APAR: The Next Generation of Airborne Polarimetric Doppler Weather Radar

2021 ◽  
Author(s):  
Vanda Grubišić ◽  
Kyu Kim ◽  
Wen-Chau Lee
Keyword(s):  
Radar Data ◽  
System Level ◽  
Design And Development ◽  
Front End ◽  
Electronically Scanned Arrays ◽  
The Status ◽  
Final Design ◽  
Design Activities ◽  
Airborne Phased Array Radar ◽  
Specific Section

<p>A novel, airborne phased array radar (APAR) is currently under design at the NCAR Earth Observing Laboratory. This novel airborne radar is to be carried by the NSF/NCAR C-130 aircraft. The APAR system will consist of four removable C-band active electronically scanned arrays (AESA), strategically placed on the fuselage of the aircraft. Conceptually, the radar system is divided into the front-end, the backend, and the aircraft-specific section. The front-end primarily consists of AESAs, the backend of the signal processor, and the aircraft specific section includes a power system and a GPS antenna.</p><p>APAR, with dual-Doppler and dual polarization capabilities at a lesser attenuating C-band wavelength, is designed to enable further advancement in understanding of in-cloud microphysical and dynamical processes within a variety of precipitation systems. Such unprecedented observations, in conjunction with the advanced radar data assimilation systems, is anticipated to significantly improve understanding and predictability of hazardous weather events.</p><p>At present, and with funding from both the National Science Foundation and the National Oceanic and Atmospheric Administration, NCAR is engaged in the risk reduction and APAR preliminary design activities. In this talk, we will provide an update on the status of these activities for various system components as well as the system-level design. For the final design and development of APAR, NCAR plans to apply for the NSF Mid-scale Research Infrastructure funds in 2021. It is anticipated that the APAR final design and development will be a five-year effort.</p>

Overview of the Airborne Phased Array Radar Observing Simulator

2021 ◽  
Author(s):  
Wen-Chau Lee ◽  
Jothiram Vivekanandan ◽  
Scott Ellis ◽  
Kevin Manning ◽  
George Bryan ◽  
...  
Keyword(s):  
Signal Processing ◽  
Phased Array ◽  
Software Infrastructure ◽  
High Data ◽  
Front End ◽  
Phased Array Radar ◽  
Trade Offs ◽  
Processing Software ◽  
Airborne Phased Array Radar ◽  
Specific Section

<p>The proposed airborne phased array radar (APAR) system consists of four removable, dual-polarized, C-band AESAs (Active Electronic Scanning Array) strategically located on the fuselage of the NSF/NCAR C-130. Conceptually, the radar system is divided into the front-end, the backend, and aircraft-specific section with the front-end primarily consisting of AESAs and the signal processor is in the backend. The aircraft specific section includes a power system and a GPS antenna.</p><p>As part of the risk reduction of the APAR development, the APAR Observing Simulator (AOS) system has been developed to provide simulated APAR data collection sampled from a C-130 flying by/through realistic numerical weather simulations of high-impact weather events. Given that APAR is designed to extend beyond capabilities of the existing airborne tail Doppler radars (e.g., NOAA TDRs and the retired NSF/NCAR ELDORA), a verification of signal processing software and algorithms is needed before the radar is physically built to ensure that the signal processing software infrastructure can handle high data rates and complicated, multiplex scanning that will be part of normal APAR operations.  Furthermore, several algorithms that will need to ingest large amounts of APAR data at very high rates are under development, including dual-Doppler wind synthesis, radar reflectivity attenuation correction, rain rate estimation, and hydrometeor classification. These algorithms need to be tested and verified before the implementation. </p><p>The AOS will also serve as a planning tool for future Principal Investigators (PIs) who will use it to design and test different flight and scanning strategies based on simulated storms to yield the best scientific outcomes before their field deployment takes place. This will enable better understanding of trade-offs among various sampling regimes/strategies during the planning and enhance future field programs' efficiency and effectiveness.</p>

Airborne Phased-Array Radar (APAR): The Next Generation of Airborne Polarimetric Doppler Weather Radar

