A new underwater positioning model based on average sound speed

2021 ◽  
pp. 1-17
Author(s):  
Yixu Liu ◽  
Xiushan Lu ◽  
Shuqiang Xue ◽  
Shengli Wang

Abstract The layout of seafloor datum points is the key to constructing the seafloor geodetic datum network, and a reliable underwater positioning model is the prerequisite for achieving precise deployment of the datum points. The traditional average sound speed positioning model is generally adopted in underwater positioning due to its simple and efficient algorithm, but it is sensitive to incident angle related errors, which lead to unreliable positioning results. Based on the relationship between incident angle and sound speed, the sound speed function model considering the incident angle has been established. Results show that the accuracy of positioning is easily affected by errors related to the incident angle; the new average sound speed correction model based on the incident angle proposed in this paper is used to significantly improve the underwater positioning accuracy.

2013 ◽  
Vol 353-356 ◽  
pp. 3438-3443
Author(s):  
Li Long Liu ◽  
Liang Ke Huang ◽  
Teng Xu Zhang ◽  
Miao Zhou ◽  
Chao Long Yao

In this paper, the relationship between zenith tropospheric delays and the altitude of stations is analyzed using the EGNOS tropospheric correction model. The new model (EHT model) is proposed for estimating zenith tropospheric delays from regional CORS data without meteorological data. The proposed model is compared with the direct interpolation method and the remove-restore method using data from Guangxi CORS. The results show that the new models significantly improve the calculated precision.


Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4373 ◽  
Author(s):  
Jinwu Tong ◽  
Xiaosu Xu ◽  
Lanhua Hou ◽  
Yao Li ◽  
Jian Wang ◽  
...  

The USBL (Ultra-Short Base Line) positioning system is widely used in underwater acoustic positioning systems due to its small size and ease of use. The traditional USBL positioning system is based on ‘slant range and azimuth’. The positioning error is an increasing function with the increase in distance and the positioning accuracy depends on the ranging accuracy of the underwater target. This method is not suitable for long-distance underwater positioning operations. This paper proposes a USBL positioning calculation model based on depth information for ‘rotating array and reusing elements’. This method does not need to measure the distance between the USBL acoustic array and target, so it can completely eliminate the influence of long-distance ranging errors in USBL positioning. The theoretical analysis and simulation experiments show that the new USBL positioning model based on ‘rotating array and reusing elements’ can completely eliminate the influence of the wavelength error and spacing error of underwater acoustic signals on the positioning accuracy of USBL. The positioning accuracy can be improved by approximately 90%, and the horizontal positioning error within a positioning distance of 1000 m is less than 1.2 m. The positioning method has high precision performance in the long distance, and provides a new idea for the engineering design of a USBL underwater positioning system.


2017 ◽  
Vol 11 (1) ◽  
pp. 1-20
Author(s):  
Ari Mulianta Ginting

Ekspor merupakan salah satu faktor terjadinya peningkatan pertumbuhan ekonomi suatu negara, sejalan dengan hipotesis export-led growth (ELG). Penelitian ini menganalisis perkembangan ekspor dan pertumbuhan ekonomi Indonesia periode kuartal I 2001 sampai dengan kuartal IV 2015. Penelitian ini menggunakan analisis deskriptif dalam menggambarkan perkembangan pertumbuhan ekonomi serta ekspor dan analisis kuantitatif metode Error Correction Model (ECM) dalam menganalisis efek jangka panjang dan jangka pendek dari ekspor terhadap pertumbuhan ekonomi. Pada periode penelitian, data yang ada menunjukkan bahwa ekspor dan pertumbuhan ekonomi Indonesia sama-sama mengalami peningkatan. Hasil regresi ECM menunjukkan bahwa ekspor memiliki pengaruh yang positif dan signifikan secara statistik terhadap pertumbuhan ekonomi Indonesia, yang mendukung hipotesis bahwa ELG berlaku untuk Indonesia. Berdasarkan hasil penelitian ini, maka untuk mendorong pertumbuhan ekonomi Indonesia diperlukan peningkatan kinerja ekspor Indonesia. Peningkatan kinerja ekspor Indonesia dapat dilakukan dengan berbagai cara, salah satunya adalah dengan perbaikan sistem administrasi ekspor, peningkatan riset dan pengembangan produk Indonesia, peningkatan sarana dan prasarana infrastruktur, stabilitas nilai tukar dan perluasan pasar non tradisional, termasuk perbaikan struktur ekspor komoditas. Export is one of the factors behind the economic growth which is in line with the export-led growth hypotesis (ELG). This research analyzes the relationship between economic growth and export of Indonesia during first quarter of 2001 until fourth quarter of 2015. It employs descriptive analysis to describe export movement and economic growth during the study period and ECM model to analyze the long run and the short run effects of export on the economic growth. The available information indicated that, during the study period, both export and economic growth showed similar increasing trends. The result of the ECM model revealed that export had a positive and statistically significant relationship with the economic growth, supporting the hypotesis of ELG in Indonesia. Hence, to accelerate economic growth, efforts are required to boost the export performance in Indonesia. The Export performance can be increased by several way, such as improving the export administration system, increasing the research and development of Indonesian products, improving the facilities and infrastructure, exchange rate stability and the non-tradisional markets expansion, and including improvement of the export commodity structure.


2013 ◽  
Vol 734-737 ◽  
pp. 1666-1670
Author(s):  
Fei Hu Yang ◽  
Peng Zhang ◽  
Xiao Wei Wang

Based on the co-integration test, error correction model and vector autoregressive model, the empirical analysis results show a long-term co-integration relationship between economic growth and energy utilization in China, energy consumption increased by 1%, GDP will increase by 1.342%. In order to raise the efficiency of energy utilization during China's economic development, suggestions like saving energy conservation, reducing emission and recycling economy have been proposed.


Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 143
Author(s):  
Qinghua Luo ◽  
Xiaozhen Yan ◽  
Chunyu Ju ◽  
Yunsai Chen ◽  
Zhenhua Luo

The ultra-short baseline underwater positioning is one of the most widely applied methods in underwater positioning and navigation due to its simplicity, efficiency, low cost, and accuracy. However, there exists environmental noise, which has negative impacts on the positioning accuracy during the ultra-short baseline (USBL) positioning process, which results in a large positioning error. The positioning result may lead to wrong decision-making in the latter processing. So, it is necessary to consider the error sources, and take effective measurements to minimize the negative impact of the noise. In our work, we propose a USBL positioning system with Kalman filtering to improve the positioning accuracy. In this system, we first explore a new kind of element array to accurately capture the acoustic signals from the object. We then organically combine the Kalman filters with the array elements to filter the acoustic signals, using the minimum mean-square error rule to obtain accurate acoustic signals. We got the high-precision phase difference information based on the non-equidistant quaternary original array and the phase difference acquisition mechanism. Finally, on account of the obtained accurate phase difference information and position calculation, we determined the coordinates of the underwater target. Comprehensive evaluation results demonstrate that our proposed USBL positioning method based on the Kalman filter algorithm can effectively enhance the positioning accuracy.


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