The 60° Doppler Angle Correction Paradigm

Author(s):  
Joseph F. Polak ◽  
Frederick W. Kremkau
Author(s):  
Jiang Gao ◽  
Jiang Gao ◽  
Keith Hentel ◽  
Qiang Zhu ◽  
Teng Ma ◽  
...  

2003 ◽  
Author(s):  
Eduardo J. V. Oliveira ◽  
Vera L. d. S. Nantes Button ◽  
Joaquim M. Maia ◽  
Eduardo T. Costa ◽  
Jorge A. G. Albuquerque

Optik ◽  
2021 ◽  
pp. 167082
Author(s):  
Changjun Jiao ◽  
Yong Shu ◽  
Zhen Zhang ◽  
Bo Wang ◽  
Feihai Gao

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2810
Author(s):  
Krzysztof Naus ◽  
Piotr Szymak ◽  
Paweł Piskur ◽  
Maciej Niedziela ◽  
Aleksander Nowak

Undoubtedly, Low-Altitude Unmanned Aerial Vehicles (UAVs) are becoming more common in marine applications. Equipped with a Global Navigation Satellite System (GNSS) Real-Time Kinematic (RTK) receiver for highly accurate positioning, they perform camera and Light Detection and Ranging (LiDAR) measurements. Unfortunately, these measurements may still be subject to large errors-mainly due to the inaccuracy of measurement of the optical axis of the camera or LiDAR sensor. Usually, UAVs use a small and light Inertial Navigation System (INS) with an angle measurement error of up to 0.5∘ (RMSE). The methodology for spatial orientation angle correction presented in the article allows the reduction of this error even to the level of 0.01∘ (RMSE). It can be successfully used in coastal and port waters. To determine the corrections, only the Electronic Navigational Chart (ENC) and an image of the coastline are needed.


2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Meng-Huang Wu ◽  
Navneet Kumar Dubey ◽  
Ching-Yu Lee ◽  
Yen-Yao Li ◽  
Chin-Chang Cheng ◽  
...  

This study was aimed at evaluating the safety and efficacy of using intraoperative computed tomography- (iCT-) guided navigation in simultaneous minimally invasive anterior and posterior surgery for infectious spondylitis. Nine patients with infectious spondylitis were enrolled in this study. The average operative time was 327.6 min (range, 210–490) and intraoperative blood loss was 407 cc (range, 50–1,200). The average duration of hospital stay was 48.9 days (range, 11–76). Out of a total of 54 pedicle screws employed, 53 screws (98.1%) were placed accurately. A reduced visual analog scale on back pain (from 8.2 to 2.2) and Oswestry disability index (from 67.1% to 25.6%) were found at the 2-year follow-up. All patients had achieved resolution of spinal infection with reduced average erythrocyte sedimentation rate (from 83.9 to 14.1 mm/hr) and average C-reactive protein (from 54.4 to 4.8 mg/dL). Average kyphotic angle correction was 10.5° (range, 8.4°–12.6°) postoperatively and 8.5° (range, 6.9°–10.1°) after 2 years. In conclusion, the current iCT-guided navigation approach has been demonstrated to be an alternative method during simultaneous minimally invasive anterior and posterior surgery for infectious spondylitis. It can provide a good intraoperative orientation and visualization of anatomic structures and also a high pedicle screw placement accuracy in patient’s lateral decubitus position.


2008 ◽  
Vol 22 (6) ◽  
pp. 681-688 ◽  
Author(s):  
Ashraf A. Saad ◽  
Thanasis Loupas ◽  
Linda G. Shapiro

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