Results 101 to 110 of about 182,284 (271)

Over‐the‐horizon radar research consortium formed

Eos, Transactions American Geophysical Union, 1994
One casualty of shrinking military budgets and the disappearance of Cold War threats has been the U.S. Air Force's over‐the‐horizon or ionospheric radar system known as OTH‐B. For the scientific community this is not all bad news: The vast potential of the six powerful 5–28‐MHz radars for geophysical monitoring may soon be available to anyone who can ...
openaire   +1 more source

NowPrecip 2: Precipitation nowcasting in the complex terrain of Switzerland. Part I: Methods

Quarterly Journal of the Royal Meteorological Society, EarlyView.
In this work we present the methods of the areal precipitation nowcasting system NowPrecip version 2. In this version a new methodology is introduced, which, although it shares philosophy and techniques with the original methodology of NowPrecip version 1, can be considered as distinct from that.
I. V. Sideris, A. Ntoumos, A. Berne, A. Hering, P. Juda, M. Boscacci, L. Clementi, U. Germann   +7 more
wiley   +1 more source

NowPrecip 2: Precipitation nowcasting in the complex terrain of Switzerland. Part II: Verification

Quarterly Journal of the Royal Meteorological Society, EarlyView.
In this work we present the verification of the NowPrecip precipitation nowcasting systems (version 1 and version 2). Using 3.5 years of data over the period 2020–2023, their performance is compared with PySTEPS and the ICON numerical weather prediction ensemble by computing deterministic and probabilistic metrics.
A. Ntoumos, I. V. Sideris, A. Berne, A. Hering, P. Juda, M. Gabella, M. Boscacci, L. Clementi, U. Germann   +8 more
wiley   +1 more source

A compact lightweight multipurpose ground-penetrating radar for glaciological applications

, 2011
We describe a compact lightweight impulse radar for radio-echo sounding of subsurface structures designed specifically for glaciological applications. The radar operates at frequencies between 10 and 75 MHz.
Frolovskiy, K., Lapazaran Izargain, Javier Jesús, Machío, F., Navarro Valero, Francisco José, Vasilenko, Evgeniy   +4 more
core   +1 more source

Investigation of the relationship between optical auroral forms and HF radar E region backscatter [PDF]

, 2000
International audienceThe SuperDARN HF radars have been employed in the past to investigate the spectral characteristics of coherent backscatter from L-shell aligned features in the auroral E region.
Milan, S. E., N. Sato, Lester, M., H. Takizawa (7612496), Villain, J.-P., J. -p. Villain, Takizawa, H., M. Lester, N. Sato (7606136), Milan, S.E., S. E. Milan, Stephen E. Milan (7612220), J. P. Villain (7612424), J.-P. Villain, Mark Lester (6477935), Sato, N., H. Takizawa   +16 more
core   +1 more source

A framework to evaluate and identify development requirements for land‐surface models at km‐scale resolution: Application to a semi‐arid and mountainous region

Quarterly Journal of the Royal Meteorological Society, EarlyView.
This article provides a first evaluation of land‐surface models at the km‐scale resolutions at which they are used in weather and Earth‐system models. At these resolutions, the lateral transfers of water that organize landscapes play an important role in predicting evaporation correctly. Riparian processes and human water management for irrigation need
Jan Polcher, Julie Collignan, Juan Pablo Sierra Perez, Gabriele Arduini, Sophie Bastin, Martin Best, Aaron Boone, Manel Bravo, Francesca Covella, Jasper M. C. Denissen, Cenlin He, Simon Munier, Marc Prange, Elena Shevliakova   +13 more
wiley   +1 more source

Cognitive HF radar

The Journal of Engineering, 2019
Radars operating in the high-frequency (HF) band can exploit propagation modes other than line-of-sight and are hence widely employed to provide over-the-horizon surveillance and remote sensing.
Stuart Anderson
doaj   +1 more source

Enabling Under Ice Glider Operations: A Backseat Driver Approach

Journal of Field Robotics, EarlyView.
ABSTRACT Polar Oceans are key locations for forcing global ocean circulation, influencing both global climate and biogeochemical cycles. Due to restricted access to these seasonally and perennially ice‐covered regions, these areas are severely undersampled.
Yaomei Wang, Benjamin Allsup, Georgios Salavasidis, Stephen Woodward, Adeniyi Adenaya, Mike Smart, Alexis Johnson, Felipe Marques Dos Santos, Jake Ludgate, Daniel Matterson, Alvaro Lorenzo, J. Alexander Brearley, Alexander Brian Phillips   +12 more
wiley   +1 more source

From Flybys to Sample Return: A Review of Space Probes and Robotic Sampling Technologies for Small Bodies

Journal of Field Robotics, EarlyView.
ABSTRACT As a crucial puzzle piece of deep space exploration, exploring small bodies can provide significant scientific insights and valuable mineral resources. Unlike missions to the Moon and Mars, small‐body missions pose distinct technical challenges, including communication delays, weak gravity, and uncertain environments. This paper reviews a full
Xin Zhang, Hao Zhou, Dalin Zhou, Zhaojie Ju   +3 more
wiley   +1 more source

Deep Reinforcement Learning Based Autonomous Decision‐Making for Cooperative Uncrewed Aerial Vehicles: A Search and Rescue Real World Application

Journal of Field Robotics, EarlyView.
ABSTRACT This paper presents the first end‐to‐end framework that combines guidance, navigation, and centralized task allocation for multiple UAVs performing autonomous search‐and‐rescue (SAR) in GNSS‐denied indoor environments. A twin delayed deep deterministic policy gradient controller is trained with an artificial potential field (APF) reward that ...
Thomas Hickling, Maxwell Hogan, Abdulla Tammam, Nabil Aouf   +3 more
wiley   +1 more source