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Multisensor Map Matching for Pedestrian and Wheelchair Navigation
Published in Hassan A. Karimi, Advanced Location-Based Technologies and Services, 2016
In pedestrian and wheelchair navigation systems, landmarks are used as references for absolute positioning. Given known locations of landmarks and estimated distances from users to those landmarks, pedestrian navigation systems can provide users with their absolute positions. Locations of known landmarks are recorded in the database server in advance. An example scenario is as follows. A user on a tour captures pictures and sends them to the server. Once landmarks shown in the pictures are matched with the known landmarks in the server, the tour system can estimate the user’s location by retrieving the known landmark’s location in the database server and computing the distance from the user to the known landmarks. Figure 9.1 shows an example image with landmarks. In this figure, the red points on the image are landmarks, which are used as reference points. When a user travels on a tour, their locations are computed and marked on the image, which are shown as query points. Steinhoff et al. (2007) concluded that the absolute positions obtained for the way-points in the tour system were more accurate than GPS.
Loran-C
Published in Laurie Tetley, David Calcutt, Electronic Navigation Systems, 2007
Modern receivers have the facility for the operator to monitor the progress of the voyage and allow for course corrections as necessary. The receiver gives a position (in TD or latitude/longitude) and has a precise clock so that it is possible to produce navigational information, such as vessel's speed and course. A waypoint is a set of co-ordinates that indicate a location of interest to the navigator, such as wrecks, buoys, channel information, and previously productive fishing areas. Waypoints can usually be stored in the receiver memory by entering the waypoint co-ordinates or as a distance and bearing from another waypoint before pressing the appropriate control button. Waypoints may be used by the navigator as route indicators for a planned route. The receiver can track progress between waypoints allowing the operator to monitor data, such as bearing to the next waypoint, time-to-go (TTG) to reach the next waypoint, and cross-track error (XTE). The latter indicates a deviation from the planned course and shows the perpendicular distance from present position to the intended track between waypoints.
A data-driven method for flight time estimation based on air traffic pattern identification and prediction
Published in Journal of Intelligent Transportation Systems, 2022
Chunwei Yang, Junfeng Zhang, Xuhao Gui, Zihan Peng, Bin Wang
The rapid growth of air traffic and increasing demand have resulted in substantial flight delays, excessive fuel consumption, and consequential pollutant emissions. To tackle these issues, Air Traffic Management (ATM) is evolving toward a Trajectory-Based Operations (TBO) paradigm (Gallego et al., 2019). TBO aims to plan and manage air traffic operations through Four-Dimensional Trajectories, which can enhance the levels of air traffic safety, improve ATM efficiency and ensure environmental sustainability. The Four-Dimensional Trajectory Prediction (4 D TP) is the critical element of TBO implementation (Zhang et al., 2018) and the performance of the 4 D TP also affects the overall performance of the ATM system. 4 D TP refers to calculating and predicting longitude, latitude, altitude, and time of the future waypoint sequence based on existing data (Wang et al., 2018).
Design framework for optimizing waypoints of vehicle trajectory considering terminal velocity and impact angle constraints
Published in Engineering Optimization, 2022
Youngil Kim, Namhoon Cho, Jongho Park, Youdan Kim
The terminal conditions at the target are set as follows: km, km, m/s and . The chosen terminal constraints are close to those of typical tactical ballistic missiles such as the Army Tactical Missile System (ATACMS) and the Russian mobile short-range ballistic missile system ISKANDER, which adopt solid rocket motor fuel and hit a specified target with the trajectory that can deliver the highest attack effectiveness. The time step of the simulation is 0.1 s, and the mass of the missile is 1000 kg. To reflect a realistic environment, the missile is limited to a minimum altitude of 2 km until it reaches waypoint 3, and an altitude of 5 km above the target is considered for waypoint 3. The maximum lateral acceleration is set as 10 g, and the altitude of waypoint 2 does not exceed the maximum altitude of the whole trajectory.
Plan B for Eliminating Mode Confusion: An Interpreter Display
Published in International Journal of Human–Computer Interaction, 2021
Other IMMI design goals were related to the representation of the autoflight system’s behavior: The interface should provide a graphical representation of the future vertical trajectory of the airplane.The interface should have a single representation in which all of the descriptions of the flight path are displayed in such a way that it is easy to determine which will be controlling in any situation.The interface should indicate lateral mode status on the map navigational display in a way that makes the mode annunciation perceptually salient.The interface should indicate impending uncommanded and automatic/conditional mode transitions.There should be an interface in which the physical layout and behavior of the displays and control maps easily onto the underlying conceptual regularities of the autoflight system.The interface should make the active waypoint perceptually more salient on the navigation display.