A Space Communications Study Final Report, Sep. 15, 1965 - Sep. 15, 1966

Reception of frequency modulated signals passed through deterministic and random time-varying channel

Stochastic resonance in electrical circuits—I: Conventional stochastic resonance.

Stochastic resonance (SR), a phenomenon in which a periodic signal in a nonlinear system can be amplified by added noise, is introduced and discussed. Techniques for investigating SR using electronic circuits are described in practical terms. The physical nature of SR, and the explanation of weak-noise SR as a linear response phenomenon, are considered. Conventional SR, for systems characterized by static bistable potentials, is described together with examples of the data obtainable from the circuit models used to test the theory

Techniques and errors in measuring cross- correlation and cross-spectral density functions

Techniques and errors in measuring cross spectral density and cross correlation functions of stationary dynamic pressure dat

Theory of phaselock techniques as applied to aerospace transponders

Phaselock techniques as applied to aerospace transponder

Communications Biophysics

Contains research objectives and reports on three research projects.U.S. Air Force under Contract AF19(604)-411

Synthesis of a model of the human operator engaged in a tracking task

Imperial Users onl

Statistical Analyses of Ozone Temporal Trends in Calgary, Alberta: an Application of Multivariate Geostatistics

The prediction of tropospheric (surface) ozone episodes is a challenging task that requires the integration of physicochemical and statistical techniques. Governmental agencies such as the U.S. Environmental Protection Agency (EPA) and Alberta Environment favor physicochemical modeling in order to capture the complexity of the underlying physical processes. Unlike physicochemical models, statistical techniques are usually based on spatial and/or temporal correlations between relevant variates. The statistical models also require less exhaustive data sets for accurate predictions; this major advantage is perhaps more obvious when ozone prediction is performed for a longer period of interest. The primary objective of this research is to investigate statistical techniques for modeling ozone and/or other pollutant concentrations given only sparse environmental records at the monitoring stations. Straightforward linear regression based techniques are implemented initially but the inadequacy of these approaches for predicting detailed temporal ozone variations is verified by the results. Then geostatistical paradigms of kriging and sequential stochastic simulation are implemented to incorporate temporal correlation in the form ofvariogram. Secondary variables (covariates) can also be useful for providing extra information and their influence is accounted for in cokriging and cosimulation. The positive-definiteness of auto and cross-covariances are ensured via a linear model of coregionalization (LMC). The "two-point" statistic (variogram) is found to be insufficient and hence this thesis strives to explore methodologies for modeling the highly fluctuating temporal profiles with a view to providing a sound framework for subsequent extensions to spatiotemporal modeling. Il

Study to investigate and evaluate means of optimizing the Ku-band combined radar/communication functions for the space shuttle

The Ku band radar system on the shuttle orbiter operates in both a search and a tracking mode, and its transmitter and antennas share time with the communication mode in the integrated system. The power allocation properties and the Costa subloop subcarrier tracking performance associated with the baseline digital phase shift implementation of the three channel orbiter Ku band modulator are discussed