Ultra Wide Band Signal Modeling for Radar Receiver Characterization

Results for modeling, simulation, and analysis of interference effects that modern wideband signals have on existing narrowband radar system performance are presented. In particular, radar detection performance is characterized using a basic radar receiver model and operational parameters consistent with those of the ARSR-4 air route surveillance radar. Two modern wideband signals (interferers) are addressed in this work, including the GPS military signal (M-Code signal) and a direct sequence ultra wideband (DS-UWB) waveform meeting outdoor emission restrictions imposed by the Federal Communications Commission (FCC). Interference effects are characterized for an unmodulated sinusoidal pulse as well as linear frequency modulated (LFM) and bi-phase Barker coded pulse compression waveforms. Finally, coherent pulse integration is addressed and interference mitigation demonstrated via improved detection performance. Worst case detection scenarios from the radar\u27s perspective are considered for all cases. M-Code interference results indicate that at proposed received power levels of -160 to -130 dBW, radar detection performance is severely degraded with expected improvement occurring when pulse integration is employed. DS-UWB interference results indicate that at maximum transmit power levels specified by the FCC, the DS-UWB waveform has minimal impact on detection performance for radar receiver/UWB transmitter separation distances beyond 0.5 meters. This separation distance is reduced further when pulse integration is employed. (8 tables, 42 figures, 25 refs.

Financial Aid Packaging at Community Colleges: Which types of awards packages increase student persistence?

Increasing college costs, coupled with decreasing financial aid has raised public concerns over the affordability of higher education. For the past four decades, the nation has seen the cost of tuition rise at levels that exceed inflation, and financial assistance rates that have not kept pace with that growth. Studies suggest that these financial resources play a role in influencing college attendance decisions and persistence for low-income students. This study examines the characteristics of zero-EFC students as compared to non-zero EFC students and determines the extent to which a gift-aid only, and gift-aid plus loans awards package affects the likelihood of persistence. Also, it explores the relationship between the ratio of loans-to-gift-aid, and the likelihood of persistence across income levels. By employing logistic regression, this study aims to determine if there are differential effects among financial aid award packages, and if the ratio of a loans-to-gift-aid package affects persistence by income status. Results demonstrated that a gift-aid only package, and a gift-aid plus loans package negatively influenced the enrollment outcomes of zero-EFC students and positively influenced the enrollment outcomes of high-income students. Additionally, when examining the ratio of loans-to-gift-aid for students with a gift-aid and loans package, results showed that the higher the ratio of loans to gift-aid, the higher the likelihood of persistence for all income levels. In an era where the rising costs of a college education are becoming more difficult to cover with present levels of financial aid, earning a higher education credential is possible if students are willing to take on educational debt. A comprehensive higher education plan that acknowledges financial barriers as fundamental obstacles to the college success of its lowest income students is necessary to preserving equal opportunity to upward social mobility

Women We Loved: Paradoxes of public and private in the biographical television drama

Broadcast to critical acclaim and relatively large audiences for its niche channel, the Women We Loved season consisted of biographical dramatisations of three prominent female figures of 20th-century British culture. These dramas shared in common narratives that centre on the two aspects of ‘the public’ and ‘the private’: the tension between public career and personal life and the discrepancy between celebrity persona and private individual. Combining theoretical insights from feminist studies of biography with close textual analysis, this article analyses how performance, aesthetics and narrative express the ambivalent placement of their protagonists between public and private spheres