AbstmctIn order to achieve highly accurate calibration of the SeaWinds scatterometer, a calibration ground station (CGS) was constructed by Jet Propulsion Lab (JPL) at White Sands, New Mexico, in association with the QuikSCAT mission. This receive-only system precisely measures the time, frequency, and power of the SeaWinds transmit signal as it passes overhead. From the CGS data, key instrumen...

The Common Ground Station (CGS) receives data from the Joint Surveillance and Target Attack Radar System (Joint STARS) aircraft and from other airborne platforms. High-resolution imagery such as that provided by an unmanned airborne vehicle (UAV) carrying an infrared (IR) and/or synthetic aperture radar (SAR) sensor will be incorporated into an Advanced Imagery CGS (AI CGS) operation. While thi...

This paper presents an IDS(VGS,VDS) model to represent PHEMT behavior in the reverse ) 0 ( < DS V , and forward zone ) 0 ( > DS V . The model predicts with high accuracy the measured data as well as higher orders derivatives of the transconductance over a large range of VDS bias. These characteristics are important for the analysis of intermodulation distortion using harmonic balance or Volterr...

STUDY OBJECTIVE To evaluate the effect of two forms of postnatal social support for disadvantaged inner city mothers on maternal and child health outcomes. DESIGN Randomised controlled trial with economic and process evaluations and follow up at 12 and 18 months. The two intervention groups received either the offer of a year of monthly supportive listening home visits by a support health vis...

Since being launched in June 1999, QuikSCAT has successfully and accurately measured ocean wind vectors. Current research is attempting to increase performance beyond the original design parameters in order to increase the utility of the data. Timing calibration is critical to this effort. Timing information is used to determine instrument performance as well as to calculate the location of eac...

We present an analytical model for Ferro PZT Al2O3/AlGaN/AlN/GaN MOSHEMT involving the solution of Poisson and Schrödinger equations. This covers most operating regimes MOSHEMT. The two-dimensional electron gas (2-DEG) sheet charge density (ns), threshold voltage (Vth), drain current (Ids), gate capacitance (Cgs Cgd), unit gain cutoff frequency(fT) equations are presented simulated with MATLAB ...

Increased interest in high resolution ocean wind measurements, as well as excellent past performance, has led to the development of enhanced resolution applications of SeaWinds on QuikSCAT scatterometer data. An essential requirement of this development is the validation of the cell location accuracy the latitude and longitude of each measurement. This paper discusses two methods of validating ...

KUANG, WEIWEI. TCAD Simulation and Modeling of AlGaN/GaN HFETs. (Under the direction of Dr. Robert J. Trew and Dr. Griff L. Bilbro). This work focused on the TCAD simulation and modeling of AlGaN/GaN HFETs. AlGaN/GaN HFETs have demonstrated excellent RF performance, which benefits from the high sheet charge density in these hetero-structures, the high carrier mobility and saturation velocity in...