SIMULATION: Transactions of The Society for Modeling and Simulation International

Wildberger, A. Martin

doi: 10.1177/003754978704900101pmid: N/A

Pratt, Charles A.

doi: 10.1177/003754978704900102pmid: N/A

Balick, Lee K.

doi: 10.1177/003754978704900103pmid: N/A

A model of forest canopy heights can support realistic remote sensing scene simulation. The final pixel (x, y) array of canopy heights results from merging structural and statistical sub-models. The structural model considers tree crowns to be structural primitives and permits explicit specification of forest structural characteristics (crown forms and spacing). The statistical model allows the inclusion of smaller scale effects (clumping or rough ness), and nonstationary effects can be introduced by merging the structural and statistical model results with spatially varying weights. The model supports several tasks in realistic scene simu lation (e.g., for use with algorithms which use surface geometry to determine pixel brightness). It also helps define realistic forest- top geometry classes or types so that simulations do not require high-level user expertise or detailed specification. The model also provides controlled test-bed data for canopy measurement and analysis technique development. By retaining tree shape and spacing information in a height surface, the model partially fills the gap between stochastic texture modeling and three- dimensional tree (object) models in scene synthesis.

Fox, Richard L.; Neyens, Patricia A.

doi: 10.1177/003754978704900104pmid: N/A

The Receiver Design Modeling (RDM) simulator can construct a model to simulate receiver architecture. It has been used to model receivers such as the crystal video, superheterodyne, chan nelized, compressive microscan, instantaneous frequency mea surement (IFM), and Bragg cell. Example receiver simulation re sults are presented for the first four of these types.RDM is implemented on a VAX 11/780 and written in FOR TRAN 77 using the VMS operating system.

Greenberg, Irwin

doi: 10.1177/003754978704900105pmid: N/A

A simple technique is described for simulations and analytical studies where the indication is of a unimodal, right-skewed dis tribution of a continuous random variable, the type of distribu tion often approximated by a gamma distribution. The technique is more realistic and more general than the "simple" techniques described in the simulation literature in that it does not require integer parameters.

McLeod, John; McLeod, Suzette

doi: 10.1177/003754978704900106pmid: N/A