SIMULATION: Transactions of The Society for Modeling and Simulation International

Pratt, Charles A.

doi: 10.1177/003754978805000401pmid: N/A

Wildberger, A. Martin

doi: 10.1177/003754978805000402pmid: N/A

Bertolini, A.; Long, J.H.

doi: 10.1177/003754978805000403pmid: N/A

The performance of a radar system is greatly affected by the elec tromagnetic scattering properties of the targets to be tracked. A key target parameter is the radar cross section, defined as an effective area that scatters incident power in the direction of the radar receiver.Two target modeling approaches used at Raytheon and their validation are described. One of the methods computes a com posite signal and equivalent cross section and glint from a num ber of discrete point scatterers. The other method, a statistical model, combines filtered and scaled noise sources from a ran dom number generator to produce the desired results.The outputs presented include plots of sample radar cross sec tion, glint and angle tracking error histories as functions of target aspect and target aspect rate. There are also comparisons of results computed by the two methods, as well as with actual flight data.

Stairmand, Malcolm C.; Kreutzer, Wolfgang

doi: 10.1177/003754978805000404pmid: N/A

POSE is part of a research program to explore potential benefits of new software technologies for various modelling paradigms. It is a SCHEME-based queueing network simulator, whose discus sion serves to demonstrate the suitability of symbolic languages and exploratory programming styles for system simulation.After justifying the use of symbolic languages and an object- oriented approach to model design, basic features of POSE are presented, using a simple example. This is followed by a brief description of the simulator's architecture. A final chapter sum marizes and reflects on our experiences, suggesting that object- oriented simulation environments hosted on powerful personal workstations may well offer major breakthroughs in terms of ef fectiveness and user acceptance. Computational efficiency, while a lesser concern to "investigative simulation," remains unsatisfac tory in simulations used for quantitative predictions. This prob lem may hopefully be overcome through future advances in soft ware and hardware technologies.

Can, Sumer; Sahinkaya, Yilmaz E.

doi: 10.1177/003754978805000405pmid: N/A

We describe a nonlinear computer simulation model of an Ana log Charge-Pump Phase Locked Loop (ACP-PLL). Offsets of the Phase Detector and Analog Charge-Pump are modeled as dis turbances to simulate their effects on the steady-state phase error of the loop.An extensive computer simulation study is carried out for the design of an example Analog CP-PLL using the proposed non linear model and comparing it to the conventional linear model. Results demonstrate the linear model is not sufficient to fully analyze and predict the behaviour of the Analog CP-PLL.

McLeod, John; McLeod, Suzette

doi: 10.1177/003754978805000406pmid: N/A