VISUALIZATION TECHNOLOGY OF AUGMENTED REALITY OBJECTS, DEPENDING ON GEOINFORMATIONAL DATA

Отображение навигационной информации в виде проекции на лобовое стекло автомобиля или стекло мотошлема обеспечивает ее восприятие водителем без переключения внимания с дороги на приборную панель, тем самым повышая безопасность дорожного движения. Используемые в настоящее время технологии визуализации информации для навигационного оснащения автомобиля или мотоцикла достаточно дороги и мало распространены, поэтому создание простого и недорогого в разработке программного обеспечения с открытым кодом, повышающего эффективность обработки и отображения информации, представляется актуальным. Предложена архитектура построения подобной системы навигации с применением технологии подсказок водителю в виде объектов дополненной реальности и использованием открытых геоинформационных сервисов. Рассмотрены применяемые в технологии структуры и типы данных, а также возможный набор аппаратных средств визуализации навигационной информации. Алгоритмы визуализации динамических объектов дополненной реальности и обработки геоданных реализованы в программном коде на языке Python. Разработан интерактивный интерфейс, обладающий интегрированным эффектом от совмещения преимуществ навигационных систем и сервисов геоинформационных данных. Приведены результаты тестирования работы кода при визуализации направления движения по заданному маршруту в режиме реального времени Displaying navigation information in the form of a projection onto the windshield of a car or the glass of a motorcycle helmet ensures its perception by the driver without switching attention from the road to the dashboard, thereby increasing road safety. The currently used information visualization technologies for the navigation equipment of a car or motorcycle are quite expensive and not widely used, therefore, the creation of simple and inexpensive open-source software that increases the efficiency of information processing and display seems to be relevant. The article proposes an architecture for building such a navigation system using the technology of prompting the driver in the form of augmented reality objects and using open geoinformation services. We considered the structures and types of data used in technology, as well as a possible set of hardware for visualization of navigation information. We implemented algorithms for visualization of dynamic objects of augmented reality and processing of geodata in the program code in the Python language. We developed an interactive interface that has an integrated effect of combining the advantages of navigation systems and geoinformation data services. We give the results of testing the code when visualizing the direction of movement along a given route in real time

A survey on the application of path-planning algorithms for multi-rotor UAVs in precision agriculture

Multi-rotor Unmanned Aerial Vehicles (UAVs), although originally designed and developed for defence and military purposes, in the last ten years have gained momentum, especially for civilian applications, such as search and rescue, surveying and mapping, and agricultural crops and monitoring. Thanks to their hovering and Vertical Take-Off and Landing (VTOL) capabilities and the capacity to carry out tasks with complete autonomy, they are now a standard platform for both research and industrial uses. However, while the flight control architecture is well established in the literature, there are still many challenges in designing autonomous guidance and navigation systems to make the UAV able to work in constrained and cluttered environments or also indoors. Therefore, the main motivation of this work is to provide a comprehensive and exhaustive literature review on the numerous methods and approaches to address path-planning problems for multi-rotor UAVs. In particular, the inclusion of a review of the related research in the context of Precision Agriculture (PA) provides a unified and accessible presentation for researchers who are initiating their endeavours in this subject.

Flexible cue anchoring strategies enable stable head direction coding in both sighted and blind animals

Vision plays a crucial role in instructing the brain's spatial navigation systems. However, little is known about how vision loss affects the neuronal encoding of spatial information. Here, recording from head direction (HD) cells in the anterior dorsal nucleus of the thalamus in mice, we find stable and robust HD tuning in blind animals. In contrast, placing sighted animals in darkness significantly impairs HD cell tuning. We find that blind mice use olfactory cues to maintain stable HD tuning and that prior visual experience leads to refined HD cell tuning in blind adult mice compared to congenitally blind animals. Finally, in the absence of both visual and olfactory cues, the HD attractor network remains intact but the preferred firing direction of HD cells continuously drifts over time. We thus demonstrate remarkable flexibility in how the brain uses diverse sensory information to generate a stable directional representation of space.

