scholarly journals Motion Compensation for Radar Terrain Imaging Based on INS/GPS System

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3895 ◽  
Author(s):  
Michal Labowski ◽  
Piotr Kaniewski ◽  
Piotr Serafin

In order to obtain good quality radar terrain images using an aerial-based synthetic aperture radar, a motion compensation procedure must be applied. This procedure can use a precise navigation system in order to determine the aircraft’s position and velocity. A major challenge is to design a motion compensation procedure that can operate in real time, which is crucial to ensure convenient data for a human analyst. The article discusses a possibility of Inertial Measurement System (INS)/Global Positioning System (GPS) navigation system usage in such a radar imaging system. A Kalman filter algorithm designed for this system is described herein, and its modifications introduced by the authors allow the use of navigational data not aligned in time and captured with different frequencies. The presented navigation system was tested using measured data. Radar images obtained with the INS/GPS-based motion compensation system were compared to the INS-only results and images obtained without navigation corrections. The evaluation results presented in the paper show that the INS/GPS system allows for better reduction of geometric distortions in images compared to the INS-based approach, which makes it more suitable for typical applications.

2014 ◽  
Vol 556-562 ◽  
pp. 3313-3316
Author(s):  
Hao Ran Song

Currently, GPS global positioning system has been in the areas of precise positioning, navigation, timing has been widely used. By GPS-OEM combined with computer and communications technologies, users are able to easily and independently developed to meet the specific needs of GPS systems. Design system based on GPS navigation navigation system requirements package, in-depth study of the main factors affecting the precision of navigation. Several factors made corresponding solutions, implements navigation navigation system the main functions of the software.


2020 ◽  
Vol 12 (20) ◽  
pp. 3463
Author(s):  
Carlo Noviello ◽  
Giuseppe Esposito ◽  
Giancarmine Fasano ◽  
Alfredo Renga ◽  
Francesco Soldovieri ◽  
...  

The present manuscript faces the problem of performing high-resolution Unmanned Aerial Vehicle (UAV) radar imaging in sounder modality, i.e., into the vertical plane defined by the along-tack and the nadir directions. Data are collected by means of a light and compact UAV radar prototype; flight trajectory information is provided by two positioning estimation techniques: standalone Global Positioning System (GPS) and Carrier based Differential Global Positioning System (CDGPS). The radar imaging is formulated as a linear inverse scattering problem and a motion compensation (MoCo) procedure, accounting for GPS or CDGPS positioning, is adopted. The implementation of the imaging scheme, which is based on the Truncated Singular Value Decomposition, is made efficient by the Shift and Zoom approach. Two independent flight tests involving different kind of targets are considered to test the imaging strategy. The results show that the CDGPS supports suitable imaging performance in all the considered test cases. On the other hand, satisfactory performance is also possible by using standalone GPS when the meter-level positioning error exhibits small variations during the radar integration time.


2013 ◽  
Vol 373-375 ◽  
pp. 1622-1625
Author(s):  
Ming Liu ◽  
Huan Zhang

A novel method has been proposed for integrated Beidou and GPS (Global Positioning System) navigation system in vessel monitoring system. Application of integrated Beidou and GPS navigation system's high precision positioning and SMS (Short Messaging Service) communication technology in vessel can well solve the problem of vessel navigation, positioning, remote monitoring and commanding. Based on 27 stations of Crustal Moment Observation Network of China, satellite visibility and availability of integrated Beidou and GPS are calculated and analyzed in detail. A data compression algorithm is proposed for Beidou SMS communication technology to get the continuous location and other state of the target vessel. Experimental results reveal that the integrated Beidou and GPS system is superior to any single system in all respects of positioning performance.


1982 ◽  
Vol 36 (1) ◽  
pp. 9-28 ◽  
Author(s):  
David E. Wells ◽  
Demitris Delikaraoglou ◽  
Petr Vaníč

The principles of operation of the NAVSTAR/GPS system are described within the context of the more familiar shore-based radionavigation systems, and of the Transit satellite navigation system. The present GPS satellite constellation of up to six prototype satellites, and the eventual constellation of up to 18 operational satellites are described. Some details of GPS signal structure, receiver operation, and error models are given. Results of our simulations of 1980 GPS marine navigation performance off eastern Canada are presented. These indicate GPS is presently capable of providing 150 m or better real-time positioning for about 11 hours a day in this region. GPS performance in the future is discussed.