2020 ◽  
Author(s):  
Vanda Grubišić ◽  
Wen-Chau Lee ◽  
Louis L. Lussier
Keyword(s):  
National Science Foundation ◽  
Phased Array ◽  
Radar Data ◽  
Simulation Software ◽  
Advisory Panel ◽  
Next Generation ◽  
Phased Array Radar ◽  
National Science ◽  
Electronically Scanned Arrays ◽  
Airborne Phased Array Radar

<p>This paper presents a configuration of a novel, airborne phased array radar (APAR) motivated by major advances in cellular technology, component miniaturization, and radar antenna simulation software. This has paved the way for a next-generation radar being designed by NCAR/EOL to be installed on the NSF/NCAR C-130 aircraft. The APAR system will consist of four removable C-band active electronically scanned arrays (AESA) strategically placed on the fuselage of the aircraft. Each AESA measures approximately 1.5 x 1.5 m and is composed of 2368 active radiating elements arranged in a total of 37 line replaceable units (LRU). Each LRU is composed of 64 radiating elements that are the building block of the APAR system.</p><p> </p><p>Polarimetric measurements are not available from current airborne tail Doppler radars. However, APAR, with dual-Doppler and dual polarization diversity at a lesser attenuating C-band wavelength, will further advance the understanding of the microphysical processes within a variety of precipitation systems<em>. </em>Such unprecedented observations, in conjunction with the advanced radar data assimilation schema, will be able to address the key science questions to improve understanding and predictability of significant weather.</p><p>A Mid-scale Research Infrastructure proposal is submitted to the National Science Foundation to request the implementation cost. The development is expected to take ~5 years after the funding is in place. It adopts a phased approach as an active risk assessment and mitigation strategy. At the present time, both the National Science Foundation and the National Oceanic and Atmospheric Administration are funding the APAR project for risk reduction activities. The APAR Team is actively seeking partners in industry and in the university community. An APAR science and engineering advisory panel has been organized.</p><p> </p><p>The authors will review the overall design and current progress of APAR and outline ambitious future development work needed to bring this exceptional tool into full operation.</p>

scholarly journals Design and Implementation of a Farrow-Interpolator-Based Digital Front-End in LTE Receivers for Carrier Aggregation

Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 231
Author(s):  
Chester Sungchung Park ◽  
Sunwoo Kim ◽  
Jooho Wang ◽  
Sungkyung Park
Keyword(s):  
Integrated Circuit ◽  
Building Block ◽  
Orthogonal Frequency Division Multiplexing ◽  
Critical Path ◽  
Phase Error ◽  
System Level ◽  
Comb Filter ◽  
Carrier Aggregation ◽  
Path Delay ◽  
Front End

A digital front-end decimation chain based on both Farrow interpolator for fractional sample-rate conversion and a digital mixer is proposed in order to comply with the long-term evolution standards in radio receivers with ten frequency modes. Design requirement specifications with adjacent channel selectivity, inband blockers, and narrowband blockers are all satisfied so that the proposed digital front-end is 3GPP-compliant. Furthermore, the proposed digital front-end addresses carrier aggregation in the standards via appropriate frequency translations. The digital front-end has a cascaded integrator comb filter prior to Farrow interpolator and also has a per-carrier carrier aggregation filter and channel selection filter following the digital mixer. A Farrow interpolator with an integrate-and-dump circuitry controlled by a condition signal is proposed and also a digital mixer with periodic reset to prevent phase error accumulation is proposed. From the standpoint of design methodology, three models are all developed for the overall digital front-end, namely, functional models, cycle-accurate models, and bit-accurate models. Performance is verified by means of the cycle-accurate model and subsequently, by means of a special C++ class, the bitwidths are minimized in a methodic manner for area minimization. For system-level performance verification, the orthogonal frequency division multiplexing receiver is also modeled. The critical path delay of each building block is analyzed and the spectral-domain view is obtained for each building block of the digital front-end circuitry. The proposed digital front-end circuitry is simulated, designed, and both synthesized in a 180 nm CMOS application-specific integrated circuit technology and implemented in the Xilinx XC6VLX550T field-programmable gate array (Xilinx, San Jose, CA, USA).