Covariance matrix transformation method in all-earth integrated navigation considering coordinate frame conversion

In the exploration of polar region, navigation is one of the most important issues to be resolved. To avoid the limitations of single navigation coordinate frame, the navigation systems usually use different navigation coordinate frames in polar and nonpolar region, such as the north-oriented geographic frame and the grid frame. However, the error states and covariance matrix are related with the definition of navigation coordinate frame, since the coordinate frame conversion will cause the integrated navigation Kalman filter overshoot and error discontinuity. To solve this problem, the transformation relationship of error states defined in different frames is deduced, whereby the covariance matrix transformation relationship is also analyzed. On this basis, covariance transformation-based the open-loop and the closed-loop Kalman filter integrated navigation algorithms are proposed. The effectiveness of algorithms is verified by flight tests with rotational strapdown inertial navigation system (RSINS)/global navigation satellite system (GNSS) integrated navigation system.

Navigation in GEO, HEO, and Lunar Trajectory Using Multi-GNSS Sidelobe Signals

Positioning of spacecraft (e.g., geostationary orbit (GEO), high elliptical orbit (HEO), and lunar trajectory) is crucial for mission completion. Instead of using ground control systems, global navigation satellite system (GNSS) can be an effective approach to provide positioning, navigation and timing service for spacecraft. In 2020, China finished the construction of the third generation of BeiDou navigation satellite system (BDS-3); this global coverage system will contribute better sidelobe signal visibility for spacecraft. Meanwhile, with more than 100 GNSS satellites, multi-GNSS navigation performance on the spacecraft is worth studying. In this paper, instead of using signal-in-space ranging errors, we simulate pseudorange observations with measurement noises varying with received signal powers. Navigation performances of BDS-3 and its combinations with other systems were conducted. Results showed that, owing to GEO and inclined geosynchronous orbit (IGSO) satellites, all three types (GEO, HEO, and lunar trajectory) of spacecraft received more signals from BDS-3 than from other navigation systems. Single point positioning (SPP) accuracy of the GEO and HEO spacecraft was 17.7 and 23.1 m, respectively, with BDS-3 data alone. Including the other three systems, i.e., GPS, Galileo, and GLONASS, improved the SPP accuracy by 36.2% and 19.9% for GEO and HEO, respectively. Navigation performance of the lunar probe was significantly improved when receiver sensitivity increased from 20 dB-Hz to 15 dB-Hz. Only dual- (BDS-3/GPS) or multi-GNSS (BDS-3, GPS, Galileo, GLONASS) could provide continuous navigation solutions with a receiver threshold of 15 dB-Hz.

Ultra-sensitive all-optical comagnetometer with laser heating

Ultra-sensitive comagnetometers, which are designed to detect nuclear-and electron-spin-dependent interaction, have important applications ranging from basic research to inertial navigation systems (INSs). Unfortunately, electric heating, which is typically used in comagnetometers, introduces systematic errors because of the unavoidable generation of a modulated magnetic field. In this study, we investigate and introduce K-Rb-21Ne comagnetometer that uses laser heating for the first time, when operated in the spin-exchange relaxation free (SERF) regime. The performance of the comagnetometer, which is equipped with both laser heating and electric heating, is investigated, and the two heating modes are compared. The temperature characteristics of the comagnetometer are studied theoretically and experimentally. By optimizing the operating temperature and power density of the pump-light, an equivalent rotation sensitivity of 2.5×10^(-7) rad/s/√Hz@1Hz is achieved in laser heating mode. The improvement of laser-heating technology could prove essential to reduce electron relaxation and increase the low-frequency sensitivity of comagnetometers. Our results indicate that laser heating can make comagnetometers more suitable for applications in basic research (fifth force, dark matter, etc.), INSs, and other accurate measurements of electronic and nuclear precession.

Experience Toward Smart Tour Guide Apps in Travelling

The integration of navigation systems and smart tour guide apps has gained popularity among travellers with the rapid development of the internet, mobile technology, and the wide acceptance of smartphones. The purpose of the study is twofold: (1) to assess the growth of smart tour guide apps in India and (2) to examine the tourists' experiences in using smart tour guide apps. To achieve the purpose of the study, a content analysis method was employed to analyse the users' reviews on the “Audio Odigos” and the “Trip My Way,” which are very popular tour guide apps in India. The results reveal that smart tour guide apps are more preferred than the human tour guide. An app-based tour guide facilitates exceptional experiences for accurate and useful information on historical monument tours, city tours, and destination tours. Thus, the findings can be used to improve the existing apps and develop more sophisticated apps in the future that can ensure sustainable smart tourism.