Avionics Ionospheric Scintillation
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2015/6/25
With the launch of the GPS-IIF satellites, the new civil navigation signals at L5 (1176.45 MHz) will become available to the GNSS community.One of the most significant benefits introduced by this new ...
Availability Benefit of Future Dual Frequency GPS Avionics under Strong Ionospheric Scintillation
Availability Benefit Future Dual Frequency GPS Avionics Ionospheric Scintillation
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2015/6/25
A Global Positioning System (GPS) receiver may lose carrier tracking lock to the GPS signal under deep and frequent fades due to ionospheric scintillation. The frequent loss of lock observed during a ...
Physical Pseudo Random Function in Radio Frequency Sources for Security
Physical Pseudo Random Function Radio Frequency Sources Security
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2015/6/25
There is tremendous market potential for location-based services (LBS), enabled by the rapid growth in the numbers of personal navigation devices and GPS-enabled mobile handsets. One of the major diff...
Vertical Protection Level Equations for Dual Frequency SBAS
Vertical Protection Level Equations Dual Frequency SBAS
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2015/6/25
The L1-only Satellite-Based Augmentation System (SBAS) Minimum Operational Performance Standards (MOPS) were developed long before any SBASs were certified for operation.