Publications
Multifunction phased array radar (MPAR) spectral usage analysis
Summary
Summary
This report addressed two technical risks associated with replacing current air traffic and weather surveillance radars with a single type of multifunction phased array radar (MPAR). The first risk is whether radio spectrum usage would increase with the MPAR network and whether the allocated band will have enough spectral space...
Nanosatellites for Earth environmental monitoring: the MicroMAS project
Summary
Summary
The Micro-sized Microwave Atmospheric Satellite (MicroMAS) is a 3U cubesat (34x10x10 cm, 4.5 kg) hosting a passive microwave spectrometer operating near the 118.75-GHz oxygen absorption line. The focus of the first MicroMAS mission (hereafter, MicroMAS-1) is to observe convective thunderstorms, tropical cyclones, and hurricanes from a near-equatorial orbit at approximately...
A preliminary investigation of Tower Flight Data Manager safety benefits
Summary
Summary
Improvements to current air traffic management technologies and techniques are required to move toward the next generation air transportation system (NextGen). The Tower Flight Data Manager (TFDM) is a prototype air traffic control system consisting of the: (1) Flight Data Manager (FDM) facilitating interaction with electronic flight data, (2) Tower...
Data-driven evaluation of a flight re-route air traffic management decision-support tool
Summary
Summary
Air traffic delays in the U.S. are problematic and often attributable to convective (thunderstorms) weather. Air traffic management is complex, dynamic, and influenced by many factors such as projected high volume of departures and uncertain forecast convective weather at airports and in the airspace. To support the complexities of making...
Loading of a surface-electrode ion trap from a remote, precooled source
Summary
Summary
We demonstrate loading of ions into a surface-electrode trap (SET) from a remote, laser-cooled source of neutral atoms. We first cool and load ~10^6 neutral 88Sr atoms into a magneto-optical trap from an oven that has no line of sight with the SET. The cold atoms are then pushed with...
Ring array antenna with optimized beamformer for simultaneous transmit and receive
Summary
Summary
In order to avoid self-interference, Simultaneous Transmit And Receive (STAR) systems require low mutual coupling between their respective transmit and receive antennas. This paper discusses the development of an 8-element transmit ring array antenna on a circular ground plane with a raised receive element. When combined with a beamformer that...
Sub-picosecond pulses at 100 W average power from a Yb:YLF chirped-pulse amplification system
Summary
Summary
We present a high-repetition-frequency, diode-pumped, and chirped-pulse amplification system operating at 106 W average output with excellent beam quality (M^2 = 1.3), based on cryogenically cooled Yb:YLF. 1 nJ seed pulses, derived from a mode-locked Ti:sapphire laser, are first amplified to 1 mJ pulse energy at 10 kHz repetition frequency...
Measurement of the third-order nonlinear optical susceptibility chi^(3) for the 1002-cm^-1 mode of benzenethiol using coherent anti-Stokes Raman scattering with continuous-wave diode lasers
Summary
Summary
The components of the third-order nonlinear optical susceptibility x^(3) for the 1002-cm^?1 mode of neat benzenethiol have been measured using coherent anti-Stokes Raman scattering with continuous-wave diode pump and Stokes lasers at 785.0 and 852.0 nm, respectively. Values of 2.8±0.3 X 10^-12, 2.0±0.2 X 10^-12, and 0.8±0.1 X 10^-12 cmg^-1...
Establishing wind information needs for four dimensional trajectory-based operations
Summary
Summary
Accurate wind information is of fundamental importance to the delivery of benefits from future air traffic concepts. A Wind Information Analysis Framework is described in this paper and its utility for assessing wind information needs for a four-dimensional trajectory based operations application is demonstrated.
Exploring the impact of advanced front-end processing on NIST speaker recognition microphone tasks
Summary
Summary
The NIST speaker recognition evaluation (SRE) featured microphone data in the 2005-2010 evaluations. The preprocessing and use of this data has typically been performed with telephone bandwidth and quantization. Although this approach is viable, it ignores the richer properties of the microphone data-multiple channels, high-rate sampling, linear encoding, ambient noise...