2021 ◽  
pp. 1-18
Author(s):  
Mariusz Specht

Abstract Research into statistical distributions of φ, λ and two-dimensional (2D) position errors of the global positioning system (GPS) enables the evaluation of its accuracy. Based on this, the navigation applications in which the positioning system can be used are determined. However, studies of GPS accuracy indicate that the empirical φ and λ errors deviate from the typical normal distribution, significantly affecting the statistical distribution of 2D position errors. Therefore, determining the actual statistical distributions of position errors (1D and 2D) is decisive for the precision of calculating the actual accuracy of the GPS system. In this paper, based on two measurement sessions (900,000 and 237,000 fixes), the distributions of GPS position error statistics in both 1D and 2D space are analysed. Statistical distribution measures are determined using statistical tests, the hypothesis on the normal distribution of φ and λ errors is verified, and the consistency of GPS position errors with commonly used statistical distributions is assessed together with finding the best fit. Research has shown that φ and λ errors for the GPS system are normally distributed. It is proven that φ and λ errors are more concentrated around the central value than in a typical normal distribution (positive kurtosis) with a low value of asymmetry. Moreover, φ errors are clearly more concentrated than λ errors. This results in larger standard deviation values for φ errors than λ errors. The differences in both values were 25–39%. Regarding the 2D position error, it should be noted that the value of twice the distance root mean square (2DRMS) is about 10–14% greater than the value of R95. In addition, studies show that statistical distributions such as beta, gamma, lognormal and Weibull are the best fit for 2D position errors in the GPS system.


2020 ◽  
Vol 8 (1) ◽  
pp. 15
Author(s):  
Santoso B Widiarto ◽  
Iman Wahyudin ◽  
Hendrik Sombo ◽  
Ahmad S Muttaqin ◽  
Prehadi . ◽  
...  

Walking shark (Hemiscyllium freycineti) was classified in the Genus Hemiscyllium, a nocturnal organism, lives in benthic zone. Walking shark has limited distribution because of its inability to swim across the sea regardless the close range. Based on those information, the survey was conducted to monitor the potential density of walking shark populations at Misool, Raja Ampat, in order to have data of population and the utilization. This research was conducted by applying Snorkeling Visual Census Method along the coastline using Global Positioning System. A number of 58 individuals walking sharks was found during the survey and they varied from around 61-70 cm (the longest) to about 20 cm (the shortest). The most common size was of 31-40 cm. The length of the survey track was 20.003,74 m (20 km) and the observation area was 109.592,69 m2 with a survey track width of 11 m, so that the density of walking sharks was about 5,29 individuals/ha.Walking shark in Misool have not been used either for food consumption or in trade demand. It can be concluded, the level of density of walking sharks in Misool is under low pressure conditions.---Hiu berjalan (Hemiscyllium freycineti) tergolong dalam genus Hemiscyllium, yang merupakan hewan nokturnal yang hidup di dasar perairan. Hiu berjalan memiliki distribusi terbatas, karena jenis ini tidak mampu berenang menyeberangi laut yang dalam meskipun hanya berjarak beberapa kilometer. Berdasarkan informasi tersebut, maka dilakukan survei kepadatan populasi hiu berjalan di perairan Misool, Raja Ampat, guna memperoleh data populasi dan pemanfaatannya. Penelitian ini dilakukan dengan metode Snorkeling Visual Census dan survei menyusuri garis pantai berbasis Global Positioning System (GPS). Dari hasil survei, didapatkan jumlah ikan hiu berjalan yang tersensus sebanyak 58 individu dengan ukuran yang bervariasi dari terpanjang sekitar 61-70 cm dan ukuran terpendek 20 cm. Ukuran ikan hiu berjalan yang dominan ditemukan ialahdengan panjang tubuh 31-40 cm (sebanyak 16 individu). Survei ini mencakup panjang lintasan 20.003,74 m (20 km), luas area pengamatan 109.592,69 m2, dan lebar lintasan survei 11 m, sehingga kepadatan ikan hiu berjalan yang diperoleh dari hasil survei yaitu 5,29 individu/ha. Hiu berjalan di Misool belum banyak dimanfaatkan, baik secara konsumsi maupun permintaan perdagangan. Dengan demikian, dapat disimpulkan, bahwa tingkat kepadatan hiu berjalan di Misool dalam kondisi tekanan rendah.


2013 ◽  
Vol 765-767 ◽  
pp. 3291-3294
Author(s):  
Cheng Lin Li ◽  
Zhi Yong Jiang

Currently, the traffic congestion is a significant problem encountered in urban development, which should be resolved depending primarily on the management and deployment under the circumstance that road construction isn't able to keep the pace of automobile growth. WSNs (Wireless sensor networks), made up of numerous sensor nodes, form a multi-hop and self-organizing cellular system by wireless communication, which can realize real-time monitoring and collecting environmental information by cooperation. In this paper, a design of real-time and dynamic city vehicle navigation system is presented based on WSNs, GPS(Global Positioning System), and GPRS(General Packet Radio Service) techniques..


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