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This paper presents method and result of analysis on the multivariate mutual information of an interferometric radar altimeter (IRA) for an application to the terrain-referenced navigation (TRN). As an effort to improve the performance of the IRA-based TRN, we have proposed a novel measurement model which utilizes three measurements. This paper addresses the preliminary study to quantify the effect...
Under GPS-denied conditions, an inertial navigation diverges easily due to integration drift in the measurement of acceleration and angular velocity. Therefore, a terrain relative navigation (TRN) is applied to correct the drift error for precise lunar landing mission. Diverse sensors are used for the TRN in these days, such as a Light and Detection and Ranging (LIDAR), laser altimeter, and optical...
This paper describes vision-based target state estimation approaches for autonomous landing on a moving ground target. The state of moving ground target is estimated by using vision information from a gimbaled camera on an Unmanned Aerial Vehicle (UAV). Using the information from vision system, the UAV estimates the state of a moving target on the ground using the Unscented Kalman Filter (UKF). In...
The robust marker tracking and relative navigation algorithms are presented for precise UAV vision-based autonomous landing. To recognize the marker in close-range, the concentric circles are adopted as the marker with ellipse fitting algorithm based on Direct Least Square. We assume that IMU provides vehicle's attitude and altitude so that we consider GPS-denied situation. Also multiple ellipses...
In this paper, we studied for the ellipse fitting problem when an unmanned aerial vehicle (UAV) reaches near a landing marker for vision-based autonomous landing. Due to limited field of view of a camera, the entire shape of the landing marker cannot be captured as the vehicle approaches it. Also, depending on the vehicle's pose, the shape of the maker is shown distortedly. In order to overcome these...
The image technology of the spacecraft offers useful information variously: weather, geography and military intelligence. Recently, demands of the image which have higher accuracy and degree of precision are rapidly increased. In this sense, scan mirror-gimbal system is implemented on the image observation devices to compensate the image error. The dynamics of the scan mirror-gimbal system and main...
A vision-only navigation system is addressed for autonomous navigation of unmanned aerial vehicles (UAVs) with monocular camera as the only sensor. Typical vision-based navigation algorithms blend inertial navigation data with vision measurements and other available information to estimate vehicle's position. In this paper, however, we propose an approach that replaces the high-cost inertial navigation...
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