Forest inventory has been relying on labor-intensive manual measurements. Using remote sensing modalities for forest gained increasing attention in the last few decades. However, tools deriving accurate tree-level metrics are limited. This paper investigates feasibility of using LiDAR units onboard uncrewed aerial vehicle (UAV) and Backpack mobile mapping systems (MMSs) equipped with an integra...

In this paper, a mechanism is designed for integration of inertial navigation system information (INS) and global positioning system information (GPS). In this type of system a series of mathematical and filtering algorithms with Tightly Coupled techniques with several objectives such as application of integrated navigation algorithms, precise calculation of flying object position, speed and at...

Transfer alignment is always a key technology in a strapdown inertial navigation system (SINS) because of its rapidity and accuracy. In this paper a transfer alignment model is established, which contains the SINS error model and the measurement model. The time delay in the process of transfer alignment is analyzed, and an H∞ filtering method with delay compensation is presented. Then the H∞ fi...

Aircraft precision approach guidance systems require accurate positioning relative to the runway with a high level of integrity. Most precision approach guidance systems in use today require ground-based electronic navigation components with at least one installation at each airport, and in many cases multiple installations to service approaches to all qualifying runway ends. A terrain-referenc...

The second and third phases of the Chinese Lunar Exploration Program (CLEP) are planning to achieve Moon landing, surface exploration and automated sample return. In these missions, the inertial navigation system (INS) and celestial navigation system (CNS) are two indispensable autonomous navigation systems which can compensate for limitations in the ground based navigation system. The accurate...

Abstract Aiming at the problem of rapid transfer alignment inertial navigation system in shipborne environment with large azimuth misalignment angle, a dimension reduction fast scheme aircraft based on CKF algorithm is designed. Firstly, nonlinear attitude error equation, velocity equation and position Global Navigation Satellite System (GNSS) assisted strapdown case are analyzed. Secondly, dim...

Purpose The purpose of this study was to examine the accuracy of implant orientation and leg length in total hip arthroplasty (THA) with an image-free navigation system based on a comparison of the intraoperative navigation and postoperative CT evaluations. Material and Methods A consecutive series of 111 patients (118 hips) who underwent THA using the current version of the image-free naviga...

Purpose To evaluate the effects of femoral lateral bowing on coronal alignment after total knee arthroplasty (TKA) and examine whether the use of navigation helps obtain better postoperative coronal alignment and component position. Materials and Methods Radiological results and outlier rates were compared between the conventional TKA group and the navigation-assisted TKA group, and factors a...

Anatomic aberrations of the femur and tibia secondary to trauma, congenital defects, and prior surgery present challenges for the reconstructive knee surgeon because of an altered mechanical axis and distorted anatomic landmarks. Five patients with arthritis of the knee and extra-articular femoral and/or tibial deformity, retained hardware, or intramedullary (IM) implants underwent total knee a...

localization of brain lesions and prevention of damage to vital structures are important in operation of brain pathologies. despite development of many techniques including angiography, mri, sonography, and frame base stereotaxy, a more accurate localizing technique is still needed (1, 2). a step forward to achieve this goal is to develop a navigation system. in this manuscript, we explained so...