Extracting Ionosphere Scintillations Index Based on Single Frequency GPS Software Receiver

2012 ◽  
Vol 190-191 ◽  
pp. 1136-1143
Author(s):  
Zhi Huang ◽  
Hong Yuan ◽  
Qi Yao Zuo

Scintillations are caused by ionospheric plasma-density irregularities and can lead to signal power fading, loss of lock of the carrier tracking loop in the GPS receiver. The traditional method of monitoring and mitigating scintillation is to transform commercial GPS receiver with modified hardware and embedded software. To better facilitate advance development GPS receiver under different condition, GPS software scintillation receiver is designed in this paper. The hardware scheme of high-speed GPS signal acquisition system is first discussed and implemented with FPGA and DSP architecture. Then, we describe receiver software processing algorithm, particularly the portion involving the scintillation signal acquisition and tracking, ionospheric scintillation index extracting and scintillation monitoring. The performance of software receiver is demonstrated under scintillation conditions. Relevant results show that software-receiver based approach can avoid weak signal loss and extract effectively ionospheric scintillation parameter compared with the traditional extracting method. Software receiver is suitable and reliable for the ionospheric scintillations monitoring, and can provide theoretical foundations and experimental preparations for future scintillation studies implemented with Chinese indigenous BeiDou-Ⅱ navigation and poisoning system.

2017 ◽  
Vol 14 (2) ◽  
pp. 1
Author(s):  
Sri Ekawati ◽  
Sefria Anggarani ◽  
Dessi Marlia

Ionospheric scintillation activity on certain region need to be known its characteristics since its occurrence can degrade satellite signal quality of global satellite navigation system (GNSS) and also satellite communication that works at L-band frequency. The occurrence of ionospheric scintillation varies with location. Therefore, this paper aimed to determine comparative charasteristics of ionospheric scintillation activity over Manado, Pontianak and Bandung from amplitude scintillation index S4 data derived from GPS receiver. The data obtained from the GPS Ionospheric Scintillation and TEC Monitor (GISTM) at Manado station (1.48o N; 124.85oE geomagnetic latitude 7.7oS), at Pontianak station (0.03o S;109.33oE geomagnetic latitude 9.7oS) and at Bandung (-6.90oS;107.6oE geomagnetic latitude 16.54oS) on July 2014 to June 2015. The data were classified into three categores : quiet, moderate and strong based on s4 index. Then we calculated percentage occurrence of scintillation monthly from each observation stastions and mapping of S4 index over Manado, Pontianak and Bandung. The results show that the presentage of strong scintillation (S4>0.5) above Manado is always lower than the other stastions. Strong scintillation was detected at one stations may not also detected at other stations. For very strong scintillastion event, the occurrence of strong scintillation could be detected by all observation stastions but vary in duration. Duration of strong scintillation over Bandung was the longest (up to 4 hours) compared to Pontianak (less than 2 hours) and Manado (less than 1 hour). Based on map of distribution scintillastion occurrence, strong scintillation occurs more intensively over Bandung than over Pontianak and Manado.


2013 ◽  
Vol 56 (2) ◽  
Author(s):  
Paul Prikryl ◽  
Yongliang Zhang ◽  
Yusuke Ebihara ◽  
Reza Ghoddousi-Fard ◽  
Periyadan T. Jayachandran ◽  
...  

<p>The global positioning system (GPS) phase scintillation caused by high-latitude ionospheric irregularities during an intense high-speed stream (HSS) of the solar wind from April 29 to May 5, 2011, was observed using arrays of GPS ionospheric scintillation and total electron content monitors in the Arctic and Antarctica. The one-minute phase-scintillation index derived from the data sampled at 50 Hz was complemented by a proxy index (delta phase rate) obtained from 1-Hz GPS data. The scintillation occurrence coincided with the aurora borealis and aurora australis observed by an all-sky imager at the South Pole, and by special sensor ultraviolet scanning imagers on board satellites of the Defense Meteorological Satellites Program. The South Pole (SP) station is approximately conjugate with two Canadian High Arctic Ionospheric Network stations on Baffin Island, Canada, which provided the opportunity to study magnetic conjugacy of scintillation with support of riometers and magnetometers. The GPS ionospheric pierce points were mapped at their actual or conjugate locations, along with the auroral emission over the South Pole, assuming an altitude of 120 km. As the aurora brightened and/or drifted across the field of view of the all-sky imager, sequences of scintillation events were observed that indicated conjugate auroras as a locator of simultaneous or delayed bipolar scintillation events. In spite of the greater scintillation intensity in the auroral oval, where phase scintillation sometimes exceeded 1 radian during the auroral break-up and substorms, the percentage occurrence of moderate scintillation was highest in the cusp. Interhemispheric comparisons of bipolar scintillation maps show that the scintillation occurrence is significantly higher in the southern cusp and polar cap.</p>


2014 ◽  
Vol 1003 ◽  
pp. 235-238
Author(s):  
Yu Yang ◽  
Chang Lin Yang ◽  
Yan Fei Liu

The paper completed the software and hardware design of GNSS intermediate frequency signal acquisition system under Linux operating system, realized the GNSS software receiver under Linux. Basing on QT C++ graphical user interface application development framework and Qwt plug-in, the software and data graphical display interface was also accomplished. By caching the data of RF module and controlling read and write signals of CY7C68013A through FPGA, the high-speed data transmission function was completed. The test results show that the data transmission rate of this data acquisition system can reach more than 200 Mbps, software receiver satisfies the requirement of positioning accuracy, has good flexibility and higher adaptability, and the algorithm of which was easy to be expanded and upgraded.


Author(s):  
Mark Kimball

Abstract This article presents a novel tool designed to allow circuit node measurements in a radio frequency (RF) integrated circuit. The discussion covers RF circuit problems; provides details on the Radio Probe design, which achieves an input impedance of 50Kohms and an overall attenuation factor of 0 dB; and describes signal to noise issues in the output signal, along with their improvement techniques. This cost-effective solution incorporates features that make it well suited to the task of differential measurement of circuit nodes within an RF IC. The Radio Probe concept offers a number of advantages compared to active probes. It is a single frequency measurement tool, so it complements, rather than replaces, active probes.


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