Results 291 to 300 of about 3,413,392 (339)

SCFNet: Semantic Condition Constraint Guided Feature Aware Network for Aircraft Detection in SAR Images

IEEE Transactions on Geoscience and Remote Sensing, 2022
Aircraft detection in synthetic aperture radar (SAR) images plays an essential role in satellite observation and military decisions. Due to discrete scattering properties, speckle noise interference, and various aircraft types, many existing methods ...
Zhen Wang, Nan Xu, Jianxin Guo, Chuanlei Zhang, Buhong Wang   +4 more
semanticscholar   +1 more source

Aircraft observations of NH3 from agricultural sources

2023
Ammonia (NH3) is mainly emitted in the atmosphere by anthropogenic activities, especially by agriculture. Excess emissions greatly disturb ecosystems, biodiversity, and air quality. Despite our awareness of these deleterious consequences, NH3 concentrations are increasing in most industrialized countries.
Lara Noppen, Lieven Clarisse, Frederik Tack, Thomas Ruhtz, Alexis Merlaud, Martin Van Damme, Michel Van Roozendael, Dirk Schuettemeyer, Pierre Coheur   +8 more
openaire   +1 more source

Aircraft observations of convective cloud electrification

Journal of Atmospheric and Terrestrial Physics, 1959
Abstract A horizontal component of the potential gradient in and around developing trade-wind and extra-tropical cumulus clouds has been measured with field meters mounted in the wingtips of an airplane. Characteristic similarities and differences in the electrostatic behaviour of all-water and of mixed-phase clouds studied in 1953–1955 are discussed.
D.R. Fitzgerald, H.R. Byers
openaire   +1 more source

OBSERVER-BASED CONTROL OF A PVTOL AIRCRAFT

IFAC Proceedings Volumes, 2005
Abstract In this paper, we propose an observed-based control for the PVTOL aircraft considering that the angular position is not measurable. The control strategy presented here, is robust with respect to observer errors and takes into account constraints imposed by the nonlinear observer.
Anand Sánchez, Isabelle Fantoni, Rogelio Lozano, Jesús De León Morales   +3 more
openaire   +1 more source

The Design of Aircraft Landing Gear

, 2021
The aircraft landing gear and its associated systems represent a compelling design challenge: simultaneously a system, a structure, and a machine, it supports the aircraft on the ground, absorbs landing and braking energy, permits maneuvering, and ...
R. K. Schmidt
semanticscholar   +1 more source

Aircraft positioning using GPS/GLONASS code observations

Aircraft Engineering and Aerospace Technology, 2019
Purpose This paper aims to present the problem of the integration of the global positioning system (GPS)/global navigation satellite system (GLONASS) data for the processing of aircraft position determination. Design/methodology/approach The aircraft coordinates were obtained based on GPS and GLONASS code observations for the single point ...
Kamil Krasuski, Janusz Cwiklak, Marek Grzegorzewski   +2 more
openaire   +1 more source

Aircraft observations of marine stratocumulus during JASIN

Quarterly Journal of the Royal Meteorological Society, 1982
AbstractObservations of marine stratocumulus obtained by three research aircraft during the JASIN experiment are presented. Detailed measurements were made of the thermodynamic, cloud physics and radiation fields. These showed an essentially well‐mixed boundary layer with cloud liquid water contents close to their adiabatic values. The mean drop radius
A. Slingo, S. Nicholls, J. Schmetz
openaire   +1 more source

Some Observations on the Mechanism of Aircraft Wing Rock

Journal of Aircraft, 1978
A pressure scale model of Northrop F-5A was tested in NASA Ames Research Center Eleven-Foot Transonic Tunnel to simulate the wing rock oscillations in a transonic maneuver. For this purpose, a flexible model support device was designed and fabricated which allowed the model to oscillate in roll at the scaled wing rock frequency. Two tunnel entries were
C. HWANG, W. PI
openaire   +1 more source

Clear-Air Turbulence: Simultaneous Observations by Radar and Aircraft

Science, 1967
Ultrasensitive radars and uninstrumented jet aircraft in concert have probed regions of the clear atmosphere in search of clear-air turbulence. All sources of clear-air radar echoes above 6 kilometers that were probed simultaneously by the aircraft were found to be turbulent.
J J, Hicks, I, Katz, C R, Landry, K R, Hardy   +3 more
openaire   +2 more sources

Transforming Aircraft Detection Through LEO Satellite Imagery and YOLOv9 for Improved Aviation Safety

2024 26th International Conference on Digital Signal Processing and its Applications (DSPA)
The utilization of object detection algorithms in conjunction with satellite imagery to detect aircraft has become a crucial focus of investigation, bearing significant implications for the management of airports, as well as for the enhancement of ...
Murat Bakirci, Irem Bayraktar
semanticscholar   +1 more source