A Cooperative-Collaborative Design System for Multi-Disciplinary Mechanical Design

2005 ◽  
Author(s):  
Zhiqiang Chen ◽  
Zahed Siddique
Keyword(s):  
Product Design ◽  
Design Process ◽  
Collaborative Design ◽  
Process Model ◽  
Mechanical Design ◽  
System Level ◽  
Design System ◽  
Design Collaboration ◽  
Design Activities ◽  
Design Process Model

The emergence of computer and network technology has provided opportunities for researchers to construct and build systems to support dynamic, real-time, and collaborative engineering design in a concurrent manner. This paper provides an understanding of the product design in a distributed environment where designers are in different geographic locations and are required to be involved in the design process to ensure successful product design. A design process model that captures the major interactions among stakeholders is presented, based on the observation of cooperation and collaboration. The stakeholders’ interactions are divided into activity and system level to distinguish the interactions in group design activities and design perspective evolution. An initial computer implementation of the design model is presented. The design system consists of a set of tools associated with design and a management system to facilitate distributed designers to support various design activities, especially conceptual design. Our research emphasis of design collaboration in this paper is: (i) Model a Cooperative-collaborative design process; (ii) Support synchronized design activities; and (iii) Structure the complex relations of various design perspectives from engineering disciplines.

The fast-neutron breeder fission: development, operational experience, and implications for future design in the United States

1990 ◽  
Vol 331 (1619) ◽  
pp. 323-338
Keyword(s):  
United States ◽  
Fuel Cycle ◽  
The United States ◽  
Commercial Application ◽  
Operational Experience ◽  
Market Penetration ◽  
Future Design ◽  
Reactor Technology ◽  
The Status ◽  
Design Activities

As the need for breeder technology in the United States has receded into the more distant future, it has become clear that an alternative justification must be found for continued priority development of sodium-cooled fast-reactor technology. Both the modular high-temperature gas-cooled reactor and the liquid-metal-cooled reactor (LMR) have technical attributes that provide more simple and transparent solutions to some of the problems confronting the nuclear enterprise, in addition to their potential for greater market penetration, resource extension, and waste management improvements. For the past five years, the LMR development programme in the United States has attempted to use these technical attributes in more innovative ways to provide more elegant solutions for the practical commercial application of nuclear energy. This paper discusses the reasons and status of the technological approaches that have evolved to support these policy considerations. For the LMR, efforts are focused on four interrelated development thrusts: (1) increased use of standardization; (2) passive safety approaches; (3) modularity; and (4) improved fuel cycle approaches. The paper also discusses the status of related design activities being conducted by the General Electric Company and a team of U. S. vendors.

Status of Eco-Design in Thai Furniture Industry

2009 ◽  
Vol 419-420 ◽  
pp. 769-772 ◽  
Author(s):  
Nongnuch Klinpikul ◽  
Panya Srichandr
Keyword(s):  
Driving Forces ◽  
Public Awareness ◽  
Basic Research ◽  
Market Force ◽  
Exploratory Research ◽  
Furniture Industry ◽  
Furniture Manufacturing ◽  
The Status ◽  
Design Activities ◽  
Implementation Problems

Furniture manufacturing is known to have considerable impacts on the environment and there is a definite trend towards environmental-friendly product designs in the industry worldwide. This paper reports the results of an exploratory research on the status of eco-design in the Thai furniture industry. Two basic research questions are addressed; 1) are there any eco-design activities and, if so, to what extent and 2) what are the driving forces that drive or hinder eco-design activities. A combination of research methodologies were employed; interviewing, survey, and actually examining selected products in the market. The results show that key personnel know very little about eco-design, but they have implemented a number of eco-design methods in their products and processes in practice. The driving force for such progress seems to be not from the environmental consciousness per se but rather the demands and requirements from the customers and the markets. The legal and supporting infrastructure to promote and move eco-design forward is just emerging and still rather weak. There are, however, considerable implementation problems and obstacles due to lack of technical know-how on the part of the personnel involved. It is concluded that the Thai furniture industry is implementing number of eco-design activities without knowing much about eco-design principles and the underlying philosophy. Public awareness and consequently the market force is key to moving eco-design forward. Effective campaigns and better education on sustainable development and eco-design, together with stronger legal and supporting infrastructure, would certainly help increase eco-design activities.